三苯氧胺诱导MA782细胞凋亡与Cyclin D1的关系

A STUDY ON RELATIONS ABOUT MA782 CELL APOPTOSIS INDUCED BY TAM WITH CYCLIN D1

目的 探讨三苯氧胺Tamoxifen(TAM)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变化 ,免疫组化检测MA782细胞cyclinD1蛋白表达(并用病理图像分析软件进行半定量分析 ) ,RT -PCR检测MA782细胞cyclinD1mRNA表达情况。结果 TAM在体外能明显抑制MA782细胞生长 ,诱导细胞凋亡 ,下调cyclinD1mRNA及蛋白表达 ,免疫组化半定量分析显示 6μmol/LTAM作用MA782细胞 72小时后 ,cyclinD1蛋白平均灰度值从 1 32 .5± 0 .0 2下降至 1 2 6.1 8± 0 .0 3,1 0 μmol/LTAM作用 72小时后下降为 73.5 6± 0 .0 2 ,与对照组相比差异极其显著 (P <0 .0 1 )。RT -PCR检测结果显示 :2 μmol/LTAM组无明显改变 ,而 6、1 0 μmol/LTAM作用于细胞 2 4、48小时后 ,细胞cyclinD1mRNA表达呈现出不同程度的下降 ,与对照组比较有统计学意义 (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 。

Objective To study if tamoxifen (TAM) can induce growth arrest or apoptosis of ER-negative MA782 mouse breast cancer cell line and to explore the molecular mnchanisms. Methods MA782 cells were Cultured in RPMI 1640 medium with TAM.The proliferative activity of cells was detected by MTT methods, and cells apoptosis by flowcytometrey methods. The expression of cyclin D1 protein was detected by immunohistochemical methods, the semi-quantity of protein expression was analyzed by pathological image analysis software, The expression of cyclin D1 mRNA was assessed by RT-PCR methods. Results TAM can induce growth aresst and apoptosis of cells. ICC results showed that MA782 cells were ER-negative. There was no change of cell cycle regulators in cells with 2 μmol/L TAM. After 48、72h with 6 μmol/L or 10 μmol/L TAM, the level of cyclin D1 proteins decreased from 132.5±0.02 to 129.67±0.03、126.18±0.03(6 μmol/L) and 109.1±0.01、73.56±0.02(10 μmol/L),The difference was significant(P<0.01), RT-PCR results showed that the expression of cyclin D1 mRNA decreased in cells exposed to 10 μmol/L TAM for 48 h. The difference was significant compared with control cells(P<0.01). Conclusions Down-regulation of cyclin D1 mRNA and proteins may be one of the mechanisms through which TAM induced growth inhibition and apoptosis of MA782 cell .