Circulating miRNA in metabolic syndrome and cancer: Machinery, diagnostics, and therapeutics.

MicroRNAs (miRNAs) are key post-transcriptional regulators that play critical roles in cellular homeostasis and disease progression. Increasing evidence indicates their involvement in cancer-associated metabolic reprogramming, in which tumor cells adapt to hypoxic and acidic microenvironments by altering glycolysis, lipid metabolism, and alternative carbon utilization pathways. Despite extensive studies on individual miRNAs, a comprehensive integration of their roles across metabolic regulation, diagnostic detection, and therapeutic targeting remains limited. This review summarizes the molecular mechanisms by which dysregulated miRNAs orchestrate metabolic pathways in cancer, with a focus on their roles in glycolytic flux, lipid metabolism, and mitochondrial function. In addition, we discuss recent advances in miRNA detection using biosensor-based platforms, including electrochemical, optical, and field-effect transistor systems, enabling sensitive, non-invasive diagnostics. Furthermore, emerging miRNA-based therapeutic strategies are highlighted, emphasizing their potential to modulate cancer metabolism and improve treatment outcomes. Collectively, this review provides an integrated perspective on miRNA-mediated metabolic regulation in cancer and underscores their potential as diagnostic biomarkers and therapeutic targets.