Fig. 3

HSP27 enhanced cell resistance to melatonin-induced cell apoptosis is mediated through PI3K/Akt. a, b Effect of melatonin stimulation on phosphorylation of Akt. SGC-7901 cells were treated with melatonin under different concentrations of melatonin for 24 h. Melatonin-stimulated phosphorylation of Akt at Ser473 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. b, c After treatment with 10 μM PI3K inhibitor LY294002 for 30 min, SGC-7901 cells were stimulated with 1 mM melatonin for 24 h and then cells were analyzed by P-Akt (b) and P-HSP27 (c) expression, and d the effect of LY294002 on the melatonin-stimulated apoptosis in SGC-7901 cells was determined. *P < 0.05, **P < 0.01