喷他脒增强K562细胞对肿瘤坏死因子相关凋亡诱导配体诱导凋亡敏感性

Pentamidine sensitizes leukemia K562 cells to TRAIL-induced apoptosis

背景与目的:肿瘤坏死因子相关凋亡诱导配体(TRAIL)是一种理想的抗肿瘤药物,但许多肿瘤细胞常对TRAIL诱导凋亡耐受。本研究探讨了喷他脒增强白血病K562细胞对TRAIL诱导凋亡敏感性。方法:利用光镜形态学和AnnexinVFITC/PI双标记凋亡细胞的流式细胞仪(FACS)测定两种方法观察喷他脒预处理K562细胞并继用TRAIL后凋亡的发生。应用蛋白印迹方法观察此过程中半胱氨酸-天冬氨酸蛋白酶(Caspase)-3,-8和聚ADP核糖聚合酶(PARP)等3种蛋白的蛋白剪切与X连锁凋亡抑制蛋白(XIAP)蛋白表达的改变。结果:在10μg/ml喷他脒作用K562细胞20h,K562细胞未发生凋亡,继用200ng/mlTRAIL作用4h后,光镜和AnnexinVFITC/PI双标记流式细胞仪方法均观察到细胞发生明显凋亡,并出现了Caspase-3,-8和PARP蛋白剪切,两者单独作用则无明显细胞凋亡发生。另外,喷他脒明显降低了XIAP表达。结论:喷他脒联合TRAIL可能成为肿瘤治疗的一种新策略。

Background and purpose： Tumor necrosis factor-related apoptosis inducing ligand （TRA1L） is a success- ful clinical anti-tumor agent, ttowever, not all tumor cells are sensitive to TRAIL-mediated apoptosis. In this study, we examined the TRAIL-induced apoptosis after pretreatment with pentanddine in K562 cells. Methods： When K562 ceils were pretreated with pentamidine followed by TRAIL, apoptosis of fells was analyzed by cellular morphology via viewing live ceils under a light micrnscope and annexin V-FlTC/propidium iodine FACS. Western blot was perfbrmed t. examine the cleavage of caspase-3,-8 and poly（ADP-ribose） polymerase （PARR） attd protein levels of X-linked inhibitor of apoptosis protein （ XIAP）. Results： Apoptotic cell death occurred and cleavage of caspase-3, -8 and PARR appeared when K562 cells were pretreated with 10μg/ml of pentamidine followed hy 200 ng/rnl of TRAIL, In addition, penlamidine decreased protein levels of X1AP. Conclusions： Combined treatment with penlamidine and TRAIL may become a new slrategy for cancer lherapy