New insights into vitamin D anticancer properties: focus on miRNA modulation.

Vitamin D anticancer properties are well known and have been demonstrated in many in vitro and in vivo studies. Mechanistic insights have given an explanation on how vitamin D exerts antineoplastic functions, which are mainly conducted via the canonical vitamin D receptor (VDR)-vitamin D response elements (VDRE) pathway. Numerous findings indicate that dietary components, including vitamin D, could exert chemopreventive effects through alterations of microRNA (miRNA) expression. As miRNAs have important roles in regulating diverse and vital cellular processes, it has been speculated that vitamin D's non-classical effects, including anticancer effects, could be mediated through alterations of miRNA expression level. The current review focuses on up-to-date experimental data on modulation of miRNA expression by vitamin D treatment in cancer, obtained in a cell culture system, animal models and human cohorts. Reported findings in the review show that vitamin D modulates expression of numerous and diverse miRNAs specific for cancer types. Even in its early phases, with many questions remaining to be answered, dissecting the molecular pathways of vitamin D miRNA modulation is an emerging area of science. The complete unraveling of vitamin D molecular mechanisms will emphasize the vitamin D dietary component as a potential chemopreventive agent in cancer and personalized nutrition.