Transcriptional activity analysis of promoter region of human PAX9 gene under dexamethasone, retinoic acid, and ergocalciferol treatment in MCF-7 and MDPC23.
ABSTRACT PAX9 gene is a member of the family homeobox of transcription factors and performs important function in development and organogenesis. Mutations in PAX9 coding sequences have been implicated in autosomal dominant oligodontia affecting predominantly permanent molars and second premolars. Previous studies have shown that PAX9 is required for secondary palate development and teratogens have been identified as inducers of a tooth and craniofacial malformations. This work focused on the analysis on the 5'-flanking region of the PAX9 gene studying the influence of retinoic acid, dexamethasone, and vitamin D on the expression of PAX9 by expression constructs that carry the reporter gene luciferase. As results, retinoic acid and dexamethasone showed progressive decrease of PAX9 expression. PAX9-pGL3B1 and PAX9-pGL3B2 promoter was inhibited under the treatment of dexamethasone and ergocalciferol. Retinoic acid and dexamethasone did not alter PAX9-pGL3B3 behavior indicating that sequences present between -1106 and +92 were important for the transcriptional activity of PAX9 promoter. In this study, we characterized the transcriptional activity of specific regions of the PAX9 promoter gene and we demonstrated that retinoic acid and ergocalciferol can modulate the transcriptional activity of PAX9 gene.
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ABSTRACT: The production of interferon was used to study the site and mechanism of action of retinoic acid (vitamin A). The data are consistent with a site of action at the gene level, because it appears that interferon production is blocked at the transcriptional step by a retinoic acid-induced protein. (i) The effect of retinoic acid is probably on an early cellular function associated with interferon production rather than an effect on the inducer [virus or poly(I).poly(C)]. (ii) The suppression of interferon production by retinoic acid is blocked by cycloheximide, indicating that a newly synthesized protein (repressor) mediates the suppression. (iii) When allowances are made for the time required for the synthesis of the retinoic acid-induced protein, the time course of retinoic acid suppression of interferon production is superimposable on the time course of actinomycin D suppression because the slopes are parallel. These data provide evidence for transcriptional control of a specific protein (interferon) by retinoic acid. Additionally, they support the existence of transcriptional control of interferon production after addition of inducer.Proceedings of the National Academy of Sciences 01/1978; 74(12):5382-6. · 9.81 Impact Factor
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ABSTRACT: The Msx1 homeobox gene is expressed at diverse sites of epithelial-mesenchymal interaction during vertebrate embryogenesis, and has been implicated in signalling processes between tissue layers. To determine the phenotypic consequences of its deficiency, we prepared mice lacking Msx1 function. All Msx1- homozygotes manifest a cleft secondary palate, a deficiency of alveolar mandible and maxilla and a failure of tooth development. These mice also exhibit abnormalities of the nasal, frontal and parietal bones, and of the malleus in the middle ear. Msx1 thus has a critical role in mediating epithelial-mesenchymal interactions during craniofacial bone and tooth development. The Msx1-/Msx1- phenotype is similar to human cleft palate, and provides a genetic model for cleft palate and oligodontia in which the defective gene is known.Nature Genetics 05/1994; 6(4):348-56. · 35.21 Impact Factor
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ABSTRACT: A genomic DNA clone for 1 alpha,25-dihydroxyvitamin D-3 (1,25-(OH)2D3) 24-hydroxylase was isolated from a human chromosome 20 library. It spans 2.42 kb, containing the first two exons, the first and part of the second introns, and a 1.26 kb 5'-flanking region. Putative transcription cis-elements were revealed throughout the 5'-flanking region, including TATA box, CAAT box, GC boxes, vitamin D-responsive elements (VDRE), AP1, and AP2 sites. In a CAT reporter gene expression assay, the 24-hydroxylase promoter with its 1.2 kb 5'-flanking sequence elicits a 1,25-(OH)2D3-induced transactivation activity. Gel mobility shift assays of those putative DREs have identified that two different elements can form specific complexes with porcine intestinal nuclear extract (PINE). The specificity of VDRE-PINE complexes was verified by supershift assay with VDR-specific monoclonal antibody VXIE10B6. The proximal element VDREp (-172/-143) consists of three direct repeat half-sites, GAGTCAgcgAGGTGAgcgAGGGCG, in anti-sense orientation. The distal element VDREd (-293/-273) consists of two direct repeat half-sites, GCGTTCaccGGGTGT, also in anti-sense orientation. Both VDREs can direct a reporter gene expression using a heterologous herpes simplex virus thymidine kinase (TK) promoter in a 1,25-(OH)2D3-dependent fashion. Further characterization of these VDREs in various constructs with either a native or TK promoter suggests that both VDREs are required for the optimal induction of 24-hydroxylase expression by 1,25-(OH)2D3.Biochimica et Biophysica Acta 08/1995; 1263(1):1-9. · 4.66 Impact Factor