人结肠癌(CCA)单克隆抗体及其识别抗原的分析(简报)

正常细胞转化成癌细胞后,其表型发生了一系列不同于正常细胞的变化,成为肿瘤细胞的标志。Gold和Freeman(1965)用人结肠癌组织的抽提物免疫兔,发现有些用人正常结肠组织吸收后的抗血清能够与肿瘤组织和胚胎肠道抽提物起反应,但不与正常组织抽提物起反应,由于这种抗原最初被发现在胚胎组织,故名为癌胚抗原(embryonic carcinoma antigen,简称CEA)。用敏感的放射免疫或免疫酶标方

STUDIES ON A NEW TUMOR MARKER WITH MONOCLONAL ANTIBODY AGAINST HUMAN COLO-RECTAL CARCINOMA ANTIGEN

A hybridoma 1 G 10 clone was derived from fusion between SP 2/0- Ag 14 myeloma cells and spleen cells of BALB/C mice immunized with the soluble Noridet P 40 extracts from a human colonic adeno-carcinoma cell line SW 620. The 1 G 10 clone was identified to be able to produce monoclonal antibody of IgG1 subclass which had sufficient titer for immunoreactivity to both extracts from SW 620 cells and surgical colonic carcinoma tissues, but no immunoreactivity to both extracts from normal adult colorectal tissues, mixed huamn lymphyocytes and normal human serum (NHS) as well as carcinoma embryonic antigen (CEA) by enzyme-linked immunosorbent assay (ELI-SA). By affinity column on Sepharose 4B coupled with 1 G10 IgG, colonic carcinoma-associated antigen (CCA) was purified from SW 620 cell extracts and thoracic ascitic fluid of a patient with lung adenocarcinoma. Western blotting analysis with 1 G 10 IgG demonstrated that one immunoreac-tive bands corresponding to 55 Kd molecule was observed in the samples of ascitic fluid and SW 620 cell extracts. The 55 Kd band could be stained with Alcian blue. The immunoreactivity of CCA to 1 G 10 antibody could be abolished completely by the treatment of the antigen with NaIO, and proteinase K. These results indicated that the determinants of CCA reacted with 1 G 10 monoclonal antibody are probably both present in polysaccharide and protein part of the molecule. The specificity of anti-CCA 1 G 10 monoclonal antibody and its possibile application for clinical oncology were discussed.