A PUTATIVE CEA MOIETY IS SHARED BY THE COTTON-TOP TAMARIN (SAGUINUS-OEDIPUS) AND HUMANS

CEA-like molecules immunologically distinct from those in humans have been described in non-human primates. These primates do not share the human predilection for colitis and subsequent development of colorecta l cancer. CEA expression has not been fully evaluated in a lower-order primate, the cotton-top tamarin (Saguinus oedipus), an animal model f or colitis and colorectal cancer. We found increased levels of CEA in both colonic washings and tissues of these animals using a commerciall y available kit, CEA AIA-PACK (Tosoh Medics, Foster City, CA). In cont rast, we observed that other CEA kits failed to detect CEA in tamarins . To elucidate the nature of the CEA-like protein detected, we used th e two component monoclonal antibodies used in the CEA AIA-PACK kit, an d identified the reactive molecules by Western blotting. A band of app roximately M(r) 50 000 was found to be common to samples from both hum ans and the tamarins. Minimal binding was observed with NCA antibody. We conclude that a CEA-like molecule shared by humans and tamarins may play a role in the pathogenesis of colitis and cancer in both species .