A nonsialylated high-molecular-weight glycoprotein defined by a monoclonal antibody to adenocarcinoma of the uterine endometrium.

A murine monoclonal antibody, MCA-97, was prepared against a human endometrial adenocarcinoma cell line. In a cellular enzyme-linked immunospecific assay, the MCA-97 antibody reacted with all adenocarcinoma cell lines tested, including four endometrial adenocarcinoma lines. The antigen defined by MCA-97 was estimated to be a nonsialylated high-molecular-weight glycoprotein containing galactose and N-acetylglucosamine in its determinant. In immunoperoxidase staining of formalin-fixed, paraffin-embedded sections, MCA-97 reacted with most endometrial adenocarcinomas and ovarian endometrioid-type adenocarcinomas, and also reacted with normal glandular epithelium of the female genital and gastrointestinal tracts. However, it was mostly unreactive with squamous cell carcinoma and ovarian serous adenocarcinoma tissues. By the reversed passive hemagglutination method, the antigen defined by MCA-97 was detected in the sera of one-third of patients with endometrial adenocarcinomas, and in half of those with ovarian endometrioid adenocarcinomas. The antigen was not demonstrable in the sera of most normal female volunteers. Thus, MCA-97 monoclonal antibody has potential clinical applications in diagnostic serology and pathology.