Effects of Diallyl Disulfide on the Proliferation and Apoptosis of Epithelial Ovarian Cancer Cells by Inducing G2/M Arrest / 中国医学科学院学报

ABSTRACT

Objective To explore the effects of diallyl disulfide(DADS)-induced G2/M phase arrest on proliferation and apoptosis of ovarian cancer cells and its possible molecular mechanism.Methods DADS was used to incubate SK-OV-3 and OVCAR-3 cells,respectively,in different concentrations. Cell proliferation was measured by MTT assay and cell apoptosis rate was detected by flow cytometry assay. Xenograft model assay were performed to analyze the antitumor effect in vivo. Cell cycle phase distribution was detected by flow cytometry. Expressions of cell cycle G2/M phase as well as proliferation- and apoptosis-related proteins were measured by Western blotting.Results MTT assay showed that,after treatment of SK-OV-3(F=247.86,P=0.000)and OVCAR-3 cells(F=302.54,P=0.000)with different concentrations of DADS,the cell proliferation inhibition rate was significantly elevated with the increase of DADS concentrations in a concentration-dependent manner. The inhibition rate of SK-OV-3(F=335.12,P=0.000)and OVCAR-3 cells(F=347.43,P=0.000)at 24 h was significantly higher than that at 12 h and 48 h,showing a significant time-dependence manner. Flow cytometry showed that,after SK-OV-3 and OVCAR-3 cells were treated with different concentrations of DADS,the apoptosis rates increased significantly with the increase of DADS concentration in a concentration-dependent manner(P<0.05). The apoptotic rates of SK-OV-3 and OVCAR-3 cells treated with DADS at 24 h was significantly higher than that at 12 h and 48 h in a significant time-dependence manner(P<0.05). Compared with the blank treatment group,intraperitoneal injection of DADS solution significantly inhibited the xenograft volume of ovarian cancer cells in nude mice(F=548.23,P=0.000;F=311.84,P=0.000). After 30 mg/L of DADS was applied to SK-OV-3 and OVCAR-3 cells for 24 h,the percentage of cells in G2 phase of SK-OV-3 and OVCAR-3 cells increased significantly(F=375.11,P=0.000;F=256.48,P=0.000),compared with the blank cells. After 30 mg/L DADS was applied to SK-OV-3 and OVCAR-3 cells for 24 h,the expressions of p-Chk1(ser345)(F=108.89,P=0.013;F=97.58,P=0.018),p-CDC25C(ser216)(F=87.25,P=0.025;F=114.25,P=0.009),p-P53(ser15)(F=112.41,P=0.011;F=255.87,P=0.000),P21WAF1(F=246.38,P=0.001;F=141.36,P=0.005)and p-CDK1(Thr14/Tyr15)protein(F=298.12,P=0.000;F=233.15,P=0.000)were significantly increased,whereas the expressions of CDK1(F=308.24,P=0.000;F=257.55,P=0.000)and CyclinB1 protein(F=223.15,P=0.001;F=241.28,P=0.000)were significantly reduced.The expressions of proliferation and apoptosis-related proteins PCNA(F=77.36,P=0.031;F=157.28,P=0.001),Ki-67(F=205.64,P=0.007;F=315.22,P=0.000)and Survivin(F=122.13,P=0.013;F=188.24,P=0.000)were significantly decreased and Cleaved-caspase3 protein was significantly increased(F=86.46,P=0.023;F=99.11,P=0.009).Conclusion DADS can inhibit the proliferation of ovarian cancer cells and induce their apoptosis,which may be related to the activation of Chk1-CDC25C and P53-P21WAF1 signaling pathways in G2/M checkpoint,decreased kinase activity of CDK1,down-regulated expressions of CDK1 and CyclinB1 proteins,and ultimately cell cycle arrest at G2/M phase.