Figure 5.

EZH2 negatively regulated p21 expression upon LDM exposure. (a) The cells were transfected with three siRNAs targeting p21 for 48 h, followed by IB analysis. (b) Depletion of p21 abolished LDM-induced senescence. The cells were transfected with siRNA targeting p21 (1#) for 24 h, and then subjected to 0.5 nM LDM treatment for 72 h before SA-β-Gal staining (× 20). Scale bar: 50 μm. (c) EZH2 Knockdown induced p21 expression. The cells were transfected with three siRNAs targeting EZH2 for 48 h, followed by IB analysis. The relative optical density for each band was quantified, normalized and labeled under each lane. (d) LDM reduced the enrichment of EZH2 and H3K27me3 levels in p21 promoter region analyzed by ChIP assay. SW620 cells were treated with LDM for 72 h before subjected to ChIP assay as described in Materials and methods section. The data were expressed as the means±S.D. of three independent experiments