title: Proteomic changes in the rat brain induced by homogenous irradiation and by the bystander effect resulting from high energy synchrotron X-ray microbeams.
abstract: OBJECTIVE
  To further evaluate the use of microbeam irradiation (MBI) as a potential means of non-invasive brain tumor treatment by investigating the induction of a bystander effect in non-irradiated tissue.
  
  
  METHODS
  Adult rats were irradiated with 35 or 350 Gy at the European Synchotron Research Facility (ESRF), using homogenous (broad beam) irradiation (HI) or a high energy microbeam delivered to the right brain hemisphere only. The proteome of the frontal lobes were then analyzed using two-dimensional electrophoresis (2-DE) and mass spectrometry.
  
  
  RESULTS
  HI resulted in proteomic responses indicative of tumourigenesis; increased albumin, aconitase and triosphosphate isomerase (TPI), and decreased dihydrolipoyldehydrogenase (DLD). The MBI bystander effect proteomic changes were indicative of reactive oxygen species mediated apoptosis; reduced TPI, prohibitin and tubulin and increased glial fibrillary acidic protein (GFAP). These potentially anti-tumourigenic apoptotic proteomic changes are also associated with neurodegeneration. However the bystander effect also increased heat shock protein (HSP) 71 turnover. HSP 71 is known to protect against all of the neurological disorders characterized by the bystander effect proteome changes.
  
  
  CONCLUSIONS
  These results indicate that the collective interaction of these MBI-induced bystander effect proteins and their mediation by HSP 71, may confer a protective effect which now warrants additional experimental attention.
authors.affiliation: Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, Canada. rsmith@mcmaster.ca
authors.forename: Richard W
authors.initials: RW
authors.lastname: Smith
authors.forename: Jiaxi
authors.initials: J
authors.lastname: Wang
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Schültke
authors.forename: Colin B
authors.initials: CB
authors.lastname: Seymour
authors.forename: Elke
authors.initials: E
authors.lastname: Bräuer-Krisch
authors.forename: Jean A
authors.initials: JA
authors.lastname: Laissue
authors.forename: Hans
authors.initials: H
authors.lastname: Blattmann
authors.forename: Carmel E
authors.initials: CE
authors.lastname: Mothersill
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000528:radiation effects; D001921:Brain / Q000166:cytology / Q000378:metabolism* / Q000528:radiation effects*; D001932:Brain Neoplasms / Q000209:etiology; D024201:Bystander Effect / Q000528:radiation effects*; D015180:Electrophoresis, Gel, Two-Dimensional; D005904:Glial Fibrillary Acidic Protein / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D006360:Heat-Shock Proteins / Q000378:metabolism / Q000528:radiation effects; D008297:Male; D008969:Molecular Sequence Data; D009381:Neoplasms, Radiation-Induced / Q000209:etiology; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D018384:Oxidative Stress / Q000528:radiation effects; D000091402:Prohibitins; D020543:Proteome / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects*; D040901:Proteomics; D051381:Rats; D017208:Rats, Wistar; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D017356:Synchrotrons; D014305:Triose-Phosphate Isomerase / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D014404:Tubulin / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects
chemical_list: D005904:Glial Fibrillary Acidic Protein; D006360:Heat-Shock Proteins; D009419:Nerve Tissue Proteins; D000091402:Prohibitins; D020543:Proteome; D012097:Repressor Proteins; D014404:Tubulin; D014305:Triose-Phosphate Isomerase