Inhibition of vitamin D3-induced cell differentiation by interferon-gamma in HL-60 cells determined by a nitroblue tetrazolium reduction test.
The combined effects of 1 alpha,25-dihydroxyvitamin D3 [1,25(OH)2D3] and interferon-gamma (IFN-gamma) or tumor necrosis factor alpha (TNF-alpha) on cell differentiation in HL-60 human promyelocytic leukemia cells were examined by a nitroblue tetrazolium (NBT) reduction test. 1,25(OH)2D3 at the concentrations of 7-70 nM induced NBT-positive cells, which was used as a criterion of cell differentiation. IFN-gamma itself showed little effect on induction of NBT-positive cells or on cell growth at a concentration up to 1000 U/ml. However, in a combination of 1,25(OH)2D3 with IFN-gamma (100 and 300 U/ml), cell differentiation was strongly inhibited and was accompanied by growth inhibition. Treatment with a combination of 1,25(OH)2D3 and TNF-alpha or IFN-gamma and TNF-alpha showed an additive effect on cell differentiation. IFN-gamma seems to act as a specific inhibitor for 1,25(OH)2D3-induced cell differentiation. To elucidate the cause of the inhibition of cell differentiation by IFN-gamma, the ability of the cells to produce superoxide (O2-) was examined after culture for 5 days in the presence of 1,25(OH)2D3 and IFN-gamma. The results indicated that the inhibition of IFN-gamma was caused by a reduction in the ability of the cells to produce O2- in response to stimulation by 12-O-tetradecanoylphorbol-13-acetate (TPA).
Yoshida
M
M
Pharmacology Division, National Cancer Center Research Institute, Tokyo, Japan.
Eguchi
T
T
Ikekawa
N
N
Saijo
N
N
D002117:Calcitriol / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002762:Cholecalciferol / Q000037:antagonists & inhibitors*; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D009580:Nitroblue Tetrazolium; D010084:Oxidation-Reduction; D015203:Reproducibility of Results; D013481:Superoxides / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D014409:Tumor Necrosis Factor-alpha; D013481:Superoxides; D002762:Cholecalciferol; D009580:Nitroblue Tetrazolium; D007371:Interferon-gamma; D002117:Calcitriol