Discovery and function exploration of microRNA-155 as a molecular biomarker for early detection of breast cancer.

Background: MicroRNA-155 (miR-155) may function as a diagnostic biomarker of breast cancer (BC). Nevertheless, the available evidence is controversial. Therefore, we performed this study to summarize the global predicting role of miR-155 for early detection of BC and preliminarily explore the functional roles of miR-155 in BC.

Methods: We first collected published studies and applied the bivariate meta-analysis model to generate the pooled diagnostic parameters of miR-155 in diagnosing BC such as sensitivity, specificity and area under curve (AUC). Then, we applied function enrichment and protein-protein interactions (PPI) analyses to explore the potential mechanisms of miR-155.

Results: A total of 21 studies were finally included. The results indicated that miR-155 allowed for the discrimination between BC patients and healthy controls with a sensitivity of 0.87 (95% CI 0.78-0.93), specificity of 0.82 (0.72-0.89), and AUC of 0.91 (0.88-0.93). In addition, the overall sensitivity, specificity and AUC for circulating miR-155 were 0.88 (0.76-0.95), 0.83 (0.72-0.90), and 0.92 (0.89-0.94), respectively. Function enrichment analysis revealed several vital ontologies terms and pathways associated with BC occurrence and development. Furthermore, in the PPI network, ten hub genes and two significant modules were identified to be involved in some important pathways associated with the pathogenesis of BC.

Conclusions: We demonstrated that miR-155 has great potential to facilitate accurate BC detection and may serve as a promising diagnostic biomarker for BC. However, well-designed cohort studies and biological experiments should be implemented to confirm the diagnostic value of miR-155 before it can be applied to routine clinical procedures.