title: Radiation induces aerobic glycolysis through reactive oxygen species.
abstract: OBJECTIVE
  Although radiation induced reoxygenation has been thought to increase radiosensitivity, we have shown that its associated oxidative stress can have radioprotective effects, including stabilization of the transcription factor hypoxia inducible factor 1 (HIF-1). HIF-1 is known to regulate many of the glycolytic enzymes, thereby promoting aerobic glycolysis, which is known to promote treatment resistance. Thus, we hypothesized that reoxygenation after radiation would increase glycolysis. We previously showed that blockade of oxidative stress using a superoxide dismutase (SOD) mimic during reoxygenation can downregulate HIF-1 activity. Here we tested whether concurrent use of this drug with radiotherapy would reduce the switch to a glycolytic phenotype.
  
  
  METHODS
  40 mice with skin fold window chambers implanted with 4T1 mammary carcinomas were randomized into (1) no treatment, (2) radiation alone, (3) SOD mimic alone, and (4) SOD mimic with concurrent radiation. All mice were imaged on the ninth day following tumor implantation (30 h following radiation treatment) following injection of a fluorescent glucose analog, 2-[N-(7-nitrobenz-2-oxa-1,3-diaxol-4-yl)amino]-2-deoxyglucose (2-NBDG). Hemoglobin saturation was measured by using hyperspectral imaging to quantify oxygenation state.
  
  
  RESULTS
  Mice treated with radiation showed significantly higher 2-NBDG fluorescence compared to controls (p=0.007). Hemoglobin saturation analysis demonstrated reoxygenation following radiation, coinciding with the observed increase in glycolysis. The concurrent use of the SOD mimic with radiation demonstrated a significant reduction in 2-NBDG fluorescence compared to effects seen after radiation alone, while having no effect on reoxygenation.
  
