title: Marker expression in circulating cancer cells of pancreatic cancer patients.
abstract: BACKGROUND
  By the time patients are diagnosed with pancreatic cancer, circulating cancer cells probably exist. Therefore, the detection of pancreatic cancer cells in the peripheral circulation could be used to diagnose early pancreatic cancer, which would otherwise not be detected by current imaging methods.
  
  
  METHODS
  The expression levels of h-TERT, CK20, CEA, and C-MET were detected in a model of circulating micrometastasis in pancreatic cancer that were enriched using immune-magnetic separation of the circulating cancer cells. The sensitivity and specificity of the measurements were evaluated. The expression of the above genes was measured in the circulating cancer cells of pancreatic cancer patients. We compared their expression rate in pancreatic cancer patients at different stages to screen for the indicator with highest sensitivity and specificity for the detection of circulating pancreatic cancer cells.
  
  
  RESULTS
  Immuno-magnetic nanoparticles combined with RT-PCR enabled the detection of one tumor cell per 1×10(7) peripheral blood mononuclear cells. The positive expression rates of C-MET, h-TERT, CK20, and CEA in the pancreatic cancer group were 80% (20/25), 100% (25/25), 84% (21/25), and 80% (20/25), respectively, while in the benign disease control group the rates were 0% (0/15), 0% (0/15), 6.77% (1/15), and 0% (0/15), respectively. There was a significant difference in the positive expression rate between the two groups (P<0.05). The specificity of h-TERT, CEA, and C-MET was higher than that of CK20. The positive expression rate of the four genes was not related to gender, age, tumor size, CA 19-9, or CEA serum levels (P>0.05). However, the positive expression of C-MET, CK20, and CEA closely correlated with tumor stage (P<0.05). Immuno-magnetic nanoparticles combined with RT-PCR were specific and sensitive for the detection of circulating cancer cells.
  
  
  CONCLUSIONS
  The positive expression of C-MET, h-TERT, CK20, and CEA in the circulation of pancreatic patients could be used as an indicator for circulating cancer cells. The combined detection of the four genes improved the specificity and sensitivity to 100%, which may be attributable to the use of immuno-magnetic separation and enrichment of the circulating pancreatic cancer cells. Our results suggest the clinical utility of this approach.
authors.affiliation: Department of Hepatic-Biliary Surgery, Affiliated Zhongda Hospital, Southeast University, Nanjing, China. zhoujh@seu.edu.cn
authors.forename: Jiahua
authors.initials: J
authors.lastname: Zhou
authors.forename: Liang
authors.initials: L
authors.lastname: Hu
authors.forename: Zeqian
authors.initials: Z
authors.lastname: Yu
authors.forename: Jie
authors.initials: J
authors.lastname: Zheng
authors.forename: Detong
authors.initials: D
authors.lastname: Yang
authors.forename: Michael
authors.initials: M
authors.lastname: Bouvet
authors.forename: Robert M
authors.initials: RM
authors.lastname: Hoffman
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics*; D002272:Carcinoembryonic Antigen / Q000235:genetics; D045744:Cell Line, Tumor; D006801:Humans; D018189:Immunomagnetic Separation; D053554:Keratin-20 / Q000235:genetics; D053758:Nanoparticles; D009360:Neoplastic Cells, Circulating / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000556:secondary*; D011379:Prognosis; D019859:Proto-Oncogene Proteins c-met / Q000235:genetics; D012680:Sensitivity and Specificity; D019098:Telomerase / Q000235:genetics
chemical_list: D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D053554:Keratin-20; D019859:Proto-Oncogene Proteins c-met; C509186:TERT protein, human; D019098:Telomerase