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Lung Cancer: Targets and Therapy logoLink to Lung Cancer: Targets and Therapy
. 2010 Sep 9;1:119–140. doi: 10.2147/LCTT.S11726

Azacitidine and decitabine have different mechanisms of action in non-small cell lung cancer cell lines

Aaron N Nguyen 1,, Paul W Hollenbach 1, Normand Richard 2, Antonio Luna-Moran 1, Helen Brady 2, Carla Heise 1, Kyle J MacBeth 1
PMCID: PMC5312472  PMID: 28210112

Abstract

Azacitidine (AZA) and decitabine (DAC) are cytidine azanucleoside analogs with clinical activity in myelodysplastic syndromes (MDS) and potential activity in solid tumors. To better understand the mechanism of action of these drugs, we examined the effects of AZA and DAC in a panel of non-small cell lung cancer (NSCLC) cell lines. Of 5 NSCLC lines tested in a cell viability assay, all were sensitive to AZA (EC50 of 1.8–10.5 µM), while only H1299 cells were equally sensitive to DAC (EC50 of 5.1 µM). In the relatively DAC-insensitive cell line A549, both AZA and DAC caused DNA methyltransferase I depletion and DNA hypomethylation; however, only AZA significantly induced markers of DNA damage and apoptosis, suggesting that mechanisms in addition to, or other than, DNA hypomethylation are important for AZA-induced cell death. Cell cycle analysis indicated that AZA induced an accumulation of cells in sub-G1 phase, whereas DAC mainly caused an increase of cells in G2/M. Gene expression analysis of AZA- and DAC-treated cells revealed strikingly different profiles, with many genes distinctly regulated by each drug. In summary, while both AZA and DAC caused DNA hypomethylation, distinct effects were demonstrated on regulation of gene expression, cell cycle, DNA damage, and apoptosis.

Keywords: apoptosis, azacitidine, decitabine, gene expression, non-small cell lung cancer

Introduction

Azacitidine (AZA) (5-azacytidine, Vidaza®; Celgene Corporation, Summit, NJ) and decitabine (DAC) (2′-deoxy-5-azacytidine, Dacogen®; Eisai Inc., Woodcliff Lake, NJ) are used clinically for the treatment of myelodysplastic syndromes (MDS), a heterogeneous group of bone marrow stem cell disorders.1,2 Both AZA and DAC are cytidine nucleoside analogs that become incorporated into newly synthesized DNA, where they bind DNA methyltransferases (DNMTs) in an irreversible, covalent manner.3,4 The sequestration of DNMTs prevents maintenance of the methylation state of DNA, leading to DNA hypomethylation.5,6 As a consequence, genes previously silenced by DNA hypermethylation can be re-expressed upon treating cancer cell lines with these DNMT inhibitors.7,8 Re-expression of aberrantly methylated genes involved in normal cell cycle control, differentiation, and apoptotic pathways is believed to contribute to the anticancer effects of these drugs.9

Clinical activities of AZA and DAC are best established in the hematological malignancies MDS and acute myeloid leukemia (AML), cancers with a high frequency of aberrantly methylated genes.10 Aberrant DNA methylation of genes involved in DNA repair, cell adhesion, cell cycle, and cell death has also been reported in multiple types of solid cancers, including colon, stomach, breast, ovary, kidney, and lung.11 For example, in non-small cell lung cancer (NSCLC), hypermethylation of tumor suppressor genes RAS association domain family 1A (RASSF1A), adenomatous polyposis coli (APC), fragile histidine triad (FHIT), and p16INK4A has been associated with poor survival.1215 Clinical trials investigating the use of AZA and DAC in solid tumors have been reported, although response rates were poor. In a Phase I study of DAC in patients with cancers involving the lungs, esophagus, and pleura, no objective responses were observed.16 Similar outcomes were obtained with DAC in patients with other forms of solid tumors.17 In a Phase II trial of AZA in patients with solid tumors, the responses were minimal and transient.18 The clinical response rate was also low for the combination of AZA and phenylbutyrate in patients with refractory solid tumors.19

A better understanding of the mechanistic activities of AZA and DAC will provide insights into rational use of these agents as therapies for solid tumor patients, including potential uses as combination therapies, adjuvant therapies, and maintenance therapies. Here, we directly compared the in vitro effects of AZA and DAC on cell viability, DNMT1 protein levels, DNA methylation, DNA damage, apoptosis, cell cycle, and gene expression in NSCLC cell lines. Although AZA and DAC caused similar effects on DNA-mediated markers such as DNMT1 depletion and DNA methylation, the drugs showed very different effects on cell viability, DNA damage, apoptosis, cell cycle, and gene expression.

Results

AZA and DAC have differential effects on NSCLC cell viability

AZA and DAC were compared in a panel of 5 NSCLC cell lines (A549, H1975, H460, H23, and H1299) for their effects on cell viability (Figure 1 and Supporting Information Figure 1). AZA reduced cell viability by at least 75% at high concentrations, with EC50 values of 1.8–10.5 µM (Table 1). In contrast, DAC did not reduce cell viability more than 55%, and EC50 values were not reached in 4 (A549, H1975, H460, and H23) of the 5 NSCLC cell lines tested. In H1299 cells, DAC EC50 values were calculated; however, the 95% confidence intervals for the EC50 values were poor (data not shown). The EC50 values for AZA and DAC are similar to those reported for drugs commonly used in NSCLC, including gemcitabine, cisplatin, and carboplatin.2022 The distinct dose-response curves and EC50 values indicate differential sensitivities of these NSCLC cell lines to AZA and DAC.

Figure 1.

Figure 1

AZA and DAC differentially affect cell viability in a panel of NSCLC cell lines. Viability of A549, H460, and H1299 cells was assessed after 72 hours of treatment with AZA or DAC (0–25 µM). Error bars represent the standard error of mean of 3 independent experiments, with triplicate wells per experiment.

Abbreviations: AZA, azacitidine; DAC, decitabine; NSCLC, non-small cell lung cancer.

Table 1.

EC50 values for AZA and DAC on NSCLC cell viability

AZA EC50 ± SEM (μM) DAC EC50 ± SEM (μM)
A549 6.3 ± 1.1 >25
H1975 8.6 ± 2.9 >25
H460 1.8 ± 0.3 >25
H23 10.5 ± 1.8 >25
H1299 5.1 ± 0.2 5.9 ± 2.1

Note: EC50 values were calculated from 3 independent experiments using Graphpad Prism software.

Abbreviations: AZA, azacitidine; DAC, decitabine; NSCLC, non-small cell lung cancer.

AZA and DAC cause DNMT1 depletion and DNA hypomethylation

To determine whether the differential sensitivities of NSCLC cell lines to AZA versus DAC in cell viability assays reflected differences in the incorporation of each drug into DNA, DNMT1 protein depletion and DNA hypomethylation were evaluated as indirect measures of drug incorporation into DNA. When A549 and H1299 cells were treated with AZA or DAC for 20 hours, DNMT1 protein levels were reduced (Figure 2). Dose-dependent decreases in DNMT1 protein were observed with AZA, while near-maximal reduction of DNMT1 protein was observed at the lowest concentration (0.05 µM) of DAC. In A549 cells, DNMT1 depletion caused by 5 µM AZA was not as much as that caused by 0.5 or 1 µM AZA, possibly as a consequence of cell growth inhibition at the higher AZA concentration.23 Reduced DNMT1 levels were detected as early as 4 hours after drug treatment (Supporting Information Figure 2). Similar results were obtained in the H460 and H23 cell lines (data not shown).

Figure 2.

Figure 2

AZA and DAC cause DNMT1 depletion in NSCLC cell lines. A549 and H1299 cells were treated with AZA or DAC (0–5 µM) for 20 hours and DNMT1 protein was detected by Western blotting of cell extracts. Alpha-tubulin was used as a loading control.

Abbreviations: AZA, azacitidine; DAC, decitabine; DNMT1, DNA methyltransferase 1; NSCLC, non-small cell lung cancer.

We next determined whether AZA and DAC caused DNA hypomethylation by examining the methylat ion status of LINE-1 elements in A549 and H1299 cells treated for 48 hours (Figure 3) or 72 hours (Supporting Information Figure 3). Both AZA and DAC decreased LINE-1 methylation; however, DAC was 3- to 10-fold more potent. Peak hypomethylation was observed at 0.3–1.0 µM AZA and 0.1 µM DAC. LINE-1 methylation was unaffected at the highest DAC concentration tested, possibly as a consequence of cell growth inhibition.23 DAC modulated the DNA-mediated markers (DNMT1 depletion and DNA hypomethylation) in both cell lines, suggesting that the relative insensitivity to DAC in cell viability assays cannot be attributed to a lack of drug uptake, phosphorylation, and DNA incorporation. These findings rule out dysfunctional deoxycytidine kinase, the rate-limiting kinase in the phosphorylation of DAC, as a possible mechanism of relative DAC-insensitivity,24 and suggest that mechanisms in addition to DNA incorporation are responsible for the greater sensitivity of NSCLC cell viability to AZA.

Figure 3.

Figure 3

AZA and DAC reduce DNA methylation in A549 and H1299 cells. LINE-1 DNA methylation was assessed in A549 and H1299 cells after 48 hours of treatment with AZA or DAC (0–3 µM). Percentage LINE-1 methylation represents the average percentage methylation of 4 CpG sites in duplicate samples, with error bars representing the standard deviation.

Abbreviations: AZA, azacitidine; DAC, decitabine.

AZA, but not DAC, robustly induces markers of DNA damage and apoptosis

Phase contrast images of A549 cell cultures after 3 days of drug treatment showed reduced cell numbers and increased debris in AZA-treated cell cultures, but healthy-looking cells in DAC-treated cultures (Figure 4). These findings confirmed results of the cell viability assays (Figure 1). To examine the mechanism(s) of drug-induced cell death, A549 and H1299 NSCLC cell lines were treated with AZA or DAC for 24 or 48 hours, and markers of double-strand DNA (dsDNA) damage (histone-H2AX(ser139) phosphorylation) and apoptosis (PARP cleavage) were evaluated by Western blot (Figure 5 and data not shown). AZA dose-dependently induced histone-H2AX(ser139) phosphorylation and PARP cleavage in A549 cells. Similar results were observed in the H460 cell line (data not shown). There was relatively high basal phosphorylation of histone-H2AX(ser139) in H1299 cells, which was further increased by 10 µM AZA. High concentrations of AZA also induced PARP cleavage in H1299 cells. In A549 and H1299 cells, DNMT1 protein was completely depleted by DAC treatment; however, neither histone-H2AX(ser139) phosphorylation nor PARP cleavage were induced.

Figure 4.

Figure 4

AZA-treated A549 cultures show reduced cell numbers. A549 cells, seeded in 6-well plates, were treated with vehicle or 1, 3, and 10 µM AZA or DAC for 72 hours. The CoolSNAP ES2 CCD camera (Photometrics) was used to take phase-contrast images of cells under the Plan Fluor 10X objective (Nikon) on the Eclipse Ti-S microscope (Nikon).

Abbreviations: AZA, azacitidine; DAC, decitabine.

Figure 5.

Figure 5

AZA, but not DAC, induces markers of DNA damage and apoptosis in NSCLC cell lines. A549 and H1299 cells were treated with AZA or DAC (0–10 µM) for 48 hours and Western blotting of cell extracts was used to detect DNMT1, cleaved-PARP, phospho-histone-H2AX(ser139), and total histone-H2AX. alpha-tubulin was used as a loading control.

Abbreviations: AZA, azacitidine; DAC, decitabine; DNMT1, DNA methyltransferase 1; NSCLC, non-small cell lung cancer.

As AZA induced PARP cleavage, we further examined early-apoptotic (AnnexinV-FITC+ and 7-AAD) and late-apoptotic (AnnexinV-FITC+ and 7-AAD+) cell populations by flow cytometry in A549 and H1299 cells treated with AZA (3 µM) or DAC (3 µM) for 72 hours (Figure 6). AZA (3 µM) treatment of A549 and H1299 cells caused a significant increase in the early- and late-apoptotic populations (Figures 6B and 6C). DAC did not significantly cause an increase in these populations. These results demonstrated that AZA, but not DAC, induced dsDNA damage and apoptosis in NSCLC cell lines.

Figure 6.

Figure 6

AZA, but not DAC, strongly induces apoptosis in NSCLC cell lines. A549 and H1299 cells were treated with AZA or DAC (3 µM) for 72 hours, and staining for AnnexinV-FITC (x-axis) and 7-AAD (y-axis) was detected by flow cytometry. A) The percentages of early apoptotic cells and late apoptotic cells are represented in the lower right and upper right quadrants, respectively. Representative data of 4 independent experiments are shown. B) Percentage (mean ± SD; n = 4) of apoptotic (early and late) cells with AZA or DAC treatment of A549 cells. *P < 0.001 versus “vehicle”. **P = 0.328 versus “vehicle”. #P < 0.001 versus “AZA (3 µM)”. C) Percentage (mean ± SD; n = 4) of apoptotic (early and late) cells with AZA or DAC treatment of H1299 cells. *P < 0.001 versus “vehicle”. **P = 0.442 versus “vehicle”. #P < 0.001 versus “AZA (3 µM)”.

Abbreviations: AZA, azacitidine; DAC, decitabine; NSCLC, non-small cell lung cancer.

DAC-treated H1299 cells show delayed DNA damage response

AZA and DAC appear to be incorporated into DNA of NSCLC cell lines, as both drugs induced DNMT1 depletion (Figure 2) and DNA hypomethylation (Figure 3). It was therefore surprising that 48-hour treatment with DAC did not induce dsDNA damage (histone-H2AX(ser139) phosphorylation) in A549 and H1299 cells (Figure 5). To better define the DNA damage response of NSCLC cell lines treated with AZA and DAC, we treated NSCLC cell lines with the drugs for an extended period of time. A549 and H1299 cells were treated with AZA or DAC for 6 days and lysates were collected on days 3 and 6 (Figure 7). At the 3-day time point in both cell lines, the results were similar to those at the 24- and 48-hour time points; AZA, but not DAC, induced histone-H2AX(ser139) phosphorylation and PARP cleavage. In A549 cells, even after 6 days of daily treatment with DAC, there was no induction of histone-H2AX(ser139) phosphorylation and PARP cleavage (Figure 7). The EC50 values for AZA and DAC were 4.4 µM and 2.5 µM, respectively, for A549 cells after 6 days of treatment (Supporting Information Table 1). Although the calculated EC50 value for DAC was lower than that of AZA, DAC did not reduce cell viability more than 75%, while AZA almost completely inhibited cell viability (Supporting Information Figure 4). In H1299 cells, substantial histone-H2AX(ser139) phosphorylation, without much effect on PARP cleavage, was observed after 6 days of DAC treatment (Figure 7). Consistent with these results, phase contrast images of H1299 cells treated with DAC for a prolonged period did not show many cells undergoing apoptosis. Rather, prolonged treatment of H1299 cells resulted in fewer cells that are enlarged (data not shown). These results suggest that DAC may have a delayed effect on inducing DNA damage in NSCLC cell lines.

Figure 7.

Figure 7

DAC-treated H1299 cells show delayed DNA damage response. A549 and H1299 cells were treated with AZA or DAC (0–10 µM) for 3 and 6 days, and Western blotting of cell extracts was used to detect DNMT1, cleaved-PARP, and phospho-histone-H2AX(ser139). Alpha-tubulin was used as a loading control.

