Abstract: Objective To investigate the effects of siRNA targeting 14-3-3ζ gene on the proliferation and apoptosis in human gastric adenocarcinoma cell line SGC-7901 and the latent mechanisms. Methods Three groups were devided as blank, siRNA-control and siRNA-14-3-3ζ groups. The 14-3-3ζ-siRNA was transfected into SGC-7901 cells by LipofectamineTM 2000. The gene silencing effect of siRNA targeting 14-3-3ζ was determined by quantity real-time PCR (RT-qPCR) and western blot at mRNA and protein levels respectively. Cell proliferation was detected by CCK8 assay. The cell cycle and apoptosis were detected by flow cytometry (FCM). The protein levels of p53, cylinD1, PUMA, Bax and Bcl-2 were analyzed by western blot. Results After transfection of 14-3-3ζsiRNA into SGC-7901 cells, the mRNA and protein levels of 14-3-3ζ were both significantly reduced. Compared with the control groups, the down-regulation of 14-3-3ζ in SGC-7901 cells resulted in significant decrease of cell proliferation (P<0.05). FCM showed significant increase G0/G1 phase of cell cycle and apoptotic rate in siRNA-14-3-3ζ cells (P<0.05). Besides, down-regulation of 14-3-3ζ cells also increased the expression of p53, PUMA and Bax protein, reduced the expression of cyclinD1 and Bcl-2 protein (P<0.05). Conclusion Down-regulation of 14-3-3ζ in SGC-7901 cells can inhibit proliferation and induce apoptosis via p53 pathway by down-regulating CcyclinD1 and Bcl-2 proteins and up-regulating PUMA and Bax proteins.

Key words: 14-3-3ζ, siRNA, proliferation, cell cycle, apoptosis