光动力治疗联合顺铂对顺铂耐药肺癌细胞的体外治疗效应

Deactivation of cisplatin-resistant lung cancer cells by photodynamic therapy combined with cisplatin in vitro

目的:探讨光敏剂焦脱镁叶绿酸-a甲酯(pyropheophorbide-a methyl ester,MPPa)介导的光动力治疗(photodynamic therapy,PDT)对顺铂(cisplatin,DDP)耐药的肺癌细胞的作用。方法:DDP、PDT和PDT+DDP处理肺癌A549和A549/DDP细胞后,应用CCK-8法、FCM法、2’,7’-二氯荧光黄双乙酸盐(2’,7’-dichlorodihydrofluorescein diacetate,DCFH-DA)和蛋白质印迹法分别检测细胞增殖、细胞凋亡、细胞内活性氧(reactive oxygen species,ROS)水平及caspase-3、Bcl-2和Bax蛋白表达水平。结果:PDT组A549和A549/DDP细胞增殖率均低于对照组(A549和A549/DDP细胞未进行任何处理)(P值均<0.05),PDT+DDP组A549和A549/DDP细胞增殖率均低于对照组、DDP组和PDT组(P值均<0.05)。PDT+DDP作用A549和A549/DDP细胞的联合指数分别为1.11和1.10,具有相加效应。PDT+DDP组A549和A549/DDP细胞凋亡率和ROS水平均高于对照组、DDP组和PDT组(P值均<0.05)。PDT组和PDT+DDP组A549和A549/DDP细胞中caspase-3和Bax蛋白表达水平均高于对照组,而Bcl-2蛋白表达水平均低于对照组(P值均<0.05)。结论:PDT或联合DDP对肺癌A549/DDP细胞具有明显杀伤作用,主要通过ROS.线粒体途径促进细胞凋亡;PDT与DDP具有相加效应。

Objective： To explore the therapeutic effect of pyropheophorbide-a methyl ester （MPPa）-mediated photodynamic therapy （PDT） on cisplatin （DDP）-resistant human lung cancer cells. Methods： After lung cancer A549 and A549/DDP cells treated with DDP and PDT alone or in combination, the cell proliferation, apoptosis, reactive oxygen species （ROS） level and the expression levels of caspase-3, Bcl-2 and Bax proteins were detected by CCK-8, FCM, 2＇, 7＇-dichlorodihydrofluorescein diacetate （DCFH-DA） and Western blotting, respectively. Results： The proliferative rates of A549 and A549/DDP cells in PDT group were lower than those in the control group （A549 and A549/DDP cells without any treatment） （both P 〈 0.05）. The proliferative rates of A549 and A549/DDP cells in the combination group were lower than those in the control group, DDP-treated group and PDT group （all P 〈 0.05）. The combination indexes of PDT combined with DDP treatment were 1.11 and 1.10 for A549 cells and A549/DDP cells, respectively, indicating that there was an additive interaction. The apoptotic rates and the ROS levels of A549 and A549/DDP cells in the combination group were higher than those in the control group, DDP-treated group and PDT group （all P 〈 0.05）. The expression levels of caspase-3 and Bax proteins in A549 and A549/DDP cells in PDT group and the combination group were higher than those in the control group, whereas the expression level of Bcl-2 protein was opposite （all P 〈 0.05）.Conclusion： PDT alone or PDT combined with DDP can efficiently deactivate the A549/DDP cells via the ROS-mitochondria apoptosis pathway. An additive interaction between PDT and DDP is discovered.