PROSTATIC DIFFERENTIATION AND SEX HORMONE METABOLISM

我们多学科研究的长期目标是理解 性激素在增殖性疾病的启动中可能发挥的作用 人类前列腺癌前病变及其进展到 恶毒。为此，我们开发了一种大鼠模型，在该模型中，我们 可持续地在背外侧(DLP)引起发育不良损害 长期同时服用睾酮(T)引起的前列腺癌 雌二醇-17β(E2)。异常增生性病变非常接近 这些物质通常存在于人类的前列腺中，和它们的同类一样， 常发展为侵袭性肿瘤。我们目前的研究计划 专注于研究内分泌和分子机制 我们认为它们与早期畸形的发病机制有关 增生性病变。具体地说，我们建议调查 雄激素支持的雌激素治疗增加了II型核的发病率 DLP中雌激素受体(ER)水平启动和维持级联反应 导致发育异常的事件。建议的受体- 介导的事件包括这种增强的转化生长因子-α/表皮生长因子和 EGF受体自分泌环与鸟苷水平升高 三磷酸(GTP)与p21(Ras)结合。为了检验这一假设，我们将 首先确认并扩展我们的初步数据，这表明有 是这种自分泌循环和ras转录表达的增强 DLPS有发育不良的病变。出于这些目的，我们将使用Northern 以及蛋白质印迹、结合分析和免疫分析 自分泌环路组件的功能水平，以及测量 GTP/GDP与p21的结合(Ras)。确定是否增强了所有 或者，一些途径成分直接由类型增加所介导 II核ER我们将给予特定的竞争性抑制物 与T、E_2同时处理的大鼠的受体结合。因为我们的 最近的合作研究表明，T-E2治疗会导致DNA 仅在DLP中形成加合物，我们还将确定是否 点突变发生在ras基因的GTPase区域，可能是 负责我们可能在与p21(Ras)的GTP结合中发现的增加。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以确定 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。 来自该项目的数据预计将产生重要信息 关于性类固醇在非典型肺炎发病机制中的作用 前列腺癌前病变的增生性病变。一种对 在我们的动物身上这些损伤发生的机制 模型应该被证明对破译前列腺癌的原因很有价值 人类发育不良。

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.