Role and underlying mechanisms of miR‑200 family in breast cancer (Review)

Βreast cancer (BC) is the most common malignant tumor among women. Its significant heterogeneity and complex molecular mechanisms pose major clinical challenges, including limited therapeutic efficacy and drug resistance. Recently, microRNAs (miRs) have been recognized as key post‑transcriptional regulators involved in tumorigenesis and tumor progression through multiple pathways. Among these, the miR‑200 family (miR‑200a, miR‑200b, miR‑200c, miR‑429 and miR‑141) has attracted considerable attention due to its pivotal role in BC. The present review systematically summarizes the genomic characteristics, expression regulation mechanisms and biological functions of the miR‑200 family in BC. Special emphasis is given to their roles in epithelial‑mesenchymal transition, cell proliferation, apoptosis, maintenance of stemness, and remodeling of the tumor microenvironment. Furthermore, members of the miR‑200 family have potential as diagnostic and prognostic biomarkers and are closely linked to chemotherapy resistance. The present review aims to provide novel insights and a theoretical foundation for the diagnosis, treatment, and deeper investigation of BC by comprehensively examining the functional mechanisms of the miR‑200.