Vitamin D Receptor Antagonists for Treating Breast Cancer
Vitamin D receptor (VDR) is a nuclear receptor that is activated by calcitriol, the active form of vitamin D. It is best known for regulating dietary calcium uptake necessary for bone growth, but it also affects cell proliferation and differentiation. Therefore, it was thought that treatment with calcitriol or its derivatives could be useful to treat the uncontrolled proliferation typical of cancer cells. However, this approach has been unsuccessful to date because it leads to toxic levels of calcium in the blood.