Functional Analysis of Cancer Genes from Human Chromosom

人类染色体癌症基因的功能分析

• 批准号: 7291849
• 负责人: MICHAEL LERMAN
• 金额: --
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7291849
• 关键词: Functional; Analysis; Cancer; Genes; Human

Background/outlineThe paradigm that mutated genes cause cancer has become a guiding principle in my research since 1980. The effect of environmental factors in cancer causation is based on their mutagenic capability to alter cancer-prone genes leading to activation of oncogenes and elimination or silencing of tumor suppressor genes. The development of cancer from incipient malignant cells to invasive tumors and finally to metastases is driven by Darwinian expansion of clonal cell populations involving additional mutated cancer genes. Our research program began in 1987 and culminated in the identification in 1993 of the VHL TSG located at 3p25. In 1993-2003 we investigated the sequence structure of the VHL gene and identified and analyzed VHL target genes to discover the VHL pathway. In parallel we intensified research on mapping and molecular cloning of cancer genes located in 3p26, 3p21.3 and 3p12 involved in the origin and/or development of major forms of lung cancer and other common carcinomas of the kidney, breast and prostate. In 2000-2003 we investigated: (1) the methylation code of the VHL locus itself and the function of VHL target genes (carbonic anhydrases, CA9 and CA12, and the transcription regulator BHLHB2/STRA13); (2) continued deletion mapping in 3p21.3 by real time PCR in tumor tissues and cell lines and completed the isolation and initial characterization of candidate cancer-causing genes from both 3p21.3 regions (centromeric, LUCA, and telomeric, AP20). These 3p21.3 regions (centromeric, LUCA, and telomeric, AP20) should be considered contiguous cancer gene regions since each harbors clusters of candidate TSG. (3) We also identified candidate cancer genes in 3p26.3 and 3p12.3In 2003-2005 we focused our research on functional analysis (by finding interacting proteins, analyzing null mutants in mice, and bioinformatics annotations) of some of these candidate TSG. Cancer gene CALL (3p26)The gene, CALL on 3p26.3 encoding a trans-membrane cell adhesion molecule (CAM) capable of both homotypic and heterotypic binding, that we cloned in 1998 was shown to be involved in general cognitive activities (g/IQ) and some neurological diseases (i.e. schizophrenia).CALL is expressed in normal tissues beside the brain and is over-expressed in a variety of human tumors. A 3p26 genomic segment (containing two genes, CALL and CNTN6) was recently shown to harbor a candidate for prostate cancer susceptibility in Finish prostate cancer families although no mutations were detected in both residing genes. Our expression studies suggest that CALL may contribute to cancer invasive growth and metastasis (depending on stage it may act either as a "tumor suppressor" or "oncogene"). We hypothesize that during initial growth CALL is not expressed (silenced) in tumor cells to facilitate in situ tumor growth. Re-expression of CALL on the edge of the tumor mass could promote local invasive growth and furthermore allow tumor cells to enter and leave the blood stream, colonize distant tissues and establish metastatic tumors. Current work and plans: We are developing specific antibodies and will validate CALL as a biomarker of invasive tumor growth and metastasis and a novel target for immune intervention in leukemia, melanoma, and some lung and ovarian cancers over-expressing CALL.We also plan to analyze CALL for miRNA mutations in sporadic prostate and other cancers.VHL TSG (3p25)Aberrant methylation of CpG promoter islands of cancer genes is now accepted as a fundamental mechanism in carcinogenesis. Using the VHL locus as a model system, we investigated the mechanisms of aberrant DNA methylation in cancer. We also aimed to use epigenetic codes (CpG and histone codes) to understand whether they harbor variations associated with inter-individual differences that may determine risk of sporadic cancers.

背景/概述自 1980 年以来，突变基因导致癌症的范式已成为我研究的指导原则。环境因素对癌症致病的影响是基于它们的诱变能力，改变易患癌症的基因，导致癌基因的激活和抑癌基因的消除或沉默。癌症从初期恶性细胞发展为侵袭性肿瘤，最后发展为转移，是由涉及额外突变癌症基因的克隆细胞群的达尔文扩张所驱动的。我们的研究计划始于 1987 年，最终于 1993 年识别出位于 3p25 的 VHL TSG。 1993-2003年，我们研究了VHL基因的序列结构，并鉴定和分析了VHL靶基因，以发现VHL通路。与此同时，我们加强了对位于 3p26、3p21.3 和 3p12 的癌症基因的定位和分子克隆的研究，这些基因涉及主要形式的肺癌和其他常见的肾癌、乳腺癌和前列腺癌的起源和/或发展。 2000-2003年我们研究了：（1）VHL位点本身的甲基化密码和VHL靶基因（碳酸酐酶、CA9和CA12以及转录调节因子BHLHB2/STRA13）的功能； (2)通过实时PCR在肿瘤组织和细胞系中继续进行3p21.3缺失定位，并完成来自3p21.3两个区域（着丝粒、LUCA和端粒、AP20）的候选致癌基因的分离和初步表征。这些 3p21.3 区域（着丝粒、LUCA 和端粒、AP20）应被视为连续的癌症基因区域，因为每个区域都包含候选 TSG 簇。 (3)我们还在3p26.3和3p12.3中鉴定了候选癌症基因。2003-2005年，我们将研究重点放在其中一些候选TSG的功能分析上（通过寻找相互作用的蛋白质、分析小鼠中的无效突变体以及生物信息学注释）。癌症基因CALL (3p26)我们于1998年克隆的基因CALL位于3p26.3上，编码能够同型和异型结合的跨膜细胞粘附分子(CAM)，该基因被证明与一般认知活动(g/IQ)和一些神经系统疾病(即精神分裂症)有关。CALL在大脑以外的正常组织中表达，并且是 在多种人类肿瘤中过度表达。最近显示，3p26 基因组片段（包含两个基因，CALL 和 CNTN6）在芬兰前列腺癌家族中含有前列腺癌易感性的候选基因，尽管在这两个基因中没有检测到突变。我们的表达研究表明，CALL 可能有助于癌症侵袭性生长和转移（根据阶段，它可能充当“肿瘤抑制基因”或“癌基因”）。我们假设在初始生长过程中，CALL 在肿瘤细胞中不表达（沉默）以促进原位肿瘤生长。 CALL在肿瘤块边缘的重新表达可以促进局部侵袭性生长，并进一步允许肿瘤细胞进入和离开血流、定植远处组织并建立转移性肿瘤。目前的工作和计划​​：我们正在开发特异性抗体，并将验证CALL作为侵袭性肿瘤生长和转移的生物标志物以及对白血病、黑色素瘤以及一些过度表达CALL的肺癌和卵巢癌进行免疫干预的新靶点。我们还计划分析CALL在散发性前列腺和其他癌症中的miRNA突变。VHL TSG (3p25)的异常甲基化 癌症基因的 CpG 启动子岛现在被认为是致癌的基本机制。使用 VHL 基因座作为模型系统，我们研究了癌症中异常 DNA 甲基化的机制。我们还旨在利用表观遗传密码（CpG 和组蛋白密码）来了解它们是否含有与个体间差异相关的变异，这些变异可能决定散发性癌症的风险。