METABOLIC DIFFERENCES AND THEIR IMPACT ON HUMAN-DISEASE - SULFOTRANSFERASE AND COLORECTAL-CANCER

Gene-environment interaction is an important aspect of human cancer ri sk. Genetic polymorphisms in acetylation and N-oxidation have previous ly been described regarding their impact on the heterocyclic amine-ind uced risk for colon cancer. Here, we report that another enzyme involv ed in the metabolism of food-borne carcinogens, sulfotransferase (ST1A 3 measured by 2-naphthol activity), may function as a potential protec tive factor for colon cancer in humans. Initially characterized in hum an liver and colon (Chou et al., 1995), TS-PST activity can also be me asured in platelets. A simple microtiter-based colorimetric technique was developed for use in this case-control study. African-Americans ha d a higher mean ST activity than Caucasians (2.32 +/- 0.24 versus 1.77 +/- 0.09 nmols/min per mg cytosolic protein, P = 0.036). Furthermore, the slow ST phenotype (ST less than or equal to 1.53) was more freque ntly associated with colon cancer than controls (57 versus 40%, P = 0. 026). These data suggest that the ST1A3 isoform may play a role in the differential risk for colorectal cancer. (C) 1997 Elsevier Science B. V.