MicroRNAs in triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is a molecular subtype of breast cancer with one of the worst prognoses. Current treatment is based on chemo- and/or radiotherapy and surgery. New targets, however, offering other therapeutic approaches, have been identified. These involve poly (ADP-ribose) polymerase (PARP), vascular endothelial growth factor receptor (VEGFR), epidermal growth factor receptor (EGFR), androgen receptor (AR), long non-coding RNAs (lncRNAs) and microRNAs (miRs). The latter are non-coding RNAs which control the expression of more than 50% of human genes via regulation of basic cellular processes at post-transcriptional level and dysregulation of miRs is found in many types of tumors. The role of dysregulated miRs in carcinogenesis lies in their acting as tumor suppressors or oncogenes, and in resistance to treatment (chemotherapy, hormonal and targeted therapy or radiotherapy). Circulating miRs are also promising prognostic and predictive biomarkers in patients with breast cancer. The aim of this review is to analyze recently published data on miRs and therapeutic targets potentially influenced by miRs in TNBC.