Spatially resolved microRNA expression in tissues: technologies, challenges, and opportunities

As the field of spatial omics continues to expand, the spatially resolved profiling of microRNA (miRNA) expression in tissues, or 'spatial miRNomics,' remains in its infancy, with only a few initial pioneering studies to date. MiRNA expression exhibits distinct spatial, temporal, and cell type-specific patterns, and the dysregulation of these patterns is associated with numerous pathological conditions. This highlights the potential of miRNAs as targets for spatial transcriptomic studies in translational and clinical research. In this review, we examine the current landscape of spatial technologies for miRNA detection from foundational methods to cutting-edge innovations, and we discuss conceptual and technical challenges. We also outline the biomedical implications of spatial miRNA profiling and set out future directions for exploring the spatial dimension of gene regulation.