MEKK3 Sustains EMT and Stemness in Pancreatic Cancer by Regulating YAP and TAZ Transcriptional Activity

Anticancer Res. 2018 Apr;38(4):1937-1946. doi: 10.21873/anticanres.12431.

Abstract

Background/aim: Pancreatic cancer is one of the most threatening and poorly understood human malignancies. MEKK3 (MAP3K3) is a serine/threonine kinase activated by different signaling pathways. YAP and TAZ are critical oncogenic effectors in pancreatic cancer. We hypothesized that MEKK3 could sustain pancreatic cancer by inducing YAP/TAZ oncogenic activities.

Materials and methods: In Panc1 and AsPC1 pancreatic cancer cell lines MEKK3 was knocked-out (KO) by the CRISPR/Cas9 method. These cells were used to evaluate MEKK3 contribution to the expression of YAP/TAZ and their target genes, cell migration, stemness, and in vivo tumor growth.

Results: MEKK3 KO reduced both EMT and cell migration, the size of 3D colonies and the percentage of CD44+/CD24+/EpCAM+ CSC, promoter recruitment of YAP/TAZ and the expression of their target genes. It reduced tumor growth and prolonged mice overall survival.

Conclusion: Silencing of MEKK3 represents a valid approach to revert in vivo the aggressiveness of pancreatic cancer by modulating YAP/TAZ transcriptional activities.

Keywords: MEKK3; TAZ; YAP; pancreatic cancer.

MeSH terms

  • Animals
  • Cell Cycle Proteins
  • Cell Line, Tumor
  • Epithelial-Mesenchymal Transition
  • Female
  • Gene Knockout Techniques
  • Heterografts
  • Humans
  • Intracellular Signaling Peptides and Proteins / genetics*
  • Intracellular Signaling Peptides and Proteins / metabolism
  • MAP Kinase Kinase Kinase 3 / genetics*
  • MAP Kinase Kinase Kinase 3 / metabolism
  • Mice
  • Mice, Nude
  • Neoplastic Stem Cells / pathology
  • Nuclear Proteins / genetics*
  • Nuclear Proteins / metabolism
  • Pancreatic Neoplasms / genetics*
  • Pancreatic Neoplasms / metabolism
  • Pancreatic Neoplasms / pathology
  • Trans-Activators
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism
  • Transcriptional Activation
  • Transcriptional Coactivator with PDZ-Binding Motif Proteins

Substances

  • Cell Cycle Proteins
  • Intracellular Signaling Peptides and Proteins
  • Nuclear Proteins
  • Trans-Activators
  • Transcription Factors
  • Transcriptional Coactivator with PDZ-Binding Motif Proteins
  • WWTR1 protein, human
  • YY1AP1 protein, human
  • MAP Kinase Kinase Kinase 3
  • MAP3K3 protein, human