Effects Of Proliferation And Apoptosis Of Gastric Carcinoma Cell Line SGC-7901 By Proteasome Inhibitor MG-132

Objective:To study the anti-tumor effect and its mechanisms of proteasome inhibitor MG-132 on human gastric carcinoma cell line SGC-7901 in vitro.Methods:In vitro, human gastric carcinoma cell line SGC-7901 was treated by MG-132 in different concentrations.The inhibitory effect of cell growth was assayed by MTT assay;cell cycles and apoptosis were analyzed by flow cytometry (FCM);the mRNA expressions of p27 ,bcl-2,caspase-3 were analyzed by RT-PCR;Immunohistochemistry was used to detect p27 ,bcl-2 ,caspase-3 protein expression.Results:(1)MTT assay indicated that the inhibitory effect of MG-132 on the proliferation of SGC-7901 cell was found in dose-and-time dependent manner. There was great statistical signification between varies medicated group and control group(P<0.05),and there also were great statistical signification between medicated group each other(P<0.05).(2)Comparing with control group,the cell apoptosis was induced by MG-132 at 48 hours, meanwhile,the ratio of G0/G1 phase was increased and the ratio of S phase was decreased, in dose-dependent manner(P<0.05). (3)RT-PCR assay showed ttat the expression of p27 and caspase-3 mRNA were upregulated and bcl-2 mRNA was downregulated by MG-132 at 48 hours with concentration incread(P<0.05).(4)Immunocytochemistry showed that the expression of p27 and caspase-3 protein were upregulated and bcl-2 protein was downregulated with concentration incread(P< 0.05).Conclusion:The growth of SGC-7901 cell in vitro is inhibited by MG-132 and in dose-and-time dependent manner. MG-132 also can arrest cell cycle at G0/G1phase, induce cell apoptosis.Maybe its mechanism is through upregulating the expressions of p27,caspase-3 mRNA and protein,downreglating the espression of bcl-2 mRNA and protein.