title: Circulating Exosomal MicroRNA-21 as a Biomarker in Each Tumor Stage of Colorectal Cancer.
abstract: OBJECTIVE
  We clarified the predictive and prognostic value of circulating plasma exosomal microRNA-21 (miR-21) in each TNM stage of colorectal cancer (CRC) patients.
  
  
  METHODS
  The microRNA (miRNA) profiles of the plasma exosomes, primary tumor tissues, and liver metastasis tissues from the same CRC patients were examined using a microarray. For validation analysis, the plasma exosome samples from 326 CRC patients were measured by TaqMan miRNA assays.
  
  
  RESULTS
  In the miRNA microarray analyses, miR-21 showed the highest upregulation in exosomes, primary tumor tissues, and liver metastasis tissues. Significant correlations were demonstrated between exosomal miR-21 and tissue miR-21 levels. As for the relationship to the pathological condition, exosomal miR-21 showed a significant association with liver metastasis and TNM stage. The overall survival (OS) rates and disease-free survival (DFS) rates in high-exosomal-miR-21 patients were significantly worse than those in low-miR-21 patients. Exosomal miR-21 levels were an independent prognostic factor for OS and DFS in CRC patients with TNM stage II or III, and for OS in patients with TNM stage IV.
  
  
  CONCLUSIONS
  Plasma exosomal miR-21 levels are a useful biomarker for the prediction of recurrence and poor prognosis in CRC patients with TNM stage II, III, or IV.
authors.affiliation: Department of Surgery, Teikyo University School of Medicine, Tokyo, Japan.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Tsukamoto
authors.forename: Hisae
authors.initials: H
authors.lastname: Iinuma
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yagi
authors.forename: Keiji
authors.initials: K
authors.lastname: Matsuda
authors.forename: Yojiro
authors.initials: Y
authors.lastname: Hashiguchi
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood* / Q000235:genetics*; D015179:Colorectal Neoplasms / Q000097:blood / Q000235:genetics* / Q000401:mortality / Q000473:pathology*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008113:Liver Neoplasms / Q000097:blood / Q000235:genetics / Q000401:mortality / Q000556:secondary; D035683:MicroRNAs / Q000097:blood* / Q000235:genetics*; D046228:Microarray Analysis; D009364:Neoplasm Recurrence, Local / Q000097:blood / Q000235:genetics; D009367:Neoplasm Staging; D011379:Prognosis; D015996:Survival Rate; D014407:Tumor Cells, Cultured
chemical_list: D014408:Biomarkers, Tumor; C524940:MIRN21 microRNA, human; D035683:MicroRNAs
keywords: Biomarker; Colorectal cancer; Exosome; Liquid biopsy; MicroRNA-21