Biomaterial Database

The synthesis of vitamin D metabolites by human melanoma cells. 1983

T L Frankel, and R S Mason, and P Hersey, and E Murray, and S Posen

Two melanin-producing human melanoma cell lines originally established from fresh surgical specimens were incubated with 25 hydroxyvitamin D3 (25 OHD3). Both cell lines produced material comigrating with 1,25 dihydroxy-vitamin D3 (1,25(OH)2D3) and 24,25 dihydroxyvitamin D3 (24,25(OH)2D3) in straight and reverse phase high performance liquid chromatography systems and displacing the relevant labeled ligands in competitive binding assays. The material designated 1,25(OH)2D3 was found almost entirely within the cells, whereas 24,25(OH)2D3 was evenly distributed between cells and medium. The synthesis of dihydroxylated materials was time dependent and was not observed if the cells were boiled before incubation with 25 OHD3. Preincubation with 1,25(OH)2D3 caused an increase in the synthesis of 24,25(OH)2D3 and a decrease in the synthesis of 1,25(OH)2D3. Michaelis-Menten constant (Km) values were 1.4 X 10(-9) mol/liter 25 OHD3 for the 1-alpha-hydroxylase enzyme and 72 X 10(-9) mol/liter for 24-hydroxylase. These studies constitute further evidence for the extrarenal synthesis of 1,25(OH)2D3. The suppressibility of 1 alpha-hydroxylase by preincubation with 1,25(OH)2D3 suggests a regulatory function for this system in the skin.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008545	Melanoma	A malignant neoplasm derived from cells that are capable of forming melanin, which may occur in the skin of any part of the body, in the eye, or, rarely, in the mucous membranes of the genitalia, anus, oral cavity, or other sites. It occurs mostly in adults and may originate de novo or from a pigmented nevus or malignant lentigo. Melanomas frequently metastasize widely, and the regional lymph nodes, liver, lungs, and brain are likely to be involved. The incidence of malignant skin melanomas is rising rapidly in all parts of the world. (Stedman, 25th ed; from Rook et al., Textbook of Dermatology, 4th ed, p2445)	Malignant Melanoma,Malignant Melanomas,Melanoma, Malignant,Melanomas,Melanomas, Malignant
D002112	Calcifediol	The major circulating metabolite of VITAMIN D3. It is produced in the LIVER and is the best indicator of the body's vitamin D stores. It is effective in the treatment of RICKETS and OSTEOMALACIA, both in azotemic and non-azotemic patients. Calcifediol also has mineralizing properties.	25-Hydroxycholecalciferol,25-Hydroxyvitamin D 3,25-Hydroxycholecalciferol Monohydrate,25-Hydroxyvitamin D3,Calcidiol,Calcifediol Anhydrous,Calcifediol, (3 alpha,5Z,7E)-Isomer,Calcifediol, (3 beta,5E,7E)-Isomer,Calderol,Dedrogyl,Hidroferol,25 Hydroxycholecalciferol,25 Hydroxycholecalciferol Monohydrate,25 Hydroxyvitamin D 3,25 Hydroxyvitamin D3,Anhydrous, Calcifediol,Monohydrate, 25-Hydroxycholecalciferol
D002117	Calcitriol	The physiologically active form of vitamin D. It is formed primarily in the kidney by enzymatic hydroxylation of 25-hydroxycholecalciferol (CALCIFEDIOL). Its production is stimulated by low blood calcium levels and parathyroid hormone. Calcitriol increases intestinal absorption of calcium and phosphorus, and in concert with parathyroid hormone increases bone resorption.	1 alpha,25-Dihydroxycholecalciferol,1 alpha,25-Dihydroxyvitamin D3,1, 25-(OH)2D3,1,25(OH)2D3,1,25-Dihydroxycholecalciferol,1,25-Dihydroxyvitamin D3,1 alpha, 25-dihydroxy-20-epi-Vitamin D3,1,25(OH)2-20epi-D3,1,25-dihydroxy-20-epi-Vitamin D3,20-epi-1alpha,25-dihydroxycholecaliferol,Bocatriol,Calcijex,Calcitriol KyraMed,Calcitriol-Nefro,Decostriol,MC-1288,MC1288,Osteotriol,Renatriol,Rocaltrol,Silkis,Sitriol,Soltriol,Tirocal,1 alpha,25 Dihydroxyvitamin D3,1,25 Dihydroxycholecalciferol,1,25 Dihydroxyvitamin D3,1,25 dihydroxy 20 epi Vitamin D3,Calcitriol Nefro,D3, 1 alpha,25-Dihydroxyvitamin,D3, 1,25-Dihydroxyvitamin,D3, 1,25-dihydroxy-20-epi-Vitamin,KyraMed, Calcitriol,MC 1288
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D004100	Dihydroxycholecalciferols	Cholecalciferols substituted with two hydroxy groups in any position.	Dihydroxyvitamins D
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D015650	24,25-Dihydroxyvitamin D 3	A physiologically active metabolite of VITAMIN D. The compound is involved in the regulation of calcium metabolism, alkaline phosphatase activity, and enhancing the calcemic effect of CALCITRIOL.	24,25-Dihydroxycholecalciferol,(24R)-24,25-Dihydroxyvitamin D3,24,25 Dihydroxyvitamin D3,24,25-Dihydroxyvitamin D 3, (3beta,5Z,7E,24R)-Isomer,24,25-Dihydroxyvitamin D3,24R,25-Dihydroxycholecalciferol,24,25 Dihydroxycholecalciferol,24,25 Dihydroxyvitamin D 3,24R,25 Dihydroxycholecalciferol,Dihydroxyvitamin D3, 24,25