Queimado L, Seruca R, Costa-Pereira A, Castedo S
Institute of Molecular Pathology and Immunology, University of Porto (IPATIMUP), Medical Faculty of Porto, Hospital de S. João, Portugal.
Genes Chromosomes Cancer. 1995 Sep;14(1):28-34. doi: 10.1002/gcc.2870140106.
Loss of heterozygosity (LOH) affecting the long arm of chromosome 6 has been found repeatedly in human cancers. Recently, our group reported that del(6)(q21-22-->qter) was the most consistent structural cytogenetic abnormality in gastric carcinomas. To determine more precisely the deleted region, we studied 51 tumors with 9 polymorphic markers on this chromosome arm. LOH of one or more markers was found in 39% of the tumors. LOH at region 6q22.3 was detected in 50% of informative tumors and at 6q26-q27 in 37% of informative tumors. By comparative analysis of LOH regions, we identified two separate regions of overlapped deletions at 6q, one between 6q16.3-q21 and 6q22.3-q23.1, another distal to 6q23-q24. A comparison of clinicopathologic features of gastric carcinomas with and without LOH at 6q revealed statistically significant or suggestive differences between LOH and young age of the patients and proximal location of the tumors. The two informative early gastric carcinomas both showed LOH at 6q. The occurrence of LOH at 6q was similar in all histological types. We conclude that two distinct regions at 6q appear to be involved in the early stages of gastric carcinogenesis.
杂合性缺失（LOH）影响6号染色体长臂，在人类癌症中已被反复发现。最近，我们小组报告说，del(6)(q21 - 22-->qter)是胃癌中最一致的结构细胞遗传学异常。为了更精确地确定缺失区域，我们用该染色体臂上的9个多态性标记研究了51个肿瘤。在39%的肿瘤中发现了一个或多个标记的LOH。在50%的信息丰富的肿瘤中检测到6q22.3区域的LOH，在37%的信息丰富的肿瘤中检测到6q26 - q27区域的LOH。通过对LOH区域的比较分析，我们在6号染色体上确定了两个重叠缺失的独立区域，一个在6q16.3 - q21和6q22.3 - q23.1之间，另一个在6q23 - q24远端。对6号染色体上有无LOH的胃癌临床病理特征进行比较，发现LOH与患者年轻及肿瘤近端位置之间存在统计学上的显著差异或提示性差异。这两个信息丰富的早期胃癌均显示6号染色体上有LOH。6号染色体上LOH的发生率在所有组织学类型中相似。我们得出结论，6号染色体上的两个不同区域似乎参与了胃癌发生的早期阶段。
