New monoclonal antibodies against colon cancer-associated antigens

Established human colon cancer cells with distinct degrees of differentiation (LoVo, well-differentiated; SW620, intermediate differentiation; and SW1116, poorly differentiated) were used to produce monoclonal antibodies (MoAbs) by standard hybridoma techniques. Specificity was tested by an enzyme-linked immunosorbent assay against human foreskin cells, 7 established human colon cancer lines, a panel of 17 established human tumor lines of different histological origins, purified carcinoembryonic antigen, panels of red blood cells, and a suspension of lymphocytes obtained from 30 random normal donors. MoAb LoVo-F4 3E4/1A1/2E10 (MoAb F4/2E10) reacted with five colon cancer lines and only slightly with MCF-7 cells (estrogen receptor positive breast carcinoma). MoAb LoVo-F4 3E4/1A1/5C10 also reacted with the previous five colon cancer lines and with two gastric cancer lines. A MoAb obtained with a LoVo 3 M KCl membrane extract reacted exclusively with LoVo cells. MoAb SW620-F1 4E5/1A3 reacted with only three colon cancer cell lines and an estrogen receptor negative breast cancer line. MoAb SW1116-F2 1E3/1A1 reacted with four colon carcinoma cell lines, one gastric cancer line, MCF-7 cells, and a lung cancer line. MoAb SW1116-F2 1F3/1B1 reacted intensely with purified carcinoembryonic antigen and with every carcinoembryonic antigen-producing cell line available in our laboratory. Further studies concentrated on the immunoglobulin G1 MoAb F4/2E10. We demonstrated that the purified MoAb did not inhibit binding of MoAb CA19-9 to any colon Ca lines and reacted with fresh human colon carcinoma specimens regardless of whether they were processed by cryostat or paraffin embedding after fixation in formalin for 24 through 96 h. Using the peroxidase-antiperoxidase technique, MoAb F4/2E10 did not react with 23 normal adult and 18 fetal (less than 3 months old) human tissue specimens. When tested on 312 specimens of diverse histological origins and diseases, the MoAb was positive in 57 of 62 colorectal cancers, in 12 of 19 villous adenomas, in 5 of 7 adenomatous polyps, and in 10 of 12 cases of ulcerative colitis. With the exception of 2 of 15 cases of Crohn's disease that were slightly positive, all tissues from nonmalignant diseases (regardless of histological origin) were consistently negative. There was only weak reactivity in 2 of 18 breast cancers, 7 of 21 squamous cell carcinomas, 4 of 27 lung tumors, 1 of 13 kidney carcinomas and in 7 miscellaneous tumors.(ABSTRACT TRUNCATED AT 400 WORDS)