紫杉醇诱导子宫颈癌H eLa细胞自噬性凋亡的观察

Autophagic apoptosis induced by paclitaxel in cervical cancer HeLa cells

目的观察紫杉醇对体外培养的子宫颈癌HeLa细胞自噬性凋亡的影响,并初步探讨其可能的机制。方法不同浓度(1.2、6、12、24、36 mg/L)的紫杉醇处理体外子宫颈癌HeLa细胞6、12、24、48、72小时后,用MTT法测定其生长抑制率,倒置显微镜及透视电镜观察细胞形态学变化,通过流式细胞术分别测定细胞凋亡率、细胞周期分布,RT-PCR检测自噬基因Beclin1表达的变化情况。结果紫杉醇呈剂量和时间依赖性抑制子宫颈癌HeLa细胞增殖;紫杉醇12 mg/L处理的HeLa细胞,早期(24小时内)可出现明显的细胞自噬性变化,细胞凋亡数明显增加,G2/M期阻滞,且自噬基因Beclin1的表达明显增高。结论紫杉醇具有抑制子宫颈癌HeLa细胞增殖、诱导细胞自噬性凋亡等作用,诱导子宫颈癌HeLa细胞发生自噬性凋亡,其机制可能与上调自噬基因Beclin1的表达水平有关。

Objective To observe autophagic apoptosis induced by paclitaxel in cervical cancer HeLa cells in vitro,and to explore its potential molecular mechanism.Methods Cervical cancer HeLa cells in vitro were treated with paclitaxel at different concentrations（1.2,6,12,24,36 mg/L） and different time（6,12,24,48,72 hours）.The paclitaxel-induced cytoxity on cervical cancer HeLa cells was observed with the methyl thiazolyl tetrazolium（MTT） assay.Inverted microscope and electron microscopy were used to observe cell morphological changes.The apoptosis ratio and cell cycle were determined by flow cytometry.The expression of autophagy gene Beclin 1 was examined by reverse transcriptase polymerase chain reaction（RT-PCR） technique.Results Paclitaxel inhibited the proliferation of cervical cancer HeLa cells in a dose-dependent and time-dependent manner.Analysis indicated that after treatment with 12 mg/L of paclitaxel for 24 hours,HeLa cells showed typical morphology of autophagy by inverted microscope and electron microscopy.Using flow cytometry,it was observed that the number of apoptotic cells were greatly increased,and G2/M phase was blocked.Moreover,detected by RT-PCR,expression of autophagy gene Beclin 1 was enhanced in cervical cancer cells.Conclusions Paclitaxel can inhibit proliferation and induce autophagic apoptosis in cervical cancer HeLa cells.The autophagic apoptosis induced by paclitaxel is related to upregulation of the expression of autophagy gene Beclin 1.