MOLECULAR GENETIC ANALYSIS OF COLORECTAL CANCER

结直肠癌的分子遗传学分析

• 批准号: 6124579
• 负责人: Bert Vogelstein
• 金额: $ 33.49万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1983
• 资助国家: 美国
• 起止时间: 1983-08-01 至 2001-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6124579
• 关键词: DNA repair; athymic mouse; clinical research; colorectal neoplasms; complementary DNA; gene induction /repression; gene mutation; genetic promoter element; human genetic material tag; human subject; molecular genetics; neoplasm /cancer genetics; tissue /cell culture; transcription factor; transforming growth factors

Colorectal tumors provide a unique opportunity to study the molecular events responsible for initiation and progression of a common human tumor type. Previous studies have shown that colorectal tumorigenesis is driven by sequential mutations of oncogenes and tumor suppressor genes. Though mutations in these genes have been well documented, knowledge about the effect of such mutations on the biology and physiology of colorectal tumor cells is rudimentary. We plan to exploit technologies recently developed in our laboratory, as well as classic genetic and biochemical methods, to further investigate three pathways thought to be important in colorectal neoplasia: l. p53 - The p53 gene is inactivated in most colorectal tumors, as well as in many other human tumor types. The p53 gene product is thought to function, in part, by activating the expression of genes controlled by specific p53-binding DNA sequences. A novel method for analyzing gene expression patterns (SAGE) will be used to identify genes that are activated in colorectal tumor cells undergoing growth arrest or apoptosis in response to p53 expression. To test the importance of gene products identified in this way, the relevant genes will be disrupted by homologous recombination and the engineered cells assessed with respect to their response to p53 and other growth-regulating agents. 2. TGF-beta - Most colorectal tumors are insensitive to this negative growth regulator, and mutations in genes participating in this pathway have been identified in a subset of colorectal tumors. other human genes that may participate in the pathway will be identified by homologous cloning methods. Such genes will then be evaluated to determine whether they are mutated in colorectal tumors. Those found to be altered will be disrupted by homologous recombination in appropriate colorectal tumor cell lines and assessed for their impact on TGF-beta signaling. 3. Mismatch repair - Four genes participating in mismatch repair (MMR) have been shown to lead to genetic instability in colorectal tumors when inherited in mutant form. A subset of these mutations are associated with unusual phenotypes or are undetectable by standard assays. We plan to develop genetic systems to evaluate the function of such MMR gene variants. Some of these systems will involve targeted disruption of the genes in suitable recipient cell types. The information derived from this study should illuminate certain basic aspects of MMR as well as provide new diagnostic opportunities.

结直肠肿瘤提供了一个独特的机会，研究分子 导致常见人类肿瘤发生和进展的事件 类型.以前的研究表明，结直肠肿瘤的发生是由 癌基因和抑癌基因的连续突变。 虽然 这些基因的突变已经有据可查，有关基因突变的知识 这些突变对结直肠肿瘤生物学和生理学的影响 细胞是基本的。 我们计划利用最近开发的技术 在我们的实验室，以及经典的遗传和生物化学方法， 进一步研究被认为在结直肠癌中重要的三种途径， 瘤形成： L. p53-p53基因在大多数结直肠肿瘤中失活， 在许多其他人类肿瘤类型中。p53基因产物被认为 部分是通过激活受 特异性p53结合DNA序列。一种新的基因分析方法 表达模式（SAGE）将用于识别基因， 在经历生长停滞或凋亡的结直肠肿瘤细胞中激活 p53表达。为了测试基因产物的重要性 以这种方式鉴定，相关基因将被同源的 重组和工程化细胞评估其 对p53和其他生长调节剂的反应。 2. TGF-β-大多数结直肠肿瘤对此阴性不敏感 生长调节因子，参与这一途径的基因突变， 在结直肠肿瘤的一个子集中被发现。其他人类基因， 将通过同源克隆鉴定可能参与该途径的 方法.然后将对这些基因进行评估，以确定它们是否 在结直肠肿瘤中发生突变。 那些被发现改变的将被打乱 通过在适当的结肠直肠肿瘤细胞系中同源重组， 评估它们对TGF-β信号传导的影响。 3.错配修复-四个基因参与错配修复（MMR）， 已被证明会导致结肠直肠肿瘤的遗传不稳定性， 以突变形式遗传。这些突变的一个子集与 不寻常的表型或通过标准测定无法检测。我们计划 开发遗传系统以评估此类MMR基因变体的功能。 其中一些系统将涉及靶向破坏基因， 合适的受体细胞类型。从这项研究中获得的信息 应阐明产妇死亡率的某些基本方面，并提供新的 诊断机会。