α-生育酚琥珀酸酯对乳腺癌细胞中IAPs家族蛋白表达的影响

Effect of α-Tocopheryl Succinate on IAPs Expression in Human Breast Cancer Cells

目的检测α-生育酚琥珀酸酯(-αTOS)对MCF7和MDA-MB-453乳腺癌细胞增殖以及细胞中凋亡抑制蛋白家族(IAPs)表达的影响。方法采用四甲基偶氮唑蓝(MTT)法测定-αTOS对人乳腺癌细胞MCF7和MDA-MB-453增殖的抑制作用,细胞分别接种于96孔板后用浓度为51、0、255、0、75、1001、25和150μmol/L的-αTOS处理48 h后检测;细胞经50μmol/L、100μmol/L-αTOS处理122、4、48 h后,用RT-PCR的方法检测细胞内c-IAP1和c-IAP2 mRNA的转录水平;用Western Blot的方法检测c-IAP1和c-IAP2的蛋白质表达水平。结果-αTOS对人乳腺癌细胞MCF7和MDA-MB-453有显著的增殖抑制作用,并表现为剂量依赖性,-αTOS对MCF7和MDA-MB-453的IC50值(细胞半数死亡的药物浓度)分别为132μmol/L和74μmol/L;RT-PCR结果显示,-αTOS使两个细胞系的c-IAP1的转录水平显著下降,且呈时间依赖性;但对c-IAP2的转录水平没有明显影响;Western Blot的结果发现-αTOS使得这两种细胞系的c-IAP1蛋白质翻译水平也呈下降趋势,该结果与mRNA转录水平下降相一致,对c-IAP2蛋白质的表达几乎无影响。因此,α-TOS可能通过抑制c-IAP1蛋白的表达而抑制MCF7和MDA-MB-453乳腺癌细胞的生长增值,a-TOS有望开发成为新的预防和治疗乳腺癌的有效药物。

Objective To study the effects caused by α-tocopheryl succinate （α-TOS） on cell growth and expression of lAPs （inhibitors of apoptosis proteins） in human breast cancer MCF7 and MDA-MB-453 cell lines. Methods MTT assay was used to measure the cell proliferation inhibition rates induced by α-TOS. Human breast cancer MCF7 and MDA-MB-453 cells were inoculated in 96-well plates, and then were treated with α-TOS （5,10,25,50,75,100,125 and 150μmol/L）, 48 h later, the proliferation inhibition rates were measured by MTT assay. Western blotting and RT-PCR were performed to detect the protein expression. Cells were treated with a-tocopheryl succinate （50 μmol/L, 100μmol/L） for 12, 24 and 48 h, then the mRNA and protein expression amounts of c-IAP1 and c-IAP2 were determined by RT-PCR and western blotting. Results α-TOS significantly inhibited proliferation of MCF7 and MDA-MB-453 cells in a dose- dependent manner. The values of IC50 were 132 μmol/L and 74 μmol/L in MCF7 and MDA-MB-453 respectively. The expression of c-IAP1 in the levels of mRNA and proteins was inhibited by α-TOS in a dose-dependent and time-dependent manner; whereas, α-TOS has no remarkable effect on the expression of c-IAP2. We can conclude that α-TOS inhibited breast cancer cells growth by reducing the expression of c-IAP1 and is a oromising anti-breast cancer drug.