Vitamin D and Breast Cancer: Emerging Concepts
Cet article passe en revue les nouveaux axes de recherche concernant les mécanismes et processus par lesquels la vitamine D a un effet chimiopréventif sur la carcinogenèse du sein
The benefit of vitamin D in cancer prevention and to certain extent therapy has been well recognized. The active form of vitamin D, 1, 25-dihydroxycholecalciferol (1, 25(OH)2 D3) is a natural ligand for vitamin D receptor (VDR). Since 1,25(OH)2D3 exerts toxic effects at a concentration that is beneficial, nearly 1500 analogs of vitamin D have been synthesized and evaluated for their efficacy in a variety of carcinogenesis and human cancer models both in vitro and in vivo. Among these only a handful of them have been approved for evaluation in clinical trials for leukemia, breast, prostate and colon cancers. The mechanism of vitamin D action is mediated by the nuclear VDR and the signaling cascade for its action is extensively reported. In this review we focus on the newer concepts for vitamin D action. These include 1. differential effects of vitamin D in maintaining cell proliferation when the cells are under stress but suppressing cell growth when the cells are transformed; 2. Functional significance of VDR polymorphism in potential vitamin D responsiveness; 3. Regulation of constitutive splicing of vitamin D target gene, CYP24a by the hormone and its significance; 4. Regulation of microRNA by vitamin D in breast cancer. It is anticipated that the new work in these selective areas would expand the understanding of vitamin D in breast cancer prevention and therapy.
http://www.sciencedirect.com/science/article/pii/S0304383512006398?v=s5