24-25-dihydroxyvitamin-d-3 and Leukemia--Myeloid--Acute

Human promyelocytic leukemia cells (HL-60 cells) incubated with (24R)-hydroxy[26,27-methyl-3H]calcidiol (0.2 microCi) or non-radioactive (24R)-hydroxycalcidiol (370 micrograms) produced significant quantities of two new vitamin D3 (calciol) metabolites. The metabolites were isolated from HL-60 cell culture media by methanol/chloroform extraction and a series of chromatographic procedures. The two new metabolites were identified as (5Z)- and (5E)-(24R)-19-nor-10-oxo-24-hydroxycalcidiol by HPLC analysis, ultraviolet absorption spectrophotometry, mass spectrometry and Fourier-transform infrared spectrophotometry. According to the isolation and purification procedures, the total amounts of 3.04 micrograms (5Z)-(24R)-19-nor-10-oxo-24-hydroxycalcidiol (lambda max = 310 nm, epsilon = 17070 M-1 cm-1) and 8.89 micrograms (5E)-(24R)-19-nor-10-oxo-24-hydroxycalcidiol (lambda max = 312 nm, e = 24,500 M-1 cm-1) were calculated, assuming an Mr of 418. The activity of 19-nor-10-oxo-(24R)-hydroxycalcidiol to promote HL-60 cell differentiation was higher than the activity of the precursor (24R)-hydroxycalcidiol suggesting a possible biological action of this metabolite in HL-60 cells.

Topics: 24,25-Dihydroxyvitamin D 3; Cell Line; Chromatography, High Pressure Liquid; Flow Cytometry; Humans; Hydroxycholecalciferols; Leukemia, Myeloid, Acute; Mass Spectrometry; Phagocytosis; Spectrophotometry; Stereoisomerism; Tritium

The induction of cell differentiation by a combination of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3], recombinant gamma-interferon (rec gamma-IFN), and a lipopolysaccharide from E. coli (LPS) was studied in a clonal population (clone-9) of human promyelocytic HL-60 leukemia cells in vitro. Treatment of clone-9 cells with 10(-9) to 10(-7)M 1,25-(OH)2D3 yielded a macrophage cell differentiation. The addition of 10 or 100 U/ml of gamma-IFN and 2 or 10 micrograms/ml LPS caused a further increase in expression of the different differentiation markers. The most pronounced effects involved increases in cell attachment to the surface of tissue-culture Petri dishes and in lysozyme, nonspecific esterase, and cytolytic activities. The combined treatment with 1,25-(OH)2D3 and rec gamma-IFN and LPS also caused an increase in the percent of multinucleated giant cells. These results indicate the effectiveness of combining different agents in inducing cell differentiation in HL-60 cells. A similar approach may be useful in controlling myeloid leukemias in vivo.

Topics: 24,25-Dihydroxyvitamin D 3; Cell Adhesion; Cell Differentiation; Cell Division; Cell Line; Dihydroxycholecalciferols; Humans; Interferon-gamma; Leukemia, Myeloid, Acute; Lipopolysaccharides; Microscopy, Electron

We studied the effects of 1,25-dihydroxyvitamin D3 and other metabolites of vitamin D3 on the maturation in liquid culture and on colony formation in semisolid media of marrow and buffy coat cells from patients with myeloid leukemias and from normal individuals. After incubation with 1,25-dihydroxy-vitamin D3, a proportion of both normal and leukemic myeloid cells resembled cells of the monocyte-macrophage lineage; these cells expressed alpha-naphthylacetate esterase and were able to phagocytize and kill candida organisms. When granulocyte-macrophage progenitor cells (CFU-GM) were incubated with 1,25-dihydroxyvitamin D3, the number of monocyte-macrophage colonies was increased and the number of granulocyte colonies was reduced; megakaryocyte colony formation (CFU-Mk) was inhibited substantially; and there was no effect on erythroid (BFU-E) or multilineage (CFU-GEMM) progenitor cell colony formation. We propose that 1,25-dihydroxyvitamin D3 may induce cells that are normally committed to differentiate along the granulocytic pathways to differentiate instead along the monocyte-macrophage pathway. If these in vitro observations reflect the in vivo activity of 1,25-dihydroxyvitamin D3, it may be involved in the modulation of collagen deposits in the bone marrow.

Topics: 24,25-Dihydroxyvitamin D 3; Bone Marrow; Calcifediol; Calcitriol; Cell Division; Cells, Cultured; Cholecalciferol; Dihydroxycholecalciferols; Granulocytes; Hematopoietic Stem Cells; Humans; Kinetics; Leukemia, Myeloid, Acute; Macrophages