Antiproliferative effect of 1α,25-dihydroxyvitamin D3 involves upregulation of cyclin-dependent kinase inhibitor p21 in human pancreatic cancer cells.

The aim of this study was to investigate the effect of 1α,25-dihydroxyvitamin D3 on proliferation of human pancreatic cancer cell lines and to identify related cell cycle regulatory proteins with antiproliferative effects.Human pancreatic cancer cell lines SUIT-2 and its four sublines, and Panc-1, AsPC-1, and MiaPaCa-2 were treated with1α,25-dihydroxyvitamin D3. The number of cells was measured by the MTT method, and the cell cycle regulatory proteins were then analyzed by Western blotting.Eight human pancreatic cancer cell lines expressed vitamin D receptor (VDR) mRNA. 1α,25-dihydroxyvitamin D3 inhibited proliferation of SUIT-2 and its sublines. We found p21 to be upregulated after 24 hours in S2-028, the cell line in which proliferation was most inhibited by 1α,25-dihydroxyvitamin D3.1α,25-dihydroxyvitamin D3 inhibited proliferation of pancreatic cancer cells and is involved in the upregulation of cyclin-dependent kinase inhibitor p21.