Frataxin participates to the hypoxia-induced response in tumors |
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| Authors: | I Guccini D Serio I Cond�� A Rufini B Tomassini A Mangiola G Maira C Anile D Fina F Pallone M P Mongiardi A Levi N Ventura R Testi F Malisan |
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| Affiliation: | 1Department of Experimental Medicine and Biochemical Sciences, Laboratory of Signal Transduction, University ‘Tor Vergata'', Rome, Italy;2Department of Neurosurgery, Catholic University School of Medicine, Rome, Italy;3Department of Internal Medicine, University ‘Tor Vergata'', Rome, Italy;4National Research Council of Italy, Cell Biology and Neurobiology Institute and IRCCS Fondazione Santa Lucia, Rome, Italy |
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| Abstract: | Defective expression of frataxin is responsible for the degenerative disease Friedreich''s ataxia. Frataxin is a protein required for cell survival since complete knockout is lethal. Frataxin protects tumor cells against oxidative stress and apoptosis but also acts as a tumor suppressor. The molecular bases of this apparent paradox are missing. We therefore sought to investigate the pathways through which frataxin enhances stress resistance in tumor cells. We found that frataxin expression is upregulated in several tumor cell lines in response to hypoxic stress, a condition often associated with tumor progression. Moreover, frataxin upregulation in response to hypoxia is dependent on hypoxia-inducible factors expression and modulates the activation of the tumor-suppressor p53. Importantly, we show for the first time that frataxin is in fact increased in human tumors in vivo. These results show that frataxin participates to the hypoxia-induced stress response in tumors, thus implying that modulation of its expression could have a critical role in tumor cell survival and/or progression. |
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| Keywords: | frataxin hypoxia p53 HIF Friedreich''s ataxia tumor |
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