CHROMOSOME BREAKPOINTS & RENAL & SMALL CELL LUNG CANCER

人类3号染色体的特定重排是典型的 与某些恶性疾病有关。杂合性丢失 研究表明，在自发性脑内，3p2l.1基因一致缺失 肾癌。细胞遗传学研究中的几个 百株小细胞和非小细胞肺癌细胞株共显示三株 不同的染色体3区持续缺失；3p3-l4.2、3p21和 3p24.2-PTER。染色体3pl4.2也是最常见的 可能参与骨质疏松症发病机制的结构性脆性部位 其中一些重排。 3pl3-p21的大小排除了识别其中所有基因的可能性。 并单独测试它们在肿瘤发展中的作用。 在本申请中，我们建议在已有的基础上 构建用于克隆和鉴定多条染色体的物理图谱 断点可能代表识别相关基因的捷径 在癌症的发展过程中。第一个是t(3；6)(p2l.l；pl3)断点 与血液系统的恶性疾病有关。我们已经分离出一名 跨越这个断裂点的粘粒，显然包含一个基因 被移位扰乱了。我们将对此进行分离和表征 基因和位于该断裂点附近200kb区域的所有其他基因。这个 第二个是与遗传性相关的t(3；8)(pl4.2；ql4.13)断点 肾细胞癌。我们已经隔离了这个侧面的标记 断点，并建议从最近的近端标记(较少 使用重叠的YAC克隆。然后我们将描述 这一区域和断裂点附近几百kb内的所有基因。 最后，我们计划扩展我们对分析的研究 发生在3pl3-14.2中的APHIDICIN诱导的脆性位点断裂 区域。使用一种敏感的基于聚合酶链式反应的分析方法，我们将对大量的 只有染色体断裂的体细胞杂交种 用APHIDICLIN诱导。这将显示是否存在集群 脆弱的场地破损。然后我们将使用最接近的侧翼探测器作为 染色体走到这个区域的起点。整个地区 将被隔离在重叠的YAC克隆中，并进行测试以确定 来自该区域的序列可以在体内诱导染色体脆性 系统。除了阐明最常见的 基因组中的脆弱部位这个项目也可能导致 小细胞肺中持续缺失基因的鉴定 和肾细胞癌。

Specific rearrangements of human chromosome 3 are characteristically associated with certain malignant disorders. Loss of heterozygosity studies have revealed a consistent deletion of 3p2l.1 in spontaneous carcinoma of the kidney. Cytogenetic studies of studies of several hundred small cell and non-small cell lung cancer cell lines reveal three distinct chromosome 3 regions consistently deleted; 3pl3-l4.2, 3p2l and 3p24.2-pter. Chromosome 3pl4.2 is also the location of the most common constitutive fragile site which may be involved in the pathogenesis of some of these rearrangements. The large size of 3pl3-p2l precludes identifying all genes in this region and testing them individually for their role in tumor development. In the present application we propose to build upon the already constructed physical map to clone and characterize several chromosome breakpoints that may represent a short-cut to identifying .genes involved in cancer development. The first is a t(3;6)(p2l.l;pl3) breakpoint associated with hematologic malignancies. We have already isolated a cosmid which spans this breakpoint and contains a gene apparently disrupted by the translocation. We will isolate and characterize this gene and all other genes in a 200 kb region around this breakpoint. The second is the t(3;8)(pl4.2;ql4.13) breakpoint associated with hereditary renal cell carcinoma. We have already isolated markers which flank this breakpoint and propose to walk from the closest proximal marker (less than 500 kb) using overlapping YAC clones. We will then characterize this region and all genes within several hundred kb of the breakpoint. Finally we plan to extend our studies on the analysis of aphidicolin-induced fragile site breaks that occur in the 3pl3-l4.2 region. Using a sensitive PCR-based assay we will screen large numbers of chromosome 3-only somatic cell hybrids in which chromosome breakage is induced with aphidicolin. This will show whether there is a clustering of fragile site breaks. We will then use the closest flanking probes as startpoints for chromosome walking to this region. The entire region will be isolated in overlapping YAC clones and tested to determine if sequences from this region can induce chromosome fragility in an in vivo system. In addition to elucidating the structure of the most common fragile site in the genome this project may also lead to the identification of genes that are consistently deleted in small cell lung and renal cell carcinoma.