title: HIF-1 in cancer therapy: two decade long story of a transcription factor.
abstract: BACKGROUND
  Oxygen (O2) homeostasis is an indispensable requirement of eukaryotes. O2concentration in cellular milieu is defined as normoxia (∼21% O2), physoxia (∼1-13% O2) or hypoxia (∼0.1-1% O2). Hypoxia, a striking micro-environmental feature in tumorigenesis, is countered by tumor cells via induction of O2governed transcription factor, hypoxia inducible factor-1 (HIF-1). Post discovery, HIF-1 has emerged as a promising anticancer therapeutic target during the last two decades. Recent reports have highlighted that enhanced levels of HIF-1 correlate with tumor metastasis leading to poor patient prognosis.
  
  
  METHODS
  A systematic search in PubMed and SciFinder for the literature on HIF-1 biology and therapeutic importance in cancer was carried out.
  
  
  RESULTS
  This review highlights the initial description as well as the recent insights into HIF-1 biology and regulation. We have focused on emerging data regarding varied classes of HIF-1 target genes affecting various levels of crosstalk among tumorigenic pathways. We have emphasized on the fact that HIF-1 acts as a networking hub coordinating activities of multiple signaling molecules influencing tumorigenesis. Emerging evidences indicate role of many HIF-induced proteomic and genomic alterations in malignant progression by mediating a myriad of genes stimulating angiogenesis, anaerobic metabolism and survival of cancer cells in O2-deficient microenvironment.
  
  
  CONCLUSIONS
  Better understanding of the crucial role of HIF-1 in carcinogenesis could offer promising new avenues to researchers and aid in elucidating various open issues regarding the use of HIF-1 as an anticancer therapeutic target. In spite of large efforts in this field, many questions still remain unanswered. Hence, future investigations are necessary to devise, assess and refine methods for translating previous research efforts into novel clinical practices in cancer treatment.
authors.affiliation: a Pharmacology and Toxicology Lab, Food and Nutraceuticals Division , CSIR-Institute of Himalayan Bioresource Technology , Palampur , India.|b Academy of Scientific and Innovative Research , New Delhi , India.
authors.forename: Sourabh
authors.initials: S
authors.lastname: Soni
authors.affiliation: a Pharmacology and Toxicology Lab, Food and Nutraceuticals Division , CSIR-Institute of Himalayan Bioresource Technology , Palampur , India.|b Academy of Scientific and Innovative Research , New Delhi , India.
authors.forename: Yogendra S
authors.initials: YS
authors.lastname: Padwad
mesh_terms: D000818:Animals; D015687:Cell Hypoxia / Q000502:physiology*; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism*; D009369:Neoplasms / Q000378:metabolism* / Q000473:pathology
chemical_list: D051795:Hypoxia-Inducible Factor 1, alpha Subunit