硫利达嗪对肺癌PC9细胞的杀伤效应及其机制

摘要

Background and objectiveRecent research shows thioridazine which is a kind of phenothiazine anti-psychotic drugs can inhibit the proliferation of various tumor cellsin vitro, but the role of thioridazine on lung cancer has not been reported. So we choose PC9 cell lines as the research object, the aim is to oberve the killing effect of thioridazine on PC9 cells and investigate its possible mechanism.MethodsAtfer being treated with different concentrations of thioridazine, the proliferation of PC9 cells was determined by methyl thiazolyltetrazolium (MTT) assay. Flow cytometry was used to measure the cell cycle distribution and apoptosis. The expressions of cell cycle-associated protein CyclinD1 and apoptosis-related proteins Caspase-3, Caspase-8, Caspase-9, Bcl-2, Bax and Bcl-xl were detected by Western blot.Results hTe proliferation of PC9 cells was signiifcantly inhibited by thioridazine in a dose- and time-dependent manner. Flow cytometry showed that cell cycle was arrested in G0/G1 phase and the apoptotic rates were signiifcantly increased with the increasing concentration of thioridazine. Compared with the control group, the differences were statistically signiifcant (P<0.05). Western blot analysis showed that, compared with the control group, thioridazine reduced the expressions of CyclinD1, Bcl-2 and Bcl-xl (P<0.01) and increased the expression of Bax (P<0.01). In the mean time, thioridazine promoted the activities of Caspase-3, Caspase-8 and Caspase-9 (P<0.01).ConclusionhTe mechanism of thioridazine inhibiting the proliferation of PC9 cells may be related to stimulation of Caspase apoptotic pathway, down-regulation of CyclinD1, Bcl-2, Bcl-xl and up-regulation of Bax.%背景与目的硫利达嗪作为一种吩噻嗪类抗精神疾病药物，近期研究显示其在体外可抑制多种肿瘤细胞的增殖，但对肺癌的作用尚未见报道。本实验以PC9细胞株为研究对象，旨在观察硫利达嗪对其杀伤效应以及探讨其可能的作用机制。方法不同浓度的硫利达嗪作用PC9细胞后，四甲基偶氮唑蓝（methyl thiazolyltetrazolium, MTT）法检测细胞增殖率，流式细胞术检测细胞周期及细胞凋亡率，Western blot检测周期相关蛋白CyclinD1及凋亡相关蛋白Caspase-3、Caspase-8、Caspase-9、Bcl-2、Bax、Bcl-xl表达水平。结果硫利达嗪可显著抑制PC9细胞的增殖，其抑制作用呈时间和浓度依赖性。流式结果显示：随着硫利达嗪药物浓度的增高，细胞发生不同程度的G0/G1期阻滞，细胞凋亡率明显增高。各实验组与对照组比较，差异有统计学意义（P<0.05）。Western blot结果显示：与对照组比较，实验组CyclinD1、Bcl-2、Bcl-xl表达水平明显下调（P<0.01），Bax表达水平明显上调（P<0.01），Caspase-3、Caspase-8、Caspase-9活性显著增加（P<0.01）。结论硫利达嗪可显著抑制PC9细胞的增殖，其机制可能与其激活Caspase内外源性凋亡途径，下调CyclinD1、Bcl-2、Bcl-xl，上调Bax有关。