RREB1 repressed miR-143/145 modulates KRAS signaling through downregulation of multiple targets

Oncogene. 2013 May 16;32(20):2576-85. doi: 10.1038/onc.2012.266. Epub 2012 Jul 2.


A lack of expression of miR-143 and miR-145 has been demonstrated to be a frequent feature of colorectal tumors. Activating KRAS mutations have been reported in 30-60% of colorectal cancers and an inverse correlation between Kras and miR-143/145 expression has been observed. Previously, we have demonstrated that oncogenic Kras leads to repression of the miR-143/145 cluster in pancreatic cancer and is dependent on the Ras responsive element (RRE) binding protein (RREB1), which negatively regulates miR-143/145 expression. In the present study, we have found that RREB1 is overexpressed in colorectal adenocarcinoma tumors and cell lines, and the expression of the miR-143/145 primary transcript is inversely related to RREB1 expression. In colorectal cancer cell lines, the miR-143/145 cluster is repressed by RREB1 downstream of constitutively active KRAS. RREB1 is activated by the MAPK pathway and negatively represses the miR-143/145 promoter through interaction with two RREs. In addition, overexpression of miR-143 or miR-145 in HCT116 cells abrogates signaling through the MAPK, PI3K and JNK pathways by downregulation of both KRAS and RREB1 in addition to downregulation of a cohort of genes in the MAPK signaling cascade. These results establish a complex network of regulation through which the miR-143/145 cluster is able to modulate KRAS signaling in colorectal cancer.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / genetics
  • Adenocarcinoma / pathology
  • Cell Line, Tumor
  • Colonic Neoplasms / genetics
  • Colonic Neoplasms / pathology
  • Colorectal Neoplasms / genetics
  • Colorectal Neoplasms / pathology
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / metabolism
  • Down-Regulation
  • Gene Expression Regulation, Neoplastic*
  • HCT116 Cells
  • Humans
  • MAP Kinase Signaling System / genetics
  • MicroRNAs / genetics*
  • Promoter Regions, Genetic
  • Signal Transduction / genetics
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism
  • ras Proteins / genetics
  • ras Proteins / metabolism*


  • DNA-Binding Proteins
  • MIRN143 microRNA, human
  • MIRN145 microRNA, human
  • MicroRNAs
  • RREB1 protein, human
  • Transcription Factors
  • ras Proteins