A structure-based mechanism of cisplatin resistance mediated by glutathione transferase P1-1

Proc Natl Acad Sci U S A. 2019 Jul 9;116(28):13943-13951. doi: 10.1073/pnas.1903297116. Epub 2019 Jun 20.

Abstract

Cisplatin [cis-diamminedichloroplatinum(II) (cis-DDP)] is one of the most successful anticancer agents effective against a wide range of solid tumors. However, its use is restricted by side effects and/or by intrinsic or acquired drug resistance. Here, we probed the role of glutathione transferase (GST) P1-1, an antiapoptotic protein often overexpressed in drug-resistant tumors, as a cis-DDP-binding protein. Our results show that cis-DDP is not a substrate for the glutathione (GSH) transferase activity of GST P1-1. Instead, GST P1-1 sequesters and inactivates cisplatin with the aid of 2 solvent-accessible cysteines, resulting in protein subunits cross-linking, while maintaining its GSH-conjugation activity. Furthermore, it is well known that GST P1-1 binding to the c-Jun N-terminal kinase (JNK) inhibits JNK phosphorylation, which is required for downstream apoptosis signaling. Thus, in turn, GST P1-1 overexpression and Pt-induced subunit cross-linking could modulate JNK apoptotic signaling, further confirming the role of GST P1-1 as an antiapoptotic protein.

Keywords: cisplatin; drug resistance; glutathione transferase; protein crystallography; protein–ligand interactions.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Apoptosis / drug effects
  • Cell Line, Tumor
  • Cisplatin / chemistry*
  • Cisplatin / pharmacology
  • Drug Resistance, Neoplasm / genetics
  • Gene Expression Regulation, Neoplastic / drug effects
  • Glutathione / chemistry
  • Glutathione S-Transferase pi / chemistry*
  • Glutathione S-Transferase pi / genetics
  • Humans
  • JNK Mitogen-Activated Protein Kinases / chemistry*
  • JNK Mitogen-Activated Protein Kinases / genetics
  • Neoplasms / drug therapy*
  • Neoplasms / genetics
  • Phosphorylation
  • Protein Binding / drug effects
  • Protein Conformation
  • Signal Transduction / drug effects

Substances

  • Glutathione S-Transferase pi
  • JNK Mitogen-Activated Protein Kinases
  • Glutathione
  • Cisplatin