Hypoxia-inducible factor 1-alpha, also known as HIF-1-alpha, is a protein that in humans is encoded by the HIF1A gene. Two alternative transcripts encoding different isoforms have been identified, the alpha and beta subunits. HIF-1 plays an essential role in cellular and systemic responses to hypoxia. HIF-1 is a critical mediator of the hypoxic response that upregulates expression of proteins that promote angiogenesis, anaerobic metabolism, and many other survival pathways. HIF-1alpha is expressed in many types of tumors. Overexpressed in the majority of common human cancers and their metastases, due to the presence of intratumoral hypoxia and as a result of mutations in genes encoding oncoproteins and tumor suppressors. Under normoxic conditions HIF-1 alpha has a short half-life. It is largely undetectable in cells or tissues grown under normoxic conditions. It is stabilized only at O2 concentrations below 5% and upon stabilization under hypoxic conditions HIF-1 translocates to the nucleus. The expression of HIF 1alpha is correlated with tumor angiogenesis,cancer progression and clinical outcome in various solid tumors including breast cancer, type 1 endometrial carcinoma, sarcoma, head and neck tumor and brain tumor. HIF-1 alpha may be of value in analyzing the cancer cell response to therapy.
Hypoxia-inducible factor 1-alpha, also known as HIF-1-alpha, is a protein that in humans is encoded by the HIF1A gene. Two alternative transcripts encoding different isoforms have been identified, the alpha and beta subunits. HIF-1 plays an essential role in cellular and systemic responses to hypoxia. HIF-1 is a critical mediator of the hypoxic response that upregulates expression of proteins that promote angiogenesis, anaerobic metabolism, and many other survival pathways. HIF-1alpha is expressed in many types of tumors. Overexpressed in the majority of common human cancers and their metastases, due to the presence of intratumoral hypoxia and as a result of mutations in genes encoding oncoproteins and tumor suppressors. Under normoxic conditions HIF-1 alpha has a short half-life. It is largely undetectable in cells or tissues grown under normoxic conditions. It is stabilized only at O2 concentrations below 5% and upon stabilization under hypoxic conditions HIF-1 translocates to the nucleus. The expression of HIF 1alpha is correlated with tumor angiogenesis,cancer progression and clinical outcome in various solid tumors including breast cancer, type 1 endometrial carcinoma, sarcoma, head and neck tumor and brain tumor. HIF-1 alpha may be of value in analyzing the cancer cell response to therapy.