Related Experiment Video
Updated: Sep 26, 2026

Induction and Testing of Hypoxia in Cell Culture
Published on: August 12, 2011
Effect of ascorbate on the activity of hypoxia-inducible factor in cancer cells
Helen J Knowles1, Raju R Raval, Adrian L Harris
1Cancer Research United Kingdom Molecular Oncology Laboratory, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford OX3 9DS.
Abstract:
Hypoxia-inducible factor (HIF) plays an important role in determining patterns of gene expression in cancer. HIF is down-regulated in oxygenated cells by a series of Fe (II) and 2-oxoglutarate dependent dioxygenases that hydroxylate specific residues in the regulatory HIF-alpha subunits. Because these enzymes require ascorbate for activity in vitro we analyzed the effects of ascorbate on HIF in human cancer cell lines. Ascorbate at physiological concentrations (25 micro M) strikingly suppressed HIF-1alpha protein levels and HIF transcriptional targets, particularly when the system was oncogenically activated in normoxic cells. Similar results were obtained with iron supplementation. These results indicate that both ascorbate and iron availability have major effects on HIF, and imply that the system is commonly regulated by limiting hydroxylase activity under normoxic tissue culture conditions.
More Related Videos
Related Concept Videos
Adaptive Mechanisms in Cancer Cells
Some of the advantages that cancer cells have on normal cells include - enhanced ability to divide without terminally differentiating, induce new blood vessel formation,...
Adaptive Mechanisms in Cancer Cells
Some of the advantages that cancer cells have on normal cells include - enhanced ability to divide without terminally differentiating, induce new blood vessel formation,...
Cancer Therapies
However, cancer treatments can pose several challenges, as therapies used to kill cancer cells are generally also toxic to normal cells. Moreover, cancer cells mutate rapidly and can develop resistance to chemical agents or radiation therapy. Besides, all types of cancer cells may not respond to the same therapy. Some cancer cells respond to one...
Regulation of Angiogenesis and Blood Supply
Electron Transport Chain: Complex I and II
ROS generation is regulated and maintained at moderate levels necessary...
mTOR Signaling and Cancer Progression
The mTOR pathway or the...