  
  CONCLUSIONS
  Radiation induces an increase in tumor glucose demand approximately 30 h following therapy during reoxygenation. The use of an SOD mimic can prevent the increase in aerobic glycolysis when used concurrently with radiation, without preventing reoxygenation.
authors.affiliation: School of Medicine, Duke University, Durham, USA.
authors.forename: Jim
authors.initials: J
authors.lastname: Zhong
authors.forename: Narasimhan
authors.initials: N
authors.lastname: Rajaram
authors.forename: David M
authors.initials: DM
authors.lastname: Brizel
authors.forename: Amy E
authors.initials: AE
authors.lastname: Frees
authors.forename: Nirmala
authors.initials: N
authors.lastname: Ramanujam
authors.forename: Ines
authors.initials: I
authors.lastname: Batinic-Haberle
authors.forename: Mark W
authors.initials: MW
authors.lastname: Dewhirst
mesh_terms: D009327:4-Chloro-7-nitrobenzofurazan / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D000332:Aerobiosis; D000818:Animals; D003847:Deoxyglucose / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D005260:Female; D006019:Glycolysis / Q000528:radiation effects*; D008325:Mammary Neoplasms, Experimental / Q000378:metabolism / Q000532:radiotherapy*; D051379:Mice; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000494:pharmacology
chemical_list: D017382:Reactive Oxygen Species; D003847:Deoxyglucose; D013482:Superoxide Dismutase; D009327:4-Chloro-7-nitrobenzofurazan; C098340:2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose
references.citation: Int J Radiat Oncol Biol Phys. 1990 Mar;18(3):559-68
references.pmid: 2318688
references.citation: Cancer Res. 2005 Jul 1;65(13):5498-505
references.pmid: 15994919
references.citation: BMC Med. 2009 Nov 05;7:68
references.pmid: 19891767
references.citation: Free Radic Biol Med. 2012 May 1;52(9):1828-34
references.pmid: 22336516
references.citation: N Engl J Med. 2011 Aug 11;365(6):537-47
references.pmid: 21830968
references.citation: Free Radic Biol Med. 2009 Oct 1;47(7):992-1004
references.pmid: 19591920
references.citation: Cell Res. 2012 Feb;22(2):285-7
references.pmid: 21946499
references.citation: Invest New Drugs. 2008 Feb;26(1):13-24
references.pmid: 17805485
references.citation: Br J Cancer. 2008 Nov 4;99(9):1442-52
references.pmid: 18854835
references.citation: J Biomed Opt. 2009 Nov-Dec;14(6):064014
references.pmid: 20059252
references.citation: Cancer Res. 2005 Jan 1;65(1):177-85
references.pmid: 15665293
references.citation: Cancer Res. 2003 Aug 1;63(15):4705-12
references.pmid: 12907653
references.citation: Int J Cancer. 2008 Nov 15;123(10):2430-7
references.pmid: 18729192
references.citation: Cancer Lett. 2012 Sep 1;322(1):78-85
references.pmid: 22348829
references.citation: Nat Rev Cancer. 2004 Nov;4(11):891-9
references.pmid: 15516961
references.citation: Nat Mater. 2009 Sep;8(9):747-51
references.pmid: 19668206
references.citation: AJR Am J Roentgenol. 2008 Jun;190(6):1630-6
references.pmid: 18492917
references.citation: J Biomed Opt. 2005 Jul-Aug;10(4):44004
references.pmid: 16178638
references.citation: Int J Hyperthermia. 2010;26(5):485-98
references.pmid: 20597627
references.citation: Cancer Cell. 2005 Aug;8(2):99-110
references.pmid: 16098463
references.citation: Radiology. 1972 Oct;105(1):135-42
references.pmid: 4506641
references.citation: Int J Radiat Oncol Biol Phys. 2005 Oct 1;63(2):545-52
references.pmid: 16168847
references.citation: Br J Cancer. 1999 Apr;79(11-12):1717-22
references.pmid: 10206282
references.citation: Free Radic Biol Med. 2011 Sep 1;51(5):1035-53
references.pmid: 21616142
references.citation: Br J Cancer. 2009 Mar 10;100(5):747-57
references.pmid: 19223896
references.citation: Nat Protoc. 2011 Aug 18;6(9):1355-66
references.pmid: 21886101
references.citation: Mol Imaging Biol. 2005 Nov-Dec;7(6):388-92
references.pmid: 16284704
references.citation: Curr Opin Oncol. 2012 Jan;24(1):62-7
references.pmid: 22123234
references.citation: Proc Natl Acad Sci U S A. 2004 Feb 10;101(6):1714-9
references.pmid: 14755057
references.citation: Biochim Biophys Acta. 2012 May;1822(5):794-814
references.pmid: 22198225
references.citation: Int J Hyperthermia. 2009;25(6):405-15
references.pmid: 19657852
references.citation: ACS Nano. 2010 Sep 28;4(9):4989-96
references.pmid: 20704337
references.citation: PLoS Biol. 2012;10(5):e1001326
references.pmid: 22589701
references.citation: Cancer Res. 2006 Sep 15;66(18):8927-30
references.pmid: 16982728
references.citation: Curr Mol Med. 2009 May;9(4):435-41
references.pmid: 19519401
references.citation: Breast J. 1999 Jan;5(1):13-21
references.pmid: 11348250
references.citation: Radiat Res. 1992 May;130(2):171-82
references.pmid: 1574573
references.citation: Int J Radiat Oncol Biol Phys. 2001 Nov 1;51(3):840-8
references.pmid: 11699496
references.citation: Cancer Chemother Pharmacol. 2009 Jan;63(2):219-28
references.pmid: 18365198
references.citation: Cancer Cell. 2004 May;5(5):429-41
references.pmid: 15144951
references.citation: J Biomed Opt. 2010 Nov-Dec;15(6):066021
references.pmid: 21198195
references.citation: Biochim Biophys Acta. 1996 Feb 9;1289(1):5-9
references.pmid: 8605231