硒酸酯多糖诱导白血病多药耐药细胞凋亡的作用机制

目的:观察硒酸酯多糖(Kappaselenocarrageenan,KSC)对K562ADM耐药细胞的诱导凋亡效应,并探讨其作用机制。方法:应用噻唑蓝(MTT)比色法、WrightGiemsa染色、DNA琼脂糖凝胶电泳和流式细胞术(Flowcytometry,FCM)观察K562ADM细胞凋亡;FCM测定K562ADM细胞Fas、P53和Bcl2蛋白表达水平;RTPCR检测Caspase3mRNA的表达。结果:50～500mg·L-1KSC抑制K562ADM细胞增殖,并诱导K562ADM细胞凋亡,细胞出现呈典型凋亡形态改变,DNA电泳可见DNA梯状条带(DNAladder);FCM分析出现亚G1期细胞群,S期细胞比例增高。Fas蛋白表达上调,Bcl2蛋白表达下调,Caspase3mRNA表达显著增强,但P53蛋白表达无明显改变。结论:KSC通过Fas依赖性Caspase3激活途径诱导K562ADM细胞凋亡。

Kappa-selenocarrageenan-induced apoptosis of multidrug-resistant human leukemia cell and its mechanism

AIM: To observe the apoptosis of K562/ADM cells induced by kappa-selenocarrageenan(KCS) and to explore its possible molecular mechanism. METHODS: MTT assay, Wright-Giemsa staining, DNA agarose gel electrophoresis and cell-cycle analysis were used for examining apoptosis in K562/ADM cells. Expression of Fas, Bcl-2 and P53 proteins was measured with Flow cytometr(FCM). RP-PCR assay was employed to detect the expression of caspase-3 mRNA. RESULTS: KCS inhibited proliferation of K562/ADM cells. Morphological typical changes of apoptosis were observed through light microscopy. DNA electrophoresis showed evident DNA fragmentation. Cell-cycle analysis indicated increased apoptotic cell population (Sub-G_1 proportion) as well as apparent S phase arrest. The expression of Fas antigens and caspase-3 mRNA significantly increased, and that of Bcl-2 antigens decreased sharply after application of KSC. There was no distinct change of the expression of P53 protein in K562/ADM cells treated with KSC. CONCLUSION: KSC induces apoptosis of K562/ADM cells via Fas-caspase-3 pathway.