钙激活中性蛋白酶抑制剂对E2诱导的乳腺癌细胞增殖效应的影响及其意义

Suppression of estradiol-induced proliferation by calcium-activated neutral protease (CANP) inhibitor,calpeptin,in breast cancer cells and its significance

目的观察钙激活中性蛋白酶(calcium-activated neutral protease,CANP)抑制剂对雌二醇(estradiol,E2)诱导的乳腺癌细胞增殖效应的影响,为探索乳腺癌治疗新药靶提供理论依据。方法以人乳腺肿瘤细胞系MCF-7为模型细胞,RPM1-1640培养,E2处理;MTT法分析细胞增殖,观察E2诱导乳腺癌细胞增殖;CANP特异性抑制剂calpeptin(CAL)或E2受体选择性调节剂他莫西芬(Tamoxifen,TAM)预处理模型细胞,观察CAL或TAM对E2诱导的肿瘤细胞增殖效应的影响及其差异。结果(1)E2诱导MCF-7细胞增殖呈时间和剂量依赖性。E2发挥最大作用的浓度为10-8mol/L,最佳作用时间为24h,增殖率达18.6%(P<0.01);(2)TAM能显著抑制E2诱导的细胞增殖,浓度为10-6mol/L时抑制效能最佳,抑制率达28.63%(P<0.01);(3)CAL也可明显抑制E2的细胞增殖效应,在CAL为10-5mol/L时抑制率最高,达26.34%(P<0.01)。比较CAL与TAM的细胞增抑制殖效能未见显著性差异。结论CANP抑制剂能有效抑制E2诱导的乳腺癌细胞增殖活动,因而以CANP作为乳腺癌治疗的候选药靶可能具有潜在的应用前景。

Objective To investigate the effects of a calcium-activated neutral protease （CANP） inhibitor, ealpeptin（CAL）, on cell proliferation induced by estradiol （E2） in cultured breast cancer cells. Methods Human breast cancer cell line MCF-7 was cultured in RPM1-1640 media and treated with E2, and monotetrazolium （MTT） assay was performed to analyze proliferation. Cell-permeable specific inhibitor for CANP, CAL, was applied to explore the effect of CANP on E2-induced proliferation in MCF-7 cells. Results Maximum proliferating effect was observed after treatment of model cells with E2 at a concentration of 10^-8 mol/L for 24 hours, with a proliferating rate at 18. 6% （P〈0. 01） TAM pre-treatment caused a marked inhibition of the E2-stimulated effect and proliferation-inhibiting rate （PIR） reached 28. 63%; Pre-treatment of cultured cells with CAL also significantly suppressed E2-induced proliferation at concentrations of between 10^-6 and 10^-5 mol/L, with a PIR at 26. 34% （P〈0. 01）. Conclusion CANP may play an important role in the signalling in which E2 stimulated proliferation of breast cancer cells, and targeting CANP may have a potential application in clinical treatment of breast cancer.