title: Elevated circulating endothelial progenitor marker CD133 messenger RNA levels predict colon cancer recurrence.
abstract: BACKGROUND
  CD133 is a specific surface marker for bone marrow-derived circulating endothelial progenitors, which are vital in postnatal physiologic and pathologic (eg, tumor) angiogenesis. In this study, the authors examined whether increased levels of expression of CD133 messenger RNA (mRNA) in peripheral blood predicted disease recurrence in patients with colon cancer.
  
  
  METHODS
  Semiquantitative real-time reverse transcriptase-polymerase chain reaction analysis was used to quantify CD133 mRNA levels in peripheral blood mononuclear cells from patients with colon cancer. The assay was developed first and tested at laboratory A (n = 34) and then was validated independently at laboratory B (n = 66). All patients were enrolled between February 2002 and December 2003. A central statistician performed the analysis.
  
  
  RESULTS
  At laboratory A, the median CD133 mRNA level was elevated in patients with recurrent disease (4.2; range, 0.017-106.9) compared with patients without recurrence (0.0017; range, 0.0-9.51; P < .001), leading to a 14.6 odds ratio of recurrence (95% confidence interval [95% CI], 1.7-126; P = .004). At laboratory B, it was confirmed that elevated CD133 mRNA levels at a cutoff point >or=4.79 versus <4.79 were associated with an odds ratio of 22.6 for recurrence (95% CI, 1.7-291.2; P = .02). By comparison, the odds ratio for recurrence was 17.2 (95% CI, 1.8-164; P = .01) for patients with stage III-IV disease versus stage I-II disease according to the Tumor, Lymph Node, Metastasis (TNM) classification. An association also was observed between elevated carcinoma embryonic antigen levels (P = .03; 1-sided) and decreased survival (P = .035; 1-sided) with a CD133 mRNA cutoff level of >or=4.79.
  
  
  CONCLUSIONS
  Elevated CD133 mRNA levels at >or=4.79 predicted colon cancer recurrence independent of TNM stage IV disease. Larger prospective studies comparing the current assay with standardized methodology are warranted.
authors.affiliation: Department of Gastrointestinal Medical Oncology, the University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA. elin@seattlecca.org
authors.forename: Edward H
authors.initials: EH
authors.lastname: Lin
authors.forename: Manal
authors.initials: M
authors.lastname: Hassan
authors.forename: Yanan
authors.initials: Y
authors.lastname: Li
authors.forename: Hua
authors.initials: H
authors.lastname: Zhao
authors.forename: Ajay
authors.initials: A
authors.lastname: Nooka
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Sorenson
authors.forename: Keping
authors.initials: K
authors.lastname: Xie
authors.forename: Richard
authors.initials: R
authors.lastname: Champlin
authors.forename: Xifeng
authors.initials: X
authors.lastname: Wu
authors.forename: Donghui
authors.initials: D
authors.lastname: Li
mesh_terms: D000071916:AC133 Antigen; D015703:Antigens, CD / Q000097:blood / Q000235:genetics*; D014408:Biomarkers, Tumor / Q000097:blood / Q000235:genetics*; D003110:Colonic Neoplasms / Q000235:genetics* / Q000556:secondary; D005260:Female; D006023:Glycoproteins / Q000097:blood / Q000235:genetics*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000235:genetics*; D010455:Peptides / Q000097:blood / Q000235:genetics*; D012333:RNA, Messenger / Q000097:blood* / Q000235:genetics; D012334:RNA, Neoplasm / Q000097:blood / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015996:Survival Rate
chemical_list: D000071916:AC133 Antigen; D015703:Antigens, CD; D014408:Biomarkers, Tumor; D006023:Glycoproteins; C000606023:PROM1 protein, human; D010455:Peptides; D012333:RNA, Messenger; D012334:RNA, Neoplasm