Hypoxia, a condition of low tissue O2 concentration, plays an important role in normal physiological processes and tumor formation. Under hypoxic conditions mammalian cells up regulate the expression of hypoxic genes, including induction of angiogenesis and a switch to anaerobic metabolism, in order to survive. HIF-1 (Hypoxia Inducible Factor-1) is one of the key regulators of the transcriptional response to oxygen deprivation (1). HIF-1 is composed of two subunits, HIF-1alphaand HIF-1beta also known as aryl hydrocarbon receptor nuclear translocator (ARNT)) that are members of the basic helix-loop-helix (bHLH) Per-Arnt-Sim (PAS) (bHLH-PAS) family of transcription factors. HIF-1 is essential for angiogenesis, embryonic development, and is associated with tumor progression, erythropoiesis, vascular development/remodeling, vasodilation, and glucose/energy metabolism. The over expression of HIF-1alphahas been demonstrated in many common human cancers including prostate and breast, in which HIF-1alpha levels are associated with increase vascularitry and tumor progression. Besides physiological hypoxia, genetic abnormalities frequently detected in human cancers, such as loss of function mutations (Von Hippel-Lindau, p53, and PTEN), are associated with induction of HIF1 activity and expression of HIF-1-inducible genes (1).
HIF1A; hypoxia inducible factor 1, alpha subunit (basic helix-loop-helix transcription factor); hypoxia-inducible factor 1-alpha; bHLHe78; HIF 1alpha; HIF1; MOP1; PASD8; HIF-1-alpha; member of PAS protein 1; ARNT interacting protein; ARNT-interacting protein; member of PAS superfamily 1; PAS domain-containing protein 8; basic-helix-loop-helix-PAS protein MOP1; class E basic helix-loop-helix protein 78; hypoxia-inducible factor 1 alpha isoform I.3; hypoxia-inducible factor 1, alpha subunit (basic helix-loop-helix transcription factor); HIF-1alpha; HIF1-ALPHA; MOP1, HIF-1alpha, PASD8, HIF1, bHLHe78; hypoxia-inducible factor 1 alpha; hypoxia-inducible factor 1, alpha subunit (basic helix-loop-helix