Figure 2.

HDACi like MTM reduce the expression of the Myc oncogene and promote the expression of the p21^waf1/cip1 tumor suppressor.

(A) Real Time RTPCR analysis reveals that TSA (0.66 μM) significantly inhibits Myc expression levels; and (B) induces p21^waf1/cip1 expression levels; (C) Western blots reveal that both sodium butyrate (5 mM) and TSA (0.66 μM) treatment reduces Myc protein levels and induces p21^waf1/cip1 protein levels; (D) Quantification of the Western blots reveals that the effects on Myc and p21^waf1/cip1 levels are significant. (E and F) Chromatin immunoprecipitation experiments show that HDACi have no effect on Sp1 occupancy on the Myc promoter, whereas they significantly induce it at the p21^waf1/cip1 promoter. Treatments were conducted for five hours and the experiments were repeated three times. Statistical analysis was conducted by 1way ANOVA followed by the Dunnett post test. Significant levels compared to control treatment alone. * p < 0.05; and ** p < 0.01; and *** p < 0.0001.