- One of the most innovative approaches to the treatment of cancer entails the use of 1α,25-dihydroxyvitamin D(3) (calcitriol) analogs to inhibit cancer cell growth. We demonstrate here that BGP-13, a new calcipotriene-based 1α,25-dihydroxyvitamin D(3) analog that we synthesized in our laboratory, inhibits the growth of prostate cancer (LNCaP), breast cancer (MCF-7), and colon cancer (HT-29) cell lines. Moreover, we also show that BGP-13 causes cells both to accumulate in G(0)-G(1) and to activate caspase-3 and undergo apoptosis. In addition, we observed elevated vitamin D receptor (VDR) mRNA and protein levels in both LNCaP and MCF-7 cells following the exposure of the two cell lines to BGP-13. Importantly, we found that both the new analog BGP-13 and also BGP-15, another calcipotriene-based analog we synthesized previously and about which we published recently, inhibit the growth of HT-29 tumor xenografts in nude mice.