Over- and under-expressed microRNAs in human colorectal cancer

Int J Oncol. 2009 Apr;34(4):1069-75. doi: 10.3892/ijo_00000233.


MicroRNAs (miRNAs) constitute a class of small (21-23 nucleotides) noncoding RNAs that function as post-transcriptional gene regulators. It is becoming increasingly clear that altered miRNA expression correlates with the pathogenesis of cancers. The purpose of this study was to determine the up-regulated miRNAs in human colorectal cancer. Total RNA was isolated from cancer tissues and corresponding noncancerous tissues from surgically resected colorectal cancers. The expression profiles of miRNAs were determined using a miRNA microarray containing 455 human miRNA probes. The expression status of selected miRNAs in paired clinical samples was then investigated by real-time RT-PCR. Twenty-one miRNAs were identified by miRNA array analysis as overexpressed in colorectal cancer tissues compared to normal epithelial tissues. Among them, the expression of miR-31, miR-183, miR-17-5p, miR-18a, miR-20a and miR-92 were confirmed to be significantly higher in cancer tissues than in normal tissues (P<0.05). In contrast, the expression of miR-143 and miR-145 in cancer tissues were significantly lower than in normal tissues (P<0.05). The miR-18a overexpression group tended to have a poorer clinical prognosis than the low expression group (P=0.07). We identified miRNAs that were overexpressed or under-expressed in colorectal cancers and which may be correlated with colorectal carcinogenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Case-Control Studies
  • Cell Line, Tumor
  • Colorectal Neoplasms / genetics*
  • Colorectal Neoplasms / metabolism*
  • Colorectal Neoplasms / mortality
  • Female
  • Gene Expression Profiling*
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Male
  • MicroRNAs / metabolism*
  • Oligonucleotide Array Sequence Analysis
  • Reverse Transcriptase Polymerase Chain Reaction
  • Time Factors
  • Treatment Outcome


  • MicroRNAs