盐霉素增强吉非替尼诱导人肺腺癌细胞株PC9凋亡作用

摘要

目的:探讨盐霉素联合吉非替尼诱导人肺腺癌细胞株PC9凋亡作用.方法:MTT法检测细胞增殖活性；流式细胞仪检测细胞凋亡及线粒体膜电位(MMP)；比色法检测Caspase-3、8和9酶活性；Western blot分析细胞色素C、bcl-2、p-EGFR、p-Akt和p-ERK蛋白水平.结果:盐霉素与吉非替尼单用均出现不同程度的细胞增殖抑制作用和诱导细胞凋亡作用；而两者合用则能更显著地抑制细胞增殖,且细胞凋亡显著增加(P＜0.05).盐霉素单独作用,细胞MMP显著下降,细胞内活性氧和Ca2+在短期显著升高,胞浆细胞色素C、Caspase-3、8和9酶活性均显著增加；吉非替尼单用则抑制p-EGFR、p-Akt和p-ERK蛋白表达,而对胞浆细胞色素C、Caspase-3、8和9酶活性影响较少.Western印迹检测发现,联合用药组的Bcl-2、p-EGFR、p-Akt和p-ERK蛋白表达量明显减少.结论:盐霉素与吉非替尼联用具有较好的协同作用,提高PC9细胞对吉非替尼的敏感性.%Objective To investigate the effects of salinomycin combined with gefitinib on the apoptosis of human non-small cell lung cancer cell line PC9. Methods The growth of PC9 cells was tested by MTT, cell apoptosis and mitochondria membrane potential (MMP) were measured by flow cytometry, the activities of caspase-3,8, and 9 were detected by colorimetry, and the levels of cytochrome C, bcl-2, p-EGFR, p-Akt, and p-ERK were analyzed by Western blot. Results Salinomycin or gefitinib alone could inhibit the growth and induce the apoptosis of PC9 cells in a dose-dependent manner; when they were combined with each other, these effects were more obvious (P ＜ 0.05). Salinomycin alone could significantly reduce the MMP and increase the levels of intracellular reactive oxygen species (ROS), cytoplasmic cytochrome C, and cytosolic Ca2+, and the activities of caspase-3, 8, and 9. Gefitinib alone could inhibit the expressions of p-EGFR, p-Akt, and p-ERK protein, and less affect the level of cytochrome C and the activities of caspase-3, 8 and 9. Western blotting showed that the expressions of Bcl-2, p-EGFR, p-Akt, and p-ERK protein were significantly decreased in combined group. Conclusion There exist synergism between salinomycin and gefitinib, and salinomycin can increase the sensitivity of PC9 cells to gefitinib.