MicroRNA 199b-5p (miR-199b-5p)

MicroRNA 199b-5p (miR-199b-5p) is a small non-coding RNA molecule that serves as a critical post-transcriptional regulator of gene expression. It is prominently recognized for its role in the Notch signaling pathway, where it directly targets the transcription factor HES1, a key regulator of cancer stem cell maintenance and self-renewal (Garzia et al., 2009, PLoS ONE). In the context of oncology, miR-199b-5p frequently acts as a tumor suppressor; its expression is often significantly reduced in aggressive cancers like medulloblastoma and hepatocellular carcinoma, and its restoration has been shown to inhibit tumor growth and metastasis (Fang et al., 2016, Int J Mol Med). Beyond cancer, miR-199b-5p is a major player in cardiovascular pathology, specifically promoting the transition from cardiac hypertrophy to heart failure by targeting the kinase DYRK1A, which in turn modulates the calcineurin/NFAT signaling pathway (da Costa Martins et al., 2010, Circ Res). Therapeutic development focuses on using synthetic miRNA mimics to replenish its levels in tumors or antagomirs to block its activity in heart disease. While promising, these oligonucleotide-based therapies face significant hurdles regarding stable delivery to target tissues and the avoidance of off-target effects.

Other names

hsa-miR-199b-5pMIR199BMicroRNA 199bmiR-199b

MicroRNA 199b-5p functions through the RNA interference (RNAi) pathway, where it binds to the 3' untranslated region (UTR) of target messenger RNAs (mRNAs) with partial complementarity. This binding leads to either the degradation of the target mRNA or the inhibition of its translation into protein, thereby silencing specific genes such as HES1, GSK3B, and DYRK1A (Garzia et al., 2009; da Costa Martins et al., 2010).