Tamoxifen诱导MA782细胞凋亡与P21/CIP1、PCNA的关系

A STUDY ON RELATIONS ABOUT MA782 CELL APOPTOSIS INDUCED BY TAM WITH P21/CIP1 AND PCNA

目的 探讨三苯氧胺 (TamoxifenTAM )诱导ER(- )小鼠乳腺癌细胞MA782细胞凋亡及其分子作用机制。方法 TAM体外作用于MA782细胞 ,用MTT法检测细胞增殖活性、流式细胞仪检测细胞凋亡和细胞周期分布 ,透射电镜观察细胞凋亡超微结构改变 ,免疫组化检测MA782细胞p2 1/CIP1、PCNA蛋白表达 ,并用病理图像分析软件进行半定量分析。 结果 6 μmol/L、10 μmol/LTAM在体外能明显抑制MA782细胞生长 ,诱导细胞凋亡 ,作用 2 4小时细胞凋亡率分别为 7.0 4 %、19.0 4 % ,10 μmol/LTAM作用 4 8小时后细胞凋亡率从 19.0 4 %上升到 5 1.2 7% ,与对照组比较有显著差异 (P <0 .0 1)。 2 μmol/LTAM作用不同时间后 ,细胞上述蛋白无明显变化 ,而 6 μmol/L、10 μmol/LTAM作用不同时间后 ,PCNA蛋白表达有不同程度的下降 ,p2 1/CIP1蛋白表达有不同程度的上升与对照组相比差异显著 (P <0 .0 5或P <0 .0 1)。结论 TAM诱导MA782细胞凋亡其分子作用机制可能与下调细胞PCNA蛋白表达及上调 p2 1/CIP1蛋白表达有关。

purpose To study if tamoxifen (TAM) can induce growth arrest and apoptosis of ER-negative MA782 mouse breast cancer cell line and to explore the molecular machanisims. Methods MA782 cells were cultured in RPMI1640 medium with TAM. The proliferative activity of cells was detected by MTT methods, and cells apoptosis by flowcytometrey methods. The expression of p21/CIP1、 PCNA proteins was detected by immunohistochemical methods, the semi-quantity of proteins expression were analyzed by pathological image analysis software. Results TAM can in duce growth arrest and apoptosis of cells. There was no change of p21 /CIP1, PCNA proteins in cells with 2 μmol/L TAM, But after 48, 72h with 6 μmol/L or 10 μmol/L TAM, the level of PCNA protein decreased while p21 /CIP1 protein increased, The difference was significant(P<0.01).Conclusion Down-regulation of PCNA protein and up- regulation of p21/CIP1 protein may be one of the mechanisms through which TAM induced growth inhibition and apoptosis of MA782 cell.