Fig. 2.

HSP27 phosphorylation is required for resistance of apoptosis by melatonin. a, b SGC-7901 cells were treated with melatonin for the indicated periods (a) and doses (b), and HSP27 phosphorylation was determined by immunoblotting assay. GAPDH was used as a loading control. *P < 0.05, **P < 0.01, referring to the difference between cells treated with and those without melatonin. c The expression of total and phosphorylation level of HSP27 after treatment with HSP27 siRNA. Total protein extracts from SGC-7901 cells transfected with HSP27 siRNA or control siRNA were analyzed by immunoblotting for P-HSP27 and HSP27. GAPDH was used as a loading control. d, e Cell apoptosis was determined by Hoechst 33258 staining in the SGC-7901 cells transfected with control siRNA or HSP27 siRNA. d Images are representative of at least three independent determinations. Scale bar 50 μm. e HSP27 siRNA treatment enhanced melatonin-induced apoptosis of SGC-7901 gastric cancer cells. Values were presented as mean ± SD of three independent experiments. **P < 0.01