Effects of proliferation and apoptosis of gastric carcinoma cell line SGC-7901 by Cetuximab

Objective To investigate the anti-tumor effect and its mechanisms of Cetuximab on human gastric carcinoma cell line SGC-7901 in vitro.Methods In vitro,human gastric carcinoma cell line SGC-7901 was treated by Cetuximab in different concentrations.The inhibitory effect of cell growth was assayed by methyl thiazol tetrazolium (MTT) assay,cell cycles and apoptosis were analyzed by flow cytometry (FCM) ; the mRNA expressions of cysteinyl aspartate-specific protease-3 ( Caspase-3 ) were analyzed by reverse transcription-polymerase chain reaction (RT-PCR) ; Immunohistochemistry was used to detect B lymphocytes/leukemia-2 (bcl-2) and p-27 protein expression.Results (1) MTT assay indicated that as the concentration of the Cetuximab on the proliferation of SGC-7901 cell increased,the inhibition ratio increased from (9.76 ± 1.41 )％ to (78.12 ± 3.88)％.the inhibition ratio was also found in 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 Cetuximab 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 and Immunocytochemistry showed that the expression of Caspase-3,p-27 mRNA and protein were upregulated and bcl-2 mRNA and protein was downregulated by Cetuximab at 48hours with concentration increased ( P ＜ 0.05 ).Conclusion The growth of SGC-7901 cell in vitro is inhibited by Cetuximab and in dose-and-time dependent manner. Cetuximab also can arrest cell cycle at G0/G1 phase,induce cell apoptosis. Maybe its mechanism is through upregulating the expressions of Caspase-3,p-27 mRNA and protein,downreglating the espression of bcl-2mRNA and protein. Key words: Gastric carcinoma cell SGC-7901; Cetuximab; Apoptosis; B lymphocytes/leukemia-2; Cysteinyl aspartate-specific protease-3; p-27