The role of microRNAs in breast cancer: Diagnostic and therapeutic implications

Breast cancer is among the commonly diagnosed malignancies with considerable mortality. Understanding the underlying molecular pathways of breast tumorigenesis can pave the way for developing novel diagnostic and therapeutic approaches. Growing evidence highlights microRNAs' (miRNAs) critical role in cancer development via regulating the expression of genes involved in tumorigenesis. Tissue-specific miRNAs found in blood and other body fluids highlight their potential as novel biomarkers for early cancer diagnosis. To detect miRNA changes associated with breast cancer onset and progression, ultrasensitive and rapid biosensors have been developed. These devices offer a low-cost, fast, sensitive, and accurate alternative to traditional screening methods. Moreover, miRNA profiling across different breast cancer subtypes enables personalized medicine by predicting drug responses and guiding the development of targeted miRNA-based therapeutic strategies. Molecular strategies such as antisense oligonucleotides, miRNA inhibitors, and artificial tumor suppressor miRNAs have been developed to inhibit breast cancer progression. However, efficient delivery to tumor sites remains a major challenge, requiring carriers that are stable, tumor-specific, non-toxic, and non-immunogenic. Naturally derived exosomes, especially engineered ones, show promise for targeted miRNA delivery. This study reviews the role of miRNAs in breast cancer and highlights recent advances in miRNA-based approaches for early detection and effective therapy.