Frequent cain of the p40/p51/p63 gene locus in primary head and neck squamous cell carcinoma

We have identified a new human p53 homologue, p40 (p51163). This gene was m apped to the distal arm of 3q and was found to be essential for normal epit helial development. We used microsatellite and FISH analyses to search for genetic alterations of p40 in primary HNSCC, A more precise localization of p40 was completed using 6 known markers on 3q and a newly isolated microsa tellite marker within the p40 gene. We also determined the genomic organiza tion of the p40 gene using human YAC and BAC clones. Microsatellite analysi s revealed that 14 of 26 (54%) primary HNSCC had allelic imbalance in at le ast I of the 7 microsatellite loci. However, FISH analysis with a p40 probe showed that a majority of HNSCC had an increased copy number of the locus regardless of allelic status, Thus, overrepresentation of the p40 locus may play an important role in the development of HNSCC, (C) 2000 Wiley-Liss, I nc.