RNA-binding motif protein 47 inhibits Nrf2 activity to suppress tumor growth in lung adenocarcinoma

Oncogene. 2016 Sep 22;35(38):5000-9. doi: 10.1038/onc.2016.35. Epub 2016 Feb 29.


RNA-binding proteins provide a new layer of posttranscriptional regulation of RNA during cancer progression. We identified RNA-binding motif protein 47 (RBM47) as a target gene of transforming growth factor (TGF)-β in mammary gland epithelial cells (NMuMG cells) that have undergone the epithelial-to-mesenchymal transition. TGF-β repressed RBM47 expression in NMuMG cells and lung cancer cell lines. Expression of RBM47 correlated with good prognosis in patients with lung, breast and gastric cancer. RBM47 suppressed the expression of cell metabolism-related genes, which were the direct targets of nuclear factor erythroid 2-related factor 2 (Nrf2; also known as NFE2L2). RBM47 bound to KEAP1 and Cullin 3 mRNAs, and knockdown of RBM47 inhibited their protein expression, which led to enhanced binding of Nrf2 to target genomic regions. Knockdown of RBM47 also enhanced the expression of some Nrf2 activators, p21/CDKN1A and MafK induced by TGF-β. Both mitochondrial respiration rates and the side population cells in lung cancer cells increased in the absence of RBM47. Our findings, together with the enhanced tumor formation and metastasis of xenografted mice by knockdown of the RBM47 expression, suggested tumor-suppressive roles for RBM47 through the inhibition of Nrf2 activity.

MeSH terms

  • Adenocarcinoma / genetics*
  • Adenocarcinoma / pathology
  • Adenocarcinoma of Lung
  • Animals
  • Cell Line, Tumor
  • Cullin Proteins / genetics
  • Cyclin-Dependent Kinase Inhibitor p21 / genetics
  • Epithelial-Mesenchymal Transition / genetics
  • Gene Expression Regulation, Neoplastic
  • Heterografts
  • Humans
  • Kelch-Like ECH-Associated Protein 1 / genetics
  • Lung Neoplasms / genetics*
  • Lung Neoplasms / pathology
  • MafK Transcription Factor / genetics
  • Mice
  • Mitochondria / genetics
  • Mitochondria / pathology
  • NF-E2-Related Factor 2 / genetics*
  • RNA-Binding Proteins / genetics*
  • Transforming Growth Factor beta / genetics


  • CDKN1A protein, human
  • CUL3 protein, human
  • Cullin Proteins
  • Cyclin-Dependent Kinase Inhibitor p21
  • Kelch-Like ECH-Associated Protein 1
  • MAFK protein, human
  • MafK Transcription Factor
  • NF-E2-Related Factor 2
  • NFE2L2 protein, human
  • RBM47 protein, human
  • RNA-Binding Proteins
  • Transforming Growth Factor beta