MicroRNA 191 (miR-191)

MicroRNA 191 (miR-191) is a conserved small non-coding RNA molecule (~22 nucleotides) encoded in humans by the MIR191 gene, located within the first intron of the DALRD3 gene on chromosome 3 (3p21.31)[1][3][5]. It is processed through Dicer into a mature functional form that becomes part of the RNA-induced silencing complex (RISC), which represses gene expression by binding to the 3′UTR of specific target mRNAs, inhibiting their translation or promoting their degradation[3][5]. miR-191 is dynamically regulated by developmental, hormonal (estrogen-responsive), and environmental (hypoxia-induced) cues[6][7]. It is implicated in a wide array of normal cellular processes, including cell proliferation, neuronal and erythroid differentiation, circadian rhythm, and cellular senescence[1][5]. Dysregulation of miR-191 is observed in multiple cancers, where it often acts as an oncogenic miRNA, promoting tumor proliferation, migration, invasion, and therapy resistance through direct regulation of targets such as TET1, p53, C/EBPβ, and TGFβ2[2][4][7]. High expression of miR-191 is associated with poor prognosis in several malignancies and serves as a candidate biomarker for cancer progression and patient stratification[4][5]. Given its multifaceted biological activities, miR-191 represents both a putative therapeutic target and a diagnostic/prognostic marker in oncology.

Other names

hsa-miR-191MIR191MIRN191hsa-mir-191MIR191-5pMIR191-3p

Downregulation of target mRNAs via RNA-induced silencing complex (RISC); Inhibition of translation; Destabilization and degradation of target mRNAs