title: Methylation of the mouse DIx5 and Osx gene promoters regulates cell type-specific gene expression.
abstract: Dlx5 and Osx are master regulatory proteins essential for initiating the cascade leading to osteoblast differentiation in mammals, but the mechanism of osteoblast-specific expression is not fully understood. DNA methylation at CpG sequences is involved in tissue and cell type-specific gene expression. We investigated the methylation status of Dlx5 and Osx in osteogenic and nonosteogenic cell lines by methylation-specific PCR (MSP). The CpG dinucleotides of the Dlx5 and Osx promoter regions were unmethylated in osteogenic cell lines transcribing these genes but methylated in nonosteogenic cell lines. Treatment of C2C12 cells with 5-AzadC induced dose- and time-dependent expression of Dlx5 and Osx mRNA by demethylating the corresponding promoters. Furthermore the mRNAs for the osteoblast markers ALP and OC, which were undetectable in untreated cells, gradually increased after 5-AzadC treatment. In addition, BMP-2 stimulation induced Dlx5 expression by hypomethylating its promoter. These findings suggest that DNA methylation plays an important role in cell type-specific expression of Dlx5 and Osx.
authors.affiliation: Department of Anatomy, School of Medicine, Kyungpook National University, Skeletal Diseases Genome Research Center, Kyungpook National University Hospital, Daegu 700-422, Korea.
authors.forename: Ji Yun
authors.initials: JY
authors.lastname: Lee
authors.forename: Yu Mi
authors.initials: YM
authors.lastname: Lee
authors.forename: Mi Jin
authors.initials: MJ
authors.lastname: Kim
authors.forename: Je Yong
authors.initials: JY
authors.lastname: Choi
authors.forename: Eui Kyun
authors.initials: EK
authors.lastname: Park
authors.forename: Shin Yoon
authors.initials: SY
authors.lastname: Kim
authors.forename: Sam Poong
authors.initials: SP
authors.lastname: Lee
authors.forename: Jae Sup
authors.initials: JS
authors.lastname: Yang
authors.forename: Dong Sun
authors.initials: DS
authors.lastname: Kim
mesh_terms: D000818:Animals; D001374:Azacitidine / Q000031:analogs & derivatives / Q000494:pharmacology; D002454:Cell Differentiation; D002460:Cell Line; D018899:CpG Islands / Q000235:genetics; D019175:DNA Methylation / Q000187:drug effects; D000077209:Decitabine; D044127:Epigenesis, Genetic; D005786:Gene Expression Regulation; D018398:Homeodomain Proteins / Q000235:genetics*; D051379:Mice; D010006:Osteoblasts / Q000166:cytology; D010012:Osteogenesis; D011401:Promoter Regions, Genetic; D000076182:Sp7 Transcription Factor; D014157:Transcription Factors / Q000235:genetics*
chemical_list: C088334:Distal-less homeobox proteins; C501120:Dlx5 protein, mouse; D018398:Homeodomain Proteins; D000076182:Sp7 Transcription Factor; C479466:Sp7 protein, mouse; D014157:Transcription Factors; D000077209:Decitabine; D001374:Azacitidine