Oncogenes: preliminary studies in head and neck cancer

DNA has been extracted from squamous cell carcinomas of the larynx, base of tongue, and nasopharynx. These tumors were excised from patients at the St. Louis University Medical Center and processed at the Institute for Molecular Virology of the St. Louis University Medical Center. NIH/3T3 cells were transfected with the DNAs from these cancers. Malignant, transformed foci of NIH/3T3 cells have been observed. These foci have been cloned and grown in quantity. The cloned foci have been injected into nude mice with the production of highly malignant sarcomas. DNA extracted from these sarcomas has shown homology with human DNA on hybridization analyses of both nasopharynx and tongue cancer. Further hybridization studies are being conducted on the larynx cancer-induced sarcomas and on the DNAs taken from the original transformed foci of NIH/3T3 cells transfected with squamous cell cancers of the larynx, nasopharynx, and tongue base. Our preliminary results indicating the presence of human sequences in the mouse sarcomas support the hypothesis that human cellular transforming gene(s) may be present in the DNA isolated from the head and neck cancers. Additional studies will include repetitive retransfection of NIH/3T3 cells, molecular cloning of putative oncogenes, and DNA sequence analysis of the cloned oncogenes. It is hoped that identification of putative oncogene sequences will result in the identification of the proteins coded for by the specific nucleotide sequences responsible for malignant cellular transformation by DNA extracted from head and neck tumors.