Abbreviations: AZA, azacitidine; DAC, decitabine; DNMT1, DNA methyl-transferase 1.

AZA and DAC differentially affect the cell cycle

The effects of AZA and DAC on cell cycle distribution were evaluated in A549 and H1299 cells treated for 72 hours (Figure 8). AZA dose-dependently increased the sub-G1 population in A549 cells, consistent with the induction of apoptosis (Figures 46). AZA also caused a minor increase in the sub-G1 population in H1299 cells (Figure 8), consistent with the induction of early-, rather than late-, apoptotic cell population at this time point (Figure 6). DAC also caused a minor increase in the sub-G1 population in these cell lines; however, the more prominent effect of DAC was an increase in the G2/M population.

Figure 8.

Figure 8

AZA increases the sub-G1 population of cells, while DAC increases the G2/M population. A549 and H1299 cells were stained with NIM-DAPI after 72 hours of treatment with AZA or DAC at 0, 0.3, 1, 3, and 10 µM. The percentage of cells in sub-G1, G2/M, S, and G0/G1 was quantified by flow cytometry. Representative data of 3 independent experiments are shown.

Abbreviations: AZA, azacitidine; DAC, decitabine.

AZA and DAC modulate expression of different sets of genes

Although both AZA and DAC caused DNMT1 depletion and DNA hypomethylation in NSCLC cell lines, the drugs had very different effects on cell viability, DNA damage, apoptosis, and cell cycle. To better understand the molecular pathways regulated by each drug, A549 and H1299 cells were treated with a dose range (0.3–3.0 µM) of AZA or DAC for 48 hours, and effects on gene expression were assessed by microarray analysis. The total number of genes regulated by AZA or DAC, and the overlap of regulated genes, are presented in Table 2. At the lower drug concentration (0.3 µM), AZA and DAC modulated few genes, with DAC modulating 4- to 20-fold more genes than AZA. At the higher drug concentrations (1 and 3 µM), many more genes were modulated, with AZA typically modulating 2- to 5-fold more genes than DAC. Interestingly, the number of genes modulated in common between the 2 drugs was low (6%–22%). For example, in A549 cells, AZA (3 µM) and DAC (3 µM) commonly upregulated 66 genes, while AZA uniquely upregulated 636 genes and DAC uniquely upregulated 413 genes (Table 2).

Table 2.

Number of genes regulated by AZA and/or DAC

Cell line [Drug] (μM) Upregulated genes
Downregulated genes
AZA-specific genes Genes in common DAC-specific genes AZA-specific genes Genes in common DAC-specific genes
A549 0.3 16 17 139 14 11 55
1.0 279 45 261 273 30 111
3.0 636 66 413 560 55 239
H1299 0.3 10 55 214 33 45 121
1.0 435 135 238 393 107 170
3.0 1368 173 303 991 153 257

Notes: A549 and H1299 cells were treated with AZA or DAC (0–3.0 µM) for 48 hours, and RNA was isolated for evaluation of gene expression using Affymetrix human U133A 2.0 gene chipset. The table shows the number of genes regulated by AZA and DAC at different drug concentrations. Duplicate samples of each were averaged and compared with untreated samples. A fold change of ≥1.7 in gene expression was considered as regulated.

Abbreviations: AZA, azacitidine; DAC, decitabine.

Functional groupings of the modulated genes were determined using Gene Ontology classifications in NextBio. Different biogroups were regulated by each drug. The top 200 biogroups most significantly regulated by each drug (at 3 µM) are shown in Supporting Information Tables 25. In H1299 cells, AZA treatment caused a general downregulation of genes within the “cell cycle”, “metabolic process”, and “biosynthetic process” biogroups. DAC treatment of H1299 cells caused a general upregulation of genes within the “cell differentiation” biogroup. In A549 cells, AZA treatment caused downregulation of genes involved in extracellular matrix, while DAC treatment caused downregulation of genes involved in cell cycle. Aside from the regulation of genes related to extracellular matrix, these results are similar to the gene expression data from AML cell lines treated with AZA and DAC.25 Interestingly, AZA treatment of A549 and H1299 cells caused a general upregulation of genes within the “response to DNA damage stimulus” and “DNA repair” biogroups (Figure 9, Supporting Information Tables 2 and 4). These results are consistent with the induction of the dsDNA damage marker (histone-H2AX(ser139) phosphorylation) by AZA in these cells (Figure 5). On the contrary, DAC treatment caused a general downregulation of genes within these bio-groups in A549 cells (Figure 9, Supporting Information Table 3), and DAC did not significantly modulate these biogroups in H1299 cells (Supporting Information Table 5). Collectively, these results indicate that AZA and DAC regulate different cellular pathways.

Figure 9.

Figure 9

AZA upregulates, while DAC downregulates, genes important in the response to DNA damage stimulus. Gene expression profiling was performed in A549 cells after 48 hours of treatment with AZA or DAC at 0, 0.3, 1, and 3 µM. NextBio (http://www.nextbio.com/) was used to identify regulated Gene Ontology biogroups from lists of regulated genes. The genes displayed represent all genes within the “response to DNA damage stimulus” biogroup that were modulated 1.7-fold or greater by AZA or DAC.

Abbreviations: AZA, azacitidine; DAC, decitabine.

Discussion

In this study, we revealed differential effects of AZA and DAC on cell viability in a panel of NSCLC cell lines, with AZA inducing greater cellular toxicity and markers of apoptosis (PARP cleavage and AnnexinV staining) in comparison to DAC. Furthermore, AZA induced phosphorylation of histone-H2AX(ser139), a marker of dsDNA damage, while DAC had no, or delayed, effect on this endpoint. The striking differences in the response of NSCLC cell lines to these structurally similar cytidine nucleoside analogs further support emerging evidence that the common perception of these agents as mechanistically interchangeable DNA hypomethylating agents should be reconsidered.25,26

Other recent publications also provide data which differentiate AZA from DAC. For example, an in vitro study evaluating the response of a panel of human cancer cell lines to AZA and DAC showed no correlation in the EC50 values of the drugs.24 Another study comparing AZA and DAC activity in the Kasumi-1 AML cell line showed that these drugs had distinct and largely non-overlapping effects on gene expression profiles.26 We have recently demonstrated that AZA and DAC have different effects on cell viability, protein synthesis, cell cycle, and gene expression in AML cell lines.25 Similar to the findings in AML cell lines,25,26 we now demonstrate notable differences between AZA and DAC effects on NSCLC cell lines.

Despite the differences in the activities of AZA and DAC on cytotoxicity and induction of dsDNA damage, both AZA and DAC were active in modulating the DNA-mediated markers of DNMT1 protein depletion and LINE-1 hypomethylation. While DNA methylation undeniably contributes to cancer development and progression,27 it is not clear that the anticancer effects of cytidine azanucleoside analogs are solely driven by their DNA hypomethylating activity. Findings from several clinical studies suggest that DNA hypomethylation may not correlate with clinical response. For example, a study found that DNMT depletion caused by DAC treatment did not necessarily result in clinical response.28 Another clinical trial demonstrated that DAC-induced LINE-1 hypomethylation tended to be greater in patients who did not respond to therapy than in patients who did respond.29 Stresemann et al showed that a subset of patients who responded to AZA treatment did not display detectable DNA hypomethylation.30 These results suggest that mechanisms in addition to, or other than, DNA hypomethylation may be critical for the anticancer effects of these drugs.

DAC’s potent activity on DNA-mediated markers (DNMT1 depletion and DNA hypomethylation) demonstrates that the lack of cytotoxic activity with DAC was not due to a lack of cellular uptake, drug phosphorylation, and DNA incorporation. It is unclear why DAC does not induce dsDNA damage, despite depleting DNMT1 protein and hypomethylating DNA in the NSCLC cell lines tested. The lack of DAC effects on dsDNA damage and on cytotoxicity is consistent with mounting evidence suggesting that DNA damage may be important for the antitumor effects observed with nucleoside analogs.3134 Published data surrounding DAC-induced DNA damage are mixed. In HeLa and HCT116 cells, DAC induced histone-H2AX(ser139) phosphorylation in a DNMT1-dependent and ataxia-telangiectasia-mutated (ATM)-dependent manner;34 however, other researchers found that DAC induced DNA single-strand breaks, but not DNA double-strand breaks (DSBs).3537 Our results suggest that AZA induces DSBs in NSCLC cell lines, coincident with its induction of apopto-sis (Figure 5). DAC did not induce as much DSBs and cell death as AZA in A549 cells. Thus, DSBs may correlate with tumor cell death. Dose and schedule will influence mechanism of action, so the potential for cumulative effects of each drug given at low doses or extended schedules should be tested. Furthermore, potential activities of AZA and DAC on cancer stem cell viability and/or differentiation were not tested here.

In summary, we found that AZA and DAC differentially affected the viability of NSCLC cell lines. While AZA and DAC similarly caused DNMT1 depletion and DNA hypomethylation, the drugs differed in their effects on DNA damage, apoptosis, cell cycle, and gene expression. Perhaps a key difference is that AZA can be incorporated into both RNA and DNA, while DAC is only incorporated into DNA.25,3841 The functional consequences of AZA incorporation into RNA can include (1) alterations in the synthesis and processing of various species of RNA, (2) inhibition of transcription, and (3) disruption of protein synthesis.25,38,4245 The in vitro anticancer activity of AZA in NSCLC models warrants its evaluation in the clinic. It will be important to consider the multiple mechanisms of AZA activity when selecting therapies for use in combination.

Materials and methods

Cell culture and drug treatments

NSCLC cell lines (H460, H1299, A549, and H1975) were purchased from American Type Culture Collection (ATCC, Manassas, VA). The H23 NSCLC cell line was obtained from the National Cancer Institute (NCI) (Bethesda, MD). Cell lines were cultured in their respective media, as recommended by ATCC and NCI. AZA was manufactured at Aptuit (Greenwich, CT) for Celgene Corporation, while DAC was purchased from Sigma-Aldrich (St Louis, MO). In all experiments, cells were seeded 24 hours before drug treatment and incubated at 37°C and 5% CO2. For cell viability assays, H460, H1299, A549, H23, and H1975 cells were seeded in triplicate at 1 × 103, 1 × 103, 1 × 103, 4 × 103, and 4 × 103 cells per well, respectively, in 96-well plates using 200 µL of medium per well. As the half-lives of AZA and DAC in cell culture are short (∼8–12 hours) (data not shown), fresh drug was added every 24 hours by replacing medium with drug-containing medium. For all other assays, cells were seeded at 0.6–1.2 × 105 cells per well, in 6-well plates, using 4 mL of medium per well, with fresh drug added directly to the medium every 24 hours. At this seeding density, cells are 30%–40% confluent at the start of drug treatments. The concentrations of AZA and DAC used in these experiments are similar to the maximum concentrations (Cmax) achieved in human plasma at clinically used dosages and schedules of administration (3–11 µM AZA and 0.3–1.6 µM DAC).28,46,47

Cell viability

Cell viability was assessed 72 hours after the initial drug treatment, using the CyQUANT assay (Life Technologies Corporation, Carlsbad, CA). Fluorescence was measured with a spectrophotometer (Molecular Devices, Sunnyvale, CA), and EC50 values were calculated from three independent experiments using Prism version 5.01 (GraphPad Software, Inc., La Jolla, CA).

Western analysis

For Western analyses of protein levels, cells were washed with phosphate-buffered saline (PBS) and lysed with radio immuno precipitation assay (RIPA) buffer (Cell Signaling Technology, Inc., Danvers, MA) supplemented with 350 mM NaCl and 0.1% sodium dodecyl sulfate (SDS). Cell lysates were sonicated with two 5-second bursts under low amplitude (20%) using the Digital Sonic Dismembrator (ThermoFisher Scientific, Inc., Waltham, MA). Proteins were separated on 4%–12% Bis-Tris NuPAGE gels (Life Technologies Corporation) and transferred to nitrocellulose membranes. DNMT1, phospho-histone-H2AX(ser139), total histone-H2AX, cleaved-PARP, and alpha-tubulin were detected using the Li-Cor Odyssey imaging system (Li-Cor Biotechnology, Lincoln, NE), following incubation with the appropriate primary and secondary antibodies. The phospho-histone-H2AX(ser139) and cleaved-PARP antibodies were obtained from Cell Signaling Technology, Inc. The total histone-H2AX (C-20) antibody was purchased from Santa Cruz Biotechnology, Inc. (Santa Cruz, CA). The alpha-tubulin and DNMT1 antibodies were purchased from EMD Chemicals, Inc. (Gibbstown, NJ) and Abcam, Inc. (Cambridge, MA), respectively. The goat anti-Rabbit IRDye 680, goat anti-Mouse IRDye 800CW, and donkey anti-Goat IRDye 800CW secondary antibodies were obtained from Li-Cor Biotechnology.

DNA methylation analysis

Genomic DNA was purified from cells using the DNeasy Blood and Tissue Kit (Qiagen, Valencia, CA), according to the manufacturer’s instructions. DNA yield was quantitated with a NanoDrop 8000 spectrophotometer (ThermoFisher Scientific, Inc.). Genomic DNA (1 µg/sample) was submitted to EpigenDx (Worcester, MA) for bisulfite conversion and pyrosequencing of LINE-1 elements. Briefly, 1 µg of DNA was bisulfite treated using the Zymo DNA Methylation Kit (Zymo Research, Orange, CA) and eluted in 10 µL volume. DNA eluate (1 µL) was used for polymerase chain reaction (PCR) with biotinylated primers to the LINE-1 locus, converting the PCR product to single-stranded DNA templates. PCR products (each 10 µL) were sequenced by the Pyrosequencing PSQ96 HS System (Biotage AB), following the manufacturer’s instructions (Biotage, Kungsgatan, Sweden). The methylation status of each locus was analyzed individually as a T/C SNP using QCpG software (Biotage). Percentage LINE-1 methylation represents the average percentage methylation of 4 CpG sites in duplicate samples. EpigenDx provided 3 controls for the LINE-1 methylation assay: (1) low methylated DNA control, which is human genomic DNA that has been chemically and enzymatically treated to remove the methyl groups; (2) high methylated DNA control, which is human genomic DNA that has been methylated in vitro; and (3) 50/50 mix control, which is an equal mixture of the low methylated DNA and high methylated DNA controls. The percentages of LINE-1 methylation for the low methylated DNA control, the 50/50 mix control, and the high methylated DNA control were 25.8 ± 8.1, 56.2 ± 4.6, and 86.3 ± 6.5, respectively (data not shown).

Flow cytometry

For cell cycle distribution, cells were stained with the NIM-DAPI reagent (Beckman Coulter, Inc., Fullerton, CA). For measurement of early- and late-apoptotic cell populations, cells were stained with AnnexinV-FITC and 7-AAD reagents (Beckman Coulter, Inc.). Samples were processed according to manufacturer’s instructions and analyzed on a Cell Lab Quanta MPL flow cytometer (Beckman Coulter, Inc.). The effects of treatment were compared using one-way ANOVA, followed by single step method for adjusting P-values in multiple testing with the bioconductor package multcomp.48

Gene expression analysis

Cells were lysed using the TRIzol reagent (Life Technologies Corporation), and total RNA was isolated using the miRNeasy kit (Qiagen). Double-stranded cDNA and biotin-labeled cRNA were synthesized using 100 ng of total RNA with Ambion’s MessageAmp Premier RNA Amplification Kit (ABI, Foster City, CA). Biotin-labeled cRNA (10 µg) was fragmented and hybridized to each human U133A 2.0 genechip (Affymetrix, Santa Clara, CA). The GC-RMA algorithm was used for normalization, and all analyses were done using GeneSpring 7.3 (Agilent, Santa Clara, CA). Averaged signals from biological duplicate samples were used to determine fold change (treated versus untreated), with an absolute fold change of ≥1.7 defining regulated genes. NextBio (http://www.nextbio.com/) was used to identify regulated gene ontology biogroups from lists of regulated genes. The top 200 biogroups are those with the lowest P-values calculated within NextBio.

