GASTRIN-RELEASING PEPTIDE GENE EXPRESSION

胃泌素释放肽基因表达

• 批准号: 3462575
• 负责人: Mary E. Sunday
• 金额: $ 9.66万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-07-01 至 1988-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3462575
• 关键词: autoradiography; cell growth regulation; developmental genetics; embryo /fetus; gastrins; gene expression; growth factor; histochemistry /cytochemistry; hormone regulation /control mechanism; human tissue; immunoelectron microscopy; lung neoplasms; mammalian embryology; messenger RNA; molecular cloning; neoplastic transformation; neuroendocrine system; nucleic acid sequence; radiotracer; secretion; vasoactive intestinal peptide

A mammalian equivalent of the amphibian peptide bombesin, designated gastrin-releasing peptide (GRP), has potent biological effects, including release of several gut peptide hormones, consistent with a neuroregulatory role. GRP also induces cell proliferation, suggesting a role in growth regulation. GRP has been found in mammalian brain, gut, fetal lung, and neuroendocrine (NE) tumors. Three mRNAs for human GRP(s) have been isolated from human pulmonary NE tumors, all of which encode GRP but differ in the C-terminal extension peptide of proGRP, due to a 19 or 21 base insertion/deletion splicing event. The major objective of this project is to determine the sequence and developmental expression of the rat gene encoding GRP. This will allow analyses of tissue-specific GRP gene expression in rat embryogenesis, which should clarify GRP's role in normal mammalian growth and development, as well as in neoplasia. Initial studies of human fetal lung development have demonstrated peak immunoreactive GRP in NE cells at 18 to 24 weeks of gestation, which follows peak mRNA levels at 16 to 22 weeks and correlates with the canalicular period of lung growth. My specific aims are: (1) to complete sequencing of the rat GRP gene, to clarify the exact structure of possible RNA splicing variants. (2) To analyze patterns of tissue-specific gene levels in normal rat embryogenesis: in whole tissue homogenates by RNA blotting and S1 mapping, and in embryo tissue sections by in situ hybridization to precisely localize cell-specific GRP mRNA. Antisera to rat GRP and proGRP(s) will be raised and used for immunoperoxidase studies to be correlated with in situ hybridization on serial embryo sections. It will be important to determine whether C-terminal peptides are also expressed, as these may have biological functions. GRP-immunoelectron microscopy and GRP receptor autoradiography will be similarly carried out to further clarify GRP's physiological role. (3) to determine GRP's involvement in pathological processes by in situ hybridization and immunohistochemical analyses for both GRP and C-terminal peptides. The major focus will be on lung tumors, where GRP has been implicated as a potential atuocrine growth factor. Thus, GRP gene(s) may be transiently expressed in developing tissues as part of programmed gene regulation in cellular differentiation, and analyses of this expression may elucidate mechanisms of gene deregulation in oncogenesis.

两栖动物肽铃蟾肽的哺乳动物等效物，命名为 胃泌素释放肽（GRP）具有有效的生物效应，包括 释放多种肠道肽激素，与神经调节一致 角色。 GRP 还可诱导细胞增殖，表明其在生长中发挥作用 规定。 GRP 已在哺乳动物的大脑、肠道、胎儿肺和 神经内分泌（NE）肿瘤。 人类 GRP 的三种 mRNA 已被 从人类肺 NE 肿瘤中分离出来，所有肿瘤均编码 GRP，但有所不同 在 proGRP 的 C 端延伸肽中，由于 19 或 21 个碱基 插入/删除剪接事件。 该项目的主要目标是 确定大鼠基因的序列和发育表达 编码 GRP。 这将允许分析组织特异性 GRP 基因 大鼠胚胎发生中的表达，这应该阐明 GRP 在正常情况下的作用 哺乳动物的生长和发育以及肿瘤形成。 初步研究 人类胎儿肺发育的峰值免疫反应性 GRP 妊娠 18 至 24 周时，NE 细胞中出现 mRNA 水平峰值 16至22周时，与肺小管周期相关 生长。 我的具体目标是：（1）完成大鼠GRP的测序 基因，以阐明可能的 RNA 剪接变体的确切结构。 (2) 分析正常大鼠组织特异性基因水平模式 胚胎发生：通过 RNA 印迹和 S1 作图在整个组织匀浆中， 并通过原位杂交在胚胎组织切片中精确地 定位细胞特异性 GRP mRNA。 大鼠 GRP 和 proGRP 的抗血清将 提出并用于与原位相关的免疫过氧化物酶研究 连续胚胎切片杂交。 确定这一点很重要 C 端肽是否也表达，因为这些肽可能具有 生物学功能。 GRP-免疫电镜和GRP受体 将进行类似的放射自显影以进一步阐明 GRP 生理作用。 (3)确定GRP参与病理过程 通过原位杂交和免疫组织化学分析进行处理 GRP 和 C 端肽。 主要关注点是肺部肿瘤， 其中 GRP 被认为是一种潜在的自分泌生长因子。 因此，GRP 基因可能在发育组织中瞬时表达为 细胞分化中程序化基因调控的一部分，以及 对该表达的分析可以阐明基因失调的机制 在肿瘤发生过程中。