In vitro and in vivo inhibition of liver cancer cells by 1,25-dihydroxyvitamin D 3

Abstract

Inhibitory effects of 1,25-dihydroxyvitamin D 3 (1,25-(OH) 2D 3) on the proliferation of a variety of cancer cell lines have been extensively reported. We have studied the effect of 1,25-(OH) 2D 3 (10 −11–10 −6 M) on the proliferation of a number of human and rat liver cancer cell lines. Additionally, the effect of 1,25-(OH) 2D 3 (0.02–0.5 μg/kg per day) on the rate of growth of liver cancer cell line xenografts in nude mice was also investigated. In vitro, proliferation of Hep-3B, PLC/PRF/5, and SKHEP-1 cells was significantly inhibited by 1,25-(OH) 2D 3, while HTC and Novikoff cells were more resistant to the inhibitory effects of the drug. In vivo, treatment of SKHEP-1 tumor bearing nude mice with different doses of 1,25-(OH) 2D 3 significantly retarded tumor growth without the development of hypercalcemia.