Supporting information figures and tables

Figure S1

Viability of H23 and H1975 cells was assessed after 72 hours of treatment with AZA or DAC (0–25 µM). Error bars represent the standard error of mean of three independent experiments, with triplicate wells per experiment.

lctt-1-119s1.tif (114.8KB, tif)
Figure S2

AZA and DAC cause DNMT1 depletion in NSCLC cell lines. A549 and H1299 cells were treated with AZA or DAC (5 µM) for 4, 8, or 16 hours and DNMT1 protein was detected by Western blotting of cell extracts. Alpha-tubulin was used as a loading control.

lctt-1-119s2.tif (352.1KB, tif)
Figure S3

AZA and DAC reduce DNA methylation in A549 and H1299 cells. LINE-1 DNA methylation was assessed in A549 and H1299 cells after 72 hours of treatment with AZA or DAC (0–3 µM). Percentage LINE-1 methylation represents the average percentage methylation of 4 CpG sites in duplicate samples, with error bars representing the standard deviation.

lctt-1-119s3.tif (109.7KB, tif)
Figure S4

Viability of A549, H460, and H1299 cells was assessed after 6 days of treatment with AZA or DAC (0–25 µM).

lctt-1-119s4.tif (156KB, tif)

Table S1.

EC50 values for AZA and DAC on NSCLC cell viability (6 days)

AZA EC50 (μM) DAC EC50 (μM)
A549 4.4 2.5
H460 2.2 4.4
H1299 4.1 0.5

Abbreviations: AZA, azacitidine; DAC, decitabine; NSCLC, non-small cell lung cancer.

Table S2.

Top 200 biogroups modulated by azacitidine (AZA) in A549 cells

A549 cells treated with 3 μM AZA (48 hours)
Biogroup name Direction P value
Proteinaceous extracellular matrix down 3.40E-18
Extracellular matrix down 4.70E-18
Transcription up 2.50E-16
Extracellular matrix structural constituent down 4.90E-16
Glycosaminoglycan binding down 7.30E-15
Polysaccharide binding down 9.60E-15
Pattern binding down 2.80E-14
Lipid biosynthetic process down 3.60E-14
Fibrillar collagen down 1.60E-13
Calcium ion binding down 2.20E-13
Fibrinogen complex down 7.20E-13
Humoral immune response down 8.90E-12
Protein binding, bridging down 9.00E-12
Collagen down 1.70E-11
Response to wounding down 6.00E-11
Response to external stimulus down 1.50E-10
Platelet activation down 2.20E-10
Ligase activity, forming aminoacyl-tRNA and related compounds up 3.30E-10
Ligase activity, forming carbon-oxygen bonds up 3.30E-10
Response to nutrient up 3.70E-10
Carbohydrate binding down 3.80E-10
Basement membrane down 1.00E-09
Lipid metabolic process down 2.20E-09
Response to nutrient levels up 2.30E-09
Steroid biosynthetic process down 2.30E-09
Collagen binding down 2.40E-09
Response to extracellular stimulus up 3.70E-09
Inflammatory response down 7.80E-09
Nucleoplasm up 8.70E-09
Acute inflammatory response down 1.30E-08
Response to stress down 1.50E-08
Blood pressure regulation down 1.50E-08
RNA binding up 1.60E-08
Cell motility down 3.40E-08
Localization of cell down 3.40E-08
Epithelial cell differentiation down 4.70E-08
tRNA binding up 4.80E-08
Steroid metabolic process down 7.20E-08
Endoplasmic reticulum down 8.00E-08
Translation up 1.30E-07
Fatty acid biosynthetic process down 1.90E-07
Parturition down 2.50E-07
Sterol metabolic process down 2.50E-07
Blood coagulation down 2.90E-07
Coagulation down 3.10E-07
Humoral immune response mediated by circulating immunoglobulin down 3.60E-07
Hemostasis down 3.60E-07
Organic acid biosynthetic process down 4.40E-07
Regulation of body fluids down 6.70E-07
Wound healing down 6.90E-07
ER-Golgi intermediate compartment down 8.00E-07
Actin binding down 9.70E-07
Anion transport down 1.10E-06
Extracellular structure organization and biogenesis down 1.10E-06
Transaminase activity up 1.10E-06
Complement activation down 1.20E-06
Extracellular matrix organization and biogenesis down 1.20E-06
Calmodulin binding down 1.90E-06
Circulation down 1.90E-06
Female pregnancy down 2.50E-06
Cellular homeostasis down 2.60E-06
Morphogenesis of an epithelium down 2.70E-06
Cell proliferation down 3.10E-06
Alkene metabolic process down 3.10E-06
Ribosome biogenesis and assembly up 3.20E-06
Complement activation, classical pathway down 3.50E-06
Ribonucleoprotein complex biogenesis and assembly up 4.90E-06
Sodium:potassium-exchanging ATPase complex down 5.20E-06
Transferase activity, transferring nitrogenous groups up 5.80E-06
Cell activation down 6.10E-06
Endoplasmic reticulum lumen down 6.60E-06
Fatty acid metabolic process down 6.90E-06
Vesicular fraction down 8.20E-06
Cellular ion homeostasis down 1.10E-05
Cellular chemical homeostasis down 1.10E-05
Positive regulation of immune system process down 1.10E-05
Positive regulation of immune response down 1.10E-05
Phosphoinositide binding down 1.40E-05
Activation of immune response down 1.50E-05
Positive regulation of multicellular organismal process down 1.60E-05
Cofactor transporter activity up 1.60E-05
Soluble fraction up 1.70E-05
Enzyme inhibitor activity down 1.70E-05
Development of primary sexual characteristics up 1.80E-05
NAD binding down 1.90E-05
Amine biosynthetic process up 1.90E-05
Cytoskeleton down 2.20E-05
Lymphocyte mediated immunity down 2.40E-05
Receptor binding down 2.50E-05
Transcription corepressor activity up 2.50E-05
Response to DNA damage stimulus up 2.60E-05
Cartilage development down 2.70E-05
SNARE complex up 2.80E-05
Gastrulation up 3.20E-05
mRNA transport up 3.50E-05
Epidermis development down 3.80E-05
Cell migration down 4.20E-05
Immune effector process down 4.20E-05
Response to hypoxia down 4.30E-05
Leukocyte mediated immunity down 4.50E-05
Adaptive immune response down 4.90E-05
Adaptive immune response based on somatic recombination of immune receptors built from immunoglobulin superfamily domains down 4.90E-05
Endopeptidase inhibitor activity down 5.00E-05
Protease inhibitor activity down 5.00E-05
Oxidoreductase activity, acting on heme group of donors down 5.30E-05
Oxidoreductase activity, acting on heme group of donors, oxygen as acceptor down 5.30E-05
Cytochrome-c oxidase activity down 5.30E-05
Heme-copper terminal oxidase activity down 5.30E-05
Germ cell migration up 6.00E-05
Coenzyme binding down 6.20E-05
Regulation of translation up 6.90E-05
Cytokine biosynthetic process up 7.30E-05
Neurotransmitter:sodium symporter activity up 7.40E-05
Ectoderm development down 7.50E-05
Establishment of RNA localization up 8.00E-05
RNA transport up 8.00E-05
Nucleic acid transport up 8.00E-05
Transcription factor binding up 8.30E-05
Regulation of immune response down 8.50E-05
Regulation of immune system process down 8.50E-05
Ligase activity up 8.60E-05
RNA localization up 9.10E-05
Neurotransmitter transporter activity up 9.30E-05
RNA export from nucleus up 9.80E-05
Phospholipid binding down 9.90E-05
Cell cycle up 0.0001
Cytosol down 0.0001
Cytoskeletal protein binding down 0.0001
Response to endogenous stimulus up 0.0001
Gonad development up 0.0001
Nucleobase, nucleoside, nucleotide and nucleic acid transport up 0.0001
Nucleolus up 0.0001
Regulation of cytokine biosynthetic process up 0.0001
Rhythmic process up 0.0001
Reproductive structure development up 0.0002
Mitochondrion organization and biogenesis up 0.0002
Structural constituent of cytoskeleton down 0.0002
Sex differentiation up 0.0002
Transcription repressor activity up 0.0002
Peroxidase activity down 0.0002
Oxidoreductase activity, acting on peroxide as acceptor down 0.0002
Laminin-1 complex down 0.0002
Transcription cofactor activity up 0.0002
Female sex differentiation up 0.0002
Development of primary female sexual characteristics up 0.0002
Oxidoreductase activity, acting on the CH-CH group of donors, NAD or NADP as acceptor down 0.0002
Nitrogen compound biosynthetic process up 0.0002
Cell structure disassembly during apoptosis up 0.0003
Amino acid transport up 0.0003
Acyl-CoA binding down 0.0003
Response to dsRNA up 0.0003
Neuron development down 0.0003
Integrator complex up 0.0003
Immune response down 0.0003
Protein dimerization activity up 0.0004
Laminin complex down 0.0004
Cofactor binding down 0.0004
Germ-line sex determination down 0.0004
Intramolecular oxidoreductase activity down 0.0004
DNA repair up 0.0004
Cell soma down 0.0004
Cellular morphogenesis during differentiation down 0.0004
RNA polymerase II transcription factor activity up 0.0005
Regulation of epithelial cell proliferation down 0.0005
Regulation of biosynthetic process up 0.0005
UDP-glycosyltransferase activity up 0.0005
Pyridoxal phosphate binding up 0.0005
Lipid binding down 0.0005
Positive regulation of programmed cell death up 0.0005
Helicase activity up 0.0006
Cell redox homeostasis down 0.0006
Cell death up 0.0006
Death up 0.0006
Epithelial cell proliferation down 0.0006
Mesenchymal cell development down 0.0006
Ovulation up 0.0006
Positive regulation of locomotion down 0.0006
Positive regulation of cell motility down 0.0006
DNA catabolic process up 0.0006
Cell differentiation down 0.0006
Basal lamina down 0.0007
Insulin-like growth factor binding mesenchymal cell differentiation Down
down
0.0007
0.0007
Sequestering of metal ion down 0.0007
Neurotransmitter transport up 0.0007
Specific RNA polymerase II transcription factor activity up 0.0007
Intramolecular oxidoreductase activity, transposing C=C bonds down 0.0007
Cellular component disassembly up 0.0008
Heme binding down 0.0008
Tetrapyrrole binding down 0.0008
Presynaptic active zone up 0.0008
Amine transport up 0.0009
Sequestering of calcium ion down 0.0009
Cell recognition down 0.0009
Endoplasmic reticulum part down 0.0009
Oxidoreductase activity, acting on the CH-OH group of donors, NAD or NADP as acceptor down 0.001
Myosin binding down 0.001
Lyase activity up 0.001
Transferase activity, transferring hexosyl groups down 0.001
Neuron differentiation down 0.001

Notes: Functional groupings of the modulated genes were determined using Gene Ontology classifications in NextBio. The top 200 biogroups most significantly regulated by AZA (at 3 µM) are shown.

Table S3.

