title: Clinical impact of circulating miR-221 in plasma of patients with pancreatic cancer.
abstract: BACKGROUND
  Several recent studies have demonstrated that microRNAs (miRNAs) are stably detectable in plasma/serum. We tested miR-221 and miR-375, which are frequently reported to be highly and poorly expressed in pancreatic cancer (PCa), as candidates for plasma biomarkers in PCa.
  
  
  METHODS
  This study was divided into three parts: (1) Confirmation of higher miR-221 levels in primary PCa tissue and cell lines than normal pancreatic tissues. (2) Evaluation of plasma miR-221 and miR-375 concentrations by comparing results from 47 consecutive PCa patients and 30 healthy volunteers. (3) Evaluation of the assay for monitoring tumour dynamics in PCa patients.
  
  
  RESULTS
  (1) Expression of miR-221 was significantly higher in PCa tissues and cell lines than normal pancreatic tissues. (2) Plasma miR-221 concentrations were significantly higher in PCa patients than that in benign pancreatic tumours (P=0.016) and controls (P<0.0005), while plasma miR-375 concentrations tended to be lower in PCa patients (P=0.064), and the miR-221/miR-375 ratio was significantly higher (P<0.0001) in PCa patients than in controls. (3) Plasma miR-221 concentrations were significantly reduced in postoperative samples (P=0.018). Furthermore, PCa patients with high plasma miR-221 concentrations had significant correlation with distant metastasis (P=0.041), and non-resectable status (P=0.021).
  
  
  CONCLUSIONS
  Plasma miR-221 could be a useful biomarker for cancer detection, monitoring tumour dynamics and predicting malignant outcomes in PCa patients, and may contribute to clinical decision making in PCa treatments.
authors: Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan.
authors: T
authors: T
authors: Kawaguchi
authors: S
authors: S
authors: Komatsu
authors: D
authors: D
authors: Ichikawa
authors: R
authors: R
authors: Morimura
authors: M
authors: M
authors: Tsujiura
authors: H
authors: H
authors: Konishi
authors: H
authors: H
authors: Takeshita
authors: H
authors: H
authors: Nagata
authors: T
authors: T
authors: Arita
authors: S
authors: S
authors: Hirajima
authors: A
authors: A
authors: Shiozaki
authors: H
authors: H
authors: Ikoma
authors: K
authors: K
authors: Okamoto
authors: T
authors: T
authors: Ochiai
authors: H
authors: H
authors: Taniguchi
authors: E
authors: E
authors: Otsuji
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood / Q000235:genetics; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000097:blood*; D010190:Pancreatic Neoplasms / Q000097:blood* / Q000235:genetics*
chemical_list: D014408:Biomarkers, Tumor; D035683:MicroRNAs; C525709:MIR221, human; C540933:MIRN375 microRNA, human