title: Epigenetically silenced miR-34b/c as a novel faecal-based screening marker for colorectal cancer.
abstract: BACKGROUND
  MicroRNAs are tiny non-coding small endogenous RNAs that regulate gene expression by translational repression, mRNA cleavage and mRNA inhibition. The aim of this study was to investigate the hypermethylation of miR-34b/c and miR-148a in colorectal cancer, and correlate this data to clinicopathological features. We also aimed to evaluate the hypermethylation of miR-34b/c in faeces specimens as a novel non-invasive faecal-DNA-based screening marker.
  
  
  METHODS
  The 5-aza-2'-deoxycytidine treatment and methylation-specific PCR were carried out to detect the hypermethylation of miR-34b/c and miR-148a.
  
  
  RESULTS
  The miR-34b/c hypermethylation was found in 97.5% (79 out of 82) of primary colorectal tumours, P=0.0110. In 75% (21 out of 28) of faecal specimens we found a hypermethylation of miR-34b/c while only in 16% (2 out of 12) of high-grade dysplasia. In addition, miR-148a was found to be hypermethylated in 65% (51 out of 78) of colorectal tumour tissues with no significant correlation to clinicopathological features. However, a trend with female gender and advanced age was found, P=0.083. We also observed a trend to lower survival rate in patients with miR-148a hypermethylation with 10-year survival probability: 48 vs 65%, P=0.561.
  
  
  CONCLUSIONS
  These findings show that aberrant hypermethylation of miR-34b/c could be an ideal class of early screening marker, whereas miR-148a could serve as a disease progression follow-up marker.
authors: Department of Internal Medicine, University of Rome Tor Vergata, Rome, Italy. m.kalimutho@qub.ac.uk
authors: M
authors: M
authors: Kalimutho
authors: S
authors: S
authors: Di Cecilia
authors: G
authors: G
authors: Del Vecchio Blanco
authors: F
authors: F
authors: Roviello
authors: P
authors: P
authors: Sileri
authors: M
authors: M
authors: Cretella
authors: A
authors: A
authors: Formosa
authors: G
authors: G
authors: Corso
authors: D
authors: D
authors: Marrelli
authors: F
authors: F
authors: Pallone
authors: G
authors: G
authors: Federici
authors: S
authors: S
authors: Bernardini
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