Human Colon Cancer: Role of the Src Tyrosine Kinase

人类结肠癌：Src 酪氨酸激酶的作用

• 批准号: 6908138
• 负责人: CHRISTINE Ann CARTWRIGHT
• 金额: $ 28.49万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-03 至 2008-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6908138
• 关键词: cell growth regulation; cell line; cell surface receptors; colon neoplasms; enzyme activity; human tissue; laboratory mouse; neoplastic transformation; posttranslational modifications; protein kinase C; protein localization; protein protein interaction; protein structure function; protein tyrosine kinase

DESCRIPTION (provided by applicant): We are interested in understanding how normal intestinal cells regulate their growth and how loss of that regulation results in malignant transformation. Our research focuses on molecular mechanisms by which the Src tyrosine kinases contributes to the regulation. We and others showed that downregulation of Src activity is important for differentiation, and upregulation is important for malignant transformation of intestinal cells. Thus, effort is directed towards identifying mechanisms that modulate Src activity during intestinal cell maturation and malignant transformation. We recently identified RACK1 as a novel Src substrate and binding partner and an inhibitor of Src activity and cell growth. We hypothesize that RACK1 is also an inhibitor of cell transformation by Src. We propose to test this as follows: Aim 1: We will assess RACK1's influence on cell transformation by Src. These studies involve analyzing NIH 3T3 and SV40LT-immortalized colonic epithelial cells that express v-Src or c-Src mutants together with wild-type or mutant RACK1 or inhibitory peptides, for anchorage-independent growth in soft agar, growth in low serum, focus formation on monolayers of normal cells, and tumor formation in nude mice; all capabilities that fully transformed v-Src cells have and normal cells lack. Aim 2: We will analyze mechanisms by which Src is activated in human colon carcinoma cells, and the functional consequences of the activation. These studies involve identifying mutations, posttranslational modifications, subcellular localization and protein-protein interactions of Src and RACK1, and assessing their influence on Src activity, cell transformation and tumorigenesis. These studies should generate significant new information regarding a novel inhibitor of Src and cell growth. Understanding how inhibitors of mitogenic signals work to regulate intestinal cell growth and how loss of that inhibition results in uncontrolled growth and malignant transformation, should impact our understanding of colonic carcinogenesis and lead to development of novel strategies for colon cancer therapy. Endogenous or peptide inhibitors of oncogenic kinases are potentially tumor suppressors; they represent exciting new targets for therapeutic intervention.

描述（由申请人提供）：我们有兴趣了解正常的肠细胞如何调节其生长以及该调节的损失如何导致恶性转化。我们的研究重点是SRC酪氨酸激酶对调节的贡献的分子机制。我们和其他人表明，SRC活性的下调对于分化很重要，上调对于肠细胞的恶性转化很重要。因此，努力是针对识别在肠细胞成熟和恶性转化过程中调节SRC活性的机制。我们最近将RACK1确定为一种新型的SRC底物和结合伴侣以及SRC活性和细胞生长的抑制剂。我们假设RACK1也是SRC细胞转化的抑制剂。我们建议对此进行如下测试：AIM 1：我们将评估RACK1对SRC对细胞转换的影响。这些研究涉及分析NIH 3T3和SV40LT赋予的结肠上皮细胞，这些结肠上皮细胞与野生型或突变型Rack1或抑制性肽一起表达V-SRC或C-SRC突变体，对于锚定琼脂的锚固生长，在低血清中的生长，对正常细胞和Tamor的单层形成noude noude noude nud ude nude nude nud ude nud ude nud ude nud ude nud ude n ude n ude n ude n ude n ude nud ude;完全转化的V-SRC细胞具有的所有功能都具有正常细胞。 AIM 2：我们将分析在人类结肠癌细胞中激活SRC的机制，以及激活的功能后果。这些研究涉及鉴定突变，翻译后修饰，亚细胞定位以及SRC和RACK1的蛋白质 - 蛋白质相互作用，并评估其对SRC活性，细胞转化和肿瘤发生的影响。这些研究应产生有关新型SRC和细胞生长抑制剂的重要新信息。了解有丝分裂信号的抑制剂如何作用于调节肠道细胞生长以及该抑制作用的损失如何导致不受控制的生长和恶性转化，这应该影响我们对结肠致癌的理解并导致结肠癌疗法的新策略发展。致癌激酶的内源性或肽抑制剂是​​潜在的肿瘤抑制剂。它们代表了令人兴奋的治疗干预目标。