m6A RNA methylation in breast cancer: from epitranscriptomic regulation to therapeutic targeting

Breast cancer remains a leading cause of cancer-related mortality worldwide, largely due to its molecular heterogeneity and therapeutic resistance. N6-methyladenosine (m6A) RNA modification has recently emerged as a critical epitranscriptomic regulator involved in diverse aspects of RNA metabolism, including stability, splicing, translation, and degradation. Accumulating evidence suggests that dysregulation of m6A modification is associated with breast cancer progression, metastasis, and treatment resistance. In this review, we systematically summarize the functional roles of m6A regulators, including writers, erasers, and readers, in breast cancer biology. We further discuss the involvement of m6A modification in key oncogenic signaling pathways, metabolic reprogramming, and tumor immune microenvironment remodeling. Importantly, we highlight the emerging clinical potential of m6A regulators as diagnostic and prognostic biomarkers, as well as therapeutic targets for overcoming drug resistance. Finally, we outline current challenges and future perspectives, emphasizing the need for integrating multi-omics approaches and developing m6A-targeted therapies to advance precision oncology in breast cancer.