microRNA 208a-5p (miR-208a-5p)

miR-208a-5p is a small, non-coding RNA molecule (~22 nucleotides) generated from the 5’ arm of the precursor microRNA-208a (MIR208A), which resides in an intron of the MYH6 gene encoding cardiac myosin. It plays a crucial role in regulating cardiac gene expression, especially in the context of cardiac hypertrophy and arrhythmias, and is normally expressed at very low levels in healthy cardiac tissue. Dysregulation—including upregulation—of miR-208a-5p has been implicated in heart disease, as well as cancer (where it can promote tumor growth and invasion by targeting key regulatory proteins, such as SRCIN1 in non-small cell lung cancer). miR-208a-5p is detected in the bloodstream after cardiac injury, making it a useful biomarker for myocardial infarction and other cardiovascular disorders. Therapies targeting miR-208a-5p are under investigation for both cardiac and cancer diseases, and its modulation poses challenges due to its involvement in fundamental cellular processes and network-wide gene regulation.

Other names

miR-208aMIR208AmicroRNA 208a

Antisense oligonucleotides (e.g., antagomirs, LNAs) inhibit miR-208a-5p by binding to the mature miRNA, preventing its association with target mRNAs and silencing its function. miRNA mimics (for replacement therapy) may increase miR-208a-5p function when deficient, though most therapeutic focus is on inhibition.