Monoclonal antibodies against squamous epithelial carcinomas of the upper aerodigestive tract

Abstract

Squamous cell carcinoma is the most common cancer of the head and neck. The application of monoclonal hybridoma technology to the identification and characterization of molecules preferentially expressed in carcinoma cells may provide potentially important diagnostic and therapeutic tools. After immunization of mice with viable squamous cell carcinoma cells derived from human tumors of the upper aerodigestive tract hybridomas were selectively grown for production of monoclonal antibodies. Monoclonal antibodies produced by 690 hybridoma clones were tested on immunoreactions with frozen sections of human squamous cell carcinoma and reactive tonsils. Immunohistochemical trials showed that monoclonal antibodies produced by hybridoma clone K-640 are strongly accumulated at the plasma membrane whereas no immunoreaction in squamous epithelium of the tonsil could be detected. By means of ELISA it could be shown that these antibodies belong to the class of IgM. Immunoblotting revealed that the antibodies recognize antigenes with approximate molecular weights of 52 and 54 kD. The experiments suggest that the hybridoma clone K-640 produces antibodies which bind to the plasmamembrane of the tumor cells. Further recloning steps of this hybridoma clone could possibly enhance the specificity of these antibodies for squamous cell carcinoma.