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(Kappa-selenocarrag-eenan, KSC) 对 K562/ADM 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、Wright-Giemsa 染色、DNA 琼脂糖凝胶电泳和流式细胞术(Flow cytometry, FCM) 观察K562/ADM 细胞凋亡;FCM 测定 K562/ADM 细胞 Fas、P53 和 Bcl-2 蛋白表达水平;RT-PCR 检测 Caspase-3 mRNA 的表达。结果: 50 ~ 500 mg°L^-1KSC 抑制 K562/ADM 细胞增殖, 并诱导 K562/ADM 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 G 1 期细胞群, S 期细胞比例增高。Fas 蛋白表达上调, Bcl-2 蛋白表达下调,Caspase-3 mRNA 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 Caspase-3 激活途径诱导K562/ADM 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.Ex-pression 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.Morpho-logical typical changes of apoptosis were observed through light microscopy. DNA electrophoresis showed evident DNA fragmentation. Cell-cycle analysis indicated in-creased apoptotic cell population (Sub-G₁ proportion) as well as apparent S phase arrest. The expression of Fas an-tigens 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 inK562/ADM cells treatedwith KSC.CONCLUSION: KSC induces apoptosis of K562/ADM cells via Fas-caspase-3 pathway.