A COMMON REGION OF ALLELIC LOSS ON CHROMOSOME REGION 3P25.3-26.3 IN NASOPHARYNGEAL CARCINOMA

Loss of heterozygosity (LOH) of chromosome arm 3p has been commonly ob served in carcinomas of various tissues, including those of nasopharyn geal carcinoma (NPC). To determine the frequency and extent of allelic loss in NPC, we investigated 16 loci on chromosome bands 3p21-26 in 2 4 tumor tissues by microsatellite analysis. LOH on 3p21-26 was found i n 16 of 24 (66.7%) tumors. The highest frequency of allelic loss was f ound in two adjacent loci, D3S1620 (11/22, 50%) and D3S1560 (9/18, 50% ). Eight cases showed LOH in one contiguous region and 5 cases in more than one region. Samples 1, 3, 4, 7, 8, 10, 16, 17, 18, 19, and 22 ha d a contiguous stretch of allelic loss between D3S1297 and D3S1597. Th e smallest common LOH/deletion region seems likely to lie between D3S1 297 (3p26.3-26.2) and D3S1560 (3p25.3). The allelic loss map defined h ere will facilitate finer mapping of putative tumor suppressor gene lo ci and positional cloning of such genes, which may play a role in carc inogenesis of NPC. (C) 1998 Wiley-Liss, Inc.