Aytekin Turkan, Ozaslan Mehmet, Cengiz Beyhan
Department of Biology, University of Gaziantep, Sahinbey-Gaziantep, Turkey.
Cancer Genet Cytogenet. 2010 Aug;201(1):32-8. doi: 10.1016/j.cancergencyto.2010.05.005.
Colorectal cancer is one of the most common cancers in the world. Colorectal cancer develops after a long and multistep process of carcinogenesis. Inactivation of tumor suppressor genes is among the most important steps in development of colorectal cancer. Analysis of loss of heterozygosity (LOH) is an effective method to determine the localization of tumor suppressor genes. In this study, we used five microsatellite markers to analyze the region 12q13-24 among 47 patients with colorectal cancer. The frequency of LOH and the clinicopathological data were compared using logistic regression and a chi-square test. In 34 of 47 tumor tissues (72%), LOH was detected at least in one marker. The highest LOH frequency was 34%, on the D12S129 locus; the lowest frequency was 23%, on the D12S78 locus. Loss of heterozygosity was detected as 32% on D12S83, 30% on D12S346, and 26% on D12S1660. No statistically significant correlation was found between the frequency of LOH and clinicopathological features (P > 0.05). Chromosome region 12q13-24 contains several known genes that may be candidate tumor suppressor genes, including RASAL1, ITGA7, STAB2, GLIPR1, and SLC5A8. Although the exact roles of these genes in colorectal cancer formation remain to be clarified, the present data point to a tumor suppressor role.
结直肠癌是世界上最常见的癌症之一。结直肠癌是在漫长的多步骤致癌过程后发生的。肿瘤抑制基因的失活是结直肠癌发生过程中最重要的步骤之一。杂合性缺失（LOH）分析是确定肿瘤抑制基因定位的有效方法。在本研究中，我们使用五个微卫星标记分析了47例结直肠癌患者的12q13 - 24区域。使用逻辑回归和卡方检验比较了LOH频率和临床病理数据。在47个肿瘤组织中的34个（72%）中，至少在一个标记处检测到LOH。最高的LOH频率为34%，位于D12S129位点；最低频率为23%，位于D12S78位点。在D12S83处检测到的杂合性缺失为32%，在D12S346处为30%，在D12S1660处为26%。未发现LOH频率与临床病理特征之间存在统计学显著相关性（P > 0.05）。染色体区域12q13 - 24包含几个已知的可能是候选肿瘤抑制基因的基因，包括RASAL1、ITGA7、STAB2、GLIPR1和SLC5A8。尽管这些基因在结直肠癌形成中的确切作用仍有待阐明，但目前的数据表明它们具有肿瘤抑制作用。
