Microsatellite Analyses of Loci at 7q31.3-q36 Reveal a Minimum of Two Common Regions of Deletion in Nasopharyngeal Carcinoma

Abstract

OBJECTIVE: Our goal was to better define the extent and specificity of deletion in the 7q32-qter chromosomal region in nasopharyngeal carcinoma (NPC). DESIGN AND SETTING: Polymerase chain reaction-based deletion analysis was performed on DNA samples from 24 paired NPCs and corresponding germlines using 13 microsatellite markers mapped to chromosome subbands 7q31.3-q36. RESULTS: Loss of heterozygosity of at least 1 marker in this interval was found in 18 (75%) of 24 tumor specimens. Particularly frequent allelic losses were identified at 5 loci: D7S495 (46%), D7S509 (42%), D7S500 (45%), D7S631 (30%), and D7S514 (35%). Two shortest regions of overlap could be identified in this interval, although the most common shortest region of overlap appeared to lie around D7S500 between but not including D7S631 and D7S495, on chromosome subband 7q32. CONCLUSION: These results suggest that at least 2 putative tumor suppressor genes important in the pathogenesis of NPC are present in the examined interval, an interval that has also been found to harbor deletions in breast and prostate carcinomas.