维生素E琥珀酸酯诱导耐药白血病K562/ADM细胞凋亡的研究

Vitamin E succinate-induced apoptosis in drug-resistant leukemia K562/ADM cells

目的:研究维生素E 琥珀酸酯(vitamin E succinate , VES)对多药耐药白血病K562/ADM细胞的诱导凋亡作用及分子机制。方法: 以体外培养的K562/ADM细胞为研究对象,采用噻唑蓝(methyl thiazolyl tetrazolium, MTT) 比色法检测细胞增殖活性, Wright Giemsa染色、DNA凝胶电泳和流式细胞术(flowcytometry, FCM)检测细胞凋亡;FCM测定细胞Fas、Bcl-2 和p53 蛋白表达水平。结果:VES可显著抑制K562/ADM细胞的生长及增殖,P= 0 .004。光镜下可见K562/ADM细胞呈典型凋亡的形态学改变。DNA凝胶电泳显示典型的凋亡DNA梯形条带。FCM细胞周期分析显示,G1 期阻滞,亚G1 期细胞比例增高,P=0 .005;Fas蛋白表达明显上调,P=0. 002;Bcl -2蛋白表达下调,P=0. 000;p53蛋白表达无明显变化。结论:VES可诱导K562/ADM细胞凋亡,作用机制可能与其上调Fas表达和下调Bcl 2表达有关。

OBJECTIVE: To explore the apoptosis of K562/ADM cells induced by Vitamin E succinate(VES) and its possible molecular mechanisms. METHODS: The multidrug-resistant K562/ADM cells cultured in vitro acted as the target cells. The proliferation of K562/ADM cells were determined with an MTT colorimetric assay; Wright-Giemsa staining was used to examine morphological changes of apoptosis. The cell cycle was analyzed by using flow cytometry (FCM); DNA fragmentation was examined by agarose gel electrophoresis; expressing level of Fas, Bcl-2 and p53 protein was measured with FCM. RESULTS: VES significantly inhibited the proliferation of K562/ADM cells,P=0.004. Typical morphological changes of apoptosis were observed through light microscopy. Cell cycle analysis indicated increased Sub-G 1 proportion and apoptosis rate, as well as apparent G 1 phase arrest,P=0.005. DNA fragmentation was significantly showed via agarose gel electrophoresis. After application of VES, expression of Fas protein increased (P=0.002)and Bcl-2 protein decreased markedly (P=0.000), and no obvious change of expression was found in p53 protein expression.CONCLUSIONS:VES induces apoptosis in multidrug-resistant K562/ADM cells, and the up-regulation of Fas protein and the down-regulation of Bcl-2 protein may play important roles in VES-induced apoptosis of K562/ADM cells.