Background: Tumor suppressor genes are important in the development of head and neck cancer. Using microsatellite markers that map close to the region 3p24-pter, we determined the frequency of allele loss close to this site with a view to narrowing the search for a putative tumor suppressor gene involved in the development of squamous cell carcinoma of the head and neck, which may facilitate future positional cloning techniques.
Design: Laboratory-based project with tumor and normal specimens subjected to molecular genetic analysis. Tumor-normal tissue DNA pairs were analyzed for allelic imbalance and microsatellite instability on chromosome 3p in the region 3p24-pter by the polymerase chain reaction and microsatellite markers D3S1304, D3S656, D3S1252, D3S1293, THRB, and D3S1266.
Setting: Molecular genetics and oncology research laboratory.
Patients: Paired tumor-normal DNA samples were obtained from 46 patients with tumors of the head and neck.
Main outcome measures: Detection of loss of heterozygosity and microsatellite instability on chromosome 3 in the region 3p24-p25.1.
Results: We found loss of heterozygosity with at least one marker in 48% of informative cases and loss of heterozygosity or microsatellite instability in 57% of informative cases. The minimal region of loss was found in the region bounded by D3S656 and D31293.
Conclusion: A putative tumor suppressor gene in head and neck cancer lies between D3S656 and D3S1293 in the 3p25.1 region.