Preparation And Characterization Of Human Colon Tumor-associated Antigen And The Clinical Significance

The monoclonal antibody (mAb) against human colon tumor-associated antigen 4D10 was employed as the ligand for the immunoaffinity chromatography to purify the colon tumor-associated antigen from the lysate of colorectal tumor cell LOVO. The purified antigen was identified by SDS-PAGE and Western blot. The expression of colon tumor-associated antigen in the sera of patients with colon cancer and in normal sera was detected by Sandwich-ELISA.Results: The purified colon tumor-associated antigen binding to mAb 4D10 was a heterodimer composed of two subunits with relative molecular mass (Mr) of 30×10~3 and 35×10~3 respectively. The antigen was significantly higher expressed in sera from patients with colon cancer than that in normal sera (P＜0.01).The tumor-associated antigen obtained from the colon tumor cells has been successfully puriffed through immunoaffinity chromatography with mAb 4D10,which may be useful for diagnosis on clinic.