The Effects of Cholesterol-Derived Oncometabolites on Nuclear Receptor Function in Cancer

Epidemiologic studies are controversial concerning the roles played by cholesterol in cancer risk and development, possibly as it is not cholesterol per se that is pathologic in cancers. Indeed, recent data reveal that the cholesterol metabolism in cancer cells can generate endogenous oncopromoter metabolites at higher levels compared with normal tissues and/or can be deregulated in the production of endogenous oncosuppressor metabolites in an opposite way. These metabolites are oxysterols, which are cholesterol oxygenation products generated by enzymatic and/or autoxidation processes. All these oxysterols are new classes of estrogen, glucocorticoid, or liver X nuclear receptor ligands, and their protumor action on their cognate receptors could explain some drug resistance, while treatment with antitumor metabolites could complement their deficiency in cancers and restore their action on their nuclear receptor. Given that hypercholesterolemia and high intakes of cholesterol-rich foods or processed foods can generate these oxysterols, their importance in cancer risk or development in overweight and obese people is to be considered. The discovery of these cholesterol-derived metabolites and the identification of the nuclear receptors mediating their pro- or antitumor activities are important findings, which should have major implications in the diagnosis, prevention, and treatment of different cancers and open new areas of research. Cancer Res; 78(17); 4803-8. ©2018 AACR.