The role of Notch signaling pathway in insulin regulation of endometrial cancer cell growth and apoptosis / 重庆医学

ABSTRACT

Objective To investigate the effects of Notch signaling pathway on proliferation of insulin-induced endometrial carcinoma cells and apoptosis related protein expression levels.Methods The endometrial carcinoma Ishikawa 3-H-12 cell line was primarily cultured and subcultured in vitro.Then,the cultured cells were divided into five groupsthe control group (3 mL PBS was added into the group),the insulin group (cells were stimulated by 1 × 106 mol/L insulin) and MW167 groups (different doses of γ-secretase inhibitor MW167 pretreated with insulin stimulation).After 48 h culturation,inhibition of endometrial carcinoma cell growth of each group was measured by MTT-colorimetric method,the apoptosis-related proteins (Caspase-3,Caspase-8) and Notch1 protein expression levels of each group were determined by Western blot.Results Insulin can promote Notch1 protein expression in endometrial carcinoma cells,after 48 h insulin stimulation,the Notch1 protein expression level was significantly higher than that in the control group (P＜0.05).MW167 can inhibit insulin-induced Notch1 protein expression in a concentration-dependent inhibition manner.The absorbance at 570 nm (A570) of endometrial carcinoma cells cultured for 24,48 and 72 h in different groups were significantly different (P＜0.05).The A570 values in the insulin group at each time point were higher than those in the control group (P＜0.05),and the insulin-induced endometrial carcinoma cell proliferation reached its highest level at 48 h.MW167 inhibited insulin-induced endometrial carcinoma cells proliferation in a concentration-and time-dependent manner,and 20 μmol/L MW167 persistently inhibited insulin-induced proliferation of endometrial carcinoma cells at 48 h.Western blot analysis showed that expression levels of Caspase-3 and Caspase-8 protein in the insulin group at each time point were lower than those in the control group (P＜0.05),and MW167 promoted the expressions of Caspase-3 and Caspase-8 in a concentration-and time-dependent manner.Conclusion MW167 can suppress the insulin-induced endometrial carcinoma cells proliferation and promote the expression of related apoptotic proteins by inhibiting Notch signaling pathway,and induce apoptosis of endometrial carcinoma ceils.