title: Expression of mesothelin mRNA in pure pancreatic juice from patients with pancreatic carcinoma, intraductal papillary mucinous neoplasm of the pancreas, and chronic pancreatitis.
abstract: OBJECTIVE
  In the gene expression analysis of pancreatic carcinoma (PCa) using serial analysis of gene expression (SAGE) according to Ryu et al, the tag for the mesothelin mRNA transcript was present in 7 of 8 SAGE libraries derived from PCa but not in the 2 SAGE libraries derived from normal pancreatic duct epithelial cells. Mesothelin mRNA expression was confirmed with in situ hybridization in all 4 resected primary PCa tumors and with RT-PCR in 18 of 20 PCa cell lines, whereas mesothelin protein expression was confirmed with immunohistochemistry in all 60 resected primary PCa tissues by Argani et al. We evaluated mesothelin mRNA expression in pure pancreatic juice (PPJ) obtained from patients with PCa, chronic pancreatitis (CP), and intraductal papillary mucinous neoplasm (IPMN) of the pancreas.
  
  
  METHODS
  We evaluated mesothelin mRNA expression in the PPJ obtained from 21 patients with PCa, 22 with CP, and 11 with IPMN with reverse transcriptase PCR (RT-PCR). The PCR products were analyzed with agarose gel electrophoresis. DNase I treatment before RT-PCR and direct sequencing of the RT-PCR bands were performed for the analysis of the RT-PCR bands.
  
  
  RESULTS
  Two products, of 308 and 226 bp, were obtained with RT-PCR, and the 308-bp RT-PCR product was confirmed as being that derived from the genomic DNA by direct DNA sequencing. Mesothelin mRNA expression was discovered using RT-PCR in 11 (52%) of 21 patients with PCa, 5 (45%) of 11 with IPMN, and 3 (14%) of 22 with CP. Fisher's exact test revealed significant differences between PCa and CP for mesothelin mRNA (P < 0.01). Moreover, the RT-PCR product (226 bp) of mesothelin mRNA in the PPJ samples with PCa was generally stronger than that in the PPJ samples with IPMN.
  
  
  CONCLUSIONS
  Expression of mesothelin mRNA in PPJ was not strictly specific to PCa and was apt to be stronger in PCa than in IPMN. Quantitative detection of mesothelin mRNA in PPJ may have potential diagnostic implications for pancreatic tumors.
authors.affiliation: Department of Internal Medicine and Medical Oncology, Cancer Research Institute, Kanazawa University, Kanazawa, Japan. watahiro@kenroku.kanazawa-u.ac.jp
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Watanabe
authors.forename: Gensaku
authors.initials: G
authors.lastname: Okada
authors.forename: Koushiro
authors.initials: K
authors.lastname: Ohtsubo
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Yamaguchi
authors.forename: Hisatsugu
authors.initials: H
authors.lastname: Mouri
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Motoo
authors.forename: Tokio
authors.initials: T
authors.lastname: Wakabayashi
authors.forename: Norio
authors.initials: N
authors.lastname: Sawabu
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000175:diagnosis* / Q000235:genetics / Q000503:physiopathology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001483:Base Sequence; D014408:Biomarkers, Tumor / Q000235:genetics; D002291:Carcinoma, Papillary / Q000175:diagnosis* / Q000235:genetics / Q000503:physiopathology; D045744:Cell Line, Tumor; D005260:Female; D058851:GPI-Linked Proteins; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics*; D000090204:Mesothelin; D008875:Middle Aged; D008969:Molecular Sequence Data; D010189:Pancreatic Juice / Q000502:physiology; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000503:physiopathology; D050500:Pancreatitis, Chronic / Q000175:diagnosis* / Q000235:genetics / Q000503:physiopathology; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D014408:Biomarkers, Tumor; D058851:GPI-Linked Proteins; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D000090204:Mesothelin