LOSS OF HETEROZYGOSITY ON CHROMOSOME-14 IN NASOPHARYNGEAL CARCINOMA

The main objective of this study was to determine the precise frequenc y of chromosome 14q loss of heterozygosity in nasopharyngeal carcinoma s and to define its minimal deletion regions. Thirty-nine tumors were selected for PCR-based deletion mapping using 19 microsatellite polymo rphic markers spanning the long arm of this chromosome, Loss of hetero zygosity for at least one marker was observed in 29 (74.4%) tumors, wh ile 24 of these tumors displayed partial loss and provided an informat ive basis for detailed deletion mapping. Three minimal regions of loss were delineated, the first defined by markers D14S278 and D14S288, th e second being between DI4S51 and the telomere, These data confirmed 2 potential tumor-suppressor-gene loci at 14q12-13 and 14 q32. Interest ingly, the third region of loss was located at the T-cell-receptor del ta chain locus. This may reflect another tumor-suppressor-gene locus a t 14q11.2, or may be the consequence of a specific genomic rearrangeme nt of this region. In addition, these allelic losses occurred with hig h frequency in all tumor grades and stages and in all histological sub -types. These findings suggest that the genetic alteration of chromoso me 14 is common and crucial during nasopharyngeal-carcinoma developmen t. (C) 1998 Wiley-Liss, Inc.