Metabolism of 26,27-hexafluoro-1 alpha,25-dihydroxyvitamin D3 and 26,27-hexafluoro-1 alpha,23(S)25-trihydroxyvitamin D3 in ROS17/2.8 cells transfected with a plasmid expressing CYP24.
1. To clarify the possibility that the metabolism of 26,27-hexafluoro-1 alpha,25-dihydroxyvitamin D3 [F6-1,25(OH)2D3] to 26,27-hexafluoro-1 alpha,23(S),25-trihydroxyvitamin D3 [F6-1,23,25(OH)3D3 and that of F6-1,23,25(OH)3D3 to 26,27-hexafluoro-23-oxo-1 alpha,25-dihydroxyvitamin D3 [F6-23-oxo-1,25(OH)2D3] are catalysed by 25-hydroxyvitamin D3 24-hydroxylase (CYP24), ROS17/2.8 cells transfected with a plasmid expressing CYP24 [pSVL-CYP24(+)] and a corresponding blank plasmid [pSLV-CYP24R(-)] were used. 2. Incubation of [1 beta-3H]-F6-1,25(OH)2D3 for 2 and 5 days with ROS17/2.8 cells transfected with pSVL-CYP24(+) generated a metabolite that co-migrated with authentic F6-1,23,25(OH)3D3 in both normal phase and reversed-phase HPLC systems. 3. Incubation of [1 beta-3H]-F6-1,23,25(OH)3D3 for 5 days with pSVL-CYP24(+)- transfected ROS 17/2.8 cells generated a metabolite that co-migrated with authentic F6-23-oxo-1,25(OH)2D3. In contrast, the metabolites F6-1,23,25(OH)3D3 or F6-23-oxo-1,25(OH)2D3 were not generated in the cells transfected with pSVL-CYP24R(-). 4. The results indicate that CYP24 catalyses the conversion of F6-1,25(OH)2D3 to F6-1,23,25(OH)3D3 and that of F6-1,23,25(OH)3D3 to F6-23-oxo-1,25(OH)2D3.
Miyahara
T
T
Department of Toxicology, Faculty of Pharmaceutical Sciences, Toyama Medical & Pharmaceutical University, 2630 Sugitani, Toyama-shi, Toyama, 930-0194, Japan.
Gomyo
S
S
Ueda
Y
Y
Ohyama
Y
Y
Sigeno
C
C
Kozakai
A
A
Takamura
T
T
Yamazaki
R
R
Higuchi
S
S
Yamamoto
M
M
Sakuma
T
T
Nemoto
N
N
D000818:Animals; D002117:Calcitriol / Q000031:analogs & derivatives* / Q000378:metabolism*; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis* / Q000502:physiology*; D008956:Models, Chemical; D010006:Osteoblasts / Q000378:metabolism; D010957:Plasmids / Q000378:metabolism; D051381:Rats; D013250:Steroid Hydroxylases / Q000096:biosynthesis* / Q000502:physiology*; D013997:Time Factors; D014162:Transfection; D014407:Tumor Cells, Cultured; D065668:Vitamin D3 24-Hydroxylase; D005466:Fluorocarbons
D002117:Calcitriol; D003577:Cytochrome P-450 Enzyme System; D013250:Steroid Hydroxylases; D065668:Vitamin D3 24-Hydroxylase; C077906:26,26,26,27,27,27-hexafluoro-1,23,25-trihydroxyvitamin D3; C040488:26,26,26,27,27,27-hexafluoro-1,25-dihydroxyvitamin D3; D005466:Fluorocarbons