Osteoblastic differentiation induced by transcription factor decoy against estrogen receptor alpha gene.
Osteoblasts have been shown to express both isoforms of estrogen receptor (ER alpha and ER beta). As a tool for the study of endogenous regulation of these genes the decoy strategy was employed. Human MG-63 osteoblast-like cells were transfected with a DNA decoy molecule containing a putative negative cis-element (DNA-102) located in the C distal promoter of ER alpha gene. Using real-time quantitative RT-PCR, we found that the DNA-102, but not scrambled DNA, produced a 36-fold increase in the level of total ER alpha mRNA and a 12-fold increase in the level of mRNA for the F isoform that is transcribed from the upstream F promoter, which is predominantly used in osteoblasts. This effect appears to be controlled by estrogen since 17-beta-estradiol downregulated the mRNA increase. Notably, the same decoy was able to induce a 6-fold increase in ER beta mRNA transcription, indicating the coregulation of the ER alpha and ER beta expression. An increase in OPN but not in BMP4 expression was also observed. In addition, in decoy-treated cells, the cell growth decreased together with an increase in alkaline phosphatase activity. These findings indicated that DNA-102 decoy was able to induce a more differentiated osteoblastic phenotype. The augmentation of ER alpha and ER beta expression by the decoy approach may offer a further possibility for patient response to estrogenic therapy in the treatment of diseases related to estrogen deficiency.
Lambertini
Elisabetta
E
Dipartimento di Biochimica e Biologia Molecolare, Università degli Studi di Ferrara, Via L. Borsari 46, 44100 Ferrara, Italy.
Penolazzi
Letizia
L
Aguiari
Gianluca
G
del Senno
Laura
L
Pezzetti
Furio
F
Sollazzo
Vincenzo
V
Piva
Roberta
R
D000469:Alkaline Phosphatase / Q000378:metabolism; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology*; D004247:DNA / Q000235:genetics / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D005786:Gene Expression Regulation / Q000235:genetics*; D006801:Humans; D009687:Nuclear Proteins / Q000378:metabolism; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D053495:Osteopontin; D011960:Receptors, Estrogen / Q000235:genetics* / Q000378:metabolism; D012795:Sialoglycoproteins / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D014407:Tumor Cells, Cultured
C525809:BMP4 protein, human; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D009687:Nuclear Proteins; D011960:Receptors, Estrogen; C506895:SPP1 protein, human; D012795:Sialoglycoproteins; D053495:Osteopontin; D004958:Estradiol; D004247:DNA; D000469:Alkaline Phosphatase