Genotypic analysis of tumor suppressor genes PTEN/MMAC1 and p53 in head and neck squamous cell carcinomas.
OBJECTIVE
Tumor suppressor gene mutations in both p53 and PTEN/MMAC1 genomic DNA have been detected in many types of cancer. The purpose of this study was to investigate the presence and importance of PTEN/MMAC1 mutations in squamous cell carcinomas.


METHODS
Exons of each gene were amplified after polymerase chain reaction (PCR) using genomic DNA derived from cell lines of squamous cell carcinoma of the head and neck (SCCHN) and snap-frozen biopsy specimens from primary established head and neck tumors. The amplified and purified DNA was then sequenced directly.


RESULTS
As anticipated, point mutations of the p53 gene were found in 80% of cell lines examined. A single base mutation in codon 151 was found in six of 10 cell lines studied. PTEN/MMAC1 gene mutations were found in neither the cell lines tested nor the tumor biopsy samples.


CONCLUSIONS
This study, as well as a large volume of data, confirms that mutations of the p53 gene are frequent events in head and neck cancer cell lines. Although PTEN/MMAC1 gene mutations have been found in a variety of carcinomas, this gene was not found to be mutated in SCCHN cell lines or in primary squamous cell carcinomas of the head and neck. This information is useful for further studies of mutations in these cell lines.
Department of Head and Neck Surgery, The University of Texas M.D. Anderson Cancer Center, Houston 77030, USA.
Y C
YC
Henderson
E
E
Wang
G L
GL
Clayman
D002294:Carcinoma, Squamous Cell / Q000235:genetics*; D004273:DNA, Neoplasm / Q000032:analysis; D016147:Genes, Tumor Suppressor; D016158:Genes, p53; D005838:Genotype; D006258:Head and Neck Neoplasms / Q000235:genetics*; D006801:Humans; D051059:PTEN Phosphohydrolase; D010744:Phosphoric Monoester Hydrolases; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D017027:Protein Tyrosine Phosphatases / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins
D004273:DNA, Neoplasm; D025521:Tumor Suppressor Proteins; D010744:Phosphoric Monoester Hydrolases; D017027:Protein Tyrosine Phosphatases; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human