title: MEK-ERK pathway regulates EZH2 overexpression in association with aggressive breast cancer subtypes.
abstract: EZH2 overexpression occurs in various malignancies and is associated with a poor outcome. We have so far demonstrated that EZH2 downregulates the important genes such as E-cadherin and RUNX3 by increasing histone H3K27 trimethylation. However, the mechanism of EZH2 overexpression in various cancer cells remains unclear. In this study we carried out a promoter analysis of the EZH2 gene and investigated whether a survival signal that is upregulated in cancer cells is related to overexpression at the transcription level. We also explored the clinical relevance of the signaling pathway that leads to EZH2 overexpression in breast cancer and demonstrated that MEK-ERK1/2-Elk-1 pathway leads to EZH2 overexpression. The triple-negative and ERBB2-overexpressing subtypes of breast cancer are known to contain more rapidly proliferating breast cancer cells. The signaling pathway connected to EZH2 overexpression was associated with both aggressive subtypes of breast cancer. We show the significance that overexpression of histone modifier protein EZH2 in cancer cells and our study could pave the way for EZH2 inhibition to become an efficient treatment for more aggressive breast cancers.
authors.affiliation: Pathology Division, Research Center for Innovative Oncology, National Cancer Center at Kashiwa, Chiba, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Fujii
authors.forename: K
authors.initials: K
authors.lastname: Tokita
authors.forename: N
authors.initials: N
authors.lastname: Wada
authors.forename: K
authors.initials: K
authors.lastname: Ito
authors.forename: C
authors.initials: C
authors.lastname: Yamauchi
authors.forename: Y
authors.initials: Y
authors.lastname: Ito
authors.forename: A
authors.initials: A
authors.lastname: Ochiai
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D045744:Cell Line, Tumor; D047369:Chromatin Immunoprecipitation; D004268:DNA-Binding Proteins / Q000378:metabolism*; D000071221:Enhancer of Zeste Homolog 2 Protein; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D005260:Female; D006801:Humans; D020930:MAP Kinase Kinase Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D063151:Polycomb Repressive Complex 2; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D034622:RNA Interference; D034741:RNA, Small Interfering; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism*; D024363:Transcription Initiation Site; D050807:ets-Domain Protein Elk-1 / Q000037:antagonists & inhibitors / Q000235:genetics
chemical_list: D004268:DNA-Binding Proteins; D000071221:Enhancer of Zeste Homolog 2 Protein; D048049:Extracellular Signal-Regulated MAP Kinases; D020930:MAP Kinase Kinase Kinases; D063151:Polycomb Repressive Complex 2; D034741:RNA, Small Interfering; D018719:Erb-b2 Receptor Tyrosine Kinases; D014157:Transcription Factors; D050807:ets-Domain Protein Elk-1; C498409:EZH2 protein, human; C508053:ERBB2 protein, human