Phenotypic alterations of a carbohydrate antigen, blood group A type 3 chain, in neoplastic transformation of uterine cervix

A monoclonal antibody, MRG-1, was established by use of a human ovarian mucinous cyst-adenocarcinoma-derived cell line, RMUG-L, as immunogen. Following its establishment, biochemical analysis revealed that its epitope was blood group A type 3 chain. Using MRG-1 as an immunohistochemical probe, uterine cervical neoplastic lesions including dysplasia, carcinoma in situ, and invasive carcinoma were investigated. Light-microscopically, normal squamous epithelium showed a strong positive reaction along the cell surface region exclusively in the intermediate cell layer. On the other hand, intracellular structures were very often strongly stained in squamous cell carcinoma. Under the electron microscope, MRG-1 binding sites in squamous cell carcinoma cells were found to be in intracytoplasmic vesicular structures as well as in the plasma membrane. This marked difference in the antigen distribution was found to be a phenomenon associated with cervical neoplastic transformation.