Refined mapping of loss of heterozygosity of 1p36.33-36.31 in sporadic colorectal carcinoma

Abstract

To screen the candidate tumor suppressor gene (TSG) related to colorectal cancer (CRC). Seven fluorescent labeled polymorphic markers (1p36.33-36.31) were analyzed in the samples of tissues of CRC and adjacent normal tissues obtained during operation performed on 83 CRC patients, 40 males and 43 females, aged 31 - 84. The PCR products were electrophoresed. The softwares Genescan 3.1 and Genotype 2.1 were used for loss of heterozygosity (LOH) scanning and analysis. Comparison between the LOH frequency and the clinicopathological factors was performed by Chi-square test. The average LOH frequency in the 1p36.33-36.31 was 31.47%, with the highest LOH frequency of 47.22% at the D1S243 locus and the lowest LOH frequency of 7.35% at the locus D1S1347. Two obvious high LOH regions were detected: D1S1347 locus (1p36.33, about 1 cM) and a region between D1S468 and D1S2660 (1p36.32-36.31 about 3 cM). The LOH rats of the loci in 1p36.33-36.31 region were not correlated with the age and sex of the patient, and the size, growth pattern, and Dukes stage of the tumor. Two obvious high frequency LOH regions, 1p36.32-36.31 and 1p36.33 have been detected in sporadic CRC where tumor-suppressor-gene (s) may exist.