Effects of vitamin D-binding proteins on HL-60 cell differentiation induced by 26,26,26,27,27,27-hexafluoro-1 alpha,25-dihydroxyvitamin D.
Monocytic differentiation-inducing activity of 26,26,26,27,27,27-hexafluoro-1 alpha,25-dihydroxyvitamin D3 [26,27-F6-1 alpha,25-(OH)2D3] was re-evaluated in human promyelocytic leukemia (HL-60) cells in serum-supplemented or serum-free culture. The order of in vitro potency for reducing nitroblue tetrazolium (NBT) was 26,27-F6-1 alpha,25-(OH)2D3 greater than 1 alpha, 25-dihydroxyvitamin D3 [1 alpha,25-(OH)2D3] = 26,26,26,27,27,27-F6-1 alpha,23(S), 25-trihydroxyvitamin D3 [26,27-F6-1 alpha,23(S), 25-(OH)3D3] under serum-supplemented culture conditions, whereas the order was 1 alpha, 25-(OH)2D3 = 26,27-F6-1 alpha,25-(OH)2D3 greater than 26,27-F6-1 alpha,23(S), 25-(OH)3D3 under serum-free culture conditions. This rank order for differentiation-inducing activity under serum-free culture conditions correlated well with the binding affinity of these analogs for vitamin D3 receptor of HL-60 cells. The order of relative % binding affinity for the vitamin D-binding protein in fetal calf serum was 1 alpha,25-(OH)2D3 (100%) much greater than 26,27-F6-1 alpha,25-(OH)2D3 (5.1%) greater than 26,27-F6-1 alpha,23(S), 25-(OH)3D3 (less than 1%). These results suggest that serum vitamin D-binding proteins apparently modulate monocytic differentiation of HL-60 cells by 26,27-F6-1 alpha,25-(OH)2D3 under serum-supplemented culture conditions.
Honda
A
A
Department of Biochemistry, Tokyo College of Pharmacy, Japan.
Nakashima
N
N
Mori
Y
Y
Katsumata
T
T
Ishizuka
S
S
D001667:Binding, Competitive; D002117:Calcitriol / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects*; D002460:Cell Line; D003470:Culture Media; D016895:Culture Media, Serum-Free; D006801:Humans; D007700:Kinetics; D015473:Leukemia, Promyelocytic, Acute; D018167:Receptors, Calcitriol; D011987:Receptors, Steroid / Q000378:metabolism; D014809:Vitamin D-Binding Protein / Q000378:metabolism / Q000494:pharmacology*; D005466:Fluorocarbons
D002117:Calcitriol; D003470:Culture Media; D016895:Culture Media, Serum-Free; D018167:Receptors, Calcitriol; D011987:Receptors, Steroid; D014809:Vitamin D-Binding Protein; C040488:26,26,26,27,27,27-hexafluoro-1,25-dihydroxyvitamin D3; D005466:Fluorocarbons