Gastrin-Releasing Peptide Receptor Desensitization

胃泌素释放肽受体脱敏

• 批准号: 7175326
• 负责人: RICHARD V BENYA
• 金额: $ 27.79万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-01 至 2009-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7175326
• 关键词: Appearance; Archives; Behavior; Bombesin Receptor; Caco-2 Cells; Cell Differentiation process; Cells; Colon Carcinoma; Data; Focal Adhesion Kinase 1; GTP-Binding Proteins; Gastrin releasing peptide; Gastrointestinal Neoplasms; Gene Mutation; Genes; Human; Individual; Lasers; Light; Link; Messenger RNA; Microscopy; Mutate; Mutation; Numbers; Peptide Receptor; Site-Directed Mutagenesis; System; Tumor Bank; cancer cell; cell growth; colon cancer cell line; desensitization; morphogens; neoplastic cell; novel; promoter; receptor; receptor binding; vector

DESCRIPTION (provided by applicant): The objective of this proposal is to determine the degree to which functional gastrin-releasing peptide receptors (GRP-R) are expressed in colon cancer, and to elucidate the mechanism(s) by which these receptors regulate the differentiation of individual colon cancer cells when expressed in functional form. We have previously shown that the GRP-R acts as a morphogen, critically regulating colon cancer differentiation (Cell Growth Diff 2000; 11: 385). We have also shown that GRP-R mRNA is aberrantly expressed by all human colon cancer cell lines studied but is frequently mutated and rendered pharmacologically non-functional (Mol Pharmacol 2000; 58: 601). In our Preliminary Data we show that the X-linked GRPR gene is also mutated in archived human colon cancers, with mutation number increasing as tumor cells de-differentiate. Poorly differentiated tumor cells contain GRPR gene mutations that cause receptor inactivation whereas this is never seen in well differentiated cells. Thus we propose the mechanistic hypothesis that expression of functional GRP-R within any particular colon cancer primarily regulates tumor cell differentiation; with receptor-inactivating mutations representing a major mechanism allowing tumor cells to de-differentiate. However the extent and effect of these mutations on GRP-R behavior, and the mechanism(s) by which expression of functional receptor modulates tumor cell appearance, have not been determined. Specific Aim 1 focuses on elucidating the mechanism(s)whereby functional GRP-R modulate tumor cell differentiation. In our Preliminary Data we show that Caco-2 cells variably express GRP-R, which when present regulates normal morphological progression by activating focal adhesion kinase (FAK). Caco-2 cells will be transfected with vectors under control of an inducible promoter allowing for the directed expression of mini-genes. The products of these mini-genes will block specific regions of the GRP-R from binding to any G protein, or block specific G proteins themselves. The ability of each construct to undergo normal morphological progression will then be assessed. Specific Aim 2 is directed to identifying mutations in the GRPR gene in human colon cancers as a function of the differentiation of individual tumor cells. Archived colon cancers maintained in the GI Tumor Bank will be randomly selected and all cells of defined differentiation removed by laser capture microscopy. The GRPR gene will be isolated, and all mutations identified recreated by site-directed mutagenesis so that they can be evaluated in a transiently transfected cell system. Overall these studies will provide critical information regarding colon cancer differentiation, and shed light on a novel mechanism regulating the inactivation, or desensitization, of a clinically important heptaspanning receptor.

描述（由申请人提供）：该提案的目的是确定在结肠癌中表达的功能性胃蛋白释放肽受体（GRP-R）的程度，并阐明这些受体在功能表达时调节单个结肠癌细胞的分化的机制。 我们先前已经表明，GRP-R充当形态学，严重调节结肠癌的分化（Cell Diff 2000; 11：385）。我们还表明，GRP-R mRNA被研究的所有人类结肠癌细胞系异常表达，但经常被突变和渲染的药理学非功能性（Mol Pharmakacol 2000; 58：601）。在我们的初步数据中，我们表明，X连锁的GRPR基因在存档的人类结肠癌中也被突变，突变数随着肿瘤细胞的去向降低而增加。分化较差的肿瘤细胞包含引起受体失活的GRPR基因突变，而在分化良好的细胞中从未见过。因此，我们提出了一种机械假说，即任何特定结肠癌中功能性GRP-R的表达主要调节肿瘤细胞分化。带有受体灭活的突变，代表了允许肿瘤细胞去分化的主要机制。但是，尚未确定这些突变对GRP-R行为的程度和影响，以及功能受体表达调节肿瘤细胞外观的机制。 特定目标1的重点是阐明功能性GRP-R调节肿瘤细胞分化的机制。在我们的初步数据中，我们表明CACO-2细胞可变地表达GRP-R，当目前调节正常形态进展时，通过激活局灶性粘附激酶（FAK）来调节正常的形态进展。 CACO-2细胞将用在可诱导的启动子控制的载体中转染，允许启动子的定向表达。这些微型生物的产物将阻止GRP-R的特定区域与任何G蛋白的结合，或阻止特定的G蛋白本身。然后将评估每个构建体经历正常形态进展的能力。 特定的目标2针对人类结肠癌中GRPR基因中的突变，这是单个肿瘤细胞分化的函数。将随机选择维持在胃肠道肿瘤库中的存档结肠癌，并通过激光捕获显微镜去除所有定义分化的细胞。 GRPR基因将分离出来，所有突变均由位置定向诱变重新创建，以便可以在瞬时转染的细胞系统中进行评估。总体而言，这些研究将提供有关结肠癌分化的关键信息，并阐明一种新的机制，该机制调节了临床上重要的七叶草受体的灭活或脱敏。

项目成果

Expression of GRP and its receptor is associated with improved survival in patients with colon cancer.

GRP 及其受体的表达与结肠癌患者生存率的提高相关。

• DOI: 10.1007/s10585-009-9265-8
• 发表时间: 2009
• 期刊: Clinical & experimental metastasis
• 影响因子: 4
• 作者: Rivera,ClaudioA;Ahlberg,NedC;Taglia,Lauren;Kumar,Mayank;Blunier,Adam;Benya,RichardV
• 通讯作者: Benya,RichardV

GRP-induced up-regulation of Hsp72 promotes CD16+/94+ natural killer cell binding to colon cancer cells causing tumor cell cytolysis.

GRP 诱导的 Hsp72 上调促进 CD16 /94 自然杀伤细胞与结肠癌细胞结合，导致肿瘤细胞溶解。

• DOI: 10.1007/s10585-008-9151-9
• 发表时间: 2008
• 期刊: Clinical & experimental metastasis
• 影响因子: 4
• 作者: Taglia,Lauren;Matusiak,Damien;Benya,RichardV
• 通讯作者: Benya,RichardV