ALLELIC IMBALANCE ON THE LONG ARM OF CHROMOSOME-5 IN ORAL SQUAMOUS-CELL CARCINOMA

To obtain a more detailed estimate of chromosome 5 loci involvement in oral squamous cell carcinoma (SCC), thirty-two oral SCCs were examine d for loss of heterozygosity (LOH) on the long arm of chromosome 5 (5q ) by PCR-LOH assay using thirteen microsatellite markers. LOH was obse rved in 16 (51.6%) of 31 informative cases. The incidence or the numbe r of regions showing LOH was significantly higher in moderately and po orly differentiated tumors than in the well differentiated ones. Among the loci tested, D5S178 exhibited LOH in 11 (39.3%) of 28 cases, sugg esting this to be the site, at 5q, of a novel candidate tumor suppress or gene. These data indicate that the incidence of LOH at chromosome 5 q is high and is associated with oral tumor differentiation.