Dual effect of 1 alpha,25-dihydroxyvitamin D3 on hsp28 and PKC beta gene expression in phorbol ester-resistant human myeloid HL-525 leukemic cells.
We investigated the effect of 1 alpha-25-dihydroxyvitamin D3 [1,25-(OH)2D3] on the expression of the 28-kDa heat shock protein gene (hsp28) and the protein kinase C beta gene (PKC beta) in the human myeloid HL-60 leukemic cell variant HL-525, which is resistant to phorbol ester-induced macrophage differentiation. Northern and western blot analysis showed little or no hsp28 gene expression in the HL-60 cell variant, HL-205, which is susceptible to such differentiation, while a relatively high basal level of hsp28 gene expression was observed in the HL-525 cells. However, both cell lines demonstrated heat shock-induced expression of this gene. During treatment with 50-300 nM 1,25-(OH)2D3, a marked reduction of hsp28 gene expression along with an induction of PKC beta gene expression was observed in HL-525 cells. A gel mobility-shift assay demonstrated that the 1,25-(OH)2D3-induced alteration of hsp28 gene expression was associated with decreased binding activity to the vitamin D3 receptor-vitamin D3 response element (VDR-VDRE), whereas binding to the heat shock transcription factor-heat shock element (HSF-HSE) was not altered. Our results suggest that the dual effect of 1,25-(OH)2D3 on hsp28 and PKC beta gene expression is due to the different sequence composition of the vitamin D response element in the promoter region as well as an accessory factor for each gene or that 1,25-(OH)2D3 increases PKC beta gene expression, which, in turn, negatively regulates the expression of the hsp28 gene or vice versa.
Lee
Y J
YJ
Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, MI 48073, USA.
Galoforo
S S
SS
Berns
C M
CM
Blackburn
R V
RV
Huberman
E
E
Corry
P M
PM
D002117:Calcitriol / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects; D050890:HSP30 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D007951:Leukemia, Myeloid / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism*; D064546:Protein Kinase C beta; D018167:Receptors, Calcitriol / Q000187:drug effects; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured / Q000187:drug effects
D050890:HSP30 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D008565:Membrane Proteins; D018167:Receptors, Calcitriol; D011493:Protein Kinase C; D064546:Protein Kinase C beta; D002117:Calcitriol; D013755:Tetradecanoylphorbol Acetate