title: Detection of miR-34a promoter methylation in combination with elevated expression of c-Met and β-catenin predicts distant metastasis of colon cancer.
abstract: OBJECTIVE
  Here, we determined whether epigenetic inactivation of miR-34a and miR-34b/c genes may serve as a prognostic marker for distant metastases in colon cancer.
  
  
  METHODS
  Using a case-control study design of 94 primary colon cancer samples with and without liver metastases, we determined CpG methylation frequencies of miR-34a and miR-34b/c promoters, expression of miR-34a, and its targets c-Met, Snail, and β-catenin and their prognostic value.
  
  
  RESULTS
  miR-34a methylation was detected in 45.1% (n = 42 of 93) of the samples and strongly associated with metastases to the liver (P = 0.003) and lymph nodes (P = 0.006). miR-34b/c methylation was detected in 91.9% of the samples (n = 79/86). A significant inverse correlation between miR-34a methylation and expression of mature miR-34a (P = 0.018) was detected. Decreased miR-34a expression was associated with upregulation of c-Met, Snail, and β-catenin protein levels (P = 0.031, 0.132, and 0.004), which were associated with distant metastases (P = 0.001, 0.017, and 0.005). In a confounder-adjusted multivariate regression model miR-34a methylation, high c-Met and β-catenin levels provided the most significant prognostic information about metastases to the liver (P = 0.014, 0.031, and 0.058) and matched pairs showed a higher prevalence of these risk factors in the samples with distant spread (P = 0.029). Finally, we obtained statistical evidence indicating that the simultaneous detection of these three markers has the highest prognostic value.
  
  
  CONCLUSIONS
  Silencing of miR-34a and upregulation of c-Met, Snail, and β-catenin expression is associated with liver metastases of colon cancer. Detection of miR-34a silencing in resected primary colon cancer may be of prognostic value, especially in combination with detection of c-Met and β-catenin expression.
authors.affiliation: Experimental and Molecular Pathology, Institute of Pathology, Institute of Pathology, and Institute for Medical Information Processing, Biometry and Epidemiology, Ludwig-Maximilians-Universität München, Munich, Germany.
authors.forename: Helge
authors.initials: H
authors.lastname: Siemens
authors.forename: Jens
authors.initials: J
authors.lastname: Neumann
authors.forename: Rene
authors.initials: R
authors.lastname: Jackstadt
authors.forename: Ulrich
authors.initials: U
authors.lastname: Mansmann
authors.forename: David
authors.initials: D
authors.lastname: Horst
authors.forename: Thomas
authors.initials: T
authors.lastname: Kirchner
authors.forename: Heiko
authors.initials: H
authors.lastname: Hermeking
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D016022:Case-Control Studies; D003110:Colonic Neoplasms / Q000235:genetics* / Q000473:pathology*; D019175:DNA Methylation; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics / Q000556:secondary; D035683:MicroRNAs / Q000235:genetics*; D009362:Neoplasm Metastasis; D011379:Prognosis; D011401:Promoter Regions, Genetic; D019859:Proto-Oncogene Proteins c-met / Q000235:genetics* / Q000378:metabolism; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D051176:beta Catenin / Q000235:genetics* / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; C522425:MIRN34 microRNA, human; D035683:MicroRNAs; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors; D051176:beta Catenin; D019859:Proto-Oncogene Proteins c-met