The role of bile acids in carcinogenesis.

Bile acids play a role in colorectal carcinogenesis as evidenced by epidemiological and experimental studies. Some bile acids stimulate growth of normal colonic and adenoma cells, but not of colorectal cancer cells. Moreover, bile acids stimulate invasion of colorectal cancer cells, at least in vitro. One possible mechanism of action is bile acid-induced DNA binding and transactivation of the activator protein-1 (AP-1) by co-operate activation of extracellular signal-regulated kinases (ERKs) and PKC signaling. In the present paper, we review the mechanisms by which bile acids influence carcinogenesis.