Top 196 biogroups modulated by decitabine (DAC) in A549 cells

A549 cells treated with 3 μM DAC (48 hours)
Biogroup name Direction P value
Mitosis down 2.00E-09
Cell cycle down 2.90E-09
Cell division down 5.70E-08
Transferase activity, transferring sulfur-containing groups up 5.80E-08
Meiosis down 1.50E-07
Meiotic cell cycle down 1.70E-07
Response to DNA damage stimulus down 1.80E-07
Male gamete generation up 6.10E-07
Response to endogenous stimulus down 7.60E-07
Chromosome segregation down 2.10E-06
Aromatic compound metabolic process up 2.70E-06
Phenol metabolic process up 2.70E-06
Structural constituent of cytoskeleton up 5.10E-06
Sister chromatid cohesion down 5.90E-06
Cellular lipid catabolic process up 6.70E-06
DNA repair down 7.20E-06
Alkali metal ion binding up 9.00E-06
Regulation of neurotransmitter levels up 1.10E-05
DNA damage response, signal transduction down 1.30E-05
Cofactor transporter activity up 1.60E-05
Sulfotransferase activity up 1.70E-05
Intermediate filament up 3.20E-05
Neurotransmitter:sodium symporter activity up 3.40E-05
Chromatin assembly down 3.90E-05
Neurotransmitter transporter activity up 4.60E-05
Cytokinesis down 5.10E-05
Chromosome down 5.30E-05
Mitotic spindle organization and biogenesis down 5.30E-05
Negative regulation of enzyme activity up 5.60E-05
Establishment of mitotic spindle localization down 6.50E-05
Establishment of spindle localization down 6.50E-05
Spindle localization down 6.50E-05
Retinol binding up 6.50E-05
Microtubule organizing center part down 7.60E-05
Mitotic sister chromatid segregation down 8.30E-05
Alcohol metabolic process up 8.60E-05
Sister chromatid segregation down 9.30E-05
Catabolic process up 0.0001
Soluble fraction up 0.0001
Retinal binding up 0.0001
Positive regulation of programmed cell death up 0.0001
Steroid biosynthetic process up 0.0002
Response to stress down 0.0002
Gamma-tubulin complex down 0.0002
Mitotic chromosome condensation down 0.0002
Transporter activity up 0.0002
Phosphopyruvate hydratase complex up 0.0002
Amino acid derivative metabolic process up 0.0003
Vitamin binding up 0.0003
Lipid catabolic process up 0.0003
Nuclear chromosome down 0.0003
Retinoid binding up 0.0003
Isoprenoid binding up 0.0003
Homologous chromosome segregation down 0.0003
Meiotic chromosome segregation down 0.0003
Meiotic spindle organization and biogenesis down 0.0003
Cell differentiation up 0.0003
NADP binding down 0.0004
Steroid metabolic process up 0.0004
Lipid raft up 0.0004
Cohesin complex down 0.0004
Meiosis I down 0.0004
Sodium:potassium-exchanging ATPase complex up 0.0004
Negative regulation of cell proliferation up 0.0004
Actin binding down 0.0005
Nuclear matrix down 0.0005
Cytoskeletal protein binding down 0.0005
Protein kinase inhibitor activity up 0.0005
Cell proliferation up 0.0006
Cytoskeleton down 0.0006
Cytoskeleton organization and biogenesis down 0.0006
Fat cell differentiation down 0.0006
Hormone metabolic process up 0.0006
Positive regulation of progression through cell cycle down 0.0006
Kinase inhibitor activity up 0.0006
Oxidoreductase activity, acting on the CH-CH group of donors, NAD or NADP as acceptor down 0.0007
Neurotransmitter transport up 0.0007
Membrane invagination down 0.0008
Endocytosis down 0.0008
Amide metabolic process up 0.0008
Spindle down 0.0008
Ion transport up 0.0009
Blastocyst growth down 0.0009
Interleukin binding down 0.0009
RNA export from nucleus down 0.0009
Tubulin binding down 0.0009
Epidermis development up 0.0009
Neurotransmitter metabolic process up 0.0011
Translation activator activity up 0.0011
Spindle pole down 0.0011
Synaptic transmission up 0.0012
Intracellular cyclic nucleotide activated cation channel complex up 0.0012
Biogenic amine metabolic process up 0.0012
Cell fate determination up 0.0013
Oxidoreductase activity, acting on iron-sulfur proteins as donors up 0.0013
Ion channel activity up 0.0013
Lipoprotein binding down 0.0014
Positive regulation of neurogenesis down 0.0014
Cytosol up 0.0018
Microtubule organizing center down 0.002
Microtubule down 0.002
Glutathione peroxidase activity up 0.0021
Odontogenesis down 0.0022
Passive transmembrane transporter activity up 0.0022
Transmission of nerve impulse up 0.0023
Oxidoreductase activity, acting on the CH-NH group of donors, NAD or NADP as acceptor down 0.0024
Dynein binding down 0.0024
Humoral immune response down 0.0024
Ectoderm development up 0.0025
Arginine metabolic process up 0.0025
Myosin binding down 0.0025
Lipid biosynthetic process up 0.0026
Muscle contraction up 0.0027
Mitochondrion organization and biogenesis up 0.0027
Fat-soluble vitamin metabolic process up 0.0028
Female gamete generation down 0.0028
Urea cycle intermediate metabolic process up 0.0029
Inclusion body down 0.0029
Folic acid transporter activity down 0.0029
Protein heterodimerization activity down 0.003
Angiogenesis up 0.003
Replication fork down 0.0031
Nucleoside metabolic process down 0.0031
Regulation of axonogenesis down 0.0032
Anatomical structure formation up 0.0033
Protein kinase regulator activity up 0.0034
Lipid metabolic process up 0.0037
Glycoprotein binding up 0.0037
Pyridoxal phosphate binding up 0.0037
Blood vessel morphogenesis up 0.004
Carbohydrate metabolic process up 0.0041
Tissue regeneration up 0.0041
Regeneration up 0.0041
Germ cell development up 0.0042
Growth factor binding down 0.0042
Peptide transporter activity up 0.0043
Nitrogen compound biosynthetic process up 0.0044
Cytokine binding down 0.0044
Nitric oxide metabolic process up 0.0047
Nitric oxide biosynthetic process up 0.0047
Centrosome down 0.0047
Embryonic morphogenesis down 0.0048
Regulation of neurogenesis down 0.0048
Oxidoreductase activity, acting on the aldehyde or oxo group of donors up 0.0048
Cytokinesis during cell cycle down 0.0049
Cell–cell signaling up 0.005
Calmodulin binding up 0.005
Structure-specific DNA binding down 0.0051
Oxidoreductase activity, acting on the CH–CH group of donors down 0.0051
Peroxidase activity up 0.0051
Oxidoreductase activity, acting on peroxide as acceptor up 0.0051
Microfibril up 0.0052
Protein–DNA complex assembly down 0.0052
Vasculature development up 0.0054
Excretion up 0.0055
mRNA transport down 0.0056
Identical protein binding up 0.0056
Vitamin transporter activity down 0.0057
Response to organic cyclic substance up 0.0059
Response to alkaloid up 0.0059
Kinase regulator activity up 0.006
Chromatin down 0.006
Electron carrier activity up 0.0061
Vitamin biosynthetic process down 0.0062
RNA transport down 0.0067
Nucleic acid transport down 0.0067
Establishment of RNA localization down 0.0067
Protein domain specific binding up 0.0068
Homophilic cell adhesion down 0.0068
RNA localization down 0.0069
Hormone biosynthetic process up 0.007
Protein dimerization activity down 0.0071
RNA binding down 0.0073
Blastocyst development down 0.0074
Cyclin binding up 0.0075
Nucleobase, nucleoside, nucleotide and nucleic acid transport down 0.0077
Cartilage development down 0.0077
Folic acid binding down 0.0079
Positive regulation of developmental process down 0.0081
Chordate embryonic development down 0.0082
NAD binding up 0.0082
Cofactor binding up 0.0082
Vesicle docking during exocytosis up 0.0084
Developmental maturation up 0.0085
Hydrolase activity, acting on carbon–nitrogen (but not peptide) bonds, in cyclic amidines up 0.0086
Lysosome up 0.0086
Embryonic digit morphogenesis down 0.0086
DNA helicase activity down 0.0089
Axon guidance down 0.0091
Membrane docking up 0.0093
Vesicle docking up 0.0093
Voltage-gated sodium channel complex down 0.0093
mRNA binding up 0.0094
Establishment of organelle localization down 0.0096
Vitamin metabolic process up 0.0096
Oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen down 0.0099

Notes: Functional groupings of the modulated genes were determined using Gene Ontology classifications in NextBio. The top 196 biogroups most significantly regulated by DAC (at 3 µM) are shown.

Table S4.

Top 200 biogroups modulated by azacitidine (AZA) in H1299 cells

H1299 cells treated with 3 μM AZA (48 hours)
Biogroup name Direction P value
Transcription up 1.90E-25
Cell cycle down 7.60E-25
Mitosis down 8.00E-24
Cell division down 1.00E-22
Cytoskeleton down 5.60E-14
Microtubule down 1.30E-13
Spindle down 1.80E-13
Mitochondrion down 1.80E-12
Sterol metabolic process down 1.40E-11
Chromosome down 1.20E-10
Alcohol metabolic process down 2.20E-10
Ligase activity up 2.40E-10
Lipid biosynthetic process down 2.70E-10
Steroid biosynthetic process down 3.00E-10
Mitotic sister chromatid segregation down 1.90E-09
Steroid metabolic process down 2.50E-09
Sister chromatid segregation down 2.90E-09
Endoplasmic reticulum down 3.60E-09
Envelope down 4.70E-09
Lipid metabolic process down 2.60E-08
Response to nutrient down 7.00E-08
Collagen binding down 1.60E-07
Centrosome down 1.70E-07
Wound healing down 1.90E-07
Response to nutrient levels down 2.00E-07
Intramolecular oxidoreductase activity down 2.50E-07
Response to extracellular stimulus down 2.70E-07
Mitochondrial membrane down 2.80E-07
Microtubule organizing center down 2.80E-07
Acid–amino acid ligase activity up 3.10E-07
Cell proliferation down 3.60E-07
Blood coagulation down 3.70E-07
Establishment of chromosome localization down 4.40E-07
Coagulation down 4.90E-07
Chromosome segregation down 5.00E-07
Nitrogen compound catabolic process down 5.20E-07
Kinase binding up 5.30E-07
Beta-catenin binding down 5.50E-07
Nucleoplasm up 6.10E-07
Enzyme inhibitor activity down 8.80E-07
Alcohol catabolic process down 9.80E-07
Hemostasis down 1.10E-06
Transcription cofactor activity up 1.10E-06
Transcription repressor activity up 1.20E-06
Midbody down 1.30E-06
Ligase activity, forming carbon-nitrogen bonds up 1.70E-06
Establishment of organelle localization down 2.00E-06
Germ-line sex determination down 2.00E-06
Oligosaccharyl transferase complex down 2.10E-06
Response to external stimulus down 2.20E-06
Oxidoreductase activity, acting on the CH-NH group of donors, NAD or NADP as acceptor down 2.20E-06
Amine catabolic process down 2.20E-06
Cytoskeleton organization and biogenesis down 2.20E-06
Cofactor binding down 2.30E-06
Coenzyme binding down 2.70E-06
Transcription corepressor activity up 3.00E-06
Cell differentiation up 3.20E-06
mRNA binding down 3.30E-06
Meiotic chromosome segregation down 3.60E-06
Homologous chromosome segregation down 3.60E-06
Nuclear envelope-endoplasmic reticulum network down 3.90E-06
Oxidoreductase activity, acting on the CH–CH group of donors, NAD or NADP as acceptor down 5.00E-06
Intramolecular oxidoreductase activity, transposing C=C bonds down 5.30E-06
Mitotic chromosome condensation down 5.50E-06
Endoplasmic reticulum part down 5.50E-06
Transcription factor binding up 5.60E-06
Organic acid transport up 5.70E-06
Carboxylic acid transport up 5.70E-06
Acyl-CoA binding down 5.70E-06
DNA-directed RNA polymerase II, holoenzyme up 5.80E-06
Interphase of mitotic cell cycle down 6.00E-06
Primary sex determination down 6.00E-06
Cell-matrix adhesion down 6.20E-06
Hormone activity down 6.30E-06
Organic acid transmembrane transporter activity up 6.30E-06
Mitochondrial inner membrane down 7.30E-06
Cell-substrate adhesion down 7.60E-06
Transcription activator activity up 7.70E-06
Mitotic spindle organization and biogenesis down 7.90E-06
Lyase activity down 8.10E-06
Sterol transport down 8.70E-06
Arginine metabolic process down 8.70E-06
Chromatin assembly down 1.00E-05
Nitrogen compound biosynthetic process down 1.10E-05
RNA polymerase II transcription factor activity up 1.10E-05
Transaminase activity up 1.20E-05
Meiotic spindle organization and biogenesis down 1.30E-05
Organelle localization down 1.40E-05
Isomerase activity down 1.40E-05
Interphase down 1.40E-05
Urea cycle intermediate metabolic process down 1.50E-05
Fatty acid biosynthetic process down 1.70E-05
Receptor binding down 1.70E-05
Regulation of body fluids down 1.80E-05
Condensin complex down 1.80E-05
Regulation of coagulation down 1.90E-05
Nuclear envelope down 2.20E-05
Caveola down 2.30E-05
Organic acid biosynthetic process down 2.30E-05
Meiotic cell cycle down 2.30E-05
Amino acid transport up 2.50E-05
NADP binding down 2.80E-05
Protein dimerization activity up 2.90E-05
Spindle pole down 3.40E-05
Ubiquitin–protein ligase activity up 3.50E-05
Transferase activity, transferring nitrogenous groups up 3.60E-05
Nucleoside metabolic process down 3.80E-05
Structural constituent of cytoskeleton down 3.90E-05
Carbohydrate catabolic process down 4.10E-05
Endoplasmic reticulum membrane down 4.30E-05
Nucleosome down 4.40E-05
Nucleotide catabolic process down 4.60E-05
Cellular chemical homeostasis down 4.70E-05
Cellular ion homeostasis down 4.70E-05
Cytokinesis down 4.90E-05
Muscle cell differentiation up 5.00E-05
Myeloid cell differentiation up 5.20E-05
Catabolic process down 5.20E-05
Oxygen and reactive oxygen species metabolic process down 5.20E-05
Chromatin down 5.30E-05
Epidermis development down 5.40E-05
Oxidoreductase activity, acting on the CH–NH group of donors down 5.60E-05
SNARE complex up 5.60E-05
Ligase activity, forming carbon–oxygen bonds up 5.70E-05
Ligase activity, forming aminoacyl–tRNA and related compounds up 5.70E-05
Soluble fraction up 5.80E-05
Endopeptidase inhibitor activity down 5.90E-05
Protease inhibitor activity down 5.90E-05
Small protein conjugating enzyme activity up 6.00E-05
AP-type membrane coat adaptor complex down 6.40E-05
Cell–cell signaling down 6.70E-05
Amine transport up 6.80E-05
Response to DNA damage stimulus up 7.20E-05
Male sex determination down 7.20E-05
Cell–cell adhesion down 8.00E-05
Protein heterodimerization activity down 8.00E-05
Enzyme binding up 8.40E-05
Oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen down 9.10E-05
Ectoderm development down 9.40E-05
Positive regulation of progression through cell cycle down 0.0001
One-carbon compound metabolic process down 0.0001
Heterogeneous nuclear ribonucleoprotein complex down 0.0001
Response to stress down 0.0001
Response to endogenous stimulus up 0.0001
Cell death up 0.0001
Death up 0.0001
Meiosis down 0.0001
Dioxygenase activity up 0.0001
Oxidoreductase activity, acting on single donors with incorporation of molecular oxygen, incorporation of two atoms of oxygen up 0.0001
Isoprenoid biosynthetic process down 0.0001
Carbon–carbon lyase activity down 0.0001
Lipid digestion down 0.0001
Nitric oxide metabolic process down 0.0001
Nitric oxide biosynthetic process down 0.0001
Cellular homeostasis down 0.0001
Positive regulation of locomotion down 0.0001
Positive regulation of cell motility down 0.0001
Sulfur compound biosynthetic process up 0.0001
Proton-transporting ATP synthase complex, catalytic core F(1) down 0.0001
Mitochondrial proton-transporting ATP synthase complex down 0.0002
Muscle development up 0.0002
Integrator complex up 0.0002
Caspase inhibitor activity down 0.0002
Fatty acid binding down 0.0002
Isoprenoid metabolic process down 0.0002
Blood vessel morphogenesis up 0.0002
Vasculogenesis up 0.0002
Kinetochore down 0.0002
Low-density lipoprotein binding down 0.0002
Cell structure disassembly during apoptosis up 0.0002
Endoplasmic reticulum lumen down 0.0002
Negative regulation of multicellular organismal process down 0.0002
Intestinal absorption down 0.0002
Organelle outer membrane down 0.0002
Proton-transporting two-sector ATPase complex, catalytic domain down 0.0002
Regulation of transforming growth factor beta receptor signaling pathway down 0.0002
Clathrin adaptor complex down 0.0002
Fatty acid metabolic process down 0.0003
Replication fork down 0.0003
Lipoprotein binding down 0.0003
Insemination up 0.0003
Behavior down 0.0003
Leukocyte differentiation up 0.0003
Single-stranded RNA binding down 0.0003
Histone acetyltransferase complex up 0.0003
Oxidoreductase activity, acting on single donors with incorporation of molecular oxygen up 0.0003
Hemopoiesis up 0.0003
Outer kinetochore of condensed down 0.0003
chromosome
Response to virus up 0.0003
Vasculature development up 0.0003
DNA-directed RNA polymerase complex up 0.0003
Perinuclear region of cytoplasm down 0.0003
Sterol binding down 0.0003
Generation of precursor metabolites and energy down 0.0003
Copulation up 0.0004
Spindle localization down 0.0004
Establishment of mitotic spindle localization down 0.0004
Establishment of spindle localization down 0.0004
Neural crest cell development down 0.0004
GTPase inhibitor activity down 0.0004

Notes: Functional groupings of the modulated genes were determined using Gene Ontology classifications in NextBio. The top 200 biogroups most significantly regulated by AZA (at 3 µM) are shown.

Table S5.

