Restoration of miR-7 expression suppresses the growth of Lewis lung cancer cells by modulating epidermal growth factor receptor signaling

Oncol Rep. 2014 Dec;32(6):2511-6. doi: 10.3892/or.2014.3519. Epub 2014 Sep 26.


microRNAs are an abundant class of short endogenous non-coding RNAs that function as important regulators of multiple target genes and participate in diverse biological roles in carcinogenesis. However, the role of miR-7 in lung cancer remains unclear and requires further elucidation. In the present study, we found a reduction of miR-7 expression in Lewis lung cancer (3LL) cells originating from mice by real-time RT-PCR. Restoration of miR-7 inhibited 3LL cell proliferation, induced cell apoptosis in vitro and reduced tumorigenicity in vivo. We further confirmed that miR-7 downregulated the expression of both epidermal growth factor receptor (EGFR) and murine leukemia viral oncogene homologue-1 (RAF-1) oncogenes by real-time PCR and western blot analysis. Furthermore, inhibition of EGFR showed similar effects to miR-7 enforcement in 3LL cells. Taken together, these findings revealed that miR-7 acts as an antitumor miRNA in 3LL by targeting and suppressing the expression of both EGFR and RAF-1 oncogenes. This study may provide a rationale for the use of miR-7 in lung cancer target therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis
  • Carcinoma, Lewis Lung / metabolism*
  • Carcinoma, Lewis Lung / pathology
  • Cell Line, Tumor
  • Cell Proliferation
  • ErbB Receptors / genetics
  • ErbB Receptors / metabolism*
  • Female
  • Gene Expression Regulation, Neoplastic
  • Mice, Inbred C57BL
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Proto-Oncogene Proteins c-raf / genetics
  • Proto-Oncogene Proteins c-raf / metabolism
  • RNA Interference
  • Signal Transduction


  • MIRN7 microRNA, mouse
  • MicroRNAs
  • EGFR protein, mouse
  • ErbB Receptors
  • Proto-Oncogene Proteins c-raf