PROSTATIC DIFFERENTIATION AND SEX HORMONE METABOLISM

前列腺分化和性激素代谢

• 批准号: 3164274
• 负责人: Irwin Leav
• 金额: $ 19.73万
• 依托单位: TUFTS UNIVERSITY BOSTON
• 依托单位国家: 美国
• 财政年份: 1978
• 资助国家: 美国
• 起止时间: 1978-09-30 至 1996-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3164274
• 关键词: DNA damage; autocrine; cell cycle; epidermal growth factor; estradiol; gene expression; growth factor receptors; guanine nucleotide binding protein; guanosine triphosphate; guanosinetriphosphatases; hormone related neoplasm /cancer; laboratory rat; nucleic acid sequence; nucleotide metabolism; phenylacetates; phosphorylation; point mutation; prostate preneoplastic state; protooncogene; receptor expression; reproductive system pharmacology; steroid hormone metabolism; testosterone; transforming growth factors

The long-term objective of our multidisciplinary research is to understand the role that sex hormones may play in the initiation of proliferative preneoplastic prostatic lesions in humans and their progression to malignancy. For these purposes we have developed a rat model in which we can consistently induce dysplastic lesions in the dorsolateral (DLP) prostate by the chronic simultaneous administration of testosterone (T) and estradiol-17beta (E2). The dysplastic lesions closely approximate those commonly found in the human prostate and, like their counterpart, frequently develop into invasive neoplasms. Our current research program is focused on investigating endocrinological and molecular mechanisms that we believe are implicated in the pathogenesis of the early aberrant proliferative lesions. Specifically, we propose to investigate whether the androgen-supported estrogen treatment increases in nuclear type II estrogen receptor (ER) levels in the DLP initiates and sustains a cascade of events responsible for dysplastic development. The proposed receptor- mediated events include this enhanced expression of the TGF-alpha/EGF and EGF receptor autocrine loop and an increase in the levels of guanosine triphosphate (GTP) bound to p21(ras). To test this hypothesis we will first confirm and extend our preliminary data which indicates that there is enhancement of this autocrine loop and ras transcript expression in DLPs harboring dysplastic lesions. For these purposes we will use Northern and Western blots, binding assays and immunoassays for assessing the functional levels of components of the autocrine loop, and measurements of GTP/GDP binding to p21(ras). To determine whether the enhancement of all or some, the pathway components are directly mediated by increases in type II nuclear ER we will administer specific competitive inhibitors of the receptor binding to rats simultaneously treated with T+E2. Since our collaborative research has recently shown that T+E2 treatment causes DNA adduct formation exclusively in the DLP, we will also determine whether point mutations occur in the GTpase regions of ras genes that could be responsible for increases we may find in GTP binding to p21(ras). For these purposes we will use single-strand conformation polymorphism to screen tissues and direct nucleotide sequencing to positively identify the mutation. Our studies will employ a multidisciplinary approach which includes pathology, endocrinology and molecular biology. Data from this project are expected to yield important information concerning the role sex steroids play in the pathogenesis of atypical proliferative pre-cancerous lesions in the prostate. An understanding of the mechanisms involved in the genesis of these lesions in our animal model should prove valuable in deciphering the causes of prostate dysplasia in humans.

我们多学科研究的长期目标是了解 性激素可能在增殖启动中发挥作用 人类前列腺癌前病变及其进展 恶性肿瘤为了这些目的，我们开发了一种大鼠模型， 可持续诱导背外侧（DLP）发育不良病变 前列腺通过长期同时给予睾酮（T） 和雌二醇-17 β（E2）。发育不良的病变 那些通常在人类前列腺中发现的，和它们的对应物一样， 经常发展成侵袭性肿瘤。我们目前的研究计划 专注于研究内分泌和分子机制， 我们认为与早期异常的 增生性病变具体而言，我们建议调查 雄激素支持的雌激素治疗增加核II型 DLP中的雌激素受体（ER）水平启动并维持级联反应 导致发育异常的事件。所提出的受体- 介导的事件包括TGF-α/EGF的表达增强， EGF受体自分泌环和鸟苷水平的增加 三磷酸（GTP）与p21（ras）结合。为了验证这个假设，我们将 首先确认并扩展我们的初步数据，这些数据表明， 是这种自分泌环和ras转录表达的增强， 具有发育异常病变的DLP。为此，我们将使用北方 和Western印迹、结合测定和免疫测定，用于评估 自分泌回路成分的功能水平，以及 GTP/GDP结合p21（ras）。为了确定是否所有的增强 或一些，途径组分直接通过增加类型介导， II核ER，我们将给予特定的竞争性抑制剂， 与同时接受T+E2治疗的大鼠的受体结合。由于我们 最近的一项合作研究表明，T+E2治疗会导致DNA 加合物的形成只在DLP，我们还将确定是否 点突变发生在ras基因的GTpase区域， 负责增加我们可能会发现GTP结合p21（ras）。为 这些目的，我们将使用单链构象多态性， 筛选组织并直接进行核苷酸测序， 突变我们的研究将采用多学科方法， 包括病理学、内分泌学和分子生物学。 预计该项目的数据将产生重要信息 关于性类固醇在非典型性 前列腺增生性癌前病变。 了解 在我们的动物中，这些病变的发生所涉及的机制 模型应该证明有价值的破译前列腺的原因， 人类发育异常。