SRF expedites metastasis and modulates the epithelial to mesenchymal transition by regulating miR-199a-5p expression in human gastric cancer

Cell Death Differ. 2014 Dec;21(12):1900-13. doi: 10.1038/cdd.2014.109. Epub 2014 Aug 1.

Abstract

Dysregulation of transcription factors (TFs) is associated with tumor progression, but little is known about TF expression patterns in the context of gastric cancer (GC) metastasis. Using array-based profile analysis, we found that 22 TFs showed differential activities between GC cell lines with low- and high-metastatic potential. Of this group of TFs, serum response factor (SRF) was significantly upregulated in metastatic GC cells. SRF expression was frequently elevated in a panel of metastatic GC cells and tissues, and high-level expression of SRF was significantly associated with a more aggressive phenotype and poor prognosis in patients with GC. In GC cell lines, overexpression of SRF potently promoted cell migration and invasion in vitro as well as the formation of intrahepatic and pulmonary metastases in vivo, whereas loss of SRF inhibited GC cell invasion and metastasis. We also performed a microRNA microarray to screen for transcriptional targets of SRF and found that SRF transactivates miR-199a-5p and miR-199a-3p by directly binding to their promoters. We further determined that overexpression of miR-199a-5p, but not miR-199a-3p, increased GC cell invasion and metastasis. In contrast, inhibition of miR-199a-5p impaired the metastatic potential of GC cells in vitro and in vivo, and E-cadherin was identified as a direct and functional target of miR-199a-5p in GC cells. Specifically, our results showed that SRF promotes GC metastasis and the epithelial to mesenchymal transition (EMT) though miR-199a-5p-mediated downregulation of E-cadherin. The present study thus provides insight into the specific biological behavior of SRF in GC metastasis. As increased activity of the SRF/miR-199a-5p/E-cadherin pathway appears to promote GC cell EMT and metastasis, these regulators may therefore be developed as therapeutic targets or biomarkers for GC progression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, CD
  • Base Sequence
  • Binding Sites
  • Cadherins / genetics
  • Cadherins / metabolism
  • Cell Adhesion
  • Cell Line, Tumor
  • Epithelial-Mesenchymal Transition*
  • Female
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Lymphatic Metastasis
  • Male
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Middle Aged
  • Neoplasm Invasiveness
  • Promoter Regions, Genetic
  • RNA Interference
  • Serum Response Factor / physiology*
  • Stomach Neoplasms / metabolism*
  • Stomach Neoplasms / pathology
  • Transcriptome
  • Wnt Signaling Pathway

Substances

  • Antigens, CD
  • CDH1 protein, human
  • Cadherins
  • MicroRNAs
  • SRF protein, human
  • Serum Response Factor
  • mirn199 microRNA, human