Substantial reduction of the gastric carcinoma critical region at 6q16.3-q23.1.
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. Genes Chromosomes Cancer 26:29-34, 1999.
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Instituto de Patologia e Imunologia da Universidade do Porto, IPATIMUP, Porto, Portugal.
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D002872:Chromosome Deletion; D002886:Chromosomes, Human, Pair 17 / Q000235:genetics; D002893:Chromosomes, Human, Pair 3 / Q000235:genetics; D002896:Chromosomes, Human, Pair 6 / Q000235:genetics*; D004273:DNA, Neoplasm / Q000235:genetics; D006801:Humans; D019656:Loss of Heterozygosity; D018895:Microsatellite Repeats; D013274:Stomach Neoplasms / Q000235:genetics*
D004273:DNA, Neoplasm