Substantial reduction of the gastric carcinoma critical region at 6q16.3–q23.1

✍ Scribed by Beatriz Carvalho; Raquel Seruca; Fátima Carneiro; Charles H.C.M. Buys; Klaas Kok

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 133 KB
• Volume: 26
• Category: Article
• ISSN: 1045-2257
• DOI: 10.1002/(sici)1098-2264(199909)26:1<29::aid-gcc4>3.0.co;2-d

✦ Synopsis

Deletions of the long arm of chromosome 6 are a common event in gastric carcinomas. In a previous study, deletion mapping of 6q identified two smallest regions of overlap (SROs) of heterozygous deletions: one interstitial, spanning 12-16 cM, bordered by D6S268 (6q16.3-q21) and ARG1 (6q22.3-q23.1), and one distal to IFNGR1 (6q23-q24), spanning more than 30 cM. Loss of heterozygosity (LOH) of the interstitial SRO was detected in 50% of informative tumors. We analyzed 60 primary gastric tumors with 19 highly polymorphic markers from 6q16.3-q23.3 to delimit the interstitial SRO further. Of the 50 tumors that were informative for at least one locus, 18 (36%) showed allelic imbalance (AI). The overlap of these cases allowed us to define an SRO of approximately 3 Mb flanked by D6S278 and D6S404. AI or LOH of this region occurs in all histologic types of gastric carcinoma and in early stages of development, indicating that loss of a gene from this region of 6q is a crucial step in a main route of gastric carcinogenesis. For cases with retention of 6q, alternative routes of gastric carcinogenesis may exist.