title: Tumour CD133 mRNA expression and clinical outcome in surgically resected colorectal cancer patients.
abstract: BACKGROUND
  Human prominin-1 (CD133) is a novel pentaspan membrane protein which was originally classified as a marker of primitive haematopoietic and neural stem cells. Cancer stem cells have been isolated and expanded from leukaemia and several solid tumours, and have been associated with metastasis, chemoresistance and relapse. CD133 is recognised as a stem cell marker and is capable of identifying a tumour-initiating subpopulation in brain, colon, melanoma and other solid tumours.
  
  
  METHODS
  We assessed CD133 mRNA expression levels by RT-QPCR in tumour and matched normal tissue from 64 stages I-III colorectal cancer (CRC) patients and correlated tumour CD133 levels with clinicopathological characteristics and clinical outcome.
  
  
  RESULTS
  In four patients, CD133 mRNA was not expressed in tumour or in normal tissue. In the remaining 60 patients, expression levels were higher in tumour than in normal tissue (p=0.001). Higher levels of CD133 expression were associated with shorter relapse-free interval (RFI) (p=0.004) and overall survival (OS) (p<0.0001). In the multivariate analyses, CD133 levels emerged as a prognostic marker for RFI and OS.
  
  
  CONCLUSIONS
  We have observed longer RFI and OS in patients with lower levels of CD133, regardless of adjuvant treatment and other clinical characteristics. If these findings are confirmed in larger prospective studies, CD133 assessment may prove useful for new diagnostic and therapeutic procedures for CRC patients.
authors.affiliation: Human Anatomy Unit, Molecular Oncology and Embryology Laboratory, School of Medicine, University of Barcelona, IDIBAPS, Barcelona, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Artells
authors.forename: I
authors.initials: I
authors.lastname: Moreno
authors.forename: T
authors.initials: T
authors.lastname: Díaz
authors.forename: F
authors.initials: F
authors.lastname: Martínez
authors.forename: B
authors.initials: B
authors.lastname: Gel
authors.forename: A
authors.initials: A
authors.lastname: Navarro
authors.forename: R
authors.initials: R
authors.lastname: Ibeas
authors.forename: J
authors.initials: J
authors.lastname: Moreno
authors.forename: M
authors.initials: M
authors.lastname: Monzó
mesh_terms: D000071916:AC133 Antigen; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000096:biosynthesis* / Q000235:genetics; D014408:Biomarkers, Tumor / Q000096:biosynthesis* / Q000235:genetics; D017024:Chemotherapy, Adjuvant; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006023:Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics; D009367:Neoplasm Staging; D010455:Peptides / Q000235:genetics; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics; D012334:RNA, Neoplasm / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D000071916:AC133 Antigen; D015703:Antigens, CD; D014408:Biomarkers, Tumor; D006023:Glycoproteins; D009363:Neoplasm Proteins; C000606023:PROM1 protein, human; D010455:Peptides; D012333:RNA, Messenger; D012334:RNA, Neoplasm