雌激素通过GPCR信号途径调控FOXL2在卵巢癌发生发展中的分子机制研究

Ovarian cancer, as a tumor in the female reproductive system, causes the most death among all the malignant tumors in women. Estrogen is strongly linked to ovarian cancer. It has been reported that forkhead transcription factor 2 (FOXL2) inhibited estrogen synthesis and cell apoptosis. As a tumor suppressor factor, FOXL2 gene mutation led to ovarian cancer. However no research on the molecular mechanism of estrogen and FOXL2 in regulating the development of ovarian cancer was reported. Estrogen not only activates genomic pathways through nuclear receptor to regulate gene transcription, but also relies on G protein-coupled receptors to initiate non-genomic pathways, including rapidly proteins post-translation modification and translocation. In this study, ovarian granule cells and mice were used as research materials. Through CRISPR/Cas9 gene knockout and estrogen detection, we can determine whether FOXL2 inhibited estrogen synthesis, estrogen up-regulated FOXL2 or through GPCR phosphorylated FOXL2. Combination of immunohistochemistry and cell physiological detection, the effect of estrogen regulation of FOXL2 on the ovarian cancer pathogenesis is examined. Finally, the transcription modulation factor and chaperone protein will be analyzed via co-immunoprecipitation and electrophoretic mobility shift assay. These studies aimed to reveal the mechanism of estrogen regulation by FOXL2 and provide a new theoretical basis for clinical treatment of ovarian cancer.

卵巢癌是女性生殖系统恶性肿瘤之一，死亡率位于妇女恶性肿瘤的首位，卵巢癌发生与雌激素水平异常密切相关。研究发现叉头转录因子2(FOXL2)抑制雌激素合成及细胞凋亡，作为抑癌因子其基因突变也会引发卵巢癌，但是目前对雌激素和FOXL2在卵巢癌发生发展中的分子机制尚无研究。雌激素可以通过核受体激活基因组途径调控基因转录，也可依赖于G蛋白偶联受体(GPCR)激活非基因组途径使蛋白质快速修饰和移位。本项目以人类卵巢颗粒细胞和小鼠为研究模型，采用CRISPR/Cas9基因敲除、雌激素检测等技术确定FOXL2抑制雌激素合成，发现雌激素促进FOXL2表达并通过GPCR调控FOXL2磷酸化；进一步结合小鼠卵巢病理学分析和细胞生理状态检测，研究雌激素调控FOXL2对卵巢癌生理过程的影响；最后分析雌激素调控FOXL2的转录因子及伴侣蛋白，揭示雌激素调控FOXL2的分子机制，为卵巢癌的临床治疗提供新的科学理论依据。

卵巢癌（Ovarian cancer）的死亡率位于女性生殖系统肿瘤的首位，颗粒性卵巢癌 (GCT) 是卵巢间质瘤的主要形式，其发生发展与雌激素水平异常密切相关，但是雌激素调控颗粒性卵巢癌的发病机制尚未充分确认。因此深入探讨雌激素调控卵巢癌发生发展的发病机制研究，是其临床分子靶向治疗和推广的必然选择。叉头转录因子2（FOXL2）与雌激素合成和卵巢早期发育分化有密切的关系，目前FOXL2抑制雌激素合成的分子机制已经基本控明确，但是雌激素调控FOXL2的分子机制尚无研究，所以迫切需要深入研究和探讨雌激素调控FOXL2在卵巢癌发生发展过程中的分子机制。本项目主要围绕FOXL2、雌激素和卵巢癌发生发展等三方面开展工作。本课题研究发现在颗粒性卵巢癌细胞中FOXL2抑制雌激素合成和分泌，雌激素又可以通过核受体激活基因组途径反馈上调FOXL2基因表达。雌激素依赖于GPCR-PKC信号激活非基因组途径使FOXL2蛋白快速发生磷酸化。雌激素抑制颗粒性卵巢癌细胞的增殖和迁移，促进颗粒性卵巢癌细胞的凋亡。敲除FOXL2明显抑制了雌激素诱导的颗粒性卵巢癌的凋亡。本研究为雌激素反馈调节FOXL2促进细胞凋亡的机制提供了新的科学依据，阐明了雌激素调控FOXL2蛋白在颗粒性卵巢癌发生发展中的分子机制，为颗粒性卵巢癌的有效治疗提供靶标基因。