A low serum microRNA-497-5p expression level is associated with primary breast cancer among Egyptian female patients

Abstract

Background/aim Circulating forms of micro(mi)RNAs are nowadays increasingly recognized as noninvasive promising biomarkers for early diagnosis and management of breast cancer (BC). Among the numerous miRNAs studied in BC, tissue expressed miR-497-5p and miR-182-5p proved to serve as promising diagnostic, prognostic, and therapeutic target tools in BC; yet little is known about their circulating forms in the peripheral blood of such patients. The study aimed to evaluate serum expression levels of miR-497-5p and miR-182-5p in Egyptian female patients with newly diagnosed BC and their possible association with different clinicopathological features. Patients and methods The study was conducted on 50 primary BC patients at the Medical Research Institute, Alexandria, Egypt, in addition to 50 healthy female volunteers as a control group. Preoperative serum samples were taken from all patients and from healthy volunteers. Relative quantifications of serum miR-182-5p and miR-497-5p expression levels were done using a reverse transcription-quantitative real time PCR. Results The study showed that the median value for fold change in serum miR-497-5p expression was significantly down regulated in BC patients group compared to the healthy control group. A receiver operating characteristics curve generated a cutoff value of 0.54. In serum miR-497-5p expression level was used to discriminate BC patients from controls with a diagnostic specificity of 88%, a sensitivity of 56%, and an overall test accuracy of 68.8%. However, no statistically significant difference was noted in serum miR-182-5p expression level between BC patients and control group. Nevertheless, its serum expression level was significantly higher in BC patients with lymph node involvement compared with BC patients without nodal involvement. Conclusion The downregulated serum miR-497-5p expression in BC patients compared with the healthy control group points to loss of its protective role in such BC patients. Further studies of this miRNA on a larger sample of patients with different molecular subtypes are recommended.