Multiple regions of deletion on chromosome arm 13q in head-and-neck squamous-cell carcinoma

Several lines of evidence suggest that the progression of head-and-neck squ amous-cell carcinoma (HNSCC) involves inactivation of at least one and poss ibly several tumor-suppressor genes on the long arm of chromosome 13. The f act that neither Rb1 nor BRCA2 appears to be inactivated in the majority of head-and-neck cancers suggests that novel tumor-suppressor genes are invol ved. We have used microsatellite repeat polymorphisms and PCR to detect sev eral distinct minimal regions of deletion on 13q in supraglottic and oral s quamous-cell carcinomas. One region maps to 13q34, the second to 13q14.3 an d a potential third region, not reported in previous studies, maps to 13q12 .1. Overall, 69% of the 145 tumors examined demonstrated allelic loss at on e or more loci on 13q. We investigated whether a novel suppressor candidate mapping to 13q14.3-q21, leukemia-associated gene I, might also be involved in the progression of squamous-cell carcinomas. Multiplexed PCR revealed h omozygous deletion of leuI in one oral cavity tumor. This suggests that thi s gene or one nearby may be the actual target of deletions in this region o f the chromosome arm. Int J. Cancer (Pred. Oncol.) 84:453-457, 1999. (C) 19 99 Wiley-Liss, Inc.