MicroRNA 21-5p (miR-21-5p)

hsa-miR-21-5p is a highly conserved, small non-coding RNA molecule that acts as a potent oncogene (oncomiR) and a key regulator of various physiological and pathological processes [1, 5]. It functions by binding to the 3' untranslated regions (UTRs) of target mRNAs, such as PTEN, PDCD4, and Sprouty1, leading to their translational repression or degradation [2, 5, 12]. This modulation influences critical pathways including PI3K/AKT and ERK-MAPK, thereby promoting cell proliferation, survival, and epithelial-mesenchymal transition while inhibiting apoptosis [5, 8, 13]. In clinical contexts, miR-21-5p is frequently overexpressed in numerous malignancies and is associated with poor prognosis, chemoresistance, and metastasis [1, 2, 10]. Beyond oncology, it plays a significant role in promoting fibrosis in the heart, kidneys, and lungs, making it a high-priority therapeutic target [5, 18, 19]. Therapeutic strategies primarily involve antisense oligonucleotides, such as Lademirsen, which aim to sequester the mature miRNA and restore the expression of its tumor-suppressive or anti-fibrotic targets [18, 23, 27].

Other names

hsa-miR-21-5pmiR-21hsa-miR-21MIMAT0000076MicroRNA 21

Antisense inhibition by hybridization with mature miRNA to prevent target mRNA silencing, or small molecule inhibition of miRNA biogenesis by blocking Dicer or Drosha processing.