Top 200 biogroups modulated by decitabine (DAC) in H1299 cells

H1299 cells treated with 3 μM DAC (48 hours)
Biogroup name Direction P value
Cofactor binding down 4.70E-12
Lipid metabolic process down 5.10E-12
Cell differentiation up 2.50E-08
Coenzyme binding down 3.70E-08
Transcription up 1.00E-07
Inner ear development up 2.20E-07
Cell fate determination up 2.50E-07
Fatty acid metabolic process down 2.90E-07
Collagen binding up 4.90E-07
Oxidoreductase activity, acting on the CH–OH group of donors, NAD or NADP as acceptor down 1.20E-06
Enzyme inhibitor activity up 1.30E-06
Nucleosome up 1.30E-06
Aldehyde metabolic process down 1.40E-06
Sensory organ development up 2.30E-06
Oxidoreductase activity, acting on CH–OH group of donors down 2.50E-06
Response to external stimulus up 2.80E-06
Hormone biosynthetic process up 3.00E-06
CoA–ligase activity down 4.00E-06
Insulin-like growth factor binding up 4.20E-06
Response to stress up 4.40E-06
Mitochondrion down 5.20E-06
Acid–thiol ligase activity down 6.30E-06
Proteinaceous extracellular matrix up 7.40E-06
Transcription repressor activity up 7.90E-06
Extracellular matrix up 8.60E-06
Muscle cell differentiation up 9.40E-06
Response to wounding up 9.50E-06
Alcohol metabolic process down 9.90E-06
Enzyme regulator activity up 9.90E-06
Neurotransmitter metabolic process up 1.00E-05
Muscle fiber development up 1.10E-05
Skeletal muscle fiber development up 1.10E-05
Peroxisome down 1.10E-05
Microbody down 1.10E-05
Ligase activity, forming carbon-sulfur bonds down 1.40E-05
Regulation of epidermis development up 2.00E-05
Cell fate commitment up 2.20E-05
Hormone metabolic process up 2.20E-05
Sterol metabolic process down 2.30E-05
Inflammatory response up 2.30E-05
Oxidoreductase activity, acting on the CH–CH group of donors, NAD or NADP as acceptor down 2.60E-05
Death up 3.20E-05
Cell death up 3.20E-05
Steroid metabolic process down 3.50E-05
Lipid biosynthetic process down 3.80E-05
Lyase activity down 4.10E-05
Glycosaminoglycan binding up 4.50E-05
Polysaccharide binding up 5.30E-05
Pyridoxal phosphate binding down 5.50E-05
Muscle development up 6.70E-05
Nitrogen compound biosynthetic process down 6.90E-05
Protease inhibitor activity up 7.60E-05
Endopeptidase inhibitor activity up 7.60E-05
Phosphatase activator activity up 8.00E-05
Phenol metabolic process up 8.40E-05
Epidermis development up 8.50E-05
Regulation of neurotransmitter levels up 9.20E-05
Pattern binding up 9.60E-05
Cofactor catabolic process down 9.80E-05
Positive regulation of developmental process up 1.00E-04
Vitamin binding down 0.0001
Oxidoreductase activity, acting on the CH–CH group of donors down 0.0001
Amino acid derivative metabolic process up 0.0001
Chromatin assembly up 0.0001
Protein–DNA complex assembly up 0.0001
Amino acid derivative biosynthetic process up 0.0001
Positive regulation of cell differentiation up 0.0001
Acute inflammatory response up 0.0001
Dopamine metabolic process up 0.0001
Growth factor binding up 0.0002
Endothelial cell development down 0.0002
Transcription corepressor activity up 0.0002
Keratinocyte differentiation up 0.0002
Ectoderm development up 0.0002
Cellular respiration down 0.0002
RNA polymerase II transcription elongation factor activity up 0.0002
Angiogenesis up 0.0003
Calcium-dependent phospholipid binding down 0.0003
Suckling behavior down 0.0003
Oxidoreductase activity, acting on the aldehyde or oxo group of donors, NAD or NADP as acceptor down 0.0003
Germ-line sex determination down 0.0003
RNA polymerase II transcription factor activity up 0.0003
Protein kinase inhibitor activity up 0.0004
Translation activator activity up 0.0004
Regulation of Notch signaling pathway up 0.0004
Fatty acid biosynthetic process down 0.0004
Kinase inhibitor activity up 0.0004
Regulation of cell differentiation up 0.0004
ER-Golgi intermediate compartment up 0.0005
UDP-glycosyltransferase activity down 0.0005
Cell maturation up 0.0005
Cell surface down 0.0005
Inner ear receptor cell fate commitment up 0.0005
Organic acid biosynthetic process down 0.0005
Negative regulation of signal transduction up 0.0006
Hydro–Lyase activity down 0.0006
Epidermal cell differentiation up 0.0007
Inner ear morphogenesis up 0.0007
Regulation of cell growth up 0.0007
Response to bacterium up 0.0007
Blood vessel morphogenesis up 0.0007
Carbohydrate metabolic process down 0.0007
Lipoprotein binding down 0.0007
Multicellular organismal movement down 0.0008
Aromatic compound metabolic process up 0.0008
Amine biosynthetic process down 0.0008
tRNA binding down 0.0008
Cell migration up 0.0008
Transcription elongation factor complex up 0.0009
Glutathione peroxidase activity up 0.0009
Oxidoreductase activity, acting on the CH–NH group of donors, NAD or NADP as acceptor down 0.0009
Primary sex determination down 0.0009
Negative regulation of cell differentiation up 0.001
Defense response to bacterium up 0.001
Nuclear envelope down 0.001
Ear morphogenesis up 0.0011
Ligase activity, forming carbon–oxygen bonds down 0.0011
Ligase activity, forming aminoacyl–tRNA and related compounds down 0.0011
Generation of precursor metabolites and energy down 0.0011
Developmental maturation up 0.0011
Peripheral nervous system development down 0.0011
Extracellular matrix structural constituent up 0.0012
Oxidoreductase activity, acting on the aldehyde or oxo group of donors down 0.0012
Biogenic amine metabolic process up 0.0012
Epidermis morphogenesis up 0.0013
Endothelial cell differentiation down 0.0013
Endoplasmic reticulum down 0.0013
Carbon–oxygen lyase activity down 0.0013
Germ cell development up 0.0014
Cell proliferation down 0.0015
Peroxidase activity up 0.0015
Oxidoreductase activity, acting on peroxide as acceptor up 0.0015
Specific RNA polymerase II transcription factor activity up 0.0015
Positive regulation of programmed cell death up 0.0016
Response to nutrient levels down 0.0016
Myeloid cell differentiation up 0.0016
Lung development up 0.0017
Oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen down 0.0017
Vasculature development up 0.0017
Respiratory tube development up 0.0018
Oxidoreductase activity, acting on single donors with incorporation of molecular oxygen, incorporation of two atoms of oxygen down 0.0018
Dioxygenase activity down 0.0018
Negative regulation of enzyme activity up 0.0019
Odontogenesis up 0.0019
Positive regulation of locomotion down 0.0019
Positive regulation of cell motility down 0.0019
Cell cycle up 0.0019
Anatomical structure formation up 0.002
Cell growth up 0.0021
Regulation of cell size up 0.0021
NAD binding down 0.0021
Steroid biosynthetic process down 0.0022
Response to extracellular stimulus down 0.0022
Endocytosis down 0.0023
Membrane invagination down 0.0023
Oxidoreductase activity, acting on single donors with incorporation of molecular oxygen down 0.0025
Musculoskeletal movement down 0.0025
Brain development up 0.0026
Immune system development up 0.0027
Negative regulation of cell growth down 0.0028
Negative regulation of cell size down 0.0028
Envelope down 0.0029
Negative regulation of developmental process up 0.0029
Chromatin up 0.003
mRNA binding up 0.0032
Antioxidant activity up 0.0033
Selenium binding up 0.0035
Receptor signaling protein serine/threonine kinase activity down 0.0036
Outer membrane-bounded periplasmic space down 0.0036
Cell envelope down 0.0036
Axon up 0.0036
Transferase activity, transferring hexosyl groups down 0.0038
Energy derivation by oxidation of organic compounds down 0.0038
Response to reactive oxygen species up 0.0038
Meiosis up 0.0038
Meiotic cell cycle up 0.0038
Enzyme activator activity up 0.0039
Hemopoiesis up 0.0043
Positive regulation of biosynthetic process up 0.0043
Regulation of transforming growth factor beta receptor signaling pathway down 0.0043
FAD binding down 0.0044
Negative regulation of growth down 0.0045
Defense response to Gram-positive bacterium up 0.0048
Sensory perception of light stimulus down 0.0048
Catabolic process down 0.0049
Hemopoietic or lymphoid organ development up 0.005
Positive regulation of protein metabolic process up 0.0051
Intermediate filament up 0.0051
Ras GTPase activator activity down 0.0052
Response to nutrient down 0.0053
Protein kinase regulator activity up 0.0053
Carbohydrate binding up 0.0054
Calcium ion binding down 0.0055
Oxidoreductase activity, acting on sulfur group of donors down 0.0056
Response to hypoxia down 0.0057
Transferase activity, transferring aldehyde or ketonic groups up 0.0058
Positive regulation of multicellular organismal process up 0.0059
Xenobiotic transporter activity up 0.0063
Xenobiotic-transporting ATPase activity up 0.0063
Phospholipase inhibitor activity up 0.0064

Notes: Functional groupings of the modulated genes were determined using Gene Ontology classifications in NextBio. The top 200 biogroups most significantly regulated by DAC (at 3 µM) are shown.

Acknowledgments

We would like to acknowledge Sharon Aukerman, Victoria Sung, and Sharianne Louie for critical review of the manuscript. We thank Gina Fusaro and Marianna Shafarenko for their assistance with manuscript editing. We also thank Xiaoyue Zhao for statistical analyses. Vidaza is a marketed product with azacitidine as the active pharmaceutical ingredient. Dacogen is a marketed product with decitabine as the active pharmaceutical ingredient.

Footnotes

Disclosure

ANN, PWH, NR, AL-M, HB, CH, and KJM are employees of Celgene and as such own stock in the company.

