MicroRNAs as Promising Novel Biomarkers for Diagnosis of Breast Cancer

Background: Breast cancer is the most common cancer worldwide, Micro RNA are 22-25 nucleotides long, single- stranded, non-protein coding RNA that, regulate gene expres-sion. Its level in the circulation is changed in association with different diseases and certain biological or pathological stages including cancer.Aim of Work: To evaluate the gene expression of miR-21 and miR-155 in serum as a novel biomarkers to diagnose breast cancer.Subject and Methods: This study included 50 female patients with breast cancer and 25 age and sex matched healthy female serving as control. Blood samples were taken to estimate Micro RNA-21 and micro RNA-155 gene expression by real-time quantitative reverse transcription PCR (qRT-PCR ).Results: A significant difference between patients and controls as regards the gene expression of miRNA- 21 (p= .001) and miRNA-155 (p=0.016) in serum was detected, were they unregulated in comparison to the control group. Receiver Operating Characteristic (ROC) Curve analysis showed that the best cutoff value for miRNA-21=l .215 with sensitivity 92% and specificity 100%, and miRNA-155=l.365 with sensitivity 60% and specificity 100%.Conclusion: Gene expression of MiRNA-21 and miR- 155 in serum can be used as a novel biomarker to diagnose breast cancer patient.