Background: Although genetic abnormalities on 3p have been suggested to be linked to the development of squamous cell carcinoma of the head and neck, to the authors' knowledge no study to date has examined such genetic abnormalities in patients with squamous cell carcinoma of the tongue. In the current study, loss of heterozygosity (LOH) was evaluated at several loci within 3p, including the von Hippel-Lindau gene (VHL), in samples of tongue squamous cell carcinoma. In addition, the coding region of the intact VHL allele was screened for sequence mutations.
Methods: DNA was extracted from tumor and nontumor tissues collected from 28 patients with tongue squamous cell carcinoma. LOH was investigated by analysis of single nucleotide polymorphisms within exon 3 of VHL and by microsatellite analysis within another 10 loci. Mutation analysis of the VHL gene was performed by polymerase chain reaction (PCR) amplification and sequencing of the coding region of the gene.
Results: LOH within VHL was found at a high frequency (45.5%) within the tumor. However, mutations of the VHL gene were not detected in all tumor samples. LOH of other microsatellite markers on 3p was observed in 27.3% to 50% of tumor samples. Eleven (58%) of 19 samples that were informative at more than 2 loci exhibited LOH of at least 1 locus; 10 of these 11 cases exhibited LOH at multiple loci.
Conclusions: A wide range of deletions in 3p, including at the VHL gene, may play a role in the development of tongue cancer.