TAM诱导MA782细胞凋亡与CDK4关系

Study on relation about MA782 cell apoptosis induced by TAM with CDK4

目的探讨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,免疫组化检测CDK4蛋白表达,并用病理图像分析软件进行半定量分析。结果6、10μmol/LTAM在体外能明显抑制MA782细胞生长,诱导细胞凋亡,作用24h细胞凋亡率分别为7.04%、19.04%,10μmol/LTAM作用48h后细胞凋亡率从19.04%上升到51.27%,与对照组比较有显著差异(P<0.01)。2μmol/LTAM作用于细胞不同时间后检测CDK4蛋白,与对照组无明显变化(P>0.05),而6、10μmol/LTAM作用不同时间后,CDK4蛋白表达有不同程度的下降,与对照组相比差异显著(P<0.05或P<0.01)。结论TAM诱导MA782细胞凋亡其分子作用机制可能与下调细胞CDK4蛋白表达有关。

[Objective] 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 MTI＂ methods, and cells apoptosis by flowcytometrey methods. The expression of CDK4 protein was detected by immunohistochemical methods, the semi-quantity of protein expression was analyzed by pathological image analysis software. [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, 72 h with 6 μmol/L or 10 μmol/L TAM,the level of CDK4 proteins decreased from （107.2±0.01） to （91.23±0.02）, （76.21±0.03） （6 μmol/L） and （83.52±0.02）, （72.03±0.01） （10 μmol/L）. The difference was significant （P 〈0.05 or 0.01）. [ Conclusions] Down-regulation of CDK4 protein may be one of the mechanisms through which TAM induced growth inhibition and apoptosis of MA782 cells.