title: Circulating microRNAs - a new horizon in molecular diagnosis of breast cancer.
abstract: BACKGROUND
  The potential use of microRNAs (miRNAs) as ideal tumor markers has been the focus of recent research.
  
  
  OBJECTIVE
  Our hypothesis was that circulating miRNAs are differentially expressed in pretherapeutic sera of breast cancer patients compared to controls.
  
  
  METHODS
  Using real-time quantitative polymerase chain reaction (qPCR) analysis, levels of 5 candidate miRNAs (miR10b, miR34a, miR155, miR195 and miR16) were quantified in sera of breast cancer patients and control individuals.
  
  
  RESULTS
  Levels of preoperative sera showed significant upregulation of 3.36 fold rise in miR10b (p<0.001), a 2.07 fold rise in miR155 (p =0.005) and remarkable over expression of 11.9 fold rise in miR195 (p<0.001) of cases than controls. There was significant down regulation of miR34a (0.032, p<0.001). The comparison with the clinicopathological data of the breast cancer patients revealed significant high serum level of miR155 (p =0.004) and miR195 (p =0.002) in patients with lymph node metastasis and higher levels of miR10b (p =0.001) and miR155 (p <0.001) with distant metastasis (M1) than without metastasis (M0), in addition to significant decrease in miR34a (p <0.001) level in M1 than M0 cases.
  
  
  CONCLUSIONS
  These findings suggest that systemic circulating miRNAs have potential use as novel biomarkers for breast cancer.
authors.affiliation: Clinical Pathology Department, Faculty of Medicine, Zagazig University, Egypt.
authors.forename: Hoda A
authors.initials: HA
authors.lastname: Hagrass
authors.affiliation: Clinical Pathology Department, Faculty of Medicine, Zagazig University, Egypt.
authors.forename: Samar
authors.initials: S
authors.lastname: Sharaf
authors.affiliation: Medical Biochemistry Department, Faculty of Medicine, Zagazig University, Egypt.
authors.forename: Heba F
authors.initials: HF
authors.lastname: Pasha
authors.affiliation: Microbiology and Immunology Department, Faculty of Medicine, Zagazig University, Egypt.
authors.forename: Enas A
authors.initials: EA
authors.lastname: Tantawy
authors.affiliation: Medical Biochemistry Department, Faculty of Medicine, Zagazig University, Egypt.
authors.forename: Randa H
authors.initials: RH
authors.lastname: Mohamed
authors.affiliation: Surgery Department, Faculty of Medicine, Zagazig University, Egypt.
authors.forename: Rasha
authors.initials: R
authors.lastname: Kassem
keywords: Biomarker; breast cancer; diagnosis; microRNAs; real time PCR