title: Investigation of MicroRNA-21 Expression Levels in Serum and Stool as a Potential Non-Invasive Biomarker for Diagnosis of Colorectal Cancer.
abstract: Most cancer studies focus on exploring non-invasive biomarkers for cancer detection. In the present study, we sought to investigate the expression level of microRNA-21 (miR-21), as a potential diagnostic marker, in serum and stool samples from 40 patients with colorectal cancer (CRC) and 40 healthy controls.
  
  
  
  Quantitative real-time RT-PCR was applied to determine the relative expression level of miR-21 in serum and stool. At the same time, the sensitivity and specificity of this marker was evaluated by receiver operating characteristic (ROC) curve analysis.
  
  
  
  miR-21 expression levels of serum and stool were up-regulated 12.1 (P<0.05, 95% CI: 5.774-34.045) and 10.0 (P<0.05, 95% CI: 0.351-16.260) times in CRC patients, respectively, when compared to the control group. The sensitivity and specificity of miR-21 was found to be 86.05% and 72.97%, respectively (an area under the ROC curve [AUC] of 0.783). The stool miR-21 level in CRC patients was much higher than that in the healthy controls, showing a sensitivity of 86.05% and a specificity of 81.08% (AUC: 0.829). The expression level of miR-21 in stool was able to significantly distinguish CRC tumor, node, metastasis stages III-IV from stages I-II, with a sensitivity and specificity of 88.1% and 81.6%, respectively (AUC: 0.872).
  
  
  
  The results of this study indicated that miR-21 expression levels in serum and stool can be considered as a potential diagnostic biomarker for the diagnosis of CRC patients. However, more studies are required to confirm the validity of miR-21 as a valuable non-invasive diagnostic tool for CRC.
authors.affiliation: Dept. of Molecular Medicine and Genetics, Research Center for Molecular Medicine, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran.
authors.forename: Saiyad
authors.initials: S
authors.lastname: Bastaminejad
authors.affiliation: Dept.of Microbiology, School of Medicine Lorestan University of Medical Sciences, Khorramabad, Iran.
authors.forename: Morovat
authors.initials: M
authors.lastname: Taherikalani
authors.affiliation: Digestive Oncology Research Center, Digestive Disease Research Institute, Tehran University of Medical Science, Tehran, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Ghanbari
authors.affiliation: Abadan School of Medical Sciences, Abadan, Iran.
authors.forename: Akbar
authors.initials: A
authors.lastname: Akbari
authors.affiliation: Dept. of Molecular Medicine and Genetics, Research Center for Molecular Medicine, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran.
authors.forename: Nooshin
authors.initials: N
authors.lastname: Shabab
authors.affiliation: Dept. of Molecular Medicine and Genetics, Research Center for Molecular Medicine, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran.
authors.forename: Massoud
authors.initials: M
authors.lastname: Saidijam
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood* / Q000235:genetics*; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000097:blood* / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology; D005243:Feces; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000097:blood* / Q000235:genetics*; D008875:Middle Aged; D009367:Neoplasm Staging; D012372:ROC Curve; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D014408:Biomarkers, Tumor; C524940:MIRN21 microRNA, human; D035683:MicroRNAs
keywords: Serum; Stool; miR-21; Biomarker; Colorectal Cancer (CRC)