Localization of a negative vitamin D response sequence in the human growth hormone gene.
1,25-Dihydroxyvitamin D(3) [1,25(OH)(2) D(3)] exerts its biological effects by binding to the vitamin D receptor (VDR), which binds in turn to the vitamin D response elements located in the target gene's promoter. We have previously demonstrated that VDR binds in vitro with high affinity to the 5'-flanking sequence of the human growth hormone (hGH) gene. In this study, we analyzed the response to 1,25(OH)(2) D(3) of hGH-promoter constructs introduced by transfection into the MCF-7 human adenocarcinoma cell line. We found that the transcriptional activity of some of these constructs was markedly reduced by 1,25(OH)(2) D(3). Deletion analyses revealed that a 34-bp sequence located between positions -62 and -29 upstream of the transcription start site is sufficient for this repressive response. This conclusion was also confirmed by gel mobility shift assays. Our results indicate that vitamin D inhibits hGH gene transcription, directly or by interference with other transcription factors.
Seoane
Samuel
S
Department of Physiology, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
Alonso
Manuela
M
Segura
Carmen
C
Pérez-Fernández
Román
R
D001483:Base Sequence; D002117:Calcitriol / Q000494:pharmacology*; D024202:Electrophoretic Mobility Shift Assay; D020868:Gene Silencing; D005982:Glutathione Transferase / Q000235:genetics; D019382:Human Growth Hormone / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D018167:Receptors, Calcitriol / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017384:Sequence Deletion; D014407:Tumor Cells, Cultured; D030181:Vitamin D Response Element
D018167:Receptors, Calcitriol; D011993:Recombinant Fusion Proteins; D019382:Human Growth Hormone; D005982:Glutathione Transferase; D002117:Calcitriol