Reid L H, West A, Gioeli D G, Phillips K K, Kelleher K F, Araujo D, Stanbridge E J, Dowdy S F, Gerhard D S, Weissman B E
Department of Pathology and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill 27599, USA.
Hum Mol Genet. 1996 Feb;5(2):239-47. doi: 10.1093/hmg/5.2.239.
Multiple studies have underscored the importance of loss of tumor suppressor genes in the development of human cancer. To identify these genes, we used somatic cell hybrids in a functional assay for tumor suppression in vivo. A tumor suppressor gene in 11p15.5 was detected by transferring single human chromosomes into the G401 Wilms' tumor cell line. In order to better map this gene, we created a series of radiation-reduced t(X;11) chromosomes and characterized them at 24 loci between H-RAS and beta-globin. Interestingly, three of the chromosomes were indistinguishable as determined by genomic and cytogenetic analyses. Each contains an interstitial deletion with one breakpoint in 11p14.1 and the other breakpoint between the D11S601 and D11S648 loci in 11p15.5. PFGE analysis localized the 11p15.5 breakpoints to a 175 kb MluI fragment that hybridized to D11S601 and D11S648 probes. Genomic fragments from this 175 kb region were hybridized to DNA from mouse hybrid lines containing the delta t(X;11) chromosomes. This analysis detected the identical 11p15.5 breakpoint which disrupts a 7.8 kb EcoRI fragment in all three of the delta t(X;11) chromosomes, suggesting they are subclones of the same parent colony. Upon transfer into G401 cells, one of the chromosomes suppressed tumor formation in nude mice, while the other two chromosomes lacked this ability. Thus, our mapping data indicate that the gene in 11p15.5 which suppresses tumor formation in G401 cells must lie telomeric to the D11S601 locus. Koi et al. (Science 260: 361-364, 1993) have used a similar functional assay to localize a growth suppressor gene for the RD cell line centromeric to the D11S724 locus. The combination of functional studies by our lab and theirs significantly narrows the location of the tumor suppressor gene in 11p15.5 to the approximately 500 kb region between D11S601 and D11S724.
多项研究强调了肿瘤抑制基因缺失在人类癌症发展中的重要性。为了鉴定这些基因，我们在一项体内肿瘤抑制功能检测中使用了体细胞杂种。通过将单个人类染色体转入G401肾母细胞瘤细胞系，检测到11p15.5区域存在一个肿瘤抑制基因。为了更好地定位该基因，我们创建了一系列辐射减少的t(X;11)染色体，并在H-RAS和β-珠蛋白之间的24个位点对其进行了表征。有趣的是，通过基因组和细胞遗传学分析确定，其中三条染色体无法区分。每条染色体都包含一个中间缺失，一个断点在11p14.1，另一个断点在11p15.5的D11S601和D11S648位点之间。脉冲场凝胶电泳（PFGE）分析将11p15.5断点定位到一个175 kb的MluI片段，该片段与D11S601和D11S648探针杂交。来自该175 kb区域的基因组片段与含有δt(X;11)染色体的小鼠杂种细胞系的DNA杂交。该分析检测到相同的11p15.5断点，该断点在所有三条δt(X;11)染色体中破坏了一个7.8 kb的EcoRI片段，表明它们是同一亲本群体的亚克隆。将其中一条染色体转入G401细胞后，它能抑制裸鼠体内肿瘤的形成，而另外两条染色体则缺乏这种能力。因此，我们的定位数据表明，11p15.5区域中抑制G401细胞肿瘤形成的基因一定位于D11S601位点的端粒侧。Koi等人（《科学》260: 361 - 364, 1993）使用了类似的功能检测将RD细胞系的生长抑制基因定位到D11S724位点的着丝粒侧。我们实验室和他们的功能研究相结合，显著缩小了11p15.5区域中肿瘤抑制基因的定位范围，至D11S601和D11S724之间约500 kb的区域。
