Specific alterations of the microRNA transcriptome and global network structure in colorectal cancer after treatment with MAPK/ERK inhibitors

J Mol Med (Berl). 2012 Dec;90(12):1421-38. doi: 10.1007/s00109-012-0918-8. Epub 2012 Jun 4.


The mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway has a master control role in various cancer-related biological processes as cell growth, proliferation, differentiation, migration, and apoptosis. It also regulates many transcription factors that control microRNAs (miRNAs) and their biosynthetic machinery. To investigate on the still poorly characterised global involvement of miRNAs within the pathway, we profiled the expression of 745 miRNAs in three colorectal cancer (CRC) cell lines after blocking the pathway with three different inhibitors. This allowed the identification of two classes of post-treatment differentially expressed (DE) miRNAs: (1) common DE miRNAs in all CRC lines after treatment with a specific inhibitor (class A); (2) DE miRNAs in a single CRC line after treatment with all three inhibitors (class B). By determining the molecular targets, biological roles, network position of chosen miRNAs from class A (miR-372, miR-663b, miR-1226*) and class B (miR-92a-1*, miR-135b*, miR-720), we experimentally demonstrated that they are involved in cell proliferation, migration, apoptosis, and globally affect the regulation circuits centred on MAPK/ERK signaling. Interestingly, the levels of miR-92a-1*, miR-135b*, miR-372, miR-720 are significantly higher in biopsies from CRC patients than in normal controls; they also are significantly higher in CRC patients with mutated KRAS than in those with wild-type genotypes (Wilcoxon test, p < 0.05): the latter could be a downstream effect of ERK pathway overactivation, triggered by KRAS mutations. Finally, our functional data strongly suggest the following miRNA/target pairs: miR-92a-1*/PTEN-SOCS5; miR-135b*/LATS2; miR-372/TXNIP; miR-663b/CCND2. Altogether, these results contribute to deepen current knowledge on still uncharacterized features of MAPK/ERK pathway, pinpointing new oncomiRs in CRC and allowing their translation into clinical practice and CRC therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / drug effects
  • Apoptosis / genetics
  • Blotting, Western
  • Butadienes / pharmacology
  • Caco-2 Cells
  • Cell Movement / drug effects
  • Cell Movement / genetics
  • Cell Survival / drug effects
  • Cell Survival / genetics
  • Colorectal Neoplasms / genetics*
  • Colorectal Neoplasms / metabolism*
  • Enzyme Inhibitors / pharmacology*
  • Extracellular Signal-Regulated MAP Kinases / antagonists & inhibitors*
  • HCT116 Cells
  • Humans
  • In Vitro Techniques
  • MicroRNAs / genetics*
  • Mitogen-Activated Protein Kinases / antagonists & inhibitors*
  • Nitriles / pharmacology
  • Pyrazoles / pharmacology
  • Pyridazines / pharmacology
  • Transcriptome / genetics


  • Butadienes
  • Enzyme Inhibitors
  • FR 180204
  • MicroRNAs
  • Nitriles
  • Pyrazoles
  • Pyridazines
  • U 0126
  • Extracellular Signal-Regulated MAP Kinases
  • Mitogen-Activated Protein Kinases