HIFs (Hypoxia-inducible factors) are transcription factors that respond to changes in available oxygen in the cellular environment, to be specific, to decreases in oxygen, or hypoxia. The HIF signaling cascade mediates the effects of hypoxia, the state of low oxygen concentration, on the cell. Hypoxia often keeps cells from differentiating. However, hypoxia promotes the formation of blood vessels, and is important for the formation of a vascular system in embryos, and cancer tumors. The hypoxia in wounds also promotes the migration of keratinocytes and the restoration of the epithelium. In general, HIFs are vital to development. In mammals, deletion of the HIF-1 genes results in perinatal death. HIF-1 has been shown to be vital to chondrocyte survival, allowing the cells to adapt to low-oxygen conditions within the growth plates of bones. HIF plays a central role in the regulation of human metabolism. Recently, several drugs that act as selective HIF prolyl-hydroxylase inhibitors have been developed.
Roxadustat is an oral hypoxia-inducible factor prolyl-hydroxylase inhibitor (HIF-PHI) that promotes erythropoiesis through increasing endogenous erythropoietin, improving iron regulation, and reducing hepcidin.
PT2977 (MK-6482) is an orally active and selective HIF-2α inhibitor with an IC50 of 9 nM. PT2977, as a second-generation HIF-2α inhibitor, increases potency and improves pharmacokinetic profile. PT2977 is a potential treatment for clear cell renal cell carcinoma (ccRCC).
Fraxinellone is isolated from the root bark of the Rutaceae plant, Dictamnus dasycarpus. Fraxinellone is a PD-L1 inhibitor and inhibits HIF-1α protein synthesis without affecting HIF-1α protein degradation. Fraxinellone has the potential to be a valuable candidate for cancer treatment by targeting PD-L1.
Deoxyshikonin is isolated from Lithospermum erythrorhizon Sieb with antitumor activity. Deoxyshikonin increases the expression of VEGF-C and VEGF-A mRNA in HMVEC-dLy, promotes HIF-1α and HIF-1β subunit interaction and binds to specific DNA sequences targeted by HIF, indicates a prolymphangiogenesis as well as a proangiogenesis effect in vitro. Deoxyshikonin shows significant synergic antimicrobial activity against S. pneumonia (MIC=17 μg/mL), also shows significantly inhibitory activities against MRSA.
Daprodustat (GSK1278863) is an orally active hypoxia-inducible factor prolyl hydroxylase inhibitor being developed for the treatment of anemia associated with chronic kidney disease.
Oltipraz has an inhibitory effect on HIF-1α activation in a time-dependent manner, completely abrogating HIF-1α induction at ≥10 μM concentrations, the IC50 of Oltipraz for HIF-1α inhibition is 10 μM. Oltipraz is a potent Nrf2 activator.
Chlorogenic acid is a major phenolic compound in coffee and tea. It plays several important and therapeutic roles such as antioxidant activity, antibacterial, hepatoprotective, cardioprotective, anti-inflammatory, antipyretic, neuroprotective, anti-obesity, antiviral, anti-microbial, anti-hypertension.
KC7F2 is a potent hypoxia inducible factor-1 (HIF-1) pathway inhibitor with an IC50 of 20 μM in LN229-HRE-AP cells, and with potential as a cancer therapy agent.
Molidustat (BAY 85-3934) is a novel inhibitor of hypoxia-inducible factor prolyl hydroxylase (HIF-PH) with mean IC50 values of 480 nM for PHD1, 280 nM for PHD2, and 450 nM for PHD3.
PT2399 is a potent and selective HIF-2α antagonist, which directly binds to HIF-2α PAS B domain with an IC50 of 6 nM. PT2399 displays potent antitumor activity in vivo.
