Platinum pyrithione induces apoptosis in chronic myeloid leukemia cells resistant to imatinib via DUB inhibition-dependent caspase activation and Bcr-Abl downregulation

Cell Death Dis. 2017 Jul 6;8(7):e2913. doi: 10.1038/cddis.2017.284.

Abstract

Chronic myelogenous leukemia (CML) is characterized by the chimeric tyrosine kinase Bcr-Abl. T315I Bcr-Abl is the most notorious point mutation to elicit acquired resistance to imatinib (IM), leading to poor prognosis. Therefore, it is urgent to search for additional approaches and targeting strategies to overcome IM resistance. We recently reported that platinum pyrithione (PtPT) potently inhibits the ubiquitin-proteasome system (UPS) via targeting the 26 S proteasome-associated deubiquitinases (DUBs), without effecting on the 20 S proteasome. Here we further report that (i) PtPT induces apoptosis in Bcr-Abl wild-type and Bcr-Abl-T315I mutation cells including the primary mononuclear cells from CML patients clinically resistant to IM, as well as inhibits the growth of IM-resistant Bcr-Abl-T315I xenografts in vivo; (ii) PtPT downregulates Bcr-Abl level through restraining Bcr-Abl transcription, and decreasing Bcr-Abl protein mediated by DUBs inhibition-induced caspase activation; (iii) UPS inhibition is required for PtPT-induced caspase activation and cell apoptosis. These findings support that PtPT overcomes IM resistance through both Bcr-Abl-dependent and -independent mechanisms. We conclude that PtPT can be a lead compound for further drug development to overcome imatinib resistance in CML patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents / pharmacology*
  • Apoptosis / drug effects
  • Apoptosis / genetics
  • Bortezomib / pharmacology
  • Caspases / genetics*
  • Caspases / metabolism
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Deubiquitinating Enzymes / antagonists & inhibitors
  • Deubiquitinating Enzymes / genetics*
  • Deubiquitinating Enzymes / metabolism
  • Drug Resistance, Neoplasm / drug effects
  • Drug Resistance, Neoplasm / genetics
  • Female
  • Fusion Proteins, bcr-abl / antagonists & inhibitors
  • Fusion Proteins, bcr-abl / genetics*
  • Fusion Proteins, bcr-abl / metabolism
  • Gene Expression Regulation, Leukemic*
  • Humans
  • Imatinib Mesylate / pharmacology
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / drug therapy*
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / genetics
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / metabolism
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / pathology
  • Leukocytes, Mononuclear / drug effects
  • Leukocytes, Mononuclear / metabolism
  • Leukocytes, Mononuclear / pathology
  • Male
  • Mice
  • Mice, Nude
  • Organoplatinum Compounds / pharmacology*
  • Proteasome Endopeptidase Complex / genetics
  • Proteasome Endopeptidase Complex / metabolism
  • Proteasome Inhibitors / pharmacology
  • Pyridines / pharmacology*
  • Signal Transduction
  • Xenograft Model Antitumor Assays

Substances

  • Antineoplastic Agents
  • BCR-ABL1 fusion protein, human
  • Organoplatinum Compounds
  • Proteasome Inhibitors
  • Pyridines
  • platinum pyrithione
  • Bortezomib
  • Imatinib Mesylate
  • Fusion Proteins, bcr-abl
  • Deubiquitinating Enzymes
  • Caspases
  • Proteasome Endopeptidase Complex
  • ATP dependent 26S protease