Hypoxia-inducible factor (HIF) (HIF)

Intracellular hypoxia-associated proteins (HAPs) refer to a broad class of proteins whose expression and activity are modulated in response to low oxygen levels (hypoxia) [physiology.org]. The most critical members of this group are the Hypoxia-inducible factors (HIFs), specifically HIF-1α and HIF-2α, which function as master transcriptional regulators of the cellular hypoxic response [nih.gov]. Under normoxic conditions, these proteins are rapidly degraded via the prolyl hydroxylase (PHD) and von Hippel-Lindau (VHL) pathway; however, under hypoxia, they stabilize and translocate to the nucleus to activate genes involved in erythropoiesis, angiogenesis, and glycolysis [longdom.org]. In oncology, HIF-2α is a validated target for clear cell renal cell carcinoma (ccRCC), with inhibitors like belzutifan showing clinical efficacy [FDA, 2021]. Conversely, in the treatment of anemia associated with chronic kidney disease, HIF prolyl hydroxylase inhibitors (HIF-PHIs) such as roxadustat are used to stabilize HIF and stimulate endogenous erythropoietin production [EMA, 2021]. Other hypoxia-associated proteins include glycolytic enzymes like GAPDH and pH regulators like Carbonic anhydrase IX (CAIX), which are often used as biomarkers for tumor hypoxia [impactfactor.org]. Therapeutic targeting of this pathway must balance the benefits of tissue protection and erythropoiesis against the risks of promoting tumor growth or causing thromboembolic events [nih.gov].

Other names

Intracellular hypoxia-associated proteinsHypoxia-inducible factorsHAPsHypoxia-regulated proteinsOxygen-sensitive proteins

Inhibition of HIF-2α transcriptional activity and inhibition of HIF prolyl hydroxylase enzymes to stabilize HIF-α subunits.