GPR30在前列腺癌间质细胞活化中的作用机制及其生物学功能的研究

Cancer-associated fibroblasts (CAFs) play a vital role in malignant transformation and progression of prostate cancer (PCa) and accumulating evidence suggests an enhancing effect of estrogens on PCa. Estrogen receptor alpha (ERα) and GPR30, the membrane estrogen receptor, are the two main receptors expressed in PCa stroma which mediates the estrogen signaling. Evidence indicates that a shorter time to hormonal relapse was associated with low staining for ERα in stromal cells and correlated to shorter patient survival rate in prostate cancer. It is reported that activation of GPR30 expressed in prostate cancer epithelial cells could inhibit tumor growth, but little is known about the role of stromal GPR30 in PCa..We have been engaged in the study of the estrogen’s biological function in PCa and BPH for many years. Recently, we found that High expression of FAP and CD44 accompanied by low expression of smooth muscle (SM) differentiation markers in the stromal cells of prostate cancer tissues and in cultured primary human prostate CAFs. Additionally, prostate CAFs showed high GPR30 and low ERαexpression, and GPR30 was observed co-localized with FAP and CD44. Further more, overexpression of GPR30 in the prostate stromal cell line WPMY-1 induced the expression of FAP and CD44, and these effects are at least partly mediated by down-regulation of ERα. .We hypothesize that the mesenchymal stem-like cells in PCa tissue express GPR30 and ERα simultaneously. GPR30 can be activated by estrogen or other ligand, and then inhibits the expression of ERα, thus up-regulates CD44 and promote the stem-like cell transit into an active phenotype. We plan to disclose the signaling pathways and molecular mechanisms through which GPR30 induces the stem-like prostate mesenchymal cells transfer to active fibroblasts. We will also use in vitro and in vivo experiments to study the effects of overexpression of GPR30 in stromal cells on the progression of prostate cancer and characterizing the active factors secretion and macrophage infiltration in the tumor microenvironment. .The research results will uncover the roles of estrogen in androgen-independent conversion of prostate cancer, and providing a theoretical basis for the novel diagnosis and treatment targets of PCa in cancer associated stromal cells.

前列腺癌（PCa）中低表达雌激素受体α（ERα）的间质细胞高表达与活化间质相关的活性因子；而且其PCa发生雄激素抵抗时间较短，患者存活率较低。本实验室长期从事雌激素在前列腺增生和PCa中作用机制的研究。近期发现在前列腺间质细胞中GPR30通过下调ERα的表达促进间质细胞活化；过表达ERα通过下调CD44的表达抑制间质细胞活化。由此提出“PCa组织间质干性细胞中表达GPR30和ERα；雌激素或者其它配体激活了干性细胞中GPR30；GPR30通过下调ERα，进而上调CD44的表达使其被诱导为活化间质细胞”的研究假设。拟用体外和异种移植在体实验阐明研究假设中GPR30使PCa间质中干性细胞转化为活化间质细胞的作用通路和分子机制；以及过表达GPR30的间质细胞对促进PCa恶性进展的影响。其研究成果将为雌激素在PCa向激素非依赖转化中的作用提供理论依据，为PCa诊断和治疗提供间质细胞中的新靶标。

前列腺癌是威胁男性健康的恶性肿瘤。前列腺癌的发生发展不仅取决于癌细胞本身，肿瘤微环境，特别是其中的主要成分癌相关成纤维细胞（CAF）对其发展进程具有重要的作用。CAF通过调节细胞外基质成分、分泌活性因子以及促进癌细胞周围巨噬细胞的分化影响癌细胞的生物学行为，包括促进癌细胞增殖、浸润和迁移。本项目系统的研究了雌激素膜受体GPR30在促进CAF表型中的作用及其分子机制；CAF中GPR30的表达水平对巨噬细胞分化的影响及其分子机制；以及CAF中表达的CD44作为功能分子通过调节CAF分泌活性因子对前列腺癌进展的影响。旨在深入了解雌激素通过活化间质细胞促进前列腺癌进展的分子机制，为以肿瘤间质为靶点治疗前列腺癌提供新的线索和理论依据。.我们的研究发现，前列腺癌组织的间质细胞和体外培养的前列腺CAF中FAP、CD44和SMemb高表达，而平滑肌细胞分化标记蛋白分子低表达。提示，CAF具有分化程度较低的间质细胞表型。前列腺CAF中雌激素受体GPR30高表达，而ERα低表达；过表达GPR30或敲除ERα能够促进正常前列腺间质细胞的活化表型；其分子机制的研究表明，GPR30能够通过抑制ERα表达和ERα下游信号通路促进前列腺间质细胞的活化表型。GPR30能够通过激活wnt信号通路促进前列腺间质细胞中CD44的表达，而ERα则有相反的作用。在正常前列腺组织间质细胞中，CD44表达定位于细胞膜，而在前列腺CAF中CD44定位在胞内；进一步的研究发现，在前列腺CAF中CD44能够作为功能分子促进其活性因子的表达，并通过旁分泌方式促进前列腺癌细胞的EMT和迁移。CAF中的GPR30能够通过促进肿瘤相关巨噬细胞（TAMs）的募集和极化以及分泌炎性因子IL-6促进前列腺癌细胞的增殖和迁移。