Estrogen-induced G1/S transition of G0-arrested estrogen-dependent breast cancer cells is regulated by mitochondrial oxidant signaling
Estrogen-induced G1/S transition of G0-arrested estrogen-dependent breast cancer cells is regulated by mitochondrial oxidant signaling
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DOI：
10.1038/sj.onc.1208667
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发表时间：
2005-07-21
期刊：
影响因子：
8
通讯作者：
Roy, D
中科院分区：
文献类型：
--
作者：
Felty, Q;Singh, KP;Roy, D
我们先前报道了17-β-雌二醇(E_2)诱导的线粒体活性氧(MtROS)作为信号分子。本研究旨在探讨雌激素诱导的线粒体ROS对细胞周期进程的影响。抗氧化剂N-乙酰-L半胱氨酸(NAC)、过氧化氢酶和谷胱甘肽过氧化物酶类似Ebselen可抑制E2诱导的细胞生长。流式细胞术显示线粒体蛋白合成阻断剂(氯霉素)、转录和复制阻断剂(溴化乙锭)和功能阻断剂(鱼藤酮、罗丹明6G)可阻断E_2诱导的G(1)向S的转变。在线粒体阻滞剂存在的情况下，E2诱导的DNA合成减少，但不影响ATP水平。此外，线粒体阻滞剂还抑制了E2诱导的细胞周期早期基因的表达，如细胞周期蛋白D1、D3、E1、E2和B2。NAC或鱼藤酮可降低E2诱导的细胞周期蛋白D1的表达。此外，NAC或鱼藤酮可抑制E_2诱导的AP-1和CREB分别与细胞周期蛋白D1启动子中的TrE和Cre反应序列的结合。此外，线粒体阻断剂可抑制E2诱导的增殖细胞核抗原、pRc1和bc1-2的表达。这些数据表明，E2诱导的mtROS参与了早期G(1)期进展的调节。由于本研究中使用的抗氧化剂和线粒体阻滞剂都没有报道与雌激素受体(ER)结合，我们的发现表明，E2诱导的mtROS通过非基因组的、ER不依赖的信号通路调节G(1)到S的转变和一些早期的G(1)基因。因此，我们的结果提示(1)雌激素诱导的线粒体氧化剂控制细胞周期进程的早期阶段的新范式；(2)为发现新的基于抗氧化剂的药物或抗氧化剂基因疗法来预防和治疗雌激素依赖性乳腺癌提供了基础。
We previously reported that 17-beta-estradiol (E2)-induced mitochondrial reactive oxygen species (mtROS) act as signaling molecules. The purpose of this study was to investigate the effects of E2-induced mtROS on cell cycle progression. E2-induced cell growth was reduced by antioxidants N-acetyl-L-cysteine (NAC), catalase, and the glutathione peroxidase mimic ebselen. Flow cytometry showed that mitochondrial blockers of protein synthesis (chloramphenicol), transcription and replication (ethidium bromide), and function (rotenone, rhodamine 6G) blocked E2-induced G(1) to S transition. Reduction of E2-induced DNA synthesis in the presence of mitochondrial blockers occurred without influencing the level of ATP. Additionally, the mitochondrial blockers inhibited the E2-induced expression of early cell cycle genes such as cyclins D1, D3, E1, E2, and B2. NAC or rotenone reduced E2-induced cyclin D1 expression. Furthermore, E2-induced binding of AP-1 and CREB to the TRE and CRE response sequences, respectively, in the promoter of cyclin D1 was inhibited by NAC or rotenone. In addition, E2-induced expression of PCNA, PRC1, and bcl-2 were inhibited by mitochondrial blockers. These data indicate that E2-induced mtROS are involved in the regulation of early G(1)-phase progression. Since neither antioxidants nor mitochondrial blockers used in this study are reported to bind the estrogen receptor (ER), our findings suggest that E2-induced mtROS modulates G(1) to S transition and some of the early G(1) genes through a nongenomic, ER-independent signaling pathway. Thus, our results suggest (1) a new paradigm that estrogen-induced mitochondrial oxidants control the early stage of cell cycle progression and (2) provide the basis for the discovery of novel antioxidant-based drugs or antioxidant gene therapies for the prevention and treatment of estrogen-dependent breast cancer.