title: Aberrant methylation of DACT1 and DACT2 are associated with tumor progression and poor prognosis in esophageal squamous cell carcinoma.
abstract: BACKGROUND
  The DACT (Dishevelled-associated antagonist of β-catenin) family of scaffold proteins may play important roles in tumorigenesis. However, the epigenetic changes of DACT1, 2, 3 and their effect on esophageal squamous cell carcinoma (ESCC) have not been investigated so far. The aim of this study was to investigate the promoter methylation and expression of DACT family, in order to elucidate more information on the role of DACT with regard to the progression and prognosis of ESCC.
  
  
  METHODS
  MSP and BGS methods were respectively applied to examine the methylation status of DACT; RT-PCR, Western blot and immunohistochemistry methods were respectively used to determine the mRNA and protein expression of DACT; MTT, Colony-formation and Wound-healing assay were performed to assess the effect of DACT1 and DACT2 on proliferation and migration of esophageal cancer cells.
  
  
  RESULTS
  Frequent reduced expression of DACT1, DACT2 and DACT3 were found in esophageal cancer cell lines and the expression levels of DACT1 and DACT2 were reversed by 5-Aza-Dc. Decreased mRNA and protein expression of DACT1 and DACT2 were observed in ESCC tumor tissues and were associated with the methylation status of transcription start site (TSS) region. The hypermethylation of CpG islands (CGI) shore region in DACT1 was observed both in tumor and corresponding adjacent tissues but wasn't related to the transcriptional inhibition of DACT1. The methylation status of TSS region in DACT1 and DACT2 and the protein expression of DACT2 were independently associated with ESCC patients' prognosis.
  
  
  CONCLUSIONS
  The TSS region hypermethylation may be one of the main mechanisms for reduced expression of DACT1 and DACT2 in ESCC. The simultaneous methylation of DACT1 and DACT2 may play important roles in progression of ESCC and may serve as prognostic methylation biomarkers for ESCC patients.
authors.affiliation: Laboratory of Pathology, Hebei Cancer Institute, The Fourth Hospital of Hebei Medical University, Jiankanglu 12, Shijiazhuang, 050011, Hebei, China.
authors.forename: Yan-Li
authors.initials: YL
authors.lastname: Guo
authors.affiliation: Laboratory of Pathology, Hebei Cancer Institute, The Fourth Hospital of Hebei Medical University, Jiankanglu 12, Shijiazhuang, 050011, Hebei, China. hbmubaoenshan@sina.com.
authors.forename: Bao-En
authors.initials: BE
authors.lastname: Shan
authors.affiliation: Laboratory of Pathology, Hebei Cancer Institute, The Fourth Hospital of Hebei Medical University, Jiankanglu 12, Shijiazhuang, 050011, Hebei, China. guowei7303@163.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Guo
authors.affiliation: Laboratory of Pathology, Hebei Cancer Institute, The Fourth Hospital of Hebei Medical University, Jiankanglu 12, Shijiazhuang, 050011, Hebei, China.
authors.forename: Zhi-Ming
authors.initials: ZM
authors.lastname: Dong
authors.affiliation: Laboratory of Pathology, Hebei Cancer Institute, The Fourth Hospital of Hebei Medical University, Jiankanglu 12, Shijiazhuang, 050011, Hebei, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Laboratory of Pathology, Hebei Cancer Institute, The Fourth Hospital of Hebei Medical University, Jiankanglu 12, Shijiazhuang, 050011, Hebei, China.
authors.forename: Su-Peng
authors.initials: SP
authors.lastname: Shen
authors.affiliation: Laboratory of Pathology, Hebei Cancer Institute, The Fourth Hospital of Hebei Medical University, Jiankanglu 12, Shijiazhuang, 050011, Hebei, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Guo
authors.affiliation: Laboratory of Pathology, Hebei Cancer Institute, The Fourth Hospital of Hebei Medical University, Jiankanglu 12, Shijiazhuang, 050011, Hebei, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Liang
authors.affiliation: Laboratory of Pathology, Hebei Cancer Institute, The Fourth Hospital of Hebei Medical University, Jiankanglu 12, Shijiazhuang, 050011, Hebei, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Kuang
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology; D002352:Carrier Proteins / Q000378:metabolism*; D045744:Cell Line, Tumor; D004938:Esophageal Neoplasms / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008745:Methylation; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D011379:Prognosis
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D014408:Biomarkers, Tumor; D002352:Carrier Proteins; C491683:DACT1 protein, human; C478653:DACT2 protein, human; D009363:Neoplasm Proteins; D009687:Nuclear Proteins
keywords: DACT gene; Esophageal squamous cell carcinoma; Methylation; Prognosis