Kim Mi-Sook, Jeong Joon, Majewski Tadeusz, Kram Andrzej, Yoon Dong-Sup, Zhang Ruo-Dan, Li Jun-Zhi, Ptaszynski Konrad, Kuang Tang C, Zhou Jain-Hua, Sathyanarayana Ubaradka G, Tuziak Tomasz, Johnston Dennis A, Grossman Herbert B, Gazdar Adi F, Scherer Steven E, Benedict William F, Czerniak Bogdan
Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
Lab Invest. 2006 Feb;86(2):175-90. doi: 10.1038/labinvest.3700378.
In this paper, we present whole-organ histologic and genetic mapping studies using hypervariable DNA markers on chromosome 13 and then integrate the recombination- and single-nucleotide polymorphic sites (SNPs)-based deletion maps with the annotated genome sequence. Using bladders resected from patients with invasive urothelial carcinoma, we studied allelic patterns of 40 microsatellite markers mapping to all regions of chromosome 13 and 79 SNPs located within the 13q14 region containing the RB1 gene. A whole-organ histologic and genetic mapping strategy was used to identify the evolution of allelic losses on chromosome 13 during the progression of bladder neoplasia. Markers mapping to chromosomal regions involved in clonal expansion of preneoplastic intraurothelial lesions were subsequently tested in 25 tumors and 21 voided urine samples of patients with bladder cancer. Four clusters of allelic losses mapping to distinct regions of chromosome 13 were identified. Markers mapping to the 13q14 region that is flanked by D13S263 and D13S276, which contains the RB1 gene, showed allelic losses associated with early clonal expansion of intraurothelial neoplasia. Such losses could be identified in approximately 32% bladder tumor tissue samples and 38% of voided urines from patients with bladder cancer. The integration of distribution patterns of clonal allelic losses revealed by the microsatellite markers with those obtained by genotyping of SNPs disclosed that the loss within an approximately 4-Mb segment centered around RB1 may represent an incipient event in bladder neoplasia. However, the inactivation of RB1 occurred later and was associated with the onset of severe dysplasia/carcinoma in situ. Our studies provide evidence for the presence of critical alternative candidate genes mapping to the 13q14 region that are involved in clonal expansion of neoplasia within the bladder antecedent to the inactivation of the RB1 gene.
在本文中，我们使用13号染色体上的高变DNA标记进行全器官组织学和基因图谱研究，然后将基于重组和单核苷酸多态性位点（SNP）的缺失图谱与注释的基因组序列整合。我们使用从浸润性尿路上皮癌患者切除的膀胱，研究了定位于13号染色体所有区域的40个微卫星标记和位于包含RB1基因的13q14区域内的79个SNP的等位基因模式。采用全器官组织学和基因图谱策略来确定膀胱肿瘤形成过程中13号染色体上等位基因缺失的演变。随后，在25例膀胱癌患者的肿瘤和21份排尿样本中检测了定位于与肿瘤前尿路上皮病变克隆扩增相关的染色体区域的标记。确定了定位于13号染色体不同区域的四组等位基因缺失。定位于13q14区域（该区域位于包含RB1基因的D13S263和D13S276两侧）的标记显示，等位基因缺失与尿路上皮肿瘤的早期克隆扩增相关。这种缺失在约32%的膀胱肿瘤组织样本和38%的膀胱癌患者排尿样本中可以检测到。微卫星标记揭示的克隆等位基因缺失分布模式与SNP基因分型获得的分布模式整合显示，以RB1为中心的约4 Mb片段内的缺失可能代表膀胱肿瘤形成的起始事件。然而，RB1的失活发生在后期，并且与重度发育异常/原位癌的发生相关。我们的研究为存在定位于13q14区域的关键替代候选基因提供了证据，这些基因在RB1基因失活之前参与膀胱内肿瘤的克隆扩增。
