Conventional and array-based comparative genomic hybridization analysis of nasopharyngeal carcinomas from the Mediterranean area

Nasopharyngeal carcinoma (NPC) occurs with a high incidence in Southeast Asia and to a lesser extent in the Mediterranean area, especially in Tunisia, Algeria, and Morocco. Cellular gene alterations combined with latent Epstein-Barr virus infection are thought to be essential for NPC oncogenesis. To date, chromosome analysis with comparative genomic hybridization (CGH) has been reported exclusively for NPCs from Southeast Asia. Although NPCs from the Mediterranean area have several distinct clinical and epidemiological features, CGH investigations have been lacking. Chromosome analysis was therefore undertaken on a series of NPC xenografts and biopsies derived from patients of Mediterranean origin. Four xenografts were investigated with a combination of conventional CGH, array-based CGH, and comparative expressed sequence hybridization. In addition, 23 fresh NPC biopsies were analyzed with conventional CGH. Data obtained from xenografts and fresh biopsies were consistent, except that amplification of genes at 18p was observed only in xenografts derived from metastatic tissues. Frequent gains associated with gene overexpression were detected at I q25similar toqter (64%) and 12p13 (50%). Losses were noticed mainly at 11q 14similar toq23 (50%),13q12similar toq31 (50%), 14q24similar toq31 (43%), and 3p13similar top23 (43%). Comparison with previous reports suggests that Mediterranean NPCs have higher frequencies of gains at 1q and losses at 13q than their Asian counterparts. (C) 2005 Elsevier Inc. All rights reserved.