Stomach Chromosome 5 in Differentiated Adenocarcinomas of the Two Distinct Regions of Deletion on the Long Arm of Updated

Frequent loss of heterozygosity (LOH) on the long arm of chromosome 5 (5q) has been reported in many types of human malignancies, including gastric carcinoma. One of the targets of 5q-LOH in colorectal carcinoma is certainly the adenomatous polyposis coil (APC) gene on 5q21. However, other evidence has suggested the presence of another tumor suppressor gene in this region which may be inactivated in gastric carcinoma. In the present study, to determine the location of the putative tumor suppressor gene on 5q, LOH at nine microsateffite loci on 5q were investigated In 38 differentiated adenocarcinomas of the stomach that probably did not carry APC mutations. LOH at any locus on Sq occurred in 37% (14 of 38) of the tumors. Although many tumors exhibited large interstitial deletions on Sq that included the APC locus (5q21), we have identified minimum regions of deletion as the D5S428 locus and the interferon regulatory factor-i (IRF-1) locus. Thus, at least two putative tumor suppressor genes, which play a crucial role In the genesis of differentiated adenocarcinoma of the stomach and are distinct from the APC gene, lie on Sq.