title: AEG-1 expression is an independent prognostic factor in rectal cancer patients with preoperative radiotherapy: a study in a Swedish clinical trial.
abstract: BACKGROUND
  Preoperative radiotherapy (RT) is widely used to downstage rectal tumours, but the rate of recurrence varies significantly. Therefore, new biomarkers are needed for better treatment and prognosis. It has been shown that astrocyte elevated gene-1 (AEG-1) is a key mediator of migration, invasion, and treatment resistance. Our aim was to analyse the AEG-1 expression in relation to RT in rectal cancer patients and to test its radiosensitising properties.
  
  
  METHODS
  The AEG-1 expression was examined by immunohistochemistry in 158 patients from the Swedish clinical trial of RT. Furthermore, we inhibited the AEG-1 expression by siRNA in five colon cancer cell lines and measured the survival after irradiation by colony-forming assay.
  
  
  RESULTS
  The AEG-1 expression was increased in the primary tumours compared with the normal mucosa independently of the RT (P<0.01). High AEG-1 expression in the primary tumour of the patients treated with RT correlated independently with higher risk of distant recurrence (P=0.009) and worse disease-free survival (P=0.007). Downregulation of AEG-1 revealed a decreased survival after radiation in radioresistant colon cancer cell lines.
  
  
  CONCLUSIONS
  The AEG-1 expression was independently related to distant recurrence and disease-free survival in rectal cancer patients with RT and could therefore be a marker to discriminate patients for distant relapse.
authors.affiliation: Division of Oncology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, County Council of Östergötland, University of Linköping, SE-58185 Linköping, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Gnosa
authors.affiliation: School of Medicine, Örebro University, SE-70128 Örebro, Sweden.
authors.forename: H
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Division of Oncology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, County Council of Östergötland, University of Linköping, SE-58185 Linköping, Sweden.
authors.forename: V P
authors.initials: VP
authors.lastname: Brodin
authors.affiliation: Division of Health and Society, Department of Medical and Health Sciences, Faculty of Health Sciences, Linköping University, SE-58185 Linköping, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Carstensen
authors.affiliation: Department of Oncology, Karolinska University Hospital, SE-11883 Stockholm, Sweden.
authors.forename: G
authors.initials: G
authors.lastname: Adell
authors.affiliation: Division of Oncology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, County Council of Östergötland, University of Linköping, SE-58185 Linköping, Sweden.
authors.forename: X-F
authors.initials: XF
authors.lastname: Sun
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000096:biosynthesis; D015815:Cell Adhesion Molecules / Q000096:biosynthesis* / Q000235:genetics; D002986:Clinical Trials as Topic; D018572:Disease-Free Survival; D005260:Female; D055785:Gene Knockdown Techniques; D006801:Humans; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000378:metabolism / Q000473:pathology; D011379:Prognosis; D016601:RNA-Binding Proteins; D012004:Rectal Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D013548:Sweden; D014162:Transfection
chemical_list: D014408:Biomarkers, Tumor; D015815:Cell Adhesion Molecules; C483039:MTDH protein, human; D008565:Membrane Proteins; D016601:RNA-Binding Proteins