MicroRNA-210 regulates mitochondrial free radical response to hypoxia and krebs cycle in cancer cells by targeting iron sulfur cluster protein ISCU.

Abstract

BACKGROUND:

Hypoxia in cancers results in the upregulation of hypoxia inducible factor 1 (HIF-1) and a microRNA, hsa-miR-210 (miR-210) which is associated with a poor prognosis.

METHODS AND FINDINGS:

In human cancer cell lines and tumours, we found that miR-210 targets the mitochondrial iron sulfur scaffold protein ISCU, required for assembly of iron-sulfur clusters, cofactors for key enzymes involved in the Krebs cycle, electron transport, and iron metabolism. Down regulation of ISCU was the major cause of induction of reactive oxygen species (ROS) in hypoxia. ISCU suppression reduced mitochondrial complex 1 activity and aconitase activity, caused a shift to glycolysis in normoxia and enhanced cell survival. Cancers with low ISCU had a worse prognosis.

CONCLUSIONS:

Induction of these major hallmarks of cancer show that a single microRNA, miR-210, mediates a new mechanism of adaptation to hypoxia, by regulating mitochondrial function via iron-sulfur cluster metabolism and free radical generation.

• Authors: Elena Favaro, Anassuya Ramachandran, Robert McCormick, Harriet Gee, Christine Blancher, Meredith Crosby, Cecilia Devlin, Christopher Blick, Francesca Buffa, Ji-Liang Li, Borivoj Vojnovic, Ricardo Pires das Neves, Peter Glazer, Francisco Iborra, Mircea Ivan, Jiannis Ragoussis, Adrian L Harris
• Journal: PloS one (PLoS One) Vol. 5 Issue 4 Pg. e10345 (Apr 26 2010) ISSN: 1932-6203 [Electronic] United States
• PMID: 20436681 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Free Radicals
• Hypoxia-Inducible Factor 1, alpha Subunit
• ISCU protein, human
• Iron-Sulfur Proteins
• MIRN210 microRNA, human
• MicroRNAs
• Electron Transport Complex I

Topics

• Cell Line, Tumor
• Citric Acid Cycle
• Electron Transport Complex I (metabolism)
• Free Radicals (metabolism)
• Humans
• Hypoxia
• Hypoxia-Inducible Factor 1, alpha Subunit
• Iron-Sulfur Proteins (metabolism)
• MicroRNAs (physiology)
• Mitochondria (metabolism)
• Neoplasms (metabolism, pathology)
• Prognosis