MOLECULAR CHARACTERIZATION OF GNRH RECEPTORS

促性腺激素释放激素（GnRH），下丘脑十肽，是 生殖过程的关键神经调节器 它的受体位于 在垂体前叶促性腺激素细胞膜上， 促黄体生成素（LH）和促卵泡激素的释放 （FSH）。 除垂体前叶外，据报道GnRH受体 存在于卵巢、睾丸、胎盘和大脑中。近年来， 许多研究者还发现，在不同的人类中， 肿瘤（乳腺、结肠、前列腺、卵巢、子宫和胰腺），而 在正常情况下，在这些组织中未检测到GnRH受体。 然而，GnRH受体在癌症中的作用尚不清楚。宽，长- 拟议研究的长期目标是研究 促性腺激素释放的LH和GnRH受体在癌症中的作用。 更具体地说，对于这项赠款申请，我们的努力将针对 对GnRH受体的分子特征进行了研究， 正常人垂体前叶及其调节 恶性组织 我们已经从一个人类祖先身上分离出了一个克隆体 垂体cDNA文库，由1557个核苷酸组成。它编码 一种拓扑结构类似于其他G蛋白偶联7- 跨膜受体克隆受体的结合研究 表现出与人类似的高亲和力和药理学性质， 人体垂体GnRH受体 人的北方印迹分析 垂体RNA揭示了3 hGnRH受体mRNA的存在和Southern杂交 对人类基因组DNA的印迹分析表明， GnRH受体基因。RNA的逆转录酶/PCR分析显示， 受体mRNA在垂体、卵巢、睾丸、肾上腺 乳腺、乳腺肿瘤、前列腺、前列腺肿瘤和乳腺肿瘤细胞系 （MCF-7）。该提案的具体目标是：克隆，测序， 表达和表征所有三种mRNA的GnRH受体cDNA; 克隆、测序和表征所有编码GnRH的基因， 受体;以确定每种受体mRNA的存在和量， 正常组织和恶性组织;制备针对正常组织和恶性组织的单克隆抗体。 用于检测和测量受体量的受体 乳腺癌和前列腺癌中的蛋白质;研究单克隆 抗体对培养物中乳腺和前列腺肿瘤细胞生长的影响; 定位染色体上每个受体的基因。这些研究 应该提供有关GnRH潜在作用的广泛新信息- 依赖性癌症中的受体。

Gonadotropin-releasing hormone (GnRH), a hypothalamic decapeptide, is the key neural regulator of the reproductive process. Its receptor is located in the cell membrane of anterior pituitary gonadotropes where it mediates the release of luteinizing hormone (LH) and follicle stimulating hormone (FSH). In addition to anterior pituitary, GnRH receptors are reported to be present in the ovary, testis, placenta and brain. In recent years, numerous investigators also have found GnRH receptors in various human tumors (breast, colon, prostate, ovarian, uterine and pancreatic), whereas under normal conditions GnRH receptors are not detected in these tissues. However, the role of GnRH receptors in cancer is unclear. The broad, long- term objective of the proposed studies is to investigate the mechanism of LH release from gonadotropes, and the role of GnRH receptors in cancer. More specifically, for this grant application our efforts will be directed toward the molecular characterization of GnRH receptors(s) cloned from the human anterior pituitary gland and their regulation in normal and malignant tissues. We have isolated a clone from a human anterior pituitary cDNA library which is composed of 1557 nucleotides. It encodes a protein with topology similar to that of other G-protein coupled 7- transmembrane receptors. Binding studies of the cloned receptor demonstrate a high affinity and pharmacological properties similar with the native human pituitary GnRH receptor. Northern blot analysis of human pituitary RNA reveals the presence of 3 hGnRH-receptor mRNAs and Southern blot analysis of human genomic DNA suggests the existence of more than one GnRH receptor gene. Reverse transcriptase/PCR analysis of RNA revealed that the receptor mRNA is expressed in pituitary, ovary, testis, adrenal, breast, breast tumor, prostate, prostate tumor, and breast tumor cell line (MCF-7). The specific aims of the proposal are to: clone, sequence, express and characterize GnRH receptor cDNAs for all three mRNAs; to clone, sequence, and characterize all the genes encoding the GnRH- receptors; to determine the presence and amount of each receptor mRNA in normal and malignant tissues; to prepare monoclonal antibodies to the receptor(s) for detection and measurement of the amount of receptor protein in breast and prostate cancers; to study the effects of monoclonal antibodies on growth of breast and prostate tumor cells in culture and; to localize the gene for each receptor(s) on the chromosome. These studies should provide extensive new information about the potential role of GnRH- receptors in hormonally-dependent cancers.