Abstract 3562: Genome-wide analysis of the vitamin D receptor (VDR) binding sites reveals vitamin D role modulating autophagy and metabolism in luminal-like breast cancer cells.

Abstract

The active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25D3), regulates gene expression through the vitamin D receptor (VDR). Even though 1,25D3 is still best known as a regulator of bodily calcium homeostasis, 1,25D3 has a plethora of physiological actions which include immune and nervous system modulation, cellular proliferation and differentiation. Epidemiological and model studies have revealed the cancer-protective properties of 1,25D3 in colon, prostate and notably in breast. We are actively investigating the anti-proliferative properties of 1,25D3 in a panel of human breast cancer cell lines. We found that 1,25D3 induces autophagy in several luminal-like breast cancer cell models, but not in basal-like or mesenchymal-like models. We performed VDR and signaling partner RXR whole-genome ChIP-seq analysis to uncover all of the direct 1,25D3 target genes involved in regulation of metabolism and autophagy. Our studies suggest that energy regulation as an important aspect of 1,25D3 anti-proliferative properties in luminal-like breast cancer cells. Citation Format: Luz E. Tavera, Thomas Westerling, Myles Brown. Genome-wide analysis of the vitamin D receptor (VDR) binding sites reveals vitamin D role modulating autophagy and metabolism in luminal-like breast cancer cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3562. doi:10.1158/1538-7445.AM2013-3562