References

  • 1.Silverman LR, Demakos EP, Peterson BL, et al. Randomized controlled trial of azacitidine in patients with the myelodysplastic syndrome: a study of the cancer and leukemia group B. J Clin Oncol. 2002;20(10):2429–2440. doi: 10.1200/JCO.2002.04.117. [DOI] [PubMed] [Google Scholar]
  • 2.Kantarjian H, Issa JP, Rosenfeld CS, et al. Decitabine improves patient outcomes in myelodysplastic syndromes: results of a phase III randomized study. Cancer. 2006;106(8):1794–1803. doi: 10.1002/cncr.21792. [DOI] [PubMed] [Google Scholar]
  • 3.Santi DV, Norment A, Garrett CE. Covalent bond formation between a DNA-cytosine methyltransferase and DNA containing 5-azacytosine. Proc Natl Acad Sci U S A. 1984;81(22):6993–6997. doi: 10.1073/pnas.81.22.6993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 4.Weisenberger DJ, Velicescu M, Cheng JC, Gonzales FA, Liang G, Jones PA. Role of the DNA methyltransferase variant DNMT3b3 in DNA methylation. Mol Cancer Res. 2004;2(1):62–72. [PubMed] [Google Scholar]
  • 5.Jones PA, Taylor SM. Cellular differentiation, cytidine analogs and DNA methylation. Cell. 1980;20(1):85–93. doi: 10.1016/0092-8674(80)90237-8. [DOI] [PubMed] [Google Scholar]
  • 6.Haaf T. The effects of 5-azacytidine and 5-azadeoxycytidine on chromosome structure and function: implications for methylation-associated cellular processes. Pharmacol Ther. 1995;65(1):19–46. doi: 10.1016/0163-7258(94)00053-6. [DOI] [PubMed] [Google Scholar]
  • 7.Chuang JC, Yoo CB, Kwan JM, et al. Comparison of biological effects of non-nucleoside DNA methylation inhibitors versus 5-aza-2′-deoxycytidine. Mol Cancer Ther. 2005;4(10):1515–1520. doi: 10.1158/1535-7163.MCT-05-0172. [DOI] [PubMed] [Google Scholar]
  • 8.Stresemann C, Brueckner B, Musch T, Stopper H, Lyko F. Functional diversity of DNA methyltransferase inhibitors in human cancer cell lines. Cancer Res. 2006;66(5):2794–2800. doi: 10.1158/0008-5472.CAN-05-2821. [DOI] [PubMed] [Google Scholar]
  • 9.Yoo CB, Jones PA. Epigenetic therapy of cancer: past, present and future. Nat Rev Drug Discov. 2006;5(2):37–50. doi: 10.1038/nrd1930. [DOI] [PubMed] [Google Scholar]
  • 10.Esteller M. Profiling aberrant DNA methylation in hematologic neoplasms: a view from the tip of the iceberg. Clin Immunol. 2003;109(1):80–88. doi: 10.1016/s1521-6616(03)00208-0. [DOI] [PubMed] [Google Scholar]
  • 11.Esteller M. CpG island hypermethylation and tumor suppressor genes: a booming present, a brighter future. Oncogene. 2002;21(35):5427–5440. doi: 10.1038/sj.onc.1205600. [DOI] [PubMed] [Google Scholar]
  • 12.Burbee DG, Forgacs E, Zöchbauer-Müller S, et al. Epigenetic inactivation of RASSF1A in lung and breast cancers and malignant phenotype suppression. J Natl Cancer Inst. 2001;93(9):691–699. doi: 10.1093/jnci/93.9.691. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 13.Brabender J, Usadel H, Danenberg KD, et al. Adenomatous polyposis coli gene promoter hypermethylation in non-small cell lung cancer is associated with survival. Oncogene. 2001;20(27):3528–3532. doi: 10.1038/sj.onc.1204455. [DOI] [PubMed] [Google Scholar]
  • 14.Kim DH, Nelson HH, Wiencke JK, et al. p16(INK4a) and histology-specific methylation of CpG islands by exposure to tobacco smoke in non-small cell lung cancer. Cancer Res. 2001;61(8):3419–3424. [PubMed] [Google Scholar]
  • 15.Maruyama R, Sugio K, Yoshino I, Maehara Y, Gazdar AF. Hypermethylation of FHIT as a prognostic marker in nonsmall cell lung carcinoma. Cancer. 2004;100(7):1472–1477. doi: 10.1002/cncr.20144. [DOI] [PubMed] [Google Scholar]
  • 16.Schrump DS, Fischette MR, Nguyen DM, et al. Phase I study of decitabine-mediated gene expression in patients with cancers involving the lungs, esophagus, or pleura. Clin Cancer Res. 2006;12(19):5777–5785. doi: 10.1158/1078-0432.CCR-06-0669. [DOI] [PubMed] [Google Scholar]
  • 17.Samlowski WE, Leachman SA, Wade M, et al. Evaluation of a 7-day continuous intravenous infusion of decitabine: inhibition of promoter-specific and global genomic DNA methylation. J Clin Oncol. 2005;23(17):3897–3905. doi: 10.1200/JCO.2005.06.118. [DOI] [PubMed] [Google Scholar]
  • 18.Weiss AJ, Metter GE, Nealon TF, et al. Phase II study of 5-azacytidine in solid tumors. Cancer Treat Rep. 1977;61(1):55–58. [PubMed] [Google Scholar]
  • 19.Lin J, Gilbert J, Rudek MA, et al. A phase I dose-finding study of 5-azacytidine in combination with sodium phenylbutyrate in patients with refractory solid tumors. Clin Cancer Res. 2009;15(19):6241–6249. doi: 10.1158/1078-0432.CCR-09-0567. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 20.Bepler G, Kusmartseva I, Sharma S, et al. RRM1 modulated in vitro and in vivo efficacy of gemcitabine and platinum in non-small cell lung cancer. J Clin Oncol. 2006;24(29):4731–4737. doi: 10.1200/JCO.2006.06.1101. [DOI] [PubMed] [Google Scholar]
  • 21.Oguri T, Achiwa H, Sato S, et al. The determinants of sensitivity and acquired resistance to gemcitabine differ in non-small cell lung cancer: a role of ABCC5 in gemcitabine sensitivity. Mol Cancer Ther. 2006;5(7):1800–1806. doi: 10.1158/1535-7163.MCT-06-0025. [DOI] [PubMed] [Google Scholar]
  • 22.Voortman J, Checinska A, Giaccone G, Rodriguez JA, Kruyt FA. Bortezomib, but not cisplatin, induces mitochondria-dependent apoptosis accompanied by up-regulation of noxa in the non-small cell lung cancer cell line NCI-H460. Mol Cancer Ther. 2007;6(3):1046–1053. doi: 10.1158/1535-7163.MCT-06-0577. [DOI] [PubMed] [Google Scholar]
  • 23.Qin T, Youssef EM, Jelinek J, et al. Effect of cytarabine and decitabine in combination in human leukemic cell lines. Clin Cancer Res. 2007;13(14):4225–4232. doi: 10.1158/1078-0432.CCR-06-2762. [DOI] [PubMed] [Google Scholar]
  • 24.Qin T, Jelinek J, Si J, Shu J, Issa JP. Mechanisms of resistance to 5-aza-2′-deoxycytidine in human cancer cell lines. Blood. 2009;113(3):659–667. doi: 10.1182/blood-2008-02-140038. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 25.Hollenbach PW, Nguyen AN, Brady H, et al. A comparison of azacitidine and decitabine activities in acute myeloid leukemia cell lines. PLoS One. 2010;5(2):e9001. doi: 10.1371/journal.pone.0009001. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 26.Flotho C, Claus R, Batz C, et al. The DNA methyltransferase inhibitors azacitidine, decitabine and zebularine exert differential effects on cancer gene expression in acute myeloid leukemia cells. Leukemia. 2009;23(6):1019–1028. doi: 10.1038/leu.2008.397. [DOI] [PubMed] [Google Scholar]
  • 27.Sadikovic B, Al-Romaih K, Squire JA, Zielenska M. Cause and consequences of genetic and epigenetic alterations in human cancer. Curr Genomics. 2008;9(6):394–408. doi: 10.2174/138920208785699580. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 28.Blum W, Klisovic RB, Hackanson B, et al. Phase I study of decitabine alone or in combination with valproic acid in acute myeloid leukemia. J Clin Oncol. 2007;25(25):3884–3891. doi: 10.1200/JCO.2006.09.4169. [DOI] [PubMed] [Google Scholar]
  • 29.Oki Y, Kantarjian HM, Gharibyan V, et al. Phase II study of low-dose decitabine in combination with imatinib mesylate in patients with accelerated or myeloid blastic phase of chronic myelogenous leukemia. Cancer. 2007;109(5):899–906. doi: 10.1002/cncr.22470. [DOI] [PubMed] [Google Scholar]
  • 30.Stresemann C, Bokelmann I, Mahlknecht U, Lyko F. Azacytidine causes complex DNA methylation responses in myeloid leukemia. Mol Cancer Ther. 2008;7(9):2998–3005. doi: 10.1158/1535-7163.MCT-08-0411. [DOI] [PubMed] [Google Scholar]
  • 31.Karpf AR, Moore BC, Ririe TO, Jones DA. Activation of the p53 DNA damage response pathway after inhibition of DNA methyltransferase by 5-aza-2′-deoxycytidine. Mol Pharmacol. 2001;59(4):751–757. [PubMed] [Google Scholar]
  • 32.Kiziltepe T, Hideshima T, Catley L, et al. 5-Azacytidine, a DNA methyltransferase inhibitor, induces ATR-mediated DNA double-strand break responses, apoptosis, and synergistic cytotoxicity with doxorubicin and bortezomib against multiple myeloma cells. Mol Cancer Ther. 2007;6(6):1718–1727. doi: 10.1158/1535-7163.MCT-07-0010. [DOI] [PubMed] [Google Scholar]
  • 33.Jiemjit A, Fandy TE, Carraway H, et al. p21(WAF1/CIP1) induction by 5-azacytosine nucleosides requires DNA damage. Oncogene. 2008;27(25):3615–3623. doi: 10.1038/sj.onc.1211018. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 34.Palii SS, van Emburgh BO, Sankpal UT, Brown KD, Robertson KD. DNA methylation inhibitor 5-Aza-2′-deoxycytidine induces reversible genome-wide DNA damage that is distinctly influenced by DNA methyltransferases 1 and 3B. Mol Cell Biol. 2008;28(2):752–771. doi: 10.1128/MCB.01799-07. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 35.D’Incalci M, Covey JM, Zaharko DS, Kohn KW. DNA alkali-labile sites induced by incorporation of 5-aza-2′-deoxycytidine into DNA of mouse leukemia L1210 cells. Cancer Res. 1985;45(7):3197–3202. [PubMed] [Google Scholar]
  • 36.Covey JM, D’Incalci M, Tilchen EJ, Zaharko DS, Kohn KW. Differences in DNA damage produced by incorporation of 5-aza-2′-deoxycytidine or 5,6-dihydro-5-azacytidine into DNA of mammalian cells. Cancer Res. 1986;46(11):5511–5517. [PubMed] [Google Scholar]
  • 37.Chai G, Li L, Zhou W, et al. HDAC inhibitors act with 5-aza-2′-deoxycytidine to inhibit cell proliferation by suppressing removal of incorporated abases in lung cancer cells. PLoS One. 2008;3(6):e2445. doi: 10.1371/journal.pone.0002445. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 38.Li LH, Olin EJ, Buskirk HH, Reineke LM. Cytotoxicity and mode of action of 5-azacytidine on L1210 leukemia. Cancer Res. 1970;30(11):2760–2769. [PubMed] [Google Scholar]
  • 39.Veselý J, Cihák A. Incorporation of a potent antileukemic agent, 5-aza-2′-deoxycytidine, into DNA of cells from leukemic mice. Cancer Res. 1977;37(10):3684–3689. [PubMed] [Google Scholar]
  • 40.Bouchard J, Momparler RL. Incorporation of 5-Aza-2′-deoxycytidine-5′-triphosphate into DNA. Interactions with mammalian DNA polymerase alpha and DNA methylase. Mol Pharmacol. 1983;24(1):109–114. [PubMed] [Google Scholar]
  • 41.Glazer RI, Knode MC. 1-beta-D-arabinosyl-5-azacytosine. Cytocidal activity and effects on the synthesis and methylation of DNA in human colon carcinoma cells. Mol Pharmacol. 1984;26(2):381–387. [PubMed] [Google Scholar]
  • 42.Cihák A. Biological effects of 5-azacytidine in eukaryotes. Oncology. 1974;30(5):405–422. doi: 10.1159/000224981. [DOI] [PubMed] [Google Scholar]
  • 43.Lu LJ, Randerath K. Effects of 5-azacytidine on transfer RNA methyltransferases. Cancer Res. 1979;39(3):940–949. [PubMed] [Google Scholar]
  • 44.Cohen MB, Glazer RI. Cytotoxicity and the inhibition of ribosomal RNA processing in human colon carcinoma cells. Mol Pharmacol. 1985;27(2):308–313. [PubMed] [Google Scholar]
  • 45.Glover AB, Leyland-Jones B. Biochemistry of azacitidine: a review. Cancer Treat Rep. 1987;71(10):959–964. [PubMed] [Google Scholar]
  • 46.Marcucci G, Silverman L, Eller M, Lintz L, Beach CL. Bioavailability of azacitidine subcutaneous versus intravenous in patients with the myelodysplastic syndromes. J Clin Pharmacol. 2005;45(5):597–602. doi: 10.1177/0091270004271947. [DOI] [PubMed] [Google Scholar]
  • 47.Cashen AF, Shah AK, Todt L, Fisher N, DiPersio J. Pharmacokinetics of decitabine administered as a 3-h infusion to patients with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) Cancer Chemother Pharmacol. 2008;61(5):759–766. doi: 10.1007/s00280-007-0531-7. [DOI] [PubMed] [Google Scholar]
  • 48.Hothorn T, Bretz F, Westfall P. Simultaneous inference in general parametric models. Biom J. 2008;50(3):346–363. doi: 10.1002/bimj.200810425. [DOI] [PubMed] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

Figure S1

Viability of H23 and H1975 cells was assessed after 72 hours of treatment with AZA or DAC (0–25 µM). Error bars represent the standard error of mean of three independent experiments, with triplicate wells per experiment.

lctt-1-119s1.tif (114.8KB, tif)
Figure S2

AZA and DAC cause DNMT1 depletion in NSCLC cell lines. A549 and H1299 cells were treated with AZA or DAC (5 µM) for 4, 8, or 16 hours and DNMT1 protein was detected by Western blotting of cell extracts. Alpha-tubulin was used as a loading control.

lctt-1-119s2.tif (352.1KB, tif)
Figure S3

AZA and DAC reduce DNA methylation in A549 and H1299 cells. LINE-1 DNA methylation was assessed in A549 and H1299 cells after 72 hours of treatment with AZA or DAC (0–3 µM). Percentage LINE-1 methylation represents the average percentage methylation of 4 CpG sites in duplicate samples, with error bars representing the standard deviation.

lctt-1-119s3.tif (109.7KB, tif)
Figure S4

Viability of A549, H460, and H1299 cells was assessed after 6 days of treatment with AZA or DAC (0–25 µM).

lctt-1-119s4.tif (156KB, tif)

Table S1.

EC50 values for AZA and DAC on NSCLC cell viability (6 days)

AZA EC50 (μM) DAC EC50 (μM)
A549 4.4 2.5
H460 2.2 4.4
H1299 4.1 0.5

Abbreviations: AZA, azacitidine; DAC, decitabine; NSCLC, non-small cell lung cancer.

Table S2.

Top 200 biogroups modulated by azacitidine (AZA) in A549 cells

A549 cells treated with 3 μM AZA (48 hours)
Biogroup name Direction P value
Proteinaceous extracellular matrix down 3.40E-18
Extracellular matrix down 4.70E-18
Transcription up 2.50E-16
Extracellular matrix structural constituent down 4.90E-16
Glycosaminoglycan binding down 7.30E-15
Polysaccharide binding down 9.60E-15
Pattern binding down 2.80E-14
Lipid biosynthetic process down 3.60E-14
Fibrillar collagen down 1.60E-13
Calcium ion binding down 2.20E-13
Fibrinogen complex down 7.20E-13
Humoral immune response down 8.90E-12
Protein binding, bridging down 9.00E-12
Collagen down 1.70E-11
Response to wounding down 6.00E-11
Response to external stimulus down 1.50E-10
Platelet activation down 2.20E-10
Ligase activity, forming aminoacyl-tRNA and related compounds up 3.30E-10
Ligase activity, forming carbon-oxygen bonds up 3.30E-10
Response to nutrient up 3.70E-10
Carbohydrate binding down 3.80E-10
Basement membrane down 1.00E-09
Lipid metabolic process down 2.20E-09
Response to nutrient levels up 2.30E-09
Steroid biosynthetic process down 2.30E-09
Collagen binding down 2.40E-09
Response to extracellular stimulus up 3.70E-09
Inflammatory response down 7.80E-09
Nucleoplasm up 8.70E-09
Acute inflammatory response down 1.30E-08
Response to stress down 1.50E-08
Blood pressure regulation down 1.50E-08
RNA binding up 1.60E-08
Cell motility down 3.40E-08
Localization of cell down 3.40E-08
Epithelial cell differentiation down 4.70E-08
tRNA binding up 4.80E-08
Steroid metabolic process down 7.20E-08
Endoplasmic reticulum down 8.00E-08
Translation up 1.30E-07
Fatty acid biosynthetic process down 1.90E-07
Parturition down 2.50E-07
Sterol metabolic process down 2.50E-07
Blood coagulation down 2.90E-07
Coagulation down 3.10E-07
Humoral immune response mediated by circulating immunoglobulin down 3.60E-07
Hemostasis down 3.60E-07
Organic acid biosynthetic process down 4.40E-07
Regulation of body fluids down 6.70E-07
Wound healing down 6.90E-07
ER-Golgi intermediate compartment down 8.00E-07
Actin binding down 9.70E-07
Anion transport down 1.10E-06
Extracellular structure organization and biogenesis down 1.10E-06
Transaminase activity up 1.10E-06
Complement activation down 1.20E-06
Extracellular matrix organization and biogenesis down 1.20E-06
Calmodulin binding down 1.90E-06
Circulation down 1.90E-06
Female pregnancy down 2.50E-06
Cellular homeostasis down 2.60E-06
Morphogenesis of an epithelium down 2.70E-06
Cell proliferation down 3.10E-06
Alkene metabolic process down 3.10E-06
Ribosome biogenesis and assembly up 3.20E-06
Complement activation, classical pathway down 3.50E-06
Ribonucleoprotein complex biogenesis and assembly up 4.90E-06
Sodium:potassium-exchanging ATPase complex down 5.20E-06
Transferase activity, transferring nitrogenous groups up 5.80E-06
Cell activation down 6.10E-06
Endoplasmic reticulum lumen down 6.60E-06
Fatty acid metabolic process down 6.90E-06
Vesicular fraction down 8.20E-06
Cellular ion homeostasis down 1.10E-05
Cellular chemical homeostasis down 1.10E-05
Positive regulation of immune system process down 1.10E-05
Positive regulation of immune response down 1.10E-05
Phosphoinositide binding down 1.40E-05
Activation of immune response down 1.50E-05
Positive regulation of multicellular organismal process down 1.60E-05
Cofactor transporter activity up 1.60E-05
Soluble fraction up 1.70E-05
Enzyme inhibitor activity down 1.70E-05
Development of primary sexual characteristics up 1.80E-05
NAD binding down 1.90E-05
Amine biosynthetic process up 1.90E-05
Cytoskeleton down 2.20E-05
Lymphocyte mediated immunity down 2.40E-05
Receptor binding down 2.50E-05
Transcription corepressor activity up 2.50E-05
Response to DNA damage stimulus up 2.60E-05
Cartilage development down 2.70E-05
SNARE complex up 2.80E-05
Gastrulation up 3.20E-05
mRNA transport up 3.50E-05
Epidermis development down 3.80E-05
Cell migration down 4.20E-05
Immune effector process down 4.20E-05
Response to hypoxia down 4.30E-05
Leukocyte mediated immunity down 4.50E-05
Adaptive immune response down 4.90E-05
Adaptive immune response based on somatic recombination of immune receptors built from immunoglobulin superfamily domains down 4.90E-05
Endopeptidase inhibitor activity down 5.00E-05
Protease inhibitor activity down 5.00E-05
Oxidoreductase activity, acting on heme group of donors down 5.30E-05
Oxidoreductase activity, acting on heme group of donors, oxygen as acceptor down 5.30E-05
Cytochrome-c oxidase activity down 5.30E-05
Heme-copper terminal oxidase activity down 5.30E-05
Germ cell migration up 6.00E-05
Coenzyme binding down 6.20E-05
Regulation of translation up 6.90E-05
Cytokine biosynthetic process up 7.30E-05
Neurotransmitter:sodium symporter activity up 7.40E-05
Ectoderm development down 7.50E-05
Establishment of RNA localization up 8.00E-05
RNA transport up 8.00E-05
Nucleic acid transport up 8.00E-05
Transcription factor binding up 8.30E-05
Regulation of immune response down 8.50E-05
Regulation of immune system process down 8.50E-05
Ligase activity up 8.60E-05
RNA localization up 9.10E-05
Neurotransmitter transporter activity up 9.30E-05
RNA export from nucleus up 9.80E-05
Phospholipid binding down 9.90E-05
Cell cycle up 0.0001
Cytosol down 0.0001
Cytoskeletal protein binding down 0.0001
Response to endogenous stimulus up 0.0001
Gonad development up 0.0001
Nucleobase, nucleoside, nucleotide and nucleic acid transport up 0.0001
Nucleolus up 0.0001
Regulation of cytokine biosynthetic process up 0.0001
Rhythmic process up 0.0001
Reproductive structure development up 0.0002
Mitochondrion organization and biogenesis up 0.0002
Structural constituent of cytoskeleton down 0.0002
Sex differentiation up 0.0002
Transcription repressor activity up 0.0002
Peroxidase activity down 0.0002
Oxidoreductase activity, acting on peroxide as acceptor down 0.0002
Laminin-1 complex down 0.0002
Transcription cofactor activity up 0.0002
Female sex differentiation up 0.0002
Development of primary female sexual characteristics up 0.0002
Oxidoreductase activity, acting on the CH-CH group of donors, NAD or NADP as acceptor down 0.0002
Nitrogen compound biosynthetic process up 0.0002
Cell structure disassembly during apoptosis up 0.0003
Amino acid transport up 0.0003
Acyl-CoA binding down 0.0003
Response to dsRNA up 0.0003
Neuron development down 0.0003
Integrator complex up 0.0003
Immune response down 0.0003
Protein dimerization activity up 0.0004
Laminin complex down 0.0004
Cofactor binding down 0.0004
Germ-line sex determination down 0.0004
Intramolecular oxidoreductase activity down 0.0004
DNA repair up 0.0004
Cell soma down 0.0004
Cellular morphogenesis during differentiation down 0.0004
RNA polymerase II transcription factor activity up 0.0005
Regulation of epithelial cell proliferation down 0.0005
Regulation of biosynthetic process up 0.0005
UDP-glycosyltransferase activity up 0.0005
Pyridoxal phosphate binding up 0.0005
Lipid binding down 0.0005
Positive regulation of programmed cell death up 0.0005
Helicase activity up 0.0006
Cell redox homeostasis down 0.0006
Cell death up 0.0006
Death up 0.0006
Epithelial cell proliferation down 0.0006
Mesenchymal cell development down 0.0006
Ovulation up 0.0006
Positive regulation of locomotion down 0.0006
Positive regulation of cell motility down 0.0006
DNA catabolic process up 0.0006
Cell differentiation down 0.0006
Basal lamina down 0.0007
Insulin-like growth factor binding mesenchymal cell differentiation Down
down
0.0007
0.0007
Sequestering of metal ion down 0.0007
Neurotransmitter transport up 0.0007
Specific RNA polymerase II transcription factor activity up 0.0007
Intramolecular oxidoreductase activity, transposing C=C bonds down 0.0007
Cellular component disassembly up 0.0008
Heme binding down 0.0008
Tetrapyrrole binding down 0.0008
Presynaptic active zone up 0.0008
Amine transport up 0.0009
Sequestering of calcium ion down 0.0009
Cell recognition down 0.0009
Endoplasmic reticulum part down 0.0009
Oxidoreductase activity, acting on the CH-OH group of donors, NAD or NADP as acceptor down 0.001
Myosin binding down 0.001
Lyase activity up 0.001
Transferase activity, transferring hexosyl groups down 0.001
Neuron differentiation down 0.001

