MCB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Erler, J. T.
Right arrow Articles by Dive, C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Erler, J. T.
Right arrow Articles by Dive, C.
Molecular and Cellular Biology, April 2004, p. 2875-2889, Vol. 24, No. 7
0270-7306/04/$08.00+0     DOI: 10.1128/MCB.24.7.2875-2889.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.

Hypoxia-Mediated Down-Regulation of Bid and Bax in Tumors Occurs via Hypoxia-Inducible Factor 1-Dependent and -Independent Mechanisms and Contributes to Drug Resistance

Janine T. Erler,1,2 Christopher J. Cawthorne,1,2 Kaye J. Williams,2 Marianne Koritzinsky,3 Bradley G. Wouters,3 Clare Wilson,4 Crispin Miller,4 Costas Demonacos,2 Ian J. Stratford,2 and Caroline Dive1,2*

Cellular and Molecular Pharmacology Group,1 Bioinformatics Group, Paterson Institute for Cancer Research, Manchester M20 4BX,4 School of Pharmacy and Pharmaceutical Sciences, University of Manchester, Manchester M13 9PT, United Kingdom,2 Grow Research Institute, University of Maastricht, Maastricht, The Netherlands3

Received 29 July 2003/ Returned for modification 12 September 2003/ Accepted 5 January 2004

Solid tumors with disorganized, insufficient blood supply contain hypoxic cells that are resistant to radiotherapy and chemotherapy. Drug resistance, an obstacle to curative treatment of solid tumors, can occur via suppression of apoptosis, a process controlled by pro- and antiapoptotic members of the Bcl-2 protein family. Oxygen deprivation of human colon cancer cells in vitro provoked decreased mRNA and protein levels of proapoptotic Bid and Bad. Hypoxia-inducible factor 1 (HIF-1) was dispensable for the down-regulation of Bad but required for that of Bid, consistent with the binding of HIF-1{alpha} to a hypoxia-responsive element (positions -8484 to -8475) in the bid promoter. Oxygen deprivation resulted in proteosome-independent decreased expression of Bax in vitro, consistent with a reduction in global translation efficiency. The physiological relevance of Bid and Bax down-regulation was confirmed in tumors in vivo. Oxygen deprivation resulted in decreased drug-induced apoptosis and clonogenic resistance to agents with different mechanisms of action. The contribution of Bid and/or Bax down-regulation to drug responsiveness was demonstrated by the relative resistance of normoxic cells that had no or reduced expression of Bid and/or Bax and by the finding that forced expression of Bid in hypoxic cells resulted in increased sensitivity to the topoisomerase II inhibitor etoposide.


* Corresponding author. Mailing address: Cancer Research UK, Paterson Institute for Cancer Research, Christie Hospital, Wilmslow Rd., Withington, Manchester M20 4BX, United Kingdom. Phone: 00 44 161 446 3606. Fax: 00 44 161 446 3061. E-mail: cdive{at}PICR.man.ac.uk.


Molecular and Cellular Biology, April 2004, p. 2875-2889, Vol. 24, No. 7
0022-538X/04/$08.00+0     DOI: 10.1128/MCB.24.7.2875-2889.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.




This article has been cited by other articles:




Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 2004 by the American Society for Microbiology. All rights reserved.