胃泌素受体拮抗剂与环氧合酶-2抑制剂对胃癌细胞增殖和凋亡的影响

目的探讨胃泌素受体拮抗剂丙谷胺与特异性环氧合酶-2(COX-2)抑制剂NS-398对人胃腺癌细胞株MKN-45增殖、凋亡的调控作用。方法MKN-45细胞常规培养于RPMI-1640培养液中,细胞长至亚单层后加丙谷胺(终浓度5.0mmol/L)和/或NS-398(10.0μmol/L),连续培养48h。四甲基偶氮唑蓝(MTT)比色分析检查细胞增殖,流式细胞仪检测细胞凋亡,逆转录聚合酶链反应(RT-PCR)和Western印迹法检测凋亡抑制基因bcl-2mRNA及蛋白表达。结果丙谷胺和NS-398协同抑制MKN-45细胞增殖;丙谷胺组、NS-398组和联合用药组的细胞凋亡率分别为24.7%±3.2%,26.7%±3.4%和36.1%±4.6%,显著高于对照组的1.6%±0.6%(均P<0.01);联合用药组的细胞凋亡率明显高于单一用药组(P<0.05)。丙谷胺和NS-398显著下调bcl-2mRNA及蛋白表达(均P<0.05)。结论丙谷胺、NS-398抑制MKN-45细胞增殖,通过下调bcl-2基因表达而诱导细胞凋亡,两者联合具有协同抗癌作用。

Effects of gastrin receptor antagonist and cyclooxygenase-2 inhibitor on proliferation and apoptosis of gastric cancer cell

OBJECTIVE: To investigate the regulative roles of the gastrin receptor antagonist proglumide and the specific cyclooxygenase (COX)-2 inhibitor NS-398 on the proliferation and apoptosis of gastric cancer cells. METHODS: Human gastric cancer cells of the line MKN-45 were routinely cultured in RPMI-1640 medium supplemented with 10% heat-inactivated fetal calf serum. Subconfluent cell cultures were treated with proglumide at a final concentration of 5 mmol/L, NS-398 at a final concentration of 10.0 micromol/L, or proglumide in combination with NS-398 for 48 h. The growth and proliferation of MKN-45 cells were analyzed with MTT assay. Flow cytometric analysis was used to detect the apoptosis of the gastric cancer cells. RT-PCR and Western blotting were used to detect the expression of apoptosis-inhibited gene bcl-2 mRNA and protein. RESULTS: The apoptosis rates of the cells treated by proglumide, NS-398, and combination of two agents were 24.7% +/- 3.2%, 26.7% +/- 3.4%, and 36.1% +/- 4.6% respectively, all significantly higher than that in the control group (1.6% +/- 0.6%, all P < 0.01). The apoptosis rates of the MKN-45 cells treated with proglumide combined with NS-398 was significantly greater than those of the cells treated by the two agents alone (both P < 0.05). Treatment with proglumide and NS-398 significantly reduced the bcl-2 mRNA and protein expression in the MKN-45 cells (P < 0.05). CONCLUSION: Both proglumide and NS-398 inhibit the proliferation and induce the apoptosis of human gastric cells. This apoptosis may be mediated by down-regulation of the expression of apoptosis-inhibited gene bcl-2. Co-treatment with proglumide and NS-398 have synergistic anticancer role.