目的 :检测化疗药物环磷酰胺及表阿霉素对 4种乳腺癌细胞增殖的抑制作用 ,以及对细胞外信号调节激酶 (ERK1/2 )及其上游激酶 (MEK1/2 )蛋白表达及活化水平的影响。方法 :按常规方法培养细胞及制备蛋白电泳样品。应用Westernblot检测培养的正常乳腺上皮细胞系MCF 10及MCF 7、T4 7D、Bcap 37、SK BR 3乳腺癌细胞系中 ,ERK1/2和MEK1/2的表达及活化 (磷酸化 )水平 ,以及这两种药物对ERK1/2和MEK1/2的表达及活化的影响。用MTT比色法检测这两种化疗药物对乳腺癌细胞增殖的抑制作用。结果 :与对照MCF 10细胞相比较 ,4种乳腺癌细胞系中 ,MEK1/2、ERK1/2蛋白的表达及活化水平均明显增高 ;两种化疗药物均可抑制乳腺癌细胞的增殖。这两种药物处理的乳腺癌细胞中 ,MEK1/2、ERK1/2蛋白的表达及其活化水平明显低于未处理组。结论 :MEK、ERK蛋白的过度表达及活化 ,可能在人乳腺癌的发生、发展中起重要作用。这两种化疗药物可能是通过抑制MEK、ERK蛋白的过度表达及活化来抑制乳腺癌细胞的增殖 OBJECTIVE: To detect the inhibitory effect of cyclophosphamide and epirubicin on the proliferation of four breast cancer cells and the expression and activation of extracellular signal-regulated kinase (ERK1 / 2) and its upstream kinase (MEK1 / 2) Impact. Methods: Cells were cultured according to conventional methods and protein electrophoresis samples were prepared. The expression and activation (phosphorylation) levels of ERK1 / 2 and MEK1 / 2 in cultured normal breast epithelial cell lines MCF 10 and MCF 7, T4 7D, Bcap 37 and SK BR 3 breast cancer cell lines were detected by Western blot Effects of two drugs on the expression and activation of ERK1 / 2 and MEK1 / 2. MTT colorimetric assay of the two chemotherapy drugs on breast cancer cell proliferation inhibition. Results: The expression and activation of MEK1 / 2 and ERK1 / 2 protein in 4 breast cancer cell lines were significantly increased compared with the control MCF 10 cells. Both chemotherapeutic agents inhibited the proliferation of breast cancer cells. The expression and activation of MEK1 / 2 and ERK1 / 2 proteins in both drug-treated breast cancer cells were significantly lower than those in the untreated group. Conclusion: Overexpression and activation of MEK and ERK proteins may play an important role in the occurrence and development of human breast cancer. Both chemotherapeutic drugs may inhibit the proliferation of breast cancer cells by inhibiting the overexpression and activation of MEK and ERK proteins