Alpha 1-antitrypsin as a biomarker in azoxymethane induced intestinal tumors in F344 rats

Alpha 1-antitrypsin ( α 1AT) has been detected in several human tumors and is thought to be a marker of neoplastic change and progression. As the biology of azoxymethane (AOM) induced intestinal tumors in F344 rats has many characteristics of human intestinal tumors, we have investigated α 1AT expression in AOM induced rat intestinal tumors. Nine of 12 colonic carcinomas and 6 8 small intestinal carcinomas had α 1AT positive tumor cells. Only 1 11 colonic adenomas and 0 3 small intestinal adenomas contained α 1AT. Thus α 1AT is a marker of malignancy in this model. Inhibition of carcinogenesis by piroxicam and difluoromethyl ornithine inhibited α 1AT expression.