Notes: Functional groupings of the modulated genes were determined using Gene Ontology classifications in NextBio. The top 200 biogroups most significantly regulated by AZA (at 3 µM) are shown.

Table S3.

Top 196 biogroups modulated by decitabine (DAC) in A549 cells

A549 cells treated with 3 μM DAC (48 hours)
Biogroup name Direction P value
Mitosis down 2.00E-09
Cell cycle down 2.90E-09
Cell division down 5.70E-08
Transferase activity, transferring sulfur-containing groups up 5.80E-08
Meiosis down 1.50E-07
Meiotic cell cycle down 1.70E-07
Response to DNA damage stimulus down 1.80E-07
Male gamete generation up 6.10E-07
Response to endogenous stimulus down 7.60E-07
Chromosome segregation down 2.10E-06
Aromatic compound metabolic process up 2.70E-06
Phenol metabolic process up 2.70E-06
Structural constituent of cytoskeleton up 5.10E-06
Sister chromatid cohesion down 5.90E-06
Cellular lipid catabolic process up 6.70E-06
DNA repair down 7.20E-06
Alkali metal ion binding up 9.00E-06
Regulation of neurotransmitter levels up 1.10E-05
DNA damage response, signal transduction down 1.30E-05
Cofactor transporter activity up 1.60E-05
Sulfotransferase activity up 1.70E-05
Intermediate filament up 3.20E-05
Neurotransmitter:sodium symporter activity up 3.40E-05
Chromatin assembly down 3.90E-05
Neurotransmitter transporter activity up 4.60E-05
Cytokinesis down 5.10E-05
Chromosome down 5.30E-05
Mitotic spindle organization and biogenesis down 5.30E-05
Negative regulation of enzyme activity up 5.60E-05
Establishment of mitotic spindle localization down 6.50E-05
Establishment of spindle localization down 6.50E-05
Spindle localization down 6.50E-05
Retinol binding up 6.50E-05
Microtubule organizing center part down 7.60E-05
Mitotic sister chromatid segregation down 8.30E-05
Alcohol metabolic process up 8.60E-05
Sister chromatid segregation down 9.30E-05
Catabolic process up 0.0001
Soluble fraction up 0.0001
Retinal binding up 0.0001
Positive regulation of programmed cell death up 0.0001
Steroid biosynthetic process up 0.0002
Response to stress down 0.0002
Gamma-tubulin complex down 0.0002
Mitotic chromosome condensation down 0.0002
Transporter activity up 0.0002
Phosphopyruvate hydratase complex up 0.0002
Amino acid derivative metabolic process up 0.0003
Vitamin binding up 0.0003
Lipid catabolic process up 0.0003
Nuclear chromosome down 0.0003
Retinoid binding up 0.0003
Isoprenoid binding up 0.0003
Homologous chromosome segregation down 0.0003
Meiotic chromosome segregation down 0.0003
Meiotic spindle organization and biogenesis down 0.0003
Cell differentiation up 0.0003
NADP binding down 0.0004
Steroid metabolic process up 0.0004
Lipid raft up 0.0004
Cohesin complex down 0.0004
Meiosis I down 0.0004
Sodium:potassium-exchanging ATPase complex up 0.0004
Negative regulation of cell proliferation up 0.0004
Actin binding down 0.0005
Nuclear matrix down 0.0005
Cytoskeletal protein binding down 0.0005
Protein kinase inhibitor activity up 0.0005
Cell proliferation up 0.0006
Cytoskeleton down 0.0006
Cytoskeleton organization and biogenesis down 0.0006
Fat cell differentiation down 0.0006
Hormone metabolic process up 0.0006
Positive regulation of progression through cell cycle down 0.0006
Kinase inhibitor activity up 0.0006
Oxidoreductase activity, acting on the CH-CH group of donors, NAD or NADP as acceptor down 0.0007
Neurotransmitter transport up 0.0007
Membrane invagination down 0.0008
Endocytosis down 0.0008
Amide metabolic process up 0.0008
Spindle down 0.0008
Ion transport up 0.0009
Blastocyst growth down 0.0009
Interleukin binding down 0.0009
RNA export from nucleus down 0.0009
Tubulin binding down 0.0009
Epidermis development up 0.0009
Neurotransmitter metabolic process up 0.0011
Translation activator activity up 0.0011
Spindle pole down 0.0011
Synaptic transmission up 0.0012
Intracellular cyclic nucleotide activated cation channel complex up 0.0012
Biogenic amine metabolic process up 0.0012
Cell fate determination up 0.0013
Oxidoreductase activity, acting on iron-sulfur proteins as donors up 0.0013
Ion channel activity up 0.0013
Lipoprotein binding down 0.0014
Positive regulation of neurogenesis down 0.0014
Cytosol up 0.0018
Microtubule organizing center down 0.002
Microtubule down 0.002
Glutathione peroxidase activity up 0.0021
Odontogenesis down 0.0022
Passive transmembrane transporter activity up 0.0022
Transmission of nerve impulse up 0.0023
Oxidoreductase activity, acting on the CH-NH group of donors, NAD or NADP as acceptor down 0.0024
Dynein binding down 0.0024
Humoral immune response down 0.0024
Ectoderm development up 0.0025
Arginine metabolic process up 0.0025
Myosin binding down 0.0025
Lipid biosynthetic process up 0.0026
Muscle contraction up 0.0027
Mitochondrion organization and biogenesis up 0.0027
Fat-soluble vitamin metabolic process up 0.0028
Female gamete generation down 0.0028
Urea cycle intermediate metabolic process up 0.0029
Inclusion body down 0.0029
Folic acid transporter activity down 0.0029
Protein heterodimerization activity down 0.003
Angiogenesis up 0.003
Replication fork down 0.0031
Nucleoside metabolic process down 0.0031
Regulation of axonogenesis down 0.0032
Anatomical structure formation up 0.0033
Protein kinase regulator activity up 0.0034
Lipid metabolic process up 0.0037
Glycoprotein binding up 0.0037
Pyridoxal phosphate binding up 0.0037
Blood vessel morphogenesis up 0.004
Carbohydrate metabolic process up 0.0041
Tissue regeneration up 0.0041
Regeneration up 0.0041
Germ cell development up 0.0042
Growth factor binding down 0.0042
Peptide transporter activity up 0.0043
Nitrogen compound biosynthetic process up 0.0044
Cytokine binding down 0.0044
Nitric oxide metabolic process up 0.0047
Nitric oxide biosynthetic process up 0.0047
Centrosome down 0.0047
Embryonic morphogenesis down 0.0048
Regulation of neurogenesis down 0.0048
Oxidoreductase activity, acting on the aldehyde or oxo group of donors up 0.0048
Cytokinesis during cell cycle down 0.0049
Cell–cell signaling up 0.005
Calmodulin binding up 0.005
Structure-specific DNA binding down 0.0051
Oxidoreductase activity, acting on the CH–CH group of donors down 0.0051
Peroxidase activity up 0.0051
Oxidoreductase activity, acting on peroxide as acceptor up 0.0051
Microfibril up 0.0052
Protein–DNA complex assembly down 0.0052
Vasculature development up 0.0054
Excretion up 0.0055
mRNA transport down 0.0056
Identical protein binding up 0.0056
Vitamin transporter activity down 0.0057
Response to organic cyclic substance up 0.0059
Response to alkaloid up 0.0059
Kinase regulator activity up 0.006
Chromatin down 0.006
Electron carrier activity up 0.0061
Vitamin biosynthetic process down 0.0062
RNA transport down 0.0067
Nucleic acid transport down 0.0067
Establishment of RNA localization down 0.0067
Protein domain specific binding up 0.0068
Homophilic cell adhesion down 0.0068
RNA localization down 0.0069
Hormone biosynthetic process up 0.007
Protein dimerization activity down 0.0071
RNA binding down 0.0073
Blastocyst development down 0.0074
Cyclin binding up 0.0075
Nucleobase, nucleoside, nucleotide and nucleic acid transport down 0.0077
Cartilage development down 0.0077
Folic acid binding down 0.0079
Positive regulation of developmental process down 0.0081
Chordate embryonic development down 0.0082
NAD binding up 0.0082
Cofactor binding up 0.0082
Vesicle docking during exocytosis up 0.0084
Developmental maturation up 0.0085
Hydrolase activity, acting on carbon–nitrogen (but not peptide) bonds, in cyclic amidines up 0.0086
Lysosome up 0.0086
Embryonic digit morphogenesis down 0.0086
DNA helicase activity down 0.0089
Axon guidance down 0.0091
Membrane docking up 0.0093
Vesicle docking up 0.0093
Voltage-gated sodium channel complex down 0.0093
mRNA binding up 0.0094
Establishment of organelle localization down 0.0096
Vitamin metabolic process up 0.0096
Oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen down 0.0099

Notes: Functional groupings of the modulated genes were determined using Gene Ontology classifications in NextBio. The top 196 biogroups most significantly regulated by DAC (at 3 µM) are shown.

Table S4.

