Vitamin D inhibition of the prostaglandin pathway as therapy for prostate cancer.

Prostaglandins have been shown to play a role in carcinogenesis and the progression of many cancers, including prostate cancer. We have recently discovered that the biologically active form of vitamin D, 1,25(OH)2D or calcitriol, regulates multiple genes involved in the prostaglandin pathway. These effects include decreasing prostaglandin synthesis, increasing prostaglandin catabolism, and inhibiting the expression of prostaglandin receptors. In combination, these three mechanisms reduce prostaglandin levels and signaling, thereby attenuating the growth-stimulatory effects of prostaglandins in prostate cancer.