microRNA-10b enhances pancreatic cancer cell invasion by suppressing TIP30 expression and promoting EGF and TGF-β actions

Oncogene. 2014 Sep 18;33(38):4664-74. doi: 10.1038/onc.2013.405. Epub 2013 Oct 7.

Abstract

Increased microRNA-10b (miR-10b) expression in the cancer cells in pancreatic ductal adenocarcinoma (PDAC) is a marker of disease aggressiveness. In the present study, we determined that plasma miR-10b levels are significantly increased in PDAC patients by comparison with normal controls. By gene profiling, we identified potential targets downregulated by miR-10b, including Tat-interacting protein 30 (TIP30). Immunoblotting and luciferase reporter assays confirmed that TIP30 was a direct miR-10b target. Downregulation of TIP30 by miR-10b or siRNA-mediated silencing of TIP30 enhanced epidermal growth factor (EGF)-dependent invasion. The actions of miR-10b were abrogated by expressing a modified TIP30 cDNA resistant to miR-10b. EGF-induced EGF receptor (EGFR) tyrosine phosphorylation and extracellular signal-regulated kinase phosphorylation were enhanced by miR-10b, and these effects were mimicked by TIP30 silencing. The actions of EGF in the presence of miR-10b were blocked by EGFR kinase inhibition with erlotinib and by dual inhibition of PI3K (phosphatidylinositol 3'-kinase) and MEK. Moreover, miR-10b, EGF and transforming growth factor-beta (TGF-β) combined to markedly increase cell invasion, and this effect was blocked by the combination of erlotinib and SB505124, a type I TGF-β receptor inhibitor. miR-10b also enhanced the stimulatory effects of EGF and TGF-β on cell migration and epithelial-mesenchymal transition (EMT) and decreased the expression of RAP2A, EPHB2, KLF4 and NF1. Moreover, miR-10b overexpression accelerated pancreatic cancer cell (PCC) proliferation and tumor growth in an orthotopic model. Thus, plasma miR-10b levels may serve as a diagnostic marker in PDAC, whereas intra-tumoral miR-10b promotes PCC proliferation and invasion by suppressing TIP30, which enhances EGFR signaling, facilitates EGF-TGF-β cross-talk and enhances the expression of EMT-promoting genes, whereas decreasing the expression of several metastasis-suppressing genes. Therefore, therapeutic targeting of miR-10b in PDAC may interrupt growth-promoting deleterious EGF-TGF-β interactions and antagonize the metastatic process at various levels.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Acetyltransferases / genetics*
  • Acetyltransferases / metabolism
  • Animals
  • Antineoplastic Agents / pharmacology
  • Base Sequence
  • Binding Sites
  • Carcinoma, Pancreatic Ductal / metabolism*
  • Carcinoma, Pancreatic Ductal / pathology
  • Cell Line, Tumor
  • Epidermal Growth Factor / physiology
  • Erlotinib Hydrochloride
  • Gene Expression
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Kruppel-Like Factor 4
  • Male
  • Mice
  • Mice, Nude
  • MicroRNAs / physiology*
  • Neoplasm Invasiveness
  • Neoplasm Transplantation
  • Pancreatic Neoplasms / metabolism*
  • Pancreatic Neoplasms / pathology
  • Quinazolines / pharmacology
  • RNA Interference
  • Signal Transduction
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism
  • Transforming Growth Factor beta / physiology

Substances

  • Antineoplastic Agents
  • KLF4 protein, human
  • Klf4 protein, mouse
  • Kruppel-Like Factor 4
  • MIRN10 microRNA, human
  • MicroRNAs
  • Quinazolines
  • Transcription Factors
  • Transforming Growth Factor beta
  • Epidermal Growth Factor
  • Erlotinib Hydrochloride
  • Acetyltransferases
  • HTATIP2 protein, human