Human squamous cell carcinoma lines express oncofetal 44-kD polypeptide defined by monoclonal antibody to mouse fetus

Most primary human carcinomas uniformly express an oncofetal epitope which has not been demonstrated previously in established human carcinoma cell lines. We successfully derived several low-passage cell lines of human squamous cell carcinoma (SCC) from head and neck tumors using an in vitro adaptation procedure, characterized these lines, and examined them for expression of a 44-kilodalton (kD) polypeptide (PP) oncofetal antigen (OFA) at the cell surface. Newly established an in vitro-passaged SCC cells retained characteristic microvilli, numerous desmosomes and tonofilaments, abundant rough endoplasmic reticulum, osmophilic keratohyaline granules, and other features of the primary SCC cells. These new cell lines and two long-term, established SCC lines (FaDu and Detroit 562) displayed OFA at the cell surface, as determined by flow cytometry using monoclonal antibody (MoAb) 115. While the FaDu and Detroit 562 lines exhibited aneuploidy during flow cytometric analysis, the new, low-passage SCC lines that we developed remained diploid as were the primary SCC cells from which they were derived. We propose that the expression of a 44-kD OFA is a common feature of human SCC. This marker may prove useful in the detection and treatment of these tumors.