Autophagy Inhibition by Chloroquine Sensitizes Cervical Cancer SiHa Cells to CPT Treatment
- 医学院－已发表论文 
自噬诱导是肿瘤细胞对化疗药物抵抗性的原因之一,该研究探讨溶酶体抑制剂氯喹对喜树碱(camptothecin,CPT)诱导的宫颈癌细胞Si Ha死亡的增敏效果。CPT和/或氯喹处理宫颈癌Si Ha细胞,MTT法检测细胞增殖,DAPI和TUNEL染色观察细胞凋亡,Western blot和免疫荧光检测自噬及凋亡相关蛋白。结果发现,CPT处理后,Si Ha细胞MAP1LC3B荧光点和LC3II(microtubuleassociated protein light chain 3II)蛋白水平增加,p62荧光点和蛋白质水平则减少;而采用氯喹特异抑制自噬后,可明显提高CPT诱导的细胞凋亡、caspase-9的激活和PARP(poly ADP-ribose polymerase)的切割,而全长caspase-2水平显著下降。以上结果提示,氯喹可通过抑制细胞自噬而增强宫颈癌细胞株Si Ha对CPT诱导细胞凋亡的敏感性。The autophagy induction is one of the reasons for the resistance of tumor cells to chemotherapy drugs. In this study, the enhanced sensitivity of cervical cancer Si Ha cells to camptothecin(CPT)-induced cell death by chloroquine(a lysosome inhibitor) was investigated. The cell viability was detected by MTT assay, meanwhile, apoptosis was observed by DAPI and TUNEL, autophagy related proteins and apoptosis proteins were analyzed by immunofluorescence(IF) staining and Western blot in Si Ha cells after CPT treatment alone or combined with chloroquine. The results found that in Si Ha cells with CPT treatment the autophagy related protein LC3 foci and microtubule-associated protein light chain 3II(LC3II) protein level was increased, but p62 foci and protein level was decreased. When autophagy was inhibited by chloroquine, the CPT-induced apoptosis was obviously enhanced, and caspase-9 was activated and PARP was cleaved, but full length caspase-2 was decreased. Taken together, these results indicated that the inhibition of autophagy by chloroquine could sensitize cervical cancer Si Ha cells to CPT inducing cell apoptosis.