Antagonistic action of novel 1alpha,25-dihydroxyvitamin D(3)-26, 23-lactone analogs on 25-hydroxyvitamin-D(3)-24-hydroxylase gene expression induced by 1alpha,25-dihydroxy-vitamin D(3) in human promyelocytic leukemia (HL-60) cells.
We have demonstrated that 1alpha,25-dihydroxyvitamin D(3)-26, 23-lactone analogs, (23S)- and (23R)-25-dehydro-1alpha-hydroxyvitamin D(3)-26,23-lactone (TEI-9647, TEI-9648, respectively), inhibit HL-60 cell differentiation induced by 1alpha,25-dihydroxyvitamin D(3) [1alpha,25(OH)(2)D(3)], but not differentiation caused by all-trans retinoic acid (D. Miura et al., 1999, J. Biol. Chem. 274, 16392). To assess whether the antagonistic actions of TEI-9647 and TEI-9648 in HL-60 cells are related to 1alpha,25(OH)(2)D(3) breakdown, we investigated their effects on catabolism of 1alpha,25(OH)(2)D(3). In HL-60 cells, the C-24 but not the C-23 side-chain oxidation pathway of 1alpha,25(OH)(2)D(3) has been reported. Here we demonstrate that 1alpha,25(OH)(2)D(3) was metabolized both to 24,25,26,27-tetranor-1alpha,23-(OH)(2)D(3) and 1alpha,25(OH)(2)D(3)-26,23-lactone; thus HL-60 cells constitutively possess both the 24- and the 23-hydroxylases. Metabolism of 1alpha, 25(OH)(2)D(3) was strongly suppressed by 10(-7) M TEI-9647 or 10(-6) M TEI-9648. 1alpha,25(OH)(2)D(3) alone slightly induced 24-hydroxylase gene expression by 8 h with full enhancement by 24-48 h; this induction was inhibited by 10(-6) M TEI-9647 and 10(-6) M TEI-9648 (86.2 and 31.9%, respectively) 24 h after treatment. However, analogs of TEI-9647 and TEI-9648 without the 25-dehydro functionality induced 24-hydroxylase gene expression. These results indicate that TEI-9647 and TEI-9648 clearly mediate their stereoselective antagonistic actions independent of their actions to block the catabolism of 1alpha,25(OH)(2)D(3). Therefore, TEI-9647 and TEI-9648 appear to be the first antagonists specific for the nuclear 1alpha,25(OH)(2)D(3) receptor-mediated genomic actions of 1alpha,25(OH)(2)D(3) in HL-60 cells.
Ishizuka
S
S
Department of Bone and Calcium Metabolism, Safety Research Department, Teijin Institute for Bio-Medical Research, 4-3-2 Asahigaoka, Hino, Tokyo, 191-8512, Japan.
Miura
D
D
Eguchi
H
H
Ozono
K
K
Chokki
M
M
Kamimura
T
T
Norman
A W
AW
D002117:Calcitriol / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D002467:Cell Nucleus / Q000201:enzymology; D002851:Chromatography, High Pressure Liquid; D003577:Cytochrome P-450 Enzyme System; D018076:DNA, Complementary / Q000378:metabolism; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics; D018922:HL-60 Cells; D006801:Humans; D013237:Stereoisomerism; D013250:Steroid Hydroxylases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D065668:Vitamin D3 24-Hydroxylase
D018076:DNA, Complementary; C400545:TEI 9647; C026947:1,25-dihydroxyvitamin D3-26,23-lactone; D003577:Cytochrome P-450 Enzyme System; D013250:Steroid Hydroxylases; D065668:Vitamin D3 24-Hydroxylase; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D002117:Calcitriol