SQM1 antibody defines a surface membrane antigen in squamous carcinoma of the head and neck.

We produced murine monoclonal antibodies (MAbs) directed against the surface membrane of squamous-cell carcinoma of the head and neck (SCCHN). One antibody, SQM1, was determined by immunofluorescence and radioimmunoassay to be reactive with 13/13 SCCHN cell lines derived from different sites of the head and neck area. No binding reaction was observed with normal fibroblasts, red blood cells, nucleated bone-marrow cells or epithelial cells from normal oral mucosa. SQM1 reactivity was observed with primary cultures of normal epidermal and bronchial epithelial cells. Significant reactivity was found with 2/4 cell lines derived from small-cell carcinoma of the lung but little or no reactivity was found with other lung cancer cell lines. Various cell lines derived from other cancers including breast, colon, and ovarian carcinomas, melanoma, neuroblastoma and leukemia were generally unreactive. Seventeen out of 18 fresh frozen specimens of SCCHN were strongly reactive with SQM1 antibody. However, autopsy specimens from the heart, liver, kidney, spleen, colon, subcutaneous fat and skin connective tissue were unreactive. SQM1 antibody may be useful in biological and clinical studies of the head and neck region.