title: Investigations for a multi-marker RT-PCR to improve sensitivity of disseminated tumor cell detection.
abstract: BACKGROUND
  In order to develop a multi-marker RT-PCR, which as such may be more sensitive than a single marker assay for the detection of disseminated tumor cells, we evaluated six RT-PCR markers: cytokeratin 20 (CK20), carcinoembryonic antigen (CEA), guanylyl cyclase C (GCC), epidermal growth factor receptor (EGFR), matrilysin (MMP-7) and HeLa metastatic gene (HLM).
  
  
  METHODS
  The expression was studied in human colon tumor cell lines, in colon cancer tissues, and in blood and/or bone marrow samples of colorectal cancer patients and control subjects.
  
  
  RESULTS
  The cell lines showed a differential expression pattern. The expression of all markers was detected in control blood samples with the lowest frequency for CK20 and EGFR. Semiquantitative analysis, which was performed to study threshold setting, demonstrated that GCC expression was elevated in patient compared to control samples. However, the reproducibility was questionable.
  
  
  CONCLUSIONS
  The results presented in this study suggest an enhanced sensitivity for a combination of RT-PCR markers. Due to limited specificity however, the development of a multi-marker RT-PCR by using conventional PCR does not seem feasible. Future studies should focus on the potential of quantitative RT-PCR.
authors.affiliation: Departments of Surgery, Pathology, University Medical Center, Nijmegen, PO Box 9101, 6500 HB Nijmegen, The Netherlands. fvlems@pathol.azn.nl
authors.forename: F A
authors.initials: FA
authors.lastname: Vlems
authors.forename: J H S
authors.initials: JH
authors.lastname: Diepstra
authors.forename: I M H A
authors.initials: IM
authors.lastname: Cornelissen
authors.forename: M J L
authors.initials: MJ
authors.lastname: Ligtenberg
authors.forename: Th
authors.initials: T
authors.lastname: Wobbes
authors.forename: C J A
authors.initials: CJ
authors.lastname: Punt
authors.forename: J H J M
authors.initials: JH
authors.lastname: van Krieken
authors.forename: T J M
authors.initials: TJ
authors.lastname: Ruers
authors.forename: G N P
authors.initials: GN
authors.lastname: van Muijen
mesh_terms: D014408:Biomarkers, Tumor / Q000096:biosynthesis / Q000097:blood / Q000235:genetics*; D001853:Bone Marrow / Q000378:metabolism / Q000502:physiology; D003110:Colonic Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D020869:Gene Expression Profiling; D006801:Humans; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D014407:Tumor Cells, Cultured
chemical_list: D014408:Biomarkers, Tumor