A cytotoxic monoclonal antibody to colon adenocarcinoma.

We have produced a monoclonal antibody CCOL1 that is cytotoxic at a titer of 1:20,000 using human sera as a complement source. CCOL1 reacts to the immunizing colon carcinoma line as well as to one other colon carcinoma line. However, it does not react with another colon adenocarcinoma line or with 28 other cultured tumor cells. It is noncytotoxic to lymphocytes, monocytes, granulocytes, RBC, and platelets. When tested by enzyme-linked immunosorbent assay against the normal cell membranes, it did not react to colon, lung, kidney cortex, heart, pancreas, liver, stomach, intestine, or kidney medulla but was strongly positive to the cell membrane of the colon adenocarcinoma line. The antibody reacted with 4 colon cancer tissue sections by immunoperoxidase. Control tissue sections of skin, spleen, kidney, brain, and uterus were negative. CCOL1 showed slight staining of epithelial cells in the tissue sections of normal lung, esophagus, colon, pancreas, and stomach. From preliminary studies, the antigen appears to be a glycoprotein, since it was highly sensitive to Pronase and sodium periodate.