PAWI-2 overcomes tumor stemness and drug resistance via cell cycle arrest in integrin β3-KRAS-dependent pancreatic cancer stem cells

Sci Rep. 2020 Jun 8;10(1):9162. doi: 10.1038/s41598-020-65804-5.

Abstract

Today, pancreatic cancer (PC) remains a major health problem in the US. The fact that cancer stem cells (CSCs) become enriched in humans following anti-cancer therapy implicates CSCs as key contributors to tumor dormancy, metastasis, and relapse in PC. A highly validated CSC model (FGβ3 cells) was used to test a novel compound (PAWI-2) to eradicate CSCs. Compared to parental bulk FG cells, PAWI-2 showed greater potency to inhibit cell viability and self-renewal capacity of FGβ3 cells. For FGβ3 cells, dysregulated integrin β3-KRAS signaling drives tumor progression. PAWI-2 inhibited β3-KRAS signaling independent of KRAS. This is clinically relevant. PAWI-2 targeted the downstream TBK1 phosphorylation cascade that was negatively regulated by optineurin phosphorylation via a feedback mechanism. This was confirmed by TBK1 genetic knockdown or co-treatment with TBK1-specific inhibitor (MRT67307). PAWI-2 also overcame erlotinib (an EGFR inhibitor) resistance in FGβ3 cells more potently than bortezomib. In the proposed working model, optineurin acts as a key regulator to link inhibition of KRAS signaling and cell cycle arrest (G2/M). The findings show PAWI-2 is a new approach to reverse tumor stemness that resensitizes CSC tumors to drug inhibition.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents
  • Cell Cycle Checkpoints / drug effects*
  • Drug Resistance, Neoplasm / drug effects*
  • Humans
  • Integrin beta3 / metabolism*
  • NF-kappa B / metabolism
  • Neoplastic Stem Cells / pathology*
  • Pancreatic Neoplasms / genetics*
  • Pancreatic Neoplasms / pathology*
  • Proto-Oncogene Proteins p21(ras) / metabolism*
  • Quinoxalines / pharmacology*
  • Signal Transduction / drug effects
  • Signal Transduction / genetics
  • Tumor Cells, Cultured

Substances

  • Antineoplastic Agents
  • Integrin beta3
  • KRAS protein, human
  • NF-kappa B
  • PAWI-2
  • Quinoxalines
  • Proto-Oncogene Proteins p21(ras)