title: Regulation of the hypoxic tumor environment in hepatocellular carcinoma using RNA interference.
abstract: OBJECTIVE
  Hypoxia is the condition where tumor cells have been deprived of oxygen and has been shown to have a role of tumor development in the hepatocellular carcinoma (HCC).
  
  
  METHODS
  Using PubMed online database and Google scholar web site, the terms "angiogenesis", "apoptosis", "RNA interference" and/or "hepatocellular carcinoma (HCC)" were searched and analyzed.
  
  
  RESULTS
  The hypoxia inducible factors (HIFs) are transcriptional regulators that affect a homeostatic response to oxidative stress and have been identified as a key transcription activator of angiogenesis, survival, and metabolism. Cytokines, such as IL-8, also controlled endothelia cells survival and angiogenesis. IL-8 was also overexpressed under hypoxia and induced tumor angiogenesis and growth.
  
  
  CONCLUSIONS
  Therefore, regulation of HIFs and IL-8 controlled the tumor microenvironment in terms of tumor angiogenesis and apoptosis. The review summarizes the results of regulation of the hypoxic tumor environment.
authors.affiliation: Division of Bioconvergence Analysis, Drug and Disease Target Group, Korea Basic Science Institute, Daejeon, Korea.
authors.forename: Sung Hoon
authors.initials: SH
authors.lastname: Choi
authors.affiliation: Department of Internal Medicine, Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jun Yong
authors.identifier: 0000-0001-6324-2224
authors.initials: JY
authors.lastname: Park
keywords: Angiogenesis; Apoptosis; HIF; Hepatocellular carcinoma; IL-8; RNAi