RESUMEN
Colorectal cancer is the second most common cancer in the United States. Various dietary, colonic, and fecal components have been implicated as causative factors. Although numerous studies have been conducted to test them, so far no one factor has stood out as the most likely cause of colorectal cancer. This review presents the evidence for and against the major factors and concludes that bile acids are the most strongly implicated factors in the etiology of colorectal cancer.
Asunto(s)
Neoplasias Colorrectales/etiología , Ácidos y Sales Biliares/efectos adversos , Ácidos y Sales Biliares/fisiología , Causalidad , División Celular , Cocarcinogénesis , Neoplasias Colorrectales/fisiopatología , Daño del ADN , Grasas de la Dieta/efectos adversos , Grasas de la Dieta/fisiología , Heces/análisis , Humanos , Cetosteroides/efectos adversos , Mutágenos/análisisRESUMEN
Literature dealing with the biological activities of cholesterol autoxidation products and related oxysterols in vivo and in vitro published since the previous 1981 monograph is reviewed. Although several oxysterols are important cholesterol metabolites implicated in bile acids and steroid hormones biosynthesis, effects on cellular membranes and on specific enzyme systems as well as cytotoxic, atherogenic, mutagenic, and carcinogenic activities characterize oxysterols as a class. Circumstantial evidence implicates oxysterols of the human diet and those formed in vivo with human health disorders, but recent work also supports an hypothesis that some oxysterols be endogenous intracellular regulators of de novo sterol biosynthesis. The true physiological relevance, if any, of these matters has not been adduced.