MicroRNA-21 as an indicator of aggressive phenotype in breast cancer.

e11010 Background: MicroRNAs (miRNAs) are a new class of non-protein-coding, endogenous, small RNAs. They have clinical significance because of their relationship to cancer pathogenesis. miRNAs act as an oncogene or a tumour supressor gene in cancer pathogenesis. MicroRNA-21 (miR-21) shows the highest expression level and acts as an oncogene in breast cancer. The purposes of this study are to measure miR-21 expression in early-stage breast cancer and to analyze its association with clinicopathologic features. Methods: Formalin-Fixed, Paraffin-Embedded (FFPE) tissue samples were collected from 15 patients who underwent surgery for primary breast cancer. The expression level of miR-21 was measured by the real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis in the tumor tissue and normal breast tissue. Levels of miR-21 expression in terms of disease stage, tumor size, nodal involvement, hormone receptor status and HER2 status were compared. Results: miR-21 expression was ...