钙激活中性蛋白酶介导雌激素增强MCF-7乳腺癌细胞的存活力

目的 探讨雌激素(E2)对MCF-7乳腺癌细胞钙激活中性蛋白酶1(CANP-1)基因表达和CANP蛋白酶活性的影响、以及CANP活性在E2增强细胞存活力中的作用.方法 以MCF-7乳腺癌细胞为研究模型、采用RT-PCR法检测mRNA表达、蛋白印迹法观察CANP特异性底物FAK蛋白剪切、血清饥饿诱导细胞死亡、锥虫蓝染色及细胞计数法检测细胞存活力.结果 E2(10 nmoL/L)可明显刺激乳腺癌细胞CANP-1基因表达上调,CANP抑制剂则可显著抑制E2诱导CANP-1基因上调；在无血清培养条件下,E2激活CANP活性及增加细胞存活力(14.3±4.9％,P＜0.05),而CANP抑制剂可显著抑制E2诱导CANP激活以及细胞存活力增强(19.2±3.9％,P＜0.05).结论 E2刺激MCF-7乳腺癌细胞CANP-1基因表达上调并增强CANP活性,后者可能参与介导血清饥饿时E2增强MCF-7细胞的存活力.

Calpain mediates estrogen-enhanced survival in MCF-7 breast cancer cells

Objective To investigate the effects of estrogen（E2）on the gene expression of calpain1 and calpain activity, and a possible role of calpain in the E2-enhanced survival in breast cancer cells. Methods Human breast cancer cell line MCF-7 was employed as a model system. RT-PCR was used to analyze the levels of mRNA expression and western blotting was employed to access proteolysis of FAK. Serum starvation was used to induce cell death, and Trypan blue staining and cell counting were used to evaluate cell viability. Results Stimulation of MCF-7 cells with E2 led to increased mRNA expression of calpain1 and calpain activity. E2 also increased cell viability by 14.29 % (P<0.05) during serum starvation, while calpain inhibitors significantly suppressed the E2-increased expression of calpain1 mRNA, calpain activity , and cell viability by 19.17% (P<0.05). Conclusion E2 causes increased expression of calpain1 mRNA and calpain activity, and this may contribute to the E2-stimulated survival during serum starvation in MCF-7 cells.