14C1, an antigen associated with human ovarian cancer, defined using a human IgG monoclonal antibody.

We have selected a human EBV-transformed cell line from the involved lymph nodes of an ovarian cancer patient which secretes an IgG1 kappa antibody, able to recognize an antigen present on the surface of ovarian cancer cells. The antigen, termed '14Cl,' has previously been shown by immunohistological techniques to be present on the surface of the malignant cells within tumour specimens. Western blotting analysis has shown that the majority of primary ovarian cancer specimens and three continuous cell lines derived therefrom express 14Cl; other tissue types were negative. Preliminary biochemical characterization has been carried out, which shows that the 14Cl antigen has a molecular weight range of 25-32 kD and an isoelectric point from pI 6.3 to 6.8. We believe that the 14Cl antigen is immunologically relevant to ovarian cancer patients and may therefore represent a novel target for both active and passive immunotherapy.