TUMOR SUPPRESSOR LOCI IN MESOTHELIOMA

描述：（改编自研究者摘要）恶性 间皮瘤是一种石棉相关的肿瘤， 这对诊断和治疗造成了巨大影响 挑战至少65%的间皮瘤有缺失的中间- 一部分染色体6长臂，值得注意的是，这同样 在乳腺癌、白血病、非霍奇金淋巴瘤中， 淋巴瘤、骨肉瘤和前列腺癌。弗莱彻医生和同事 假设6q16.3-q21区域的肿瘤抑制基因是 在大多数间皮瘤中缺失和/或突变， 假设该基因在非间皮瘤中具有广泛相关性 肿瘤发生弗莱彻博士将通过精细绘图来解决这些假设 通过定位、分离和表征， 平衡的细胞遗传学重排，中断这一地区， 评估间皮瘤和非间皮瘤中的候选肿瘤抑制基因 6 q缺失的间皮瘤肿瘤。映射将在两个 阶段。最初，弗莱彻博士将绘制染色体的一个广泛区域 6长臂在30原发性间皮瘤细胞系中使用已建立的 10-mega-YAC的FISH小组成员，间隔为2-10 mega-YAC。这 定位阶段将定义关键缺失区域， 同时评估额外删除的可能性 地区在第二阶段，弗莱彻博士将重新评估同一组 间皮瘤使用细菌人工染色体（BAC）FISH 以500 kb间隔跨越关键缺失区的图。这些 研究可能揭示细胞遗传学在明显的杂合子和 纯合缺失，这将进一步缩小关键缺失 地区 缺失定位将与mega-YAC FISH协调 平衡细胞遗传学断裂点的定位和克隆 共有缺失区内的重排。 筛查 候选肿瘤抑制基因将通过直接cDNA 选择使用100-250 kb BAC DNA序列，其含有关键的 缺失区和细胞遗传学断裂点。候选抑癌 将根据拷贝数（FISH）评价基因， 失活点突变（SSCP/测序）和表达（北方 在原发性间皮瘤、间皮瘤细胞系和非间皮瘤细胞系中， 已知6 q缺失的间皮瘤癌症。长期目标 包括评估6 q肿瘤抑制基因作为潜在的 间皮瘤的诊断标志物及其生物学评价 这些基因的功能研究。

DESCRIPTION: (adapted from the investigator's abstract) Malignant mesothelioma is an asbestos-associated neoplasm which is a growing public health concern and which poses tremendous diagnostic and therapeutic challenges. At least 65% of mesotheliomas have deletion of the mid- portion of the chromosome 6 long arm, and it is notable that this same region is deleted nonrandomly in breast cancer, leukemia, non-Hodgkin's lymphoma, osteosarcoma, and prostate cancer. Dr. Fletcher and coworkers hypothesize that a tumor suppressor gene in the 6q16.3-q21 region is deleted and/or mutated in the majority of mesotheliomas, and they also hypothesize that this gene has broad relevance in non-mesothelioma tumorigenesis. Dr. Fletcher will address these hypotheses by fine mapping of the 6q deletion region, by mapping, isolating, and characterizing balanced cytogenetic rearrangements that interrupt this region, and by evaluating candidate tumor suppressor genes in mesotheliomas and in non- mesothelioma tumors with 6q deletions. Mapping will be performed in two phases. Initially, Dr. Fletcher will map a broad region of the chromosome 6 long arm in 30 primary mesotheliomas in cell lines using an established 10-member FISH panel of mega-YACs spaced at 2-10 megabase intervals. This phase of mapping will define the critical deletion region while simultaneously evaluating the possibility of additional deletion regions. In the second phase Dr. Fletcher will re-evaluate the same group of mesotheliomas using a bacterial artificial chromosome (BAC) FISH panel spanning the critical deletion region at 500 kb intervals. These studies may reveal cytogenetically in apparent heterozygous and homozygous deletions which will further narrow the critical deletion region. The deletion mapping will be coordinated with mega-YAC FISH mapping and cloning of breakpoints for balanced cytogenetic rearrangements within the consensus deletion region. Screening for candidate tumor suppressor genes will then be accomplished by direct cDNA selection using 100-250 kb BAC DNA sequences containing the critical deletion region and a cytogenetic breakpoint. Candidate tumor suppressor genes will be evaluated with a respect to copy number (FISH), inactivating point mutations (SSCP/sequencing), and expression (Northern blotting) in primary mesotheliomas, mesothelioma cell lines, and in non- mesothelioma cancers with known 6q deletions. Long-term objectives include evaluation of the 6q tumor suppressor gene as a potential diagnostic marker in mesothelioma and evaluation of the biological elements of this gene through functional studies.