Allelic loss on the short arm of chromosome 8 in oral squamous cell carcinoma

Allelic deletions on the short arm of chromosome 8 (8p) are frequent events in many different types of malignant tumors, including head and neck tumor s and oropharyngeal cancers. These regions are thought to harbor tumor supp ressor genes. However, there has been no detailed analysis of loss of heter ozygosity (LOH) on the chromosome arm 8p in oral squamous cell carcinoma (S CC). In order to estimate details of 8p loci involved in oral SCC, 32 patie nts with oral SCCs were examined for the LOH state 8p by PCR-LOH assay usin g 14 microsatellite markers. Based on our results a detailed deletion map o f 8p showed LOH in at least one of the loci tested in 62.5% (20 of 32) of p atients; and microsatellite instability (MI) was observed in 50% (16 of 32) . The frequent LOH on this chromosome arm was identified at D8S87 and D8S25 8, mapped on 8p12 and 8p22, respectively. Fisher's exact test revealed no s ignificant statistical correlation between the incidence of LOH or MI and c linicopathological features. Our observations indicate that the short arm o f chromosome 8 may play a role in the pathogenesis of oral SCC; and that th e two loci identified in this study may be tumor suppressor gene loci on 8p .