GENETIC MECHANISMS OF BREAST TUMOR PROGRESSION

乳腺肿瘤进展的遗传机制

• 批准号: 3194794
• 负责人: FRANCIS G. KERN
• 金额: $ 21.56万
• 依托单位: GEORGETOWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-09-01 至 1994-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3194794
• 关键词: athymic mouse; breast neoplasms; cell bank /registry; deficient growth media; estrogen receptors; fibroblast growth factor; gene expression; genetic library; hormone related neoplasm /cancer; immunoprecipitation; molecular cloning; neoplasm /cancer genetics; neoplastic cell; neoplastic growth; regulatory gene; tissue /cell culture; transfection

A frequent occurrence during the treatment of breast tumors that originally respond to hormonal therapy with antiestrogens is the outgrowth of resistant populations of cells having a more aggressive malignant phenotype. Two approaches will be used to investigate the genetic mechanisms underlying this form of breast tumor progression. The first approach uses cDNA libraries constructed in a novel Epstein-Barr virus-based shuttle vector to transfect and efficiently retrieve cDNAs whose vector-driven expression can confer a hormoneindependent phenotype to cells that are originally hormone-dependent. This is a new approach to finding which of the many genes that are differentially-regulated in hormone-responsive and hormone-independent cells or which of the many genes that are induced by estrogen treatment are the key regulatory genes that are responsible for the promotion of cellular growth. Preliminary results Indicate that this approach is indeed capable of finding a regulatory gene involved in growth factor secretion. This result will be confirmed and the expression vector will be refined in a manner that will allow its efficient use in in vitro and in vivo selections schemes aimed at isolating genes responsible for the hormoneindependent growth of breast cancer cells. The second approach is based on the hypothesis that estrogen-independence results from the acquisition of the ability to constitutively produce growth factors that are normally induced by circulating estrogens in estrogen-dependent tumors. These growth factors can have an autocrine and/or paracrine function in stimulating tumor growth. A newly identified member of the fibroblast growth factor family found in the conditioned medium of an estrogen-independent cell line will be purified and molecularly cloned. The biological relevance of production of this growth factor will be assessed by examining the range and extent of expression of the gene in hormonedependent and hormone-independent breast cancer cell lines and primary tumor tissues. Through transfection studies, it will be determined whether constitutive expression of the gene in a hormone-responsive cell line can confer estrogen-independence either in vitro or in vivo.

在治疗乳腺肿瘤期间，经常发生 抗雌激素应对激素疗法的反应是 具有更具侵略性恶性肿瘤的细胞的抗性种群 表型。将使用两种方法来研究遗传 这种形式的乳腺肿瘤进展的机制。第一个 方法使用新型爱泼斯坦 - 巴尔（Epstein-Barr）构建的cDNA库 基于病毒的穿梭载体转染和有效检索cDNA 其载体驱动的表达可以赋予激素独立的表型 最初依赖激素的细胞。这是一种新的方法 查找差异调节的众多基因中的哪一个 激素反应性和激素独立的细胞或许多基因中的哪个 雌激素治疗引起的是关键调节基因 负责促进细胞生长。初步结果 表明这种方法确实能够找到调节基因 参与生长因子分泌。该结果将得到确认，并 表达向量将以允许其有效的方式进行完善 用于旨在隔离基因的体外和体内选择方案 负责乳腺癌细胞的激素独立生长。这 第二种方法是基于雌激素独立的假设 从组成性生产的能力获得的结果 通常由循环雌激素诱导的生长因子 雌激素依赖性肿瘤。这些增长因素可以具有自分泌 和/或旁分泌功能在刺激肿瘤生长中。一个新确定的 在条件中发现的成纤维细胞生长因子家族的成员 雌激素独立的细胞系的培养基将被纯化，并 分子克隆。生产这种增长的生物学相关性 将通过检查表达范围和表达程度来评估因素 激素依赖性和激素独立的乳腺癌细胞中的基因 线条和原发性肿瘤组织。通过转染研究，将是 确定基因在A中的本构表达是否 激素反应性细胞系可以赋予雌激素独立的依赖性 体外或体内。