NO对胃癌细胞系AGS增殖的影响

Effect of nitric oxide on the proliferation of AGS gastric cancer cells

背景与目的:一氧化氮(nitric oxide,NO)参与机体内的多种生理和病理反应,它作为重要的生物介质在肿瘤发生、发展和死亡中的作用已成为肿瘤研究的热点。本实验通过研究NO供体硝普钠(sodium nitroprusside,SNP)对胃癌细胞系AGS的作用,探讨NO对胃癌细胞生长增殖的影响。方法:应用MTT法评价SNP对细胞生长的抑制,流式细胞术检测细胞周期的变化,RT-PCR检测增殖细胞核抗原(PCNA)和caspase-3的mRNA基因表达,Westernblot检测PCNA和caspase-3蛋白的表达。结果:SNP可剂量依赖性地抑制AGS细胞的生长,100、500、1000、1500、2000μmol/L SNP处理24h,细胞生长抑制率分别为(2.02±2.96)%、(10.82±2.21)%、(18.95±3.35)%、(26.88±2.54)%、(42.57±1.27)%;SNP可以使细胞周期发生变化,与对照组比较100、500、1000、1500、2000μmol/LSNP处理24h,S期细胞分别减少2.29%、7.8%、11.34%、20.49%、23.6%,G0/G1期细胞分别增加3.33%、9.3%、13.46%、21.37%、24.73%(P<0.05);随着SNP剂量增加和作用时间延长,PCNAmRNA和蛋白表达逐渐降低;caspase-3mRNA表达无改变,但caspase-3酶原被裂解活化。结论:NO能抑制AGS细胞的生长和增殖,诱导细胞的凋亡,其作用呈显著的浓度依赖性。

Background and Objective：Nitric oxide （NO） is involved in many physiologic and pathologic processes. As an important biologic mediator, NO has been the focus of cancer study for its function in tumorigenesis, tumor progression, and death. This study investigated the effect of NO donor sodium nitroprusside （SNP） on the growth and proliferation of gastric cancer cell line AGS. Methods： The growth inhibition of AGS cells was analyzed by MTT assay. The cell cycle was measured using flow cytometry. The changes of mRNA expression of proliferating cell nuclear antigen （PCNA） and caspase-3 were examined by reverse transcriptase polymerase chain reaction （RT-PCR）, and the protein expressions of PCNA and caspase-3 were analyzed by Western blot. Results： Dose-dependent SNP inhibited cell growth and proliferation. When the AGS cells were treated with SNP at 100, 500, 1000, 1500, and 2000 μmol/L for 24 h, the growth inhibition rates were （2.02 ± 2.96）%, （10.82 ± 2.21）%, （18.95 ± 3.35）%, （26.88 ± 2.54）%, and （42.57 ± 1.27）%, respectively （P 〈 0.05）. SNP altered the cell cycle in AGS cells. Compared with the control group, treatment with SNP at 100, 500, 1000, 1500, and 2000 μmol/L for 24 h reduced the number of cells in the S phase by 2.29%, 7.8%, 11.34%, 20.49%, and 23.6%,respectively, and enhanced the number of cells in the G1/G0 phases by 3.33%, 9.3%, 13.46%, 21.37%, and 24.73%, respectively （P 〈 0.05）. With the increasing concentration and action time of SNP, the expressions of PCNA mRNA and protein decreased. The expression of caspase-3 mRNA remained unchanged, but procaspase-3 was activated. Conclusions： NO not only inhibits cell growth and proliferation, but also induces apoptosis in gastric cancer cells, and such effects of NO showed significant dosedependent activity.