Location of candidate tumour suppressor gene loci at chromosomes 3p, 8p and 9p for oral squamous cell carcinomas.

To help define the location of tumour suppressor genes implicated in the pathogenesis of oral squamous cell carcinoma (SCC), we have used microsatellite assay and restriction fragment length polymorphism (RFLP) analysis to screen 48 primary SCC for allelic imbalance (AI) with 32 polymorphic markers at chromosome 3p, and prepared a detailed deletion map. The finding of a high frequency of AI at specific regions, together with the presence of multiple small interstitial deletions involving these loci, identifies 5 areas at this chromosome arm that may harbour tumour suppressor genes. No sequence aberrations affecting the von Hippel Lindau (VHL) and fragile histidine triad (FHIT) genes, which reside within the candidate tumour suppressor gene areas at this chromosome arm, were identified. A more limited analysis of polymorphic sequences at 8p and 9p supports the existence of at least 2 areas that harbour tumour suppressor genes at 8p and evidence that additional targets for deletion reside centromeric and telomeric to the p16 gene at 9p21.