title: Analysis of serum exosomal microRNAs and clinicopathologic features of patients with pancreatic adenocarcinoma.
abstract: BACKGROUND
  Altered expression of serum microRNAs (miRNAs) have been reported to correlate with carcinogenesis and progression of pancreatic adenocarcinoma (PC), but descriptions of serum exosomal miRNAs in PC are still lacking. This study was designed to evaluate serum exosomal miRNA levels in PC patients and to investigate their relationships with clinicopathologic features and prognosis.
  
  
  METHODS
  Four miRNAs (miR-17-5p, miR-21, miR-155 and miR-196a) related to PC were selected for examination in our research. Serum miRNA was examined by RT-PCR in a group of 49 patients, including 22 with PCs, 6 with benign pancreatic tumors, 7 with ampullary carcinomas, 6 with chronic pancreatitis and 8 healthy participants. The clinicopathologic data were also collected, and PC patients were classified according to the presence of metastasis, tumor differentiation and advanced stage.
  
  
  RESULTS
  There were low expressions of exosomal miR-155 and miR-196a in serum samples of PC patients when U-6 was used as a control. Serum exosomal miR-17-5p was higher in PC patients than in non-PC patients and healthy participants. High levels of miR-17-5p were significantly correlated with metastasis and advanced stage of PC. The serum exosomal miR-21 level in PC was higher than that in the normal and chronic pancreatitis groups, but was not significantly correlated with PC differentiation and tumor stage.
  
  
  CONCLUSIONS
  There were high expressions of serum exosomal miR-17-5p and miR-21 in PC patients. Examination of serum exosomal microRNA is a useful serum biomarker for PC diagnosis other than serum-free microRNA. It is postulated that exosomal miR-17-5p participates in the progression of PC.
authors.affiliation: Department of General Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China. cao@zju.edu.cn.
authors.forename: Risheng
authors.initials: R
authors.lastname: Que
authors.forename: Guoping
authors.initials: G
authors.lastname: Ding
authors.forename: Jionghuang
authors.initials: J
authors.lastname: Chen
authors.forename: Liping
authors.initials: L
authors.lastname: Cao
mesh_terms: D000230:Adenocarcinoma / Q000097:blood / Q000235:genetics / Q000473:pathology*; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood* / Q000235:genetics; D016022:Case-Control Studies; D055354:Exosomes / Q000235:genetics*; D005260:Female; D005500:Follow-Up Studies; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000097:blood* / Q000235:genetics; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000097:blood / Q000235:genetics / Q000473:pathology*; D050500:Pancreatitis, Chronic / Q000097:blood / Q000235:genetics / Q000473:pathology*; D011379:Prognosis; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D014408:Biomarkers, Tumor; C524942:MIRN155 microRNA, human; C524941:MIRN17 microRNA, human; C542543:MIRN196 microRNA, human; C524940:MIRN21 microRNA, human; D035683:MicroRNAs