Marked and rapid effects of pharmacological HIF-2α antagonism on hypoxic ventilatory control

J Clin Invest. 2020 May 1;130(5):2237-2251. doi: 10.1172/JCI133194.

Abstract

Hypoxia-inducible factor (HIF) is strikingly upregulated in many types of cancer, and there is great interest in applying inhibitors of HIF as anticancer therapeutics. The most advanced of these are small molecules that target the HIF-2 isoform through binding the PAS-B domain of HIF-2α. These molecules are undergoing clinical trials with promising results in renal and other cancers where HIF-2 is considered to be driving growth. Nevertheless, a central question remains as to whether such inhibitors affect physiological responses to hypoxia at relevant doses. Here, we show that pharmacological HIF-2α inhibition with PT2385, at doses similar to those reported to inhibit tumor growth, rapidly impaired ventilatory responses to hypoxia, abrogating both ventilatory acclimatization and carotid body cell proliferative responses to sustained hypoxia. Mice carrying a HIF-2α PAS-B S305M mutation that disrupts PT2385 binding, but not dimerization with HIF-1β, did not respond to PT2385, indicating that these effects are on-target. Furthermore, the finding of a hypomorphic ventilatory phenotype in untreated HIF-2α S305M mutant mice suggests a function for the HIF-2α PAS-B domain beyond heterodimerization with HIF-1β. Although PT2385 was well tolerated, the findings indicate the need for caution in patients who are dependent on hypoxic ventilatory drive.

Keywords: Cancer; Respiration; Therapeutics; hypoxia.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Substitution
  • Animals
  • Aryl Hydrocarbon Receptor Nuclear Translocator / genetics
  • Aryl Hydrocarbon Receptor Nuclear Translocator / metabolism*
  • Basic Helix-Loop-Helix Transcription Factors / antagonists & inhibitors*
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Basic Helix-Loop-Helix Transcription Factors / metabolism
  • Hypoxia / drug therapy
  • Hypoxia / genetics
  • Hypoxia / metabolism*
  • Hypoxia / pathology
  • Indans / pharmacology*
  • Mice
  • Mice, Mutant Strains
  • Mutation, Missense*
  • Sulfones / pharmacology*

Substances

  • Arnt protein, mouse
  • Basic Helix-Loop-Helix Transcription Factors
  • Indans
  • PT2385
  • Sulfones
  • Aryl Hydrocarbon Receptor Nuclear Translocator
  • endothelial PAS domain-containing protein 1