Investigation of loss of heterozygosity on 12q13-24 region in patients with colorectal cancer

Colorectal cancer is one of the most common cancers in the world. Colorectal cancer develops after a long and multistep carcinogenesis process. Inactivation of tumor suppressor genes is one of the most important steps in development of colorectal cancer. Loss of heterozygosity (LOH) analysis is an effective method that is frequently used to determine the localization of the tumor suppressor genes. In this study, we analyzed chromosome 12q13-24 region among 47 patients with colorectal cancer by using 5 microsatellite markers. The frequency of LOH and the clinicopathological data were compared with logistic regression and ?2 test. In 34 of 47 tumor tissues (72,3%), LOH was detected at least in one marker. The highest LOH frequency was 34,3% on D12S129 locus, and the lowest frequency was 23,3% on D12S78 locus. LOH was detected as 31,5% on D12S83 locus, 29,6% on D12S346 locus and 25,5% on D12S1660 locus. No statistically significant correlation was found between the frequency of LOH and clinicopathological features (p> 0,05). Chromosome 12q13-24 region contains a few known genes (RASAL1, ITGA7, STAB2, GLIPR1 and SLC5A8) that may be candidate tumor suppressor genes. Precise roles of these genes in colorectal cancer formation will be clarified by later studies.