Estrogens, Paracrine Factors, and Endometrial Cancer

雌激素、旁分泌因子和子宫内膜癌

• 批准号: 6612583
• 负责人: David G. Kaufman
• 金额: $ 25.9万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6612583
• 关键词: RNA directed DNA polymerase; SDS polyacrylamide gel electrophoresis; binding proteins; cell cell interaction; cell growth regulation; cell proliferation; epithelium; estrogen inhibitor; estrogen receptors; estrogens; expression cloning; genistein; hormone regulation /control mechanism; immunoprecipitation; insulinlike growth factor; microarray technology; paracrine; phytoestrogens; protein structure function; proteomics; receptor expression; tamoxifen; telomerase; tissue /cell culture; transfection; uterus neoplasms

DESCRIPTION (provided by applicant): In the human endometrium, the mitotic effect of estrogen on epithelial cells is, normally mediated by paracrine factors that are secreted by endometrial stromal cells and act on the epithelial cells. Despite this, Selective Estrogen Receptor Modulators (SERMs) and protective, anti-proliferative phytoestrogens that influence this process have only been characterized in malignant epithelial cell lines where this indirect control mechanism is absent. Insulin-like Growth Factor (IGF) is thought to be the principal paracrine factor secreted by endometrial stromal cells that induces the proliferation of endometrial epithelial cells. We hypothesize that estrogens regulate secretion of paracrine factors, yielding the uterotrophic effect of tamoxifen or antiestrogenic protective effects of phytoestrogens in vivo, by differential signaling via estrogen receptors (ER) alpha and beta in stromal cells. The modulating effects of estrogen on epithelial proliferation could be explained either directly by inhibition of IGF synthesis in stromal cells, or indirectly by changing the ratio of the IGF Binding Proteins in stromal cells. To facilitate investigation of these mechanisms we recently developed strains and lines of human endometrial stromal cells immortalized by transduction of the telomerase reverse transcriptase gene. Using these cells and specific inhibitors of ER alpha and ER beta we will investigate the respective roles of the two receptors in regulating the synthesis of paracrine factors. In this revised application, factors secreted by stromal cell lines, particularly the IGF family of peptides, will be assessed under the influence of estrogen agonists and antagonists, in the presence or absence of specific ER-alpha or ER-beta inhibitors. This will test whether estrogen signaling either through ER alpha or ER beta produces different profiles of IGF pathway components which explain differences in the mitotic rates of endometrial epithelial cells. Conditioned medium, produced by stromal cells following stimulation by these estrogens will be tested for mitogenic activity on Ishikawa endometrial cancer cells and primary normal endometrial epithelial cell cultures. To prove their roles, we will test conditioned medium where IGF components and other factors have been depleted by immunoprecipitation. This study will test whether the hypothesized mechanism explains the differing responses of endometrium to estrogens and may allow development of a better assay of effects of SERMs and phytoestrogens on endometrium.

描述（由申请人提供）：在人子宫内膜中，雌激素对上皮细胞的有丝分裂作用通常是由旁分泌因子介导的，这些因子由子宫内膜基质细胞分泌并作用于上皮细胞。 尽管如此，选择性的雌激素受体调节剂（SERM）和影响该过程的保护性，抗增殖性植物雌激素仅在缺乏这种间接控制机制的恶性上皮细胞系中进行了表征。 胰岛素样生长因子（IGF）被认为是子宫内膜基质细胞分泌的主要旁分泌因子，诱导子宫内膜上皮细胞的增殖。 我们假设雌激素调节旁分泌因子的分泌，从而通过通过雌激素受体（ER）α和β的差异信号传导在体内的植物雌激素在体内对植物雌激素的子宫嗜性作用。 雌激素对上皮增殖的调节作用可以直接通过抑制基质细胞中的IGF合成，或通过改变基质细胞中IGF结合蛋白的比率间接地解释。 为了促进对这些机制的研究，我们最近开发了通过转导端粒酶逆转录酶基因永生的人子宫内膜基质细胞的菌株和线条。 使用这些细胞和ERα和ERβ的特异性抑制剂，我们将研究两个受体在调节旁分泌因子合成中的各自作用。 在此修订后的应用中，在存在或不存在特定的ER-α或ER-β抑制剂的情况下，将在雌激素激动剂和拮抗剂的影响下评估基质细胞系，特别是IGF家族的基质细胞系，特别是IGF家族的因素。 这将测试通过ER Alpha或ERβ的雌激素信号是否产生不同的IGF途径成分的曲线，这些途径解释了子宫内膜上皮细胞的有丝分裂速率的差异。 这些雌激素刺激后，由基质细胞产生的条件培养基将在石川子宫内膜癌细胞和原发性子宫内膜上皮细胞培养物上测试有丝分裂活性。 为了证明自己的作用，我们将测试条件培养基，其中IGF成分和其他因素因免疫沉淀而耗尽。 这项研究将测试假设的机制是否解释了子宫内膜对雌激素的不同反应，并可以更好地开发出Serm和植物雌激素对子宫内膜的影响的更好测定。