title: JMJD2A contributes to breast cancer progression through transcriptional repression of the tumor suppressor ARHI.
abstract: BACKGROUND
  Breast cancer is a worldwide health problem and the leading cause of cancer death among females. We previously identified Jumonji domain containing 2A (JMJD2A) as a critical mediator of breast cancer proliferation, migration and invasion. We now report that JMJD2A could promote breast cancer progression through transcriptional repression of the tumor suppressor aplasia Ras homolog member I (ARHI).
  
  
  METHODS
  Immunohistochemistry was performed to examine protein expressions in 155 cases of breast cancer and 30 non-neoplastic tissues. Spearman correlation analysis was used to analyze the correlation between JMJD2A expression and clinical parameters as well as several tumor regulators in 155 cases of breast cancer. Gene and protein expressions were monitored by quantitative polymerase chain reaction (qPCR) and Western blot. Results from knockdown of JMJD2A, overexpression of JMJD2A, Co-immunoprecipitation (Co-IP) assay, dual luciferase reporter gene assay and chromatin immunoprecipitation (ChIP) elucidated molecular mechanisms of JMJD2A action in breast cancer progression. Furthermore, the effects of ARHI overexpression on JMJD2A-mediated tumor progression were investigated in vitro and in vivo. For in vitro experiments, cell proliferation, wound-healing, migration and invasion were monitored by cell counting, scratch and Boyden Chamber assays. For in vivo experiments, control cells and cells stably expressing JMJD2A alone or together with ARHI were inoculated into mammary fat pads of mice. Tumor volume, tumor weight and metastatic nodules were measured by caliper, electronic balance and nodule counting, respectively.
  
  
  RESULTS
  JMJD2A was highly expressed in human breast cancers and positively correlated with tumor progression. Knockdown of JMJD2A increased ARHI expression whereas overexpression of JMJD2A decreased ARHI expression at both protein and mRNA levels. Furthermore, E2Fs and histone deacetylases were involved in the transcriptional repression of ARHI expression by JMJD2A. And the aggressive behavior of JMJD2A in breast cancers could be reversed by re-expression of ARHI in vitro and in vivo.
  
  
  CONCLUSIONS
  We demonstrated a cancer-promoting effect of JMJD2A and defined a novel molecular pathway contributing to JMJD2A-mediated breast cancer progression.
authors.forename: Li-Liang
authors.initials: LL
authors.lastname: Li
authors.forename: Ai-Min
authors.initials: AM
authors.lastname: Xue
authors.forename: Bei-Xu
authors.initials: BX
authors.lastname: Li
authors.forename: Yi-Wen
authors.initials: YW
authors.lastname: Shen
authors.forename: Yu-Hua
authors.initials: YH
authors.lastname: Li
authors.forename: Cheng-Liang
authors.initials: CL
authors.lastname: Luo
authors.forename: Ming-Chang
authors.initials: MC
authors.lastname: Zhang
authors.forename: Jie-Qing
authors.initials: JQ
authors.lastname: Jiang
authors.forename: Zu-De
authors.initials: ZD
authors.lastname: Xu
authors.forename: Jian-Hui
authors.initials: JH
authors.lastname: Xie
authors.forename: Zi-Qin
authors.initials: ZQ
authors.lastname: Zhao
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D049109:Cell Proliferation / Q000235:genetics; D018450:Disease Progression; D050684:E2F Transcription Factors / Q000235:genetics; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D016147:Genes, Tumor Suppressor; D057809:HEK293 Cells; D006655:Histone Deacetylases / Q000235:genetics; D006801:Humans; D056484:Jumonji Domain-Containing Histone Demethylases / Q000096:biosynthesis / Q000235:genetics*; D061986:MCF-7 Cells; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009361:Neoplasm Invasiveness / Q000235:genetics; D009368:Neoplasm Transplantation; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding / Q000235:genetics; D034622:RNA Interference; D012333:RNA, Messenger / Q000096:biosynthesis; D034741:RNA, Small Interfering; D014158:Transcription, Genetic / Q000235:genetics*; D014183:Transplantation, Heterologous; D014945:Wound Healing / Q000235:genetics; D020741:rho GTP-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics
chemical_list: C117386:DIRAS3 protein, human; D050684:E2F Transcription Factors; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D056484:Jumonji Domain-Containing Histone Demethylases; C494424:KDM4A protein, human; D006655:Histone Deacetylases; D020741:rho GTP-Binding Proteins