High frequency loss of heterozygosity on the long arms of chromosomes 13 and 14 in nasopharyngeal carcinoma in Southern China

To investigate the loss of heterozygosity (LOH) on chromosomal arms 13q and 14q in nasopharyngeal carcinoma (NPC) using 21 microsatellite polymorphic markers an d to study whether there is a correlation between LOH and clinicopathologic para meters and/or Epstein Barr virus (EBV) infection in NPC Methods Sixty cases of NPC were studied using polymerase chain reaction based microsa tellite analysis with genescan and genotyping techniques Results LOH was detected on 13q in 78% of NPC tumors, high frequency LOH loci (more than 30%) clustered to 13q12 3 q14 3 and 13q32 On chromosome 14q, LOH was detec ted in 80% of NPC tumors; high frequency LOH loci clustered to 14q11 q13, 14q21 q24 and 14q32 High frequency LOH at 13q31 q32 correlated with a lower l evel of EBV infection; LOH on chromosome 14q was closely associated with poor di fferentiation of NPC tumor cells Conclusion Our results suggest that in NPC, LOH on chromosome 13q and 14q are common geneti c events, and putative tumor suppressor genes (TSG) residing in these regions ma y be involved in tumorigenesis