Loss Of Alleles On Chromosomes 3, 7, And 9 In Human Esophageal Carcinomas (EC)

Allelic loss at specific chromosomal loci is a common genetic alteration in human tumours and is thought to be critical for unmasking the recessive genetic changes for tumorigenesis. Loss of a wild-type tumor suppressor gene on a chromosome may give the recessive mutant allele on the homologue an opportunity to express the phenotype and push the carcinogenic process of the cell carring this single mutant allele to the next step.According to the data of karyotypic analysis of human esopha-geal carcinoma cells in recent years, and in order to learn how many loci on human chromosomes would be involved in deletion of alleles, which may contribute to the development of esophageal carcinomas (EC), 30 patients with EC were analyzed by a molecular genetic approach using 13 polymorphic DNA probes covering regions on 6 different chromosomes and by comparing the genotypes of tumor cells and normal cells of the patients after Southern hybridization with the probes. Loss of heterozygosity (LOH) was detected on chromosome 3pter-q21 in 6 of 10 informative cases (60%), 7pter-q22 in 2 Of 11 (18%), 9q12-q13 in 1 of 6 (17%), and 9q11-q22 in 4 of 8 (50%), probed with B67, MS31, DR47, and pAS-1 respectively. These results indicate that allelic loss on chromosomes 3, 7 and 9 may play an important role in the carcinogenesis and/or progression of EC and those regions where LOH occurred may represent the locations of the putative tumor suppressor genes related to human EC. Our results also suggest that several...