Top 200 biogroups modulated by azacitidine (AZA) in H1299 cells

H1299 cells treated with 3 μM AZA (48 hours)
Biogroup name Direction P value
Transcription up 1.90E-25
Cell cycle down 7.60E-25
Mitosis down 8.00E-24
Cell division down 1.00E-22
Cytoskeleton down 5.60E-14
Microtubule down 1.30E-13
Spindle down 1.80E-13
Mitochondrion down 1.80E-12
Sterol metabolic process down 1.40E-11
Chromosome down 1.20E-10
Alcohol metabolic process down 2.20E-10
Ligase activity up 2.40E-10
Lipid biosynthetic process down 2.70E-10
Steroid biosynthetic process down 3.00E-10
Mitotic sister chromatid segregation down 1.90E-09
Steroid metabolic process down 2.50E-09
Sister chromatid segregation down 2.90E-09
Endoplasmic reticulum down 3.60E-09
Envelope down 4.70E-09
Lipid metabolic process down 2.60E-08
Response to nutrient down 7.00E-08
Collagen binding down 1.60E-07
Centrosome down 1.70E-07
Wound healing down 1.90E-07
Response to nutrient levels down 2.00E-07
Intramolecular oxidoreductase activity down 2.50E-07
Response to extracellular stimulus down 2.70E-07
Mitochondrial membrane down 2.80E-07
Microtubule organizing center down 2.80E-07
Acid–amino acid ligase activity up 3.10E-07
Cell proliferation down 3.60E-07
Blood coagulation down 3.70E-07
Establishment of chromosome localization down 4.40E-07
Coagulation down 4.90E-07
Chromosome segregation down 5.00E-07
Nitrogen compound catabolic process down 5.20E-07
Kinase binding up 5.30E-07
Beta-catenin binding down 5.50E-07
Nucleoplasm up 6.10E-07
Enzyme inhibitor activity down 8.80E-07
Alcohol catabolic process down 9.80E-07
Hemostasis down 1.10E-06
Transcription cofactor activity up 1.10E-06
Transcription repressor activity up 1.20E-06
Midbody down 1.30E-06
Ligase activity, forming carbon-nitrogen bonds up 1.70E-06
Establishment of organelle localization down 2.00E-06
Germ-line sex determination down 2.00E-06
Oligosaccharyl transferase complex down 2.10E-06
Response to external stimulus down 2.20E-06
Oxidoreductase activity, acting on the CH-NH group of donors, NAD or NADP as acceptor down 2.20E-06
Amine catabolic process down 2.20E-06
Cytoskeleton organization and biogenesis down 2.20E-06
Cofactor binding down 2.30E-06
Coenzyme binding down 2.70E-06
Transcription corepressor activity up 3.00E-06
Cell differentiation up 3.20E-06
mRNA binding down 3.30E-06
Meiotic chromosome segregation down 3.60E-06
Homologous chromosome segregation down 3.60E-06
Nuclear envelope-endoplasmic reticulum network down 3.90E-06
Oxidoreductase activity, acting on the CH–CH group of donors, NAD or NADP as acceptor down 5.00E-06
Intramolecular oxidoreductase activity, transposing C=C bonds down 5.30E-06
Mitotic chromosome condensation down 5.50E-06
Endoplasmic reticulum part down 5.50E-06
Transcription factor binding up 5.60E-06
Organic acid transport up 5.70E-06
Carboxylic acid transport up 5.70E-06
Acyl-CoA binding down 5.70E-06
DNA-directed RNA polymerase II, holoenzyme up 5.80E-06
Interphase of mitotic cell cycle down 6.00E-06
Primary sex determination down 6.00E-06
Cell-matrix adhesion down 6.20E-06
Hormone activity down 6.30E-06
Organic acid transmembrane transporter activity up 6.30E-06
Mitochondrial inner membrane down 7.30E-06
Cell-substrate adhesion down 7.60E-06
Transcription activator activity up 7.70E-06
Mitotic spindle organization and biogenesis down 7.90E-06
Lyase activity down 8.10E-06
Sterol transport down 8.70E-06
Arginine metabolic process down 8.70E-06
Chromatin assembly down 1.00E-05
Nitrogen compound biosynthetic process down 1.10E-05
RNA polymerase II transcription factor activity up 1.10E-05
Transaminase activity up 1.20E-05
Meiotic spindle organization and biogenesis down 1.30E-05
Organelle localization down 1.40E-05
Isomerase activity down 1.40E-05
Interphase down 1.40E-05
Urea cycle intermediate metabolic process down 1.50E-05
Fatty acid biosynthetic process down 1.70E-05
Receptor binding down 1.70E-05
Regulation of body fluids down 1.80E-05
Condensin complex down 1.80E-05
Regulation of coagulation down 1.90E-05
Nuclear envelope down 2.20E-05
Caveola down 2.30E-05
Organic acid biosynthetic process down 2.30E-05
Meiotic cell cycle down 2.30E-05
Amino acid transport up 2.50E-05
NADP binding down 2.80E-05
Protein dimerization activity up 2.90E-05
Spindle pole down 3.40E-05
Ubiquitin–protein ligase activity up 3.50E-05
Transferase activity, transferring nitrogenous groups up 3.60E-05
Nucleoside metabolic process down 3.80E-05
Structural constituent of cytoskeleton down 3.90E-05
Carbohydrate catabolic process down 4.10E-05
Endoplasmic reticulum membrane down 4.30E-05
Nucleosome down 4.40E-05
Nucleotide catabolic process down 4.60E-05
Cellular chemical homeostasis down 4.70E-05
Cellular ion homeostasis down 4.70E-05
Cytokinesis down 4.90E-05
Muscle cell differentiation up 5.00E-05
Myeloid cell differentiation up 5.20E-05
Catabolic process down 5.20E-05
Oxygen and reactive oxygen species metabolic process down 5.20E-05
Chromatin down 5.30E-05
Epidermis development down 5.40E-05
Oxidoreductase activity, acting on the CH–NH group of donors down 5.60E-05
SNARE complex up 5.60E-05
Ligase activity, forming carbon–oxygen bonds up 5.70E-05
Ligase activity, forming aminoacyl–tRNA and related compounds up 5.70E-05
Soluble fraction up 5.80E-05
Endopeptidase inhibitor activity down 5.90E-05
Protease inhibitor activity down 5.90E-05
Small protein conjugating enzyme activity up 6.00E-05
AP-type membrane coat adaptor complex down 6.40E-05
Cell–cell signaling down 6.70E-05
Amine transport up 6.80E-05
Response to DNA damage stimulus up 7.20E-05
Male sex determination down 7.20E-05
Cell–cell adhesion down 8.00E-05
Protein heterodimerization activity down 8.00E-05
Enzyme binding up 8.40E-05
Oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen down 9.10E-05
Ectoderm development down 9.40E-05
Positive regulation of progression through cell cycle down 0.0001
One-carbon compound metabolic process down 0.0001
Heterogeneous nuclear ribonucleoprotein complex down 0.0001
Response to stress down 0.0001
Response to endogenous stimulus up 0.0001
Cell death up 0.0001
Death up 0.0001
Meiosis down 0.0001
Dioxygenase activity up 0.0001
Oxidoreductase activity, acting on single donors with incorporation of molecular oxygen, incorporation of two atoms of oxygen up 0.0001
Isoprenoid biosynthetic process down 0.0001
Carbon–carbon lyase activity down 0.0001
Lipid digestion down 0.0001
Nitric oxide metabolic process down 0.0001
Nitric oxide biosynthetic process down 0.0001
Cellular homeostasis down 0.0001
Positive regulation of locomotion down 0.0001
Positive regulation of cell motility down 0.0001
Sulfur compound biosynthetic process up 0.0001
Proton-transporting ATP synthase complex, catalytic core F(1) down 0.0001
Mitochondrial proton-transporting ATP synthase complex down 0.0002
Muscle development up 0.0002
Integrator complex up 0.0002
Caspase inhibitor activity down 0.0002
Fatty acid binding down 0.0002
Isoprenoid metabolic process down 0.0002
Blood vessel morphogenesis up 0.0002
Vasculogenesis up 0.0002
Kinetochore down 0.0002
Low-density lipoprotein binding down 0.0002
Cell structure disassembly during apoptosis up 0.0002
Endoplasmic reticulum lumen down 0.0002
Negative regulation of multicellular organismal process down 0.0002
Intestinal absorption down 0.0002
Organelle outer membrane down 0.0002
Proton-transporting two-sector ATPase complex, catalytic domain down 0.0002
Regulation of transforming growth factor beta receptor signaling pathway down 0.0002
Clathrin adaptor complex down 0.0002
Fatty acid metabolic process down 0.0003
Replication fork down 0.0003
Lipoprotein binding down 0.0003
Insemination up 0.0003
Behavior down 0.0003
Leukocyte differentiation up 0.0003
Single-stranded RNA binding down 0.0003
Histone acetyltransferase complex up 0.0003
Oxidoreductase activity, acting on single donors with incorporation of molecular oxygen up 0.0003
Hemopoiesis up 0.0003
Outer kinetochore of condensed down 0.0003
chromosome
Response to virus up 0.0003
Vasculature development up 0.0003
DNA-directed RNA polymerase complex up 0.0003
Perinuclear region of cytoplasm down 0.0003
Sterol binding down 0.0003
Generation of precursor metabolites and energy down 0.0003
Copulation up 0.0004
Spindle localization down 0.0004
Establishment of mitotic spindle localization down 0.0004
Establishment of spindle localization down 0.0004
Neural crest cell development down 0.0004
GTPase inhibitor activity down 0.0004

Notes: Functional groupings of the modulated genes were determined using Gene Ontology classifications in NextBio. The top 200 biogroups most significantly regulated by AZA (at 3 µM) are shown.

Table S5.

Top 200 biogroups modulated by decitabine (DAC) in H1299 cells

H1299 cells treated with 3 μM DAC (48 hours)
Biogroup name Direction P value
Cofactor binding down 4.70E-12
Lipid metabolic process down 5.10E-12
Cell differentiation up 2.50E-08
Coenzyme binding down 3.70E-08
Transcription up 1.00E-07
Inner ear development up 2.20E-07
Cell fate determination up 2.50E-07
Fatty acid metabolic process down 2.90E-07
Collagen binding up 4.90E-07
Oxidoreductase activity, acting on the CH–OH group of donors, NAD or NADP as acceptor down 1.20E-06
Enzyme inhibitor activity up 1.30E-06
Nucleosome up 1.30E-06
Aldehyde metabolic process down 1.40E-06
Sensory organ development up 2.30E-06
Oxidoreductase activity, acting on CH–OH group of donors down 2.50E-06
Response to external stimulus up 2.80E-06
Hormone biosynthetic process up 3.00E-06
CoA–ligase activity down 4.00E-06
Insulin-like growth factor binding up 4.20E-06
Response to stress up 4.40E-06
Mitochondrion down 5.20E-06
Acid–thiol ligase activity down 6.30E-06
Proteinaceous extracellular matrix up 7.40E-06
Transcription repressor activity up 7.90E-06
Extracellular matrix up 8.60E-06
Muscle cell differentiation up 9.40E-06
Response to wounding up 9.50E-06
Alcohol metabolic process down 9.90E-06
Enzyme regulator activity up 9.90E-06
Neurotransmitter metabolic process up 1.00E-05
Muscle fiber development up 1.10E-05
Skeletal muscle fiber development up 1.10E-05
Peroxisome down 1.10E-05
Microbody down 1.10E-05
Ligase activity, forming carbon-sulfur bonds down 1.40E-05
Regulation of epidermis development up 2.00E-05
Cell fate commitment up 2.20E-05
Hormone metabolic process up 2.20E-05
Sterol metabolic process down 2.30E-05
Inflammatory response up 2.30E-05
Oxidoreductase activity, acting on the CH–CH group of donors, NAD or NADP as acceptor down 2.60E-05
Death up 3.20E-05
Cell death up 3.20E-05
Steroid metabolic process down 3.50E-05
Lipid biosynthetic process down 3.80E-05
Lyase activity down 4.10E-05
Glycosaminoglycan binding up 4.50E-05
Polysaccharide binding up 5.30E-05
Pyridoxal phosphate binding down 5.50E-05
Muscle development up 6.70E-05
Nitrogen compound biosynthetic process down 6.90E-05
Protease inhibitor activity up 7.60E-05
Endopeptidase inhibitor activity up 7.60E-05
Phosphatase activator activity up 8.00E-05
Phenol metabolic process up 8.40E-05
Epidermis development up 8.50E-05
Regulation of neurotransmitter levels up 9.20E-05
Pattern binding up 9.60E-05
Cofactor catabolic process down 9.80E-05
Positive regulation of developmental process up 1.00E-04
Vitamin binding down 0.0001
Oxidoreductase activity, acting on the CH–CH group of donors down 0.0001
Amino acid derivative metabolic process up 0.0001
Chromatin assembly up 0.0001
Protein–DNA complex assembly up 0.0001
Amino acid derivative biosynthetic process up 0.0001
Positive regulation of cell differentiation up 0.0001
Acute inflammatory response up 0.0001
Dopamine metabolic process up 0.0001
Growth factor binding up 0.0002
Endothelial cell development down 0.0002
Transcription corepressor activity up 0.0002
Keratinocyte differentiation up 0.0002
Ectoderm development up 0.0002
Cellular respiration down 0.0002
RNA polymerase II transcription elongation factor activity up 0.0002
Angiogenesis up 0.0003
Calcium-dependent phospholipid binding down 0.0003
Suckling behavior down 0.0003
Oxidoreductase activity, acting on the aldehyde or oxo group of donors, NAD or NADP as acceptor down 0.0003
Germ-line sex determination down 0.0003
RNA polymerase II transcription factor activity up 0.0003
Protein kinase inhibitor activity up 0.0004
Translation activator activity up 0.0004
Regulation of Notch signaling pathway up 0.0004
Fatty acid biosynthetic process down 0.0004
Kinase inhibitor activity up 0.0004
Regulation of cell differentiation up 0.0004
ER-Golgi intermediate compartment up 0.0005
UDP-glycosyltransferase activity down 0.0005
Cell maturation up 0.0005
Cell surface down 0.0005
Inner ear receptor cell fate commitment up 0.0005
Organic acid biosynthetic process down 0.0005
Negative regulation of signal transduction up 0.0006
Hydro–Lyase activity down 0.0006
Epidermal cell differentiation up 0.0007
Inner ear morphogenesis up 0.0007
Regulation of cell growth up 0.0007
Response to bacterium up 0.0007
Blood vessel morphogenesis up 0.0007
Carbohydrate metabolic process down 0.0007
Lipoprotein binding down 0.0007
Multicellular organismal movement down 0.0008
Aromatic compound metabolic process up 0.0008
Amine biosynthetic process down 0.0008
tRNA binding down 0.0008
Cell migration up 0.0008
Transcription elongation factor complex up 0.0009
Glutathione peroxidase activity up 0.0009
Oxidoreductase activity, acting on the CH–NH group of donors, NAD or NADP as acceptor down 0.0009
Primary sex determination down 0.0009
Negative regulation of cell differentiation up 0.001
Defense response to bacterium up 0.001
Nuclear envelope down 0.001
Ear morphogenesis up 0.0011
Ligase activity, forming carbon–oxygen bonds down 0.0011
Ligase activity, forming aminoacyl–tRNA and related compounds down 0.0011
Generation of precursor metabolites and energy down 0.0011
Developmental maturation up 0.0011
Peripheral nervous system development down 0.0011
Extracellular matrix structural constituent up 0.0012
Oxidoreductase activity, acting on the aldehyde or oxo group of donors down 0.0012
Biogenic amine metabolic process up 0.0012
Epidermis morphogenesis up 0.0013
Endothelial cell differentiation down 0.0013
Endoplasmic reticulum down 0.0013
Carbon–oxygen lyase activity down 0.0013
Germ cell development up 0.0014
Cell proliferation down 0.0015
Peroxidase activity up 0.0015
Oxidoreductase activity, acting on peroxide as acceptor up 0.0015
Specific RNA polymerase II transcription factor activity up 0.0015
Positive regulation of programmed cell death up 0.0016
Response to nutrient levels down 0.0016
Myeloid cell differentiation up 0.0016
Lung development up 0.0017
Oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen down 0.0017
Vasculature development up 0.0017
Respiratory tube development up 0.0018
Oxidoreductase activity, acting on single donors with incorporation of molecular oxygen, incorporation of two atoms of oxygen down 0.0018
Dioxygenase activity down 0.0018
Negative regulation of enzyme activity up 0.0019
Odontogenesis up 0.0019
Positive regulation of locomotion down 0.0019
Positive regulation of cell motility down 0.0019
Cell cycle up 0.0019
Anatomical structure formation up 0.002
Cell growth up 0.0021
Regulation of cell size up 0.0021
NAD binding down 0.0021
Steroid biosynthetic process down 0.0022
Response to extracellular stimulus down 0.0022
Endocytosis down 0.0023
Membrane invagination down 0.0023
Oxidoreductase activity, acting on single donors with incorporation of molecular oxygen down 0.0025
Musculoskeletal movement down 0.0025
Brain development up 0.0026
Immune system development up 0.0027
Negative regulation of cell growth down 0.0028
Negative regulation of cell size down 0.0028
Envelope down 0.0029
Negative regulation of developmental process up 0.0029
Chromatin up 0.003
mRNA binding up 0.0032
Antioxidant activity up 0.0033
Selenium binding up 0.0035
Receptor signaling protein serine/threonine kinase activity down 0.0036
Outer membrane-bounded periplasmic space down 0.0036
Cell envelope down 0.0036
Axon up 0.0036
Transferase activity, transferring hexosyl groups down 0.0038
Energy derivation by oxidation of organic compounds down 0.0038
Response to reactive oxygen species up 0.0038
Meiosis up 0.0038
Meiotic cell cycle up 0.0038
Enzyme activator activity up 0.0039
Hemopoiesis up 0.0043
Positive regulation of biosynthetic process up 0.0043
Regulation of transforming growth factor beta receptor signaling pathway down 0.0043
FAD binding down 0.0044
Negative regulation of growth down 0.0045
Defense response to Gram-positive bacterium up 0.0048
Sensory perception of light stimulus down 0.0048
Catabolic process down 0.0049
Hemopoietic or lymphoid organ development up 0.005
Positive regulation of protein metabolic process up 0.0051
Intermediate filament up 0.0051
Ras GTPase activator activity down 0.0052
Response to nutrient down 0.0053
Protein kinase regulator activity up 0.0053
Carbohydrate binding up 0.0054
Calcium ion binding down 0.0055
Oxidoreductase activity, acting on sulfur group of donors down 0.0056
Response to hypoxia down 0.0057
Transferase activity, transferring aldehyde or ketonic groups up 0.0058
Positive regulation of multicellular organismal process up 0.0059
Xenobiotic transporter activity up 0.0063
Xenobiotic-transporting ATPase activity up 0.0063
Phospholipase inhibitor activity up 0.0064

Notes: Functional groupings of the modulated genes were determined using Gene Ontology classifications in NextBio. The top 200 biogroups most significantly regulated by DAC (at 3 µM) are shown.


Articles from Lung Cancer: Targets and Therapy are provided here courtesy of Dove Press

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