BWS AND EMBRYONAL TUMOR SUPPRESSOR GENES ON 11P15

描述：（改编自研究者摘要）申请人的 一个实验室在11p15上发现了几个遗传变异， 表明该区域在肾母细胞瘤（WT）和其他 胚胎癌 包括11 p15的杂合性缺失（洛）; 与Beckwith-Wiedemann综合征（BWS）11p15的遗传连锁， 导致胎儿过度生长，易患各种各样的 胚胎性肿瘤，包括WT和横纹肌肉瘤; 印迹（LOI），一类新的遗传改变，导致双等位基因 通常由单个亲本等位基因表达的基因的表达。 为了定位BWS基因，申请人已经分子克隆了 来自BWS的7个种系平衡染色体排列断点 患者 令人惊讶的是，这些断点发生在两个独立的区域 11p15，间隔4 Mb。 申请人还开发了一种新颖的 定位和分离肿瘤的通用遗传互补策略 抑制基因，使用亚染色体可转移片段（STF）， 可以被导入任何哺乳动物细胞。 申请人已申请 这种策略是分离导致体外生长停滞的区域， 横纹肌肉瘤细胞 该区域与端粒较多的BWS重叠 断点簇 这些结果表明，11p15上的多个基因 与胚胎性肿瘤的发病机制有关。 申请人 现在确定更多端粒BWS断点簇中的基因。 其中之一是p57KIP2，最近发现的细胞周期蛋白依赖性激酶 抑制剂，第二个是一个新的基因，可能涉及核小体 组装件. 申请人将继续分离两个BWS种系中的基因 他们克隆的染色体重排断裂点簇。 他 将使用他们新的STFs遗传互补方法， 确定是否有第二个胚胎肿瘤抑制基因， 11p15对应于BWS断裂点的更多着丝粒组。 酵母人工染色体将直接转入肿瘤 细胞，以进一步划定这些基因的区域。 BWS和胚胎性肿瘤中候选基因的改变也将被研究。 鉴定 最后，申请人将确定正常功能 这些基因，包括它们的组织和细胞定位， 表达的发展模式，它们的表达对 正常细胞和肿瘤细胞，以及基因改变的后果， 体外和体内。 这些研究应该提供新的见解， 在单个大的染色体结构域中的多个遗传改变使得 形成胚胎性肿瘤。

DESCRIPTION: (adapted from the investigator's abstract) The applicant's laboratory has discovered several genetic alterations on 11p15 that suggest a crucial role for this region in Wilms tumor (WT) and other embryonal cancers. These include loss of heterozygosity (LOH) of 11p15; genetic linkage to 11p15 of Beckwith-Wiedemann syndrome (BWS), which causes fetal overgrowth and predisposition to a wide variety of embryonal tumors, including WT and rhabdomyosarcoma; and loss of imprinting (LOI), a novel class of genetic alteration causing biallelic expression of genes normally expressed from a single parental allele. In order to localize a BWS gene, the applicant has molecularly cloned 7 germline balanced chromosomal arrangement breakpoints from BWS patients. Surprisingly, these breakpoints occur in two separate regions of 11p15 separated by 4 Mb. The applicant has also developed a novel general genetic complementation strategy to localize and isolate tumor suppressor genes, using subchromosomal transferable fragments (STFs) that can be introduced into any mammalian cell. The applicant has applied this strategy to isolate a region that causes in vitro growth arrest of rhabdomyosarcoma cells. This region overlaps the more telomeric BWS breakpoint cluster. These results suggest that multiple genes on 11p15 are involved in the pathogenesis of embryonal tumors. The applicant is now identifying genes within the more telomeric BWS breakpoint cluster. One of these is p57KIP2, a recently identified cyclin-dependent kinase inhibitor, and a second is a novel gene likely involved in nucleosome assembly. The applicant will continue to isolate genes within the two BWS germline chromosomal rearrangement breakpoint clusters that they have cloned. He will use their novel genetic complementation approach of STFs to determine whether there is a second embryonal tumor suppressor gene on 11p15 corresponding to the more centromeric group of BWS breakpoints. Yeast artificial chromosomes will be transferred directly into tumor cells, in order to further delimit the regions harboring these genes. Alterations in candidate genes in BWS and embryonal tumors will be also identified. Finally, the applicant will determine the normal function of these genes, including their tissue and cellular localization, their developmental pattern of expression, the effect of their expression on normal and tumor cells, and the consequences of gene alteration both in vitro and in vivo. These studies should provide novel insights into how multiple genetic alterations in a single large chromosomal domain give rise to embryonal tumors.