Experimental Study For Regulatory Effect Of Growth And Advancing Chemosensitivity Of Cisplatin On Human Gastric Cancer Cell Treated With Trichostatin A

Objective To investigate the regulatory effect of growth and advancing chemosensitivity of cisplatin (DDP) by Trichostatin A (TSA) on human gastric cancer cell line SGC-7901 in virtro, and to explore its possible mechanism of these effects.Methods (1) Human gastric cancer cell line SGC-7901 was cultured in vitro. (2) MTT colorimetric assay was used to determine the proliferation rate of cells, when SGC7901 cells were cultured in medium containing the TSA in different time and concentrations. (3) Experiment was divided into four groups:negative,400nmol/L,800nmol/L,1600nmol/L TSA group,The flow cytometry(FCM) method was used to study the apoptosis and cell cycle induced by TSA in SGC-7901 cells. The expression of bcl-2,caspase-3 mRNA were determined by reverse transcriplase polymerase chain reaction(RT-PCR). The expression of bcl-2,caspase-3 protein were analyzed by Immunocytochemistry(SP).(4) Experiment was divided into two groups:DDP,TSA+DDP, MTT colorimetric assay was used to determine the proliferation rate of cells,Colony forming assay was used to detect colony forming rate,Hochest 33258 staining was used to detect cell apoptosis.Results (1) MTT assay indicated that the inhibitory effect of TSA on the proliferation of SGC-7901 cells was found in does-and-time dependent manner;(2) Comparing with control group,the cell apoptosis was induced by TSA at 48 hours,meanwhile,the ratio of G0/G1 phase was increased in does-dependent manner(P<0.05); RT-PCR assay showed that the expression of bcl-2 mRNA was downregulated and caspase-3 mRNA was upregulated by TSA at 48 hours with concentration increased (P<0.05); Immunocytochemistry showed that the expression of bcl-2 protein was downregulated and caspase-3 protein was upregulated with concentration increased(P<0.05).(3) MTT assay indicated that the inhibitory effect of 40nmol/L TSA+DDP was higher than DDP on the proliferation of SGC-7901 cells(P<0.05);Colony forming assay indicated that the colony forming rate of 40nmol/L TSA+DDP was higher than DDP(P<0.05);Hochest 33258 staining manifested that the apoptosis of 40nmol/L TSA+DDP group is more evident than DDP group.Conclusion The growth of SGC-7901 cell in virtro is inhibited by TSA and in dose-and-time dependent manner.TSA also can induce cell apoptosis, arrest cell cycle at G0/G1 phase.Maybe its mechanism is through downgulating the expression of bcl-2, upregulating the expression of caspase-3. A certain concentration of TSA can enhance the chemosensitivity of gastric cancer cell line SGC-7901 to DDP.