Hypoxia-Activated Prodrugs of PERK Inhibitors.

Abstract

Tumour hypoxia plays an important role in tumour progression and resistance to therapy. Under hypoxia unfolded proteins accumulate in the endoplasmic reticulum (ER) and this stress is relieved through the protein kinase R-like ER kinase (PERK) signalling arm of the unfolded protein response (UPR). Targeting the UPR through PERK kinase inhibitors provides tumour growth inhibition, but also elicits on-mechanism normal tissue toxicity. Hypoxia presents a target for tumour-selective drug delivery using hypoxia-activated prodrugs. We designed and prepared hypoxia-activated prodrugs of modified PERK inhibitors using a 2-nitroimidazole bioreductive trigger. The new inhibitors retained PERK kinase inhibitory activity and the corresponding prodrugs were strongly deactivated. The prodrugs were able to undergo fragmentation following radiolytic reduction, or bioreduction in HCT116 cells, to release their effectors, albeit inefficiently. We examined the effects of the prodrugs on PERK signalling in hypoxic HCT116 cells. This study has identified a 2-substituted nitroimidazole carbamate prodrug with potential to deliver PERK inhibitors in a hypoxia-selective manner.

• Authors: Lydia P Liew, Dean C Singleton, Way W Wong, Gary J Cheng, Stephen M F Jamieson, Michael P Hay
• Journal: Chemistry, an Asian journal (Chem Asian J) Vol. 14 Issue 8 Pg. 1238-1248 (Apr 15 2019) ISSN: 1861-471X [Electronic] Germany
• PMID: 30615821 (Publication Type: Journal Article)
• Copyright: © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chemical References

• Nitroimidazoles
• Prodrugs
• Protein Kinase Inhibitors
• EIF2AK3 protein, human
• eIF-2 Kinase

Topics

• Dose-Response Relationship, Drug
• Drug Design
• HCT116 Cells
• Humans
• Hypoxia (metabolism)
• Molecular Structure
• Nitroimidazoles (chemical synthesis, chemistry, metabolism, pharmacology)
• Prodrugs (chemical synthesis, chemistry, metabolism)
• Protein Kinase Inhibitors (chemical synthesis, chemistry, metabolism, pharmacology)
• Structure-Activity Relationship
• Tumor Cells, Cultured
• eIF-2 Kinase (antagonists & inhibitors, metabolism)