2. Academic Validation
  3. Development and pre-clinical testing of a novel hypoxia-activated KDAC inhibitor

Development and pre-clinical testing of a novel hypoxia-activated KDAC inhibitor

  • Cell Chem Biol. 2021 Sep 16;28(9):1258-1270.e13. doi: 10.1016/j.chembiol.2021.04.004.
Anna Skwarska 1,  Ewen D D Calder 2,  Deborah Sneddon 2,  Hannah Bolland 1,  Maria L Odyniec 2,  Ishna N Mistry 1,  Jennifer Martin 1,  Lisa K Folkes 1,  Stuart J Conway 3,  Ester M Hammond 4
Affiliations

Affiliations

  • 1 Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ, UK.
  • 2 Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK.
  • 3 Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK. Electronic address: [email protected].
  • 4 Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ, UK. Electronic address: [email protected].
PMID: 33910023 DOI: 10.1016/j.chembiol.2021.04.004
Abstract

Tumor hypoxia is associated with therapy resistance and poor patient prognosis. Hypoxia-activated prodrugs, designed to selectively target hypoxic cells while sparing normal tissue, represent a promising treatment strategy. We report the pre-clinical efficacy of 1-methyl-2-nitroimidazole panobinostat (NI-Pano, CH-03), a novel bioreductive version of the clinically used lysine deacetylase inhibitor, panobinostat. NI-Pano was stable in normoxic (21% O2) conditions and underwent NADPH-CYP-mediated enzymatic bioreduction to release panobinostat in hypoxia (<0.1% O2). Treatment of cells grown in both 2D and 3D with NI-Pano increased acetylation of histone H3 at lysine 9, induced Apoptosis, and decreased clonogenic survival. Importantly, NI-Pano exhibited growth delay effects as a single agent in tumor xenografts. Pharmacokinetic analysis confirmed the presence of sub-micromolar concentrations of panobinostat in hypoxic mouse xenografts, but not in circulating plasma or kidneys. Together, our pre-clinical results provide a strong mechanistic rationale for the clinical development of NI-Pano for selective targeting of hypoxic tumors.

Keywords

HAP; HDAC; KDAC; hypoxia.

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