RRC ID 45505
Author Sakamoto A, Akiyama Y, Shimada S, Zhu WG, Yuasa Y, Tanaka S.
Title DNA Methylation in the Exon 1 Region and Complex Regulation of Twist1 Expression in Gastric Cancer Cells.
Journal PLoS One
Abstract Twist1 overexpression is frequently observed in various cancers including gastric cancer (GC). Although DNA methylation of the Twist1 gene has been reported in cancer cells, the mechanisms underlying transcriptional activation remain uncertain. In this study, we first examined epigenetic alterations of the Twist1 using Twist1 transcription-positive and -negative cell lines that are derived from our established diffuse-type GC mouse model. Treatment with a DNA demethylation agent 5-aza-dC re-activated Twist1 expression in Twist1 expression-negative GC cells. According to methylation-specific PCR and bisulfite sequencing analysis, methylation at the CpG-rich region within Twist1 coding exon 1, rather than its promoter region, was tightly linked to transcriptional silencing of the Twist1 expression in mouse GC cells. Chromatin immunoprecipitation assays revealed that active histone mark H3K4me3 was enriched in Twist1 expression-positive cells, and inactive histone mark H3K9me3 was enriched in Twist1 expression-negative cells. The expression levels of Suv39h1 and Suv39h2, histone methyltransferases for H3K9me3, were inversely correlated with Twist1 expression, and knockdown of Suv39h1 or Suv39h2 induced Twist1 expression. Moreover, Sp1 transcription factor bound to the exon 1 CpG-rich region in Twist1 expression-positive cell lines, and Twist1 expression was diminished by mithramycin, which that interferes with Sp1 binding to CpG-rich regulatory sequences. Our studies suggested that the Twist1 transcription in GC cells might be regulated through potential cooperation of DNA methylation, histone modification in complex with Sp1 binding to CpG-rich regions within the exon 1 region.
Volume 10(12)
Pages e0145630
Published 2015-1-1
DOI 10.1371/journal.pone.0145630
PII PONE-D-15-40710
PMID 26695186
PMC PMC4687923
MeSH Animals CpG Islands DNA Methylation* DNA, Neoplasm / genetics DNA, Neoplasm / metabolism* Exons* Gene Expression Regulation, Neoplastic* Mice Mice, Knockout Neoplasm Proteins / biosynthesis* Neoplasm Proteins / genetics Neoplasms, Experimental / genetics Neoplasms, Experimental / metabolism* Neoplasms, Experimental / pathology Nuclear Proteins / biosynthesis* Nuclear Proteins / genetics Plicamycin / pharmacology Stomach Neoplasms / genetics Stomach Neoplasms / metabolism* Stomach Neoplasms / pathology Transcription, Genetic / drug effects Transcription, Genetic / genetics Twist-Related Protein 1 / biosynthesis* Twist-Related Protein 1 / genetics
IF 2.776
Times Cited 17
Human and Animal Cells