Losses of heterozygosity in oral and oropharyngeal epithelial carcinomas

We analyzed 25 oral and oropharyngeal epithelial carcinomas for loss of het erozygosity (LOH) and microsatellite instability by using 55 oligonucleotid e repeat markers located in 45 chromosomal regions. The aim was to identify which chromosomal regions and tumor-suppressor genes (TSGs) ore preferenti ally lost in these tumors and to relate LOH at specific loci to clinicopath ologic data. The analysis ir as performed on tumor tissue and on a correspo nding normal tissue (blood lymphocytes) with the use of the polymerase chai n reaction technique followed Lc microsatellite allele separation with dena turing gel electrophoresis. Thirty-two of 45 chromosomal regions demonstrat ed a significant (greater than or equal to 20%) incidence of LOH. An alleli c loss of greater than or equal to 50% rr-as found in 9p21 (77.8%), 8p22-23 (70%), 3p12 (61.5%) 1p36.1 and 12q22 (60%), 3q28 (57.1%). 5q23.3 (54.5%), 3p25-26, 3p24, and 7q35 (50%). We did not find any microsatellite instabili ty. Our results suggest that in addition to a,group of TSGs, pleiotropic fo r several tumor types. other suppressor genes are specifically involved in oral and oropharyngeal carcinogenesis. (C) Elsevier Science Inc, 2000. All rights reserved.