Production of Monoclonal Antibodies Against Human Colon Cancer Cell Line(SNU-C1) and Study of the Antigen.

Abstract

To study human colon cancer antigens, monoclonal antibodies were produced by immunizing balb/c mice with colon cancer cells(SNlJ-CI, originated from a Korean colon cancer patient). Among these monoclonal antibodies, one of IgM type antibody 7E02 was selected for further study. The 7E02 was proved to be effective for immunohistological staining of colorectal cancer tissues. After purification by ammonium sulfate fractionation and Sephacryl S-3OO gel filtration, 7E02 was labeled by 1-125. Using the radiolabeled 7E02, its dissociation constants (Kd) against SNlJ-Cl and SNlJ-C4 were measured by Scatchard plotting, and found to be 10.7 nM and 7.1 nM, respectively. When SNlJ-CI was treated with 10 mM sodium periodate, 7E02 was not bound to the cell surface. However, SNlJ-CI preserved the activity to bind to 7E02 after N-acetyl neuraminidase treatment. With these results, we could conclude that the 7E02 binds to carbohydrate antigen that exists on the surface of colon cancer cell and excreted mucin. The antigen was proved not to contain terminal sialic acid.