雌激素饥饿增强TRAIL诱导乳腺癌细胞凋亡

Estrogen Starvation Promotes TRAIL Induction of Breast Cancer Cells Apoptosis

目的:探讨雌激素饥饿对肿瘤坏死因子相关凋亡诱导配体(TRAIL)诱导乳腺癌细胞MCF-7凋亡的影响及作用机制。方法:MCF-7细胞培养贴壁之后,用雌激素饥饿处理后加入TRAIL,用荧光染料Hoechst染色法检测细胞的凋亡,用细胞计数法检测细胞的存活。在雌激素饥饿处理MCF-7细胞后,收集对照和饥饿组蛋白用Westernblot法检测相关的蛋白表达。结果:单独使用雌激素饥饿处理或者单独使用TRAIL处理乳腺癌细胞MCF-7都能诱导细胞凋亡,但是它们诱导凋亡的活性较小,两种方法联合使用可以极大地增加诱导细胞凋亡的活性(P<0.001)。雌激素饥饿处理后的乳腺癌细胞,死亡受体5(DR5)表达上调。结论:乳腺癌细胞MCF-7对TRAIL敏感度不高,雌激素饥饿可以增加TRAIL诱导乳腺癌细胞凋亡的活性,DR5与雌激素饥饿诱导TRAIL活性增加相关。

Objective： To determine the impact of estrogen starvation on the activity of tumor necrosis factor-related apoptosis inducing ligand （TRAIL） to induce breast cancer cells apoptosis and its mechanism. Methods： MCF-7 were cultured with or without estrogen and treated with or without TRAIL, then cell apoptosis and survival with Hoechst staining and cell counting were detected, respectively. Western blot was used to detect protein expression in cells cultured in medium with or without estrogen. Results： When treated with estrogen starvation or TRAIL respectively, breast cancer cells underwent subtle apoptosis. However, combination of estrogen starvation and TRAIL greatly pro- moted cancer cells apoptosis. Estrogen starvation could up regulate the expression of death receptor 5 （DRS）, a receptor of TRAIL. Conclusion： Estrogen starvation can enhance the activity of TRAIL to induce breast cancer cell apoptosis, which may be mediated by DR5.