瘦素干扰他莫昔芬抑制乳腺癌细胞MCF-7增殖作用的机制

Mechanism of leptin inhibiting the growth effect of antiestrogen tamoxifen in MCF-7 breast cancer cells

目的:检测乳腺癌细胞株MCF-7中瘦素受体(leptin receptor)的表达,并探讨瘦素(leptin,LEP)对他莫昔芬(tamox-ifen,TAM)抑制MCF-7细胞增殖的影响及机制。方法:用免疫荧光及Western blot法检测MCF-7细胞中瘦素受体的表达。以100 ng/ml的LEP及1 000 nmol/L的TAM同时处理MCF-7细胞,用MTT法检测LEP及TAM对细胞增殖的影响,并用West-ern blot及免疫荧光的方法检测作用前后雌激素受体(ERα)表达水平的变化。合成人雌激素反应元件(estrogen response ele-ment,ERE)的核心片段,并将其插入pGL3-promoter载体的多克隆位点,构建成含有ERE报告基因的质粒pERE-LUC,用脂质体转染的方法将该质粒瞬转到MCF-7细胞中,用LEP及TAM处理后检测荧光素酶的表达,以探讨其对ERα转录的影响。结果:MCF-7细胞呈瘦素受体的阳性表达。100 ng/ml的LEP能够削弱TAM对MCF-7细胞的增殖抑制作用,并能够通过上调ERα的转录及表达水平来干扰TAM对细胞增殖的抑制作用。结论:LEP能够干扰TAM抑制乳腺癌细胞增殖的作用,LEP与乳腺癌患者TAM治疗的疗效可能存在着一定的关系。

Objective：To identify the expression of leptin receptor in breast cancer cell line MCF-7,and to explore the effects and mechanisms of leptin on the anti-proliferative effect of tamoxifen on MCF-7.Methods：The expression of leptin receptor was detected by immunofluorescence and Western blot.After treated with 100 ng/ml of leptin and 1 000 nmol/L of tamoxifen（TAM）,cell proliferation and the levels of estrogen receptor α（ERα） in MCF-7 were examined.Plasmid pERE-LUC which containing estrogen response element（ERE） and reporter gene luciferase was constructed and transfected into MCF-7 cells,the expression of luciferase was detected to reflect the effects of leptin on the transcription of ERα.Results：Leptin receptor was positively expressed in MCF-7 cells.Leptin weaken the inhibition of TAM on MCF-7 proliferation by upreglulating the transcription of ERα.Conclusion：Leptin could interfere with the inhibition of TAM on breast cancer cells,it may contribute to the efficacy of tamoxifen treatment for breast cancer patients.