Appendix 1.
Summary of the Selected Articles
| Author | Year | Cell Line | Gene and observed change | Methodology | Validation | Investigations on tissue samples | Conclusion |
|---|---|---|---|---|---|---|---|
| Dong., et al | 2015 | OSCC-BD | ↓ p53 expression ↓Rb expression 154 genes showed 2 fold increase(proteomic analysis) |
Western Blot Analysis, Proteomic analysis | The molecular mechanisms of several novel cancer related proteins in tumorigenesis are still unknown and further research is required to explore Oral Leukoplakia malignant transformation | ||
| Goessel., et al | 2015 | OKF6, OKM1 | Over expression of Cyclin D1, inactivation of p53, over expression of EGFR, over expression of c-myc | Western Blot Analysis, TRAP assay, anchorage dependent growth assay, Tumorigenicity assay | Molecular HLA analysis, Microsatellite analysis | Transformation of Oral cells were made possible by overexpression of Cyclin D1, p53 inactivation, EGFR overexpression, telomerase reactivation and c-myc over expression | |
| Wang., et al | 2016 | DOK, NOK, KB, HN5, HN13, FaDu, Hep-2, CAL27, SCC-4, Tca8113 | ↓expression of miRNA-451, ↑c-myc expression | RT-PCR | Western Blot | RT-PCR in HNSCC Tissues | A tumor suppressor role of miRNA-451 was demonstrated which played a part in HNSCC cell malignant proliferation by regulating c-myc expression proving to be a novel biomarker |
| Dalley., et al | 2014 | PE/CA-PJ15, DOK, POE-9n, OKF6-TERT2, SCC04, SCC15, SCC25, SCC09 | ↑ expression of ABCG2 and Bmi1 seen in dysplastic cell lines | Multi-color Flow cytometry | RT-PCR | IHC for ABCG2 and Bmi1 done in normal, dysplastic and SCC tissues | Study provides an evidence of increased density of ABCG2 and Bmi-1 positive cells in malignant and potentially malignant lesions |
| Wang., et al | 2015 | Hep-2 | ↓ expression of miR-206 | RT-PCR, Cell cycle analysis using flow cytometry, Tumour Growth Assay | Western Blot | RT-PCR in LSCC Tissues | miR-206 is down-regulated in LNSCC tissue and increased expression leads to cell proliferation suppression proving to play a role in tumorigenesis |
| Miyazaki., et al | 2015 | Ca9-27, HSC-3, HSC-4 | ↑ expression of hTERT seen in HSC-3 and HSC-4 cell lines subjected to inflammatory cytokines | PCR- ELISA | Western Blot | IHC for hTERT done in dysplastic and SCC tissues | Findings suggest that progressive epithelial dysplasia and long term exposure to inflammatory cytokines lead to telomerase expression leading to malignant transformation |
| Li., et al | 2015 | SiHa, CaSki | silencing of E6 and E7 results in decreased methylation of tumour suppressor genes | Transfection using shRNA, RT-PCR, Methylation Analysis, Cell viability assays, Apoptosis analysis | Immunoblot analysis | Continuous expression of HPV16 E6 and E7 leads to inactivation of various tumor suppressor pathways via methylation of tumor suppressor genes | |
| Lee., et al | 2015 | HOK, CGHNK2, CGHNK6, DOK | ↓ LDOC1 expression | Microarray analysis, Knockout of LDOC1 followed by proliferation assay and soft agar assay | RT-PCR | IHC for LDOC1 was done on normal, hyperplastic, benign tumours and SCC. | The study suggests that LDOC1 plays a critical role in tobacco related cancers and can be used as a molecular marker for screening of smokers at high risk of cancer |
| Hung., et al | 2014 | NOK, SAS, OECM-1 | ↑miR-31 expression and hTERT expression | RT PCR | Western Blot | ISH for miR-31 in normal and precancerous tissue samples | miR-31 contributes to early oral carcinogenesis by facilitating VEGF during the carcinogenesis process |
| Jiang., et al | 2016 | NOK, FaDu | ↑ E6, E7 and CD21 expression | RT PCR, Cell proliferation Assay, Cell Invasion | IHC for detection of HBV and EBV infection in normal and cancerous tissues | HBV and EBV co-infection leads to a greater risk in malignant potential and increases cell invasiveness | |
| Wang., et al | 2015 | HN4. HN6, Tca8113, HIOEC Cal27, SCC9, SCC25 | ↑ expression of LIN28B in OSCC cell lines | RT PCR | Western Blot, Cellular immunofluorescence | IHC for LIN28B performed in SCC tissue samples | LIN28B may be involved in tumor initiation and progression as its up-regulation correlates with the aggressive behavior of OSCC |
| Optiz., et al | 2001 | OKF6, OKF6-D1, OKF6-LacZ, OKF6-Δp53, OKF6-D1Δp53 | ↑ expression of cyclin D1, p53 inactivation in normal keratinocyte cell lines induces malignant transformation | Western Blot analysis | Tumorigenicity assays performed on mouse to confirm malignant transformation | Over expression of Cyclin D1 along with dominant negative form of p53 leads to immortalization of oral keratinocytes through Alternate telomerase lengthening mechanism | |
| Zhao., et al | 2015 | HOECS | ↑ expression of hTERT in primary human oral epithelial cells prolongs lifespan and downregulates p53 expression and induces epithelial mesenchymal transition | Western Blot analysis, Confocal Fluorescence microscopy, | Migration assay, Wound healing assay | IHC for hTERT done on OED and OSCC tissue samples | hTERT plays a major role in promoting Epithelial Mesenchymal Transition proving to be involved in carcinogenesis and progression |
| Pal., et al | 2013 | NOF, SCC4, H357 | Down-regulation of miR-145 seen in NOF treated with CSC | Tiling low-density array (TLDA), viability and proliferation assays, in vitro wound healing assay | RT-PCR, miRNAS transfection and cell migration assay of transfected cells | Study implicates miRNA in the response to cigarette smoke exposure as well as providing proof that miR-145 plays a role in carcinogenesis | |
| Gemenetzidis., et al | 2009 | NHOK1-5, 16, 355, 376, 881, POE9n, DOK, D19, D20, CA1, UK1, CaLH2, CaLH3, CaDec11, CaDec12, H357, 5PT, PE3/JA, VB6, CaLH2-R | FOXM1 up-regulation seen in HNSCC tissues | Microarray analysis | RT PCR, IHC, Western Blot analysis | RT PCR to check for expression levels of FOXM1 in normal, dysplastic and SCC tissues | FOXM1 is upregulated during early carcinogenesis and thus can be used as a biomarker for early detection |
| Shin., et al | 2016 | MC-3, HSC-3 | Mcl-1 downregulation prevents malignant transformation of MC-3 and HSC-3 cells | Western Blot analysis | Tryptan blue exclusion assay, anchorage dependent growth assay | Western Blot to check for Mcl-1 expression | Malignant potential of Oral Lichen Planus may correlate with Mcl-1 expression and its subsequent down-regulation may prevent its malignant potential |
| Lee., et al | 2015 | DOK, OE-CMI, OC3, CAL-27, SCC-15, TW2.6 | IL-1β is upregulated in DOK cells after treatment with 4-Nitroquinolin-1-oxide and arecoline | RT-PCR | IL-1β ELISA, Cell migration assay, Morphology assay | IL-1β increases the invasiveness of OSCC cells through EMT and thus providing insights on mechanisms underlying tumorigenesis |