title: Radiation-induced effects on gene expression: an in vivo study on breast cancer.
abstract: OBJECTIVE
  Breast cancer is diagnosed worldwide in approximately one million women annually and radiation therapy is an integral part of treatment. The purpose of this study was to investigate the molecular basis underlying response to radiotherapy in breast cancer tissue.
  
  
  METHODS
  Tumour biopsies were sampled before radiation and after 10 treatments (of 2 Gray (Gy) each) from 19 patients with breast cancer receiving radiation therapy. Gene expression microarray analyses were performed to identify in vivo radiation-responsive genes in tumours from patients diagnosed with breast cancer. The mutation status of the TP53 gene was determined by using direct sequencing.
  
  
  CONCLUSIONS
  Several genes involved in cell cycle regulation and DNA repair were found to be significantly induced by radiation treatment. Mutations were found in the TP53 gene in 39% of the tumours and the gene expression profiles observed seemed to be influenced by the TP53 mutation status.
authors.affiliation: Department of Genetics, Institute for Cancer Research, Rikshospitalet-Radiumhospitalet Medical Center, Oslo, Norway. ahelland@labmed.uio.no <ahelland@labmed.uio.no>
authors.forename: Aslaug
authors.initials: A
authors.lastname: Helland
authors.forename: Hilde
authors.initials: H
authors.lastname: Johnsen
authors.forename: Caroline
authors.initials: C
authors.lastname: Frøyland
authors.forename: Hege B K
authors.initials: HB
authors.lastname: Landmark
authors.forename: Anna B
authors.initials: AB
authors.lastname: Saetersdal
authors.forename: Marit Muri
authors.initials: MM
authors.lastname: Holmen
authors.forename: Turid
authors.initials: T
authors.lastname: Gjertsen
authors.forename: Jahn M
authors.initials: JM
authors.lastname: Nesland
authors.forename: William
authors.initials: W
authors.lastname: Ottestad
authors.forename: Stefanie S
authors.initials: SS
authors.lastname: Jeffrey
authors.forename: Lars O
authors.initials: LO
authors.lastname: Ottestad
authors.forename: Olag K
authors.initials: OK
authors.lastname: Rodningen
authors.forename: Gavin
authors.initials: G
authors.lastname: Sherlock
authors.forename: Anne-Lise
authors.initials: AL
authors.lastname: Børresen-Dale
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000532:radiotherapy*; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D005260:Female; D015870:Gene Expression / Q000528:radiation effects; D016158:Genes, p53 / Q000528:radiation effects*; D006801:Humans; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis / Q000235:genetics*
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; C117669:DDB2 protein, human; D004268:DNA-Binding Proteins; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53