title: Histone deacetylase inhibition is associated with transcriptional repression of the Hmga2 gene.
abstract: The high-mobility-group A2 protein (HMGA2) plays important functional roles in transcriptional regulation, DNA replication and chromatin structure. In this study, the effect of histone deacetylase inhibition on the transcriptional activity of the Hmga2 gene was investigated in vivo both at the endogenous gene level and in a variety of cell lines using transiently transfected promoter constructs. Trichostatin A (TSA) repressed both transfected murine and human Hmga2 promoter constructs 3-8-fold in NIH3T3, F9 and HeLa cells. Steady-state Hmga2 mRNA levels in NIH3T3 cells decreased 4-5-fold following TSA treatment, while pre- treatment of NIH3T3 cells with the transcriptional inhibitor, actinomycin D, completely blocked TSA mediated repression of the Hmga2 gene. Cross-linked chromatin immunoprecipitation (X-ChIP) analysis revealed a 5-6-fold decrease in endogenous Hmga2 promoter bound Sp1 and Sp3 proteins following TSA treatment in parallel with observed loss of acetylated histone H3 and H4. In addition, the poly-pyrimidine-tract-binding protein (PTB) was observed to bind to the Hmga2 promoter in both TSA treated and untreated NIH3T3 cells. Together, these results suggest TSA treatment leads to a decrease in Hmga2 gene transcription, and a significant decrease in promoter bound Sp1, Sp3 and acetylated histones H3 and H4.
authors.affiliation: Laboratory of Biochemistry and Molecular Biology, The Wheeler Institute for Biomedical Research, Johns Hopkins University Bayview Campus, Baltimore, MD 21224, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Ferguson
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Henry
authors.forename: R Alexander
authors.initials: RA
authors.lastname: Currie
mesh_terms: D016475:3T3 Cells; D000818:Animals; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D020868:Gene Silencing; D011905:Genes, ras; D025743:HMGA2 Protein / Q000096:biosynthesis / Q000235:genetics*; D006367:HeLa Cells; D056572:Histone Deacetylase Inhibitors; D006657:Histones / Q000378:metabolism; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology; D051379:Mice; D038941:Polypyrimidine Tract-Binding Protein / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D016329:Sp1 Transcription Factor / Q000378:metabolism; D051705:Sp3 Transcription Factor; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D025743:HMGA2 Protein; D056572:Histone Deacetylase Inhibitors; D006657:Histones; D006877:Hydroxamic Acids; D012333:RNA, Messenger; C497121:SP3 protein, human; D016329:Sp1 Transcription Factor; C497122:Sp3 protein, mouse; D014157:Transcription Factors; D038941:Polypyrimidine Tract-Binding Protein; D051705:Sp3 Transcription Factor; C012589:trichostatin A