Mechanisms of Growth Factor-Estrogen Receptor Crosstalk

生长因子-雌激素受体串扰的机制

• 批准号: 7107869
• 负责人: Stephen H. Safe
• 金额: $ 21.31万
• 依托单位: TEXAS A&M UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-02-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7107869
• 关键词: G protein; MCF7 cell; athymic mouse; biological signal transduction; breast neoplasms; cell growth regulation; cell proliferation; enzyme activity; estradiol; estrogen receptors; fos protein; gene expression; growth factor; growth factor receptors; insulinlike growth factor; mitogen activated protein kinase; neoplastic cell; neoplastic growth; phosphatidylinositol 3 kinase; protein protein interaction; protein structure function; protooncogene; tissue /cell culture; transfection

DESCRIPTION (provided by applicant): Breast cancer is one of the leading causes of premature death in women and development of chemoprevention and chemotherapeutic interventions wilt require understanding of the important steps that lead to tumor formation, growth and metastasis. Estrogen receptor (ER)-positive and -negative breast cancer cells have been extensively used as models for studying signaling pathways that are important for breast tumor growth. Both 17beta-estradiol (E2) and polypeptide growth factors (GFs) have been identified as important mitogens for breast cancer cell growth. We hypothesize that ERalpha-dependent activation of nongenomic phosphatidyl inositol 3-kinase (PI3-K) and mitogen-activated protein kinase (MAPK) pathways by E2 are important for breast cancer cell proliferation, and the proposed studies will investigate the mechanisms of non-genomic activation by E2. Aim 1 will focus on the role of ERalpha in activation of PI3-K and MAPK using ER-positive breast cancer cells (MCF-7 and ZR-75) and ER-negative (CHO and COS) cells as models. The domains of ERalpha required for activation of kinases and the importance of cell context will be determined in transient transfection studies. The mechanisms of non-genomic action of E2 and the role of specific kinases in mediating activation of PI3-K and MAPK will be investigated in Aim 2. The studies will also determine the biological significance of direct ERalpha interactions with Src-SH2, G proteins, the p85 regulatory subunit of PI3-K and the IGF-1 receptor. Aim 3 will focus on downstream mechanisms of ERalpha-dependent activation of c-fos by kinases. Dominant negative p85, MAPKK and Src expression plasmids transiently or stably transfected into breast cancer cells will be used to investigate the contribution of the MAPK and PI3-K pathways to the mitogenic activity of E2 in breast cancer cells (in vitro) and mammary tumors in athymic nude mice bearing breast cancer cell xenografts. The in vitro mechanistic studies will also be complemented by research on the contributions of kinase activation by E2 on cell proliferation and tumor growth and thereby define potential therapeutic targets for treating breast cancer.

描述（由申请人提供）：乳腺癌是女性过早死亡的主要原因之一，化学预防和化疗干预措施的开发需要了解导致肿瘤形成、生长和转移的重要步骤。雌激素受体（ER）阳性和阴性乳腺癌细胞已被广泛用作研究对乳腺肿瘤生长重要的信号通路的模型。 17β-雌二醇 (E2) 和多肽生长因子 (GF) 均已被确定为乳腺癌细胞生长的重要有丝分裂原。我们假设E2对非基因组磷脂酰肌醇3激酶（PI3-K）和丝裂原激活蛋白激酶（MAPK）途径的ERα依赖性激活对于乳腺癌细胞增殖很重要，并且拟议的研究将调查非基因组磷脂酰肌醇3激酶（PI3-K）和丝裂原激活蛋白激酶（MAPK）通路的非基因组激活的机制。 E2 的基因组激活。目标 1 将使用 ER 阳性乳腺癌细胞（MCF-7 和 ZR-75）和 ​​ER 阴性（CHO 和 COS）细胞作为模型，重点研究 ERalpha 在 PI3-K 和 MAPK 激活中的作用。激酶激活所需的 ERα 结构域和细胞背景的重要性将在瞬时转染研究中确定。目标 2 将研究 E2 的非基因组作用机制以及特定激酶在介导 PI3-K 和 MAPK 激活中的作用。这些研究还将确定 ERalpha 与 Src-SH2、G 蛋白直接相互作用的生物学意义，PI3-K 的 p85 调节亚基和 IGF-1 受体。目标 3 将重点关注激酶对 c-fos 的 ERα 依赖性激活的下游机制。瞬时或稳定转染乳腺癌细胞的显性阴性p85、MAPKK和Src表达质粒将用于研究MAPK和PI3-K途径对乳腺癌细胞（体外）和乳腺肿瘤中E2促有丝分裂活性的贡献。携带乳腺癌细胞异种移植物的无胸腺裸鼠。体外机制研究还将通过 E2 激酶激活对细胞增殖和肿瘤生长的贡献的研究来补充，从而确定治疗乳腺癌的潜在治疗靶点。