MicroRNA 378b (MIR378B)

MicroRNA 378b (MIR378B) is a member of the microRNA gene family, short (20–24 nucleotide) non-coding RNAs that modulate gene expression by targeting mRNAs for destabilization or translational inhibition. MIR378B is embedded in the human genome and processed from a stem-loop precursor transcript, ultimately incorporated into RISC complexes to perform its regulatory role. In brown adipose tissue, miR-378b promotes expansion through direct repression of Pde1b, increasing cAMP signaling and fostering metabolic adaptation. In muscle, it coordinates autophagy and apoptosis by targeting PDK1 (autophagy initiation) and Caspase 9 (apoptosis), thereby maintaining muscle homeostasis and preventing muscle wasting. In cancer, miR-378b acts either as an oncogene or a tumor suppressor, modulating cell survival, proliferation, migration, and invasion via suppression of targets like Sufu, Fus-1, ATG12, CCND1, and pRb. Its levels are aberrant in many tumor types and linked to prognosis and disease aggressiveness. Experimental therapeutics focus on its regulation via mimics or inhibitors, with ongoing research into its clinical utility and safety implications.

Other names

hsa-mir-378bmiR-378bMIR378BmicroRNA 378b

Antisense oligonucleotides/inhibitors bind to MIR378B and block its function, leading to derepression of its target genes (e.g., PDK1, Caspase 9, Sufu, Fus-1, ATG12). miRNA mimics or overexpression can reinforce MIR378B function, suppressing targets and altering cell survival, growth, and apoptosis.