title: Pilot Study of Serum MicroRNA-21 as a Diagnostic and Prognostic Biomarker in Egyptian Breast Cancer Patients.
abstract: BACKGROUND
  MicroRNAs are small RNA molecules that bind to complementary sequences of target messenger RNAs and down-regulate their translation to protein or degrade them. MicroRNAs play critical roles in many different cellular processes. Hence, aberrant microRNA expression is common in a variety of disorders, including cancer.
  
  
  METHODS
  In this work, we quantified serum microRNA-21 (miR-21) expression levels in 30 breast cancer patients, 30 cancer-free individuals with risk factors for developing breast cancer, and another 30 controls without risk factors, in order to test the role of miR-21 as a possible diagnostic and prognostic biomarker in breast cancer.
  
  
  RESULTS
  Our results indicated that miR-21 expression was elevated in asymptomatic high-risk individuals (2.98-fold) compared with healthy non-risk controls (p < 0.001), and was increased in almost all sera of cancer patients (12.72-fold) compared with healthy controls (p < 0.001). Higher levels of serum miR-21 were also correlated with tumors of higher grades, more nodal involvement, distal metastasis and advanced clinical stages (p < 0.01). Furthermore, over-expression levels declined towards normal after surgical tumor resection (p < 0.001).
  
  
  CONCLUSIONS
  In conclusion, our findings demonstrate that serum miR-21 expression profile may serve as a potential non-invasive diagnostic and prognostic biomarker for breast cancer.
authors.affiliation: Genetics Unit, Department of Histology and Cell Biology, Faculty of Medicine, Suez Canal University, Circular Road, Ismailia, 41522, Egypt, emantoraih@gmail.com.
authors.forename: Eman A
authors.initials: EA
authors.lastname: Toraih
authors.forename: Eman A
authors.initials: EA
authors.lastname: Mohammed
authors.forename: Sherif
authors.initials: S
authors.lastname: Farrag
authors.forename: Nevene
authors.initials: N
authors.lastname: Ramsis
authors.forename: Somaya
authors.initials: S
authors.lastname: Hosny
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000097:blood* / Q000235:genetics; D001943:Breast Neoplasms / Q000097:blood / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology*; D016022:Case-Control Studies; D004534:Egypt; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D035683:MicroRNAs / Q000097:blood* / Q000235:genetics; D008875:Middle Aged; D010865:Pilot Projects; D011379:Prognosis; D015854:Up-Regulation
chemical_list: D014408:Biomarkers, Tumor; C524940:MIRN21 microRNA, human; D035683:MicroRNAs