Figure 8.

Effect of 5b on histone modifications and sp1 at p21 promoter in MCF-7 and MDA-MB-231 cells. (A) Schematic diagram of the human p21WAF1 promoter illustrating regulatory factor binding sites;−2260 (p53), −2080 (sp1-distal) and −100 (sp1 proximal). Arrow indicates transcriptional start site at +1. (B) Two different binding sites (distal and proximal) of sp1 in the p21 promoter were considered for ChIP analysis after treating the cells with SAHA and 5b at 4 μM concentration for 24 h. H3K9ac, H3K14ac, H3K9Me2 and H3K27me3 antibodies were used for the study. (B-G) Representation of gel pictures of chromatin DNA amplified with distal and proximal promoter specific primers and their respective histograms. Each experiment was performed thrice from which standard deviation derived and error bars were plotted. Bars with * and ** are significantly different from all the other groups at p ≤ 0.05 and p ≤ 0.01 respectively; bars with ˆ superscript are indifferent from each other in Oneway-ANOVA, posthoc-LSD in MCF-7. In MDA-MB-231 bars with * and ** are significantly different from all the other groups at p ≤ 0.05 and p ≤ 0.01 respectively in Oneway-ANOVA, posthoc-LSD.