Feedback activation of AMPK-mediated autophagy acceleration is a key resistance mechanism against SCD1 inhibitor-induced cell growth inhibition

PLoS One. 2017 Jul 13;12(7):e0181243. doi: 10.1371/journal.pone.0181243. eCollection 2017.

Abstract

Elucidating the bioactive compound modes of action is crucial for increasing success rates in drug development. For anticancer drugs, defining effective drug combinations that overcome resistance improves therapeutic efficacy. Herein, by using a biologically annotated compound library, we performed a large-scale combination screening with Stearoyl-CoA desaturase-1 (SCD1) inhibitor, T-3764518, which partially inhibits colorectal cancer cell proliferation. T-3764518 induced phosphorylation and activation of AMPK in HCT-116 cells, which led to blockade of downstream fatty acid synthesis and acceleration of autophagy. Attenuation of fatty acid synthesis by small molecules suppressed the growth inhibitory effect of T-3764518. In contrast, combination of T-3764518 with autophagy flux inhibitors synergistically inhibited cellular proliferation. Experiments using SCD1 knock-out cells validated the results obtained with T-3764518. The results of our study indicated that activation of autophagy serves as a survival signal when SCD1 is inhibited in HCT-116 cells. Furthermore, these findings suggest that combining SCD1 inhibitor with autophagy inhibitors is a promising anticancer therapy.

MeSH terms

  • AMP-Activated Protein Kinases / administration & dosage
  • AMP-Activated Protein Kinases / metabolism*
  • AMP-Activated Protein Kinases / physiology
  • Antineoplastic Agents / pharmacology
  • Autophagy / drug effects
  • Autophagy / physiology*
  • Cell Proliferation / drug effects*
  • Cell Proliferation / genetics
  • Drug Resistance, Neoplasm* / drug effects
  • Drug Resistance, Neoplasm* / genetics
  • Drug Screening Assays, Antitumor
  • Feedback, Physiological / physiology
  • Gene Knockout Techniques
  • Growth Inhibitors / pharmacology*
  • HCT116 Cells
  • Humans
  • Oxadiazoles / pharmacology*
  • Phosphorylation / drug effects
  • Pyridazines / pharmacology*
  • Stearoyl-CoA Desaturase / antagonists & inhibitors*
  • Stearoyl-CoA Desaturase / genetics

Substances

  • Antineoplastic Agents
  • Growth Inhibitors
  • Oxadiazoles
  • Pyridazines
  • T-3764518
  • SCD1 protein, human
  • Stearoyl-CoA Desaturase
  • AMP-Activated Protein Kinases

Grants and funding

This study was financially supported by Takeda Pharmaceutical Company Limited. Employees of Takeda played roles in study design, data collection and analysis, decision to publish, or preparation of the manuscript.