MOLECULAR CHARACTERIZATION OF GNRH RECEPTORS

描述：(改编自申请者摘要)释放促性腺激素 激素(GnRH)，通过其G蛋白偶联的高亲和力受体 位于垂体前叶促性腺激素上，刺激分泌 促性腺激素(促黄体生成素和促卵泡刺激素)。现已知促性腺激素释放激素受体(GnRHR) 也存在于脑垂体外组织、激素反应性肿瘤和 肿瘤来源的细胞系，提示GnRH可能具有更多的 功能。GnRHR的表达在UP和UP中都受到高度调控 受其同源配体、性腺类固醇和多肽的下调。 然而，改变基因表达速率所涉及的机制 GnRHR在分子水平上的表达尚不清楚。为了理解这一规定 促性腺激素释放激素受体基因在垂体和垂体外组织中的表达 激素反应性肿瘤，PI分离了人GnRHR基因并定义了 它的基因组结构。人促性腺激素释放激素受体基因由两个内含子组成 和三个外显子，跨度超过20kb。它包含多个转录因子 起始点和大量推测的调控序列 各种荷尔蒙和其他调节因素增加了 严格调控的受体基因的差异表达，这可能 是特定于组织的。因此，GnRHR可能在调节 激素反应型肿瘤生长及其对不同刺激的反应性 和/或它的表达可能受到这样的刺激的调节。 长久以来的目标是在分子水平上理解DNA 负责组织的成分和转录因子 人促性腺激素释放激素受体基因的特异性表达和激素调节 明确GnRH抑制肿瘤细胞生长的分子机制。 其具体目的是：1)鉴定其启动子序列 促性腺激素释放激素受体基因在垂体、垂体外组织和激素中的表达 反应性肿瘤，2)研究促性腺激素释放激素受体，通过 雌激素、孕激素、糖皮质激素、睾酮、促性腺激素释放激素、抑制素、TPA和 CAMP，3)用来鉴定肿瘤中表达GnRH受体的细胞 4)检测GnRH和GnRHR的表达。 正常组织和肿瘤组织。这些研究可能会提供更大的 了解促性腺激素释放激素受体基因的调节，并允许我们 更好地理解其转录调控的复杂机制。 这些研究有可能为开发 一类治疗激素反应性肿瘤的新药。

DESCRIPTION: (adapted from the applicants abstract) Gonadotropin releasing hormone (GnRH), through its G-protein -coupled, high-affinity receptor located on gonadotropes of the anterior pituitary, stimulates the secretion of gonadotropins (LH and FSH). It is now known that GnRH receptors (GnRHR) are also present in extra pituitary tissues, hormone-responsive tumors and tumors derived cell lines, suggesting that GnRH may serve additional functions. GnRHR expression is highly regulated in exhibiting both up and down regulation by its cognate ligand, by gonadal steroids and peptides. However, the mechanisms involved in altering the rate of expression of the GnRHR at molecular levels is unknown. In order to understand the regulation of GnRHR gene expression in the pituitary, extra-pituitary tissues and hormone responsive tumors, the PI isolated the human GnRHR gene and defined its genomic organization. The human GnRHR gene is composed of two introns and three exons, and spans over 20 kb. It contains multiple transcriptional initiation sites and a large number of putative regulatory sequences for various hormones and other regulatory factors raising the possibility of tightly-regulated, differential expression of the receptor gene, which may be tissue specific. Thus the GnRHR may play a key role in the regulation of hormone-responsive tumors growth and its responsiveness to various stimuli and/or it's expression may be regulated by such stimuli. The long termed goals are to understand at the molecular level the DNA components and transcriptional factors that are responsible for the tissue specific expression and hormonal regulation of the human GnRHR gene, and to define the molecular mechanism of inhibition of tumor cell growth by GnRH. The specific aims are: 1) To characterize the promoter sequence for GnRH-receptor gene in pituitary, extra-pituitary tissue and in hormone responsive tumors, 2) To study GnRHR, transcriptional regulation by estrogen, progesterone, glucocorticoid, testosterone, GnRH, inhibin, TPA and cAMP, 3) To identify the cells in tumors expressing GnRH receptor using a monoclonal antibody, and 4) To determine the expression of GnRH and GnRHR in normal and tumor tissues. These studies will likely provide a greater understanding of the regulation of the GnRH-receptor gene and allow us to better understand the complex mechanism of its transcriptional regulation. These studies have the potential to provide the basis for the development of a new class of drugs for treatments of hormone-responsive tumors.