LncRNAs at the Crossroads of Breast Cancer Metastasis: Emerging Mechanisms and Therapeutic Prospects.

Breast cancer metastasis is one of the leading causes of cancer-related mortality in women, which occurs through an intricate molecular network and cellular events. Over time, lncRNAs have emerged as an important regulator of metastatic progression. These RNAs affect important processes including EMT, ECM remodelling, angiogenesis, immune evasion, and can-cer stemness. LncRNAs regulate this process by acting as molecular decoys, scaffolds, guides, or competing endogenous RNAs, thereby controlling gene expression at both transcriptional and post-transcriptional levels. Various lncRNAs, including HOTAIR, BCAR4, and LINC00511, are known to promote metastasis by driving chromatin remodelling and activating pro-tumorigenic signalling pathways. In contrast, lncRNAs such as GAS5, LINC01133, and TINCR act as metas-tasis suppressors, thereby limiting tumor spreading. A wide range of experimental approaches, including CRISPR/Cas9, RNA interference, in-vitro functional assays, in-vivo models, and bio-informatic analyses, have helped define critical lncRNA-driven regulatory networks. Despite these advances, challenges related to lncRNA conservation, delivery strategies, and context-spe-cific functions persist. Nevertheless, progress in RNA therapeutics and multi-omics technologies is steadily advancing the integration of lncRNA signatures into liquid biopsies, diagnostics, and precision medicine approaches for metastatic breast cancer.