MUTATIONAL ANALYSIS OF THE PTEN GENE IN HEAD AND NECK SQUAMOUS-CELL CARCINOMA

Loss of heterozygosity (LOH) at chromosome band 10q23 occurs frequentl y in a wide variety of human tumors. A recently identified candidate t umor suppressor gene, PTEN located on 10q23, is mutated in multiple ad vanced cancers. To explore whether PTEN is associated with human squam ous cell carcinoma of the head and neck (SCCHN), DNAs from both normal muscle and tumor tissue in 19 SCCHN were used for detecting LOH at ch romosome 10q23 and mutational analysis of PTEN by direct polymerase ch ain reaction (PCR)-DNA sequencing, LOH at 10q23 was identified in 6/15 SCCHN. Mutation of PTEN was identified in 3/19 SCCHN. Of these 3 pati ents, 2 had stage IV disease; the third patient, with recurrent, metas tatic and stage III disease, showed a 36 bp germline heterozygous dele tion within intron 7, Furthermore, a missense mutation at codon 501 (T CT --> TTT: Ser --> Phe) in exon 8 was also found in tumor from the sa me patient, Our results suggest that PTEN may play a role in the genes is of some SCCHNs. (C) 1998 Wiley-Liss, Inc.