Tyrphostins AG1478对内分泌耐药乳腺癌细胞的作用

目的：研究表皮生长因子受体（EGFR）抑制剂对内分泌治疗耐药的激素依赖性乳腺癌细胞的作用,探讨EGFR抑制剂的应用前景.方法：选择雌激素受体（ER）阳性的乳腺癌细胞MCF-7,建立三苯氧胺（TAM）耐药的乳腺癌细胞（T-MCF-7）.研究EGFR抑制剂Tyrphostins AG1478对T-MCF-7细胞的作用,采用四甲基偶氮唑蓝（MTT）比色法进行细胞生长抑制试验,流式细胞仪（FCM）检测细胞周期的影响,Western blot方法分析EGFR及其信号通路的改变.结果：MCF-7细胞在持续给予TAM（10-7mol/L）处理6个月后获得耐药细胞T-MCF-7.与MCF-7细胞相比,T-MCF-7对AG1478的敏感性增高.AG1478可使T-MCF-7细胞周期阻滞,增殖指数下降,凋亡率增加;对T-MCF-7细胞的EGFR和细胞外信号调节激酶（ERK1/2）蛋白水平无影响,但使其磷酸化-ERK1/2水平下降,降低了EGFR下游信号通路的活性水平.结论：激素依赖性乳腺癌细胞给予TAM长期处理后,更依赖于EGFR信号转导通路的作用.EGFR抑制剂可抑制EGFR信号通路的活性,提高乳腺癌内分泌治疗的效果.

The effect of tyrphostins AG1478 to anti-endocrine breast cancer cells

Objective: To investigate the function of epidermal growth factor receptor(EGFR) inhibitor to anti-endocrine estrogen-depend breast cancer cells,and the clinical prospects of EGFR inhibitors.Methods: Anti-endocrine breast cancer cells(T-MCF-7) was established by estrogen receptor positive(ER ) breast cancer cells(MCF-7) keeping on exposing to Tamoxifen(TAM) for an enough time.The effect of Tyrphostins AG1478 to T-MCF-7 cells was studied including the cell growth inhibitory test by MTT method,the cell cycles by flow cytometry(FCM),the proteins expression of EGFR,extracellular signal-regulated kinase(ERK1/2) and phosphorylation-ERK1/2 by western blot,respectively.Results: MCF-7 cells have been becoming anti-endocrine cells(T-MCF-7) after exposing to TAM for about six months.Comparing to MCF-7,T-MCF-7 was more sensitive to the EGFR inhibitor Tyrphostins AG1478.After being exposed to Tyrphostins AG1478,the T-MCF-7 cells was discovered the cell cycles was blocked,the apoptosis rate increased,the proliferation index(PI) and the express of p-ERK1/2 protein decreased,while the express of EGFR and ERK1/2 protein has no changes.Conclusions: T-MCF-7 cells,estrogen-depend breast cancer cells exposing to TAM for a long time,would depend on the function of EGFR signaling transduction pathway.EGFR inhibitors would depress the activity of EGFR down-signaling pathway and increase the endocrine therapeutic effects of the breast cancer.