Identification of dysregulated microRNAs associated with diagnosis and prognosis in triple‑negative breast cancer: An in silico study

Triple‑negative breast cancer (TNBC) is a highly aggressive subtype of breast cancer with limited treatment options combined with poor rates of survival. Given the lack of appropriate prognostic biomarkers for TNBC patients, the present study aimed to identify potential dysregulated miRNAs capable of providing a diagnosis and predicting overall survival for TNBC patients. A total of 289 miRNAs were aberrantly regulated in TNBC tissue compared to adjacent, non‑cancerous tissues and 96 microRNAs (miRNAs) in TNBC compared with non‑triple‑negative breast cancer (nTNBC) samples. Receiver operating characteristic (ROC) curve analysis suggested that 4 miRNAs (hsa‑miR‑10a, hsa‑miR‑18a, hsa‑miR‑135b and hsa‑miR‑577) had diagnostic value [area under curve (AUC) >0.8]. A 4‑miRNA signature consisting of hsa‑miR‑148b, hsa‑miR‑203a, hsa‑miR‑203b and hsa‑miR‑3922 was constructed for prediction of prognosis. A multivariate Cox's proportional hazards regression model indicated that the 4‑miRNA signature was an independent prognostic factor of other clinical variables in patients with TNBC. Functional analysis of the target genes of the miRNA signature demonstrated that the prolactin signaling pathway and miRNAs in cancer were significantly enriched. In conclusion, the results in the present study may highlight efficient biomarkers for the diagnosis of TNBC and its prognosis. In‑depth exploitation of these miRNAs will help define and develop novel molecular therapeutic strategies and improve prognosis for TNBC patients.