Tankyrase Inhibitor Sensitizes Lung Cancer Cells to Endothelial Growth Factor Receptor (EGFR) Inhibition via Stabilizing Angiomotins and Inhibiting YAP Signaling

J Biol Chem. 2016 Jul 15;291(29):15256-66. doi: 10.1074/jbc.M116.722967. Epub 2016 May 26.

Abstract

YAP signaling pathway plays critical roles in tissue homeostasis, and aberrant activation of YAP signaling has been implicated in cancers. To identify tractable targets of YAP pathway, we have performed a pathway-based pooled CRISPR screen and identified tankyrase and its associated E3 ligase RNF146 as positive regulators of YAP signaling. Genetic ablation or pharmacological inhibition of tankyrase prominently suppresses YAP activity and YAP target gene expression. Using a proteomic approach, we have identified angiomotin family proteins, which are known negative regulators of YAP signaling, as novel tankyrase substrates. Inhibition of tankyrase or depletion of RNF146 stabilizes angiomotins. Angiomotins physically interact with tankyrase through a highly conserved motif at their N terminus, and mutation of this motif leads to their stabilization. Tankyrase inhibitor-induced stabilization of angiomotins reduces YAP nuclear translocation and decreases downstream YAP signaling. We have further shown that knock-out of YAP sensitizes non-small cell lung cancer to EGFR inhibitor Erlotinib. Tankyrase inhibitor, but not porcupine inhibitor, which blocks Wnt secretion, enhances growth inhibitory activity of Erlotinib. This activity is mediated by YAP inhibition and not Wnt/β-catenin inhibition. Our data suggest that tankyrase inhibition could serve as a novel strategy to suppress YAP signaling for combinatorial targeted therapy.

Keywords: CRISPR/Cas; drug resistance; functional genomics; protein degradation; signal transduction; yes-associated protein (YAP).

MeSH terms

  • Adaptor Proteins, Signal Transducing / antagonists & inhibitors*
  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism
  • Angiomotins
  • Antineoplastic Agents / pharmacology
  • CRISPR-Cas Systems
  • Carcinoma, Non-Small-Cell Lung / drug therapy*
  • Carcinoma, Non-Small-Cell Lung / metabolism*
  • Cell Line, Tumor
  • Down-Regulation
  • ErbB Receptors / antagonists & inhibitors*
  • Erlotinib Hydrochloride / pharmacology
  • Gene Knockout Techniques
  • HEK293 Cells
  • Humans
  • Intercellular Signaling Peptides and Proteins / chemistry
  • Intercellular Signaling Peptides and Proteins / genetics
  • Intercellular Signaling Peptides and Proteins / metabolism*
  • Lung Neoplasms / drug therapy*
  • Lung Neoplasms / metabolism*
  • Membrane Proteins / chemistry
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Microfilament Proteins
  • Phosphoproteins / antagonists & inhibitors*
  • Phosphoproteins / genetics
  • Phosphoproteins / metabolism
  • Protein Interaction Domains and Motifs
  • Protein Stability / drug effects
  • RNA, Small Interfering / genetics
  • Signal Transduction / drug effects
  • Tankyrases / antagonists & inhibitors*
  • Tankyrases / chemistry
  • Tankyrases / genetics
  • Transcription Factors
  • Ubiquitin-Protein Ligases / metabolism
  • YAP-Signaling Proteins

Substances

  • AMOT protein, human
  • Adaptor Proteins, Signal Transducing
  • Angiomotins
  • Antineoplastic Agents
  • Intercellular Signaling Peptides and Proteins
  • Membrane Proteins
  • Microfilament Proteins
  • Phosphoproteins
  • RNA, Small Interfering
  • Transcription Factors
  • YAP-Signaling Proteins
  • YAP1 protein, human
  • Erlotinib Hydrochloride
  • RNF146 protein, human
  • Ubiquitin-Protein Ligases
  • TNKS2 protein, human
  • Tankyrases
  • TNKS protein, human
  • EGFR protein, human
  • ErbB Receptors