MicroRNA let-7a-3 (MIRLET7A3)

MicroRNA let-7a-3 is a precursor and functional microRNA within the highly conserved let-7 family, encoded in humans by the MIRLET7A3 gene. It is processed into mature let-7a microRNA, which functions by associating with Argonaute proteins in the miRNA-induced silencing complex (miRISC) to downregulate a broad array of genes involved in cell growth, differentiation, metabolism, apoptosis, and inflammation. Uniquely, let-7a-3 can escape regulation by LIN28 proteins, a mechanism that otherwise suppresses let-7 biogenesis in stem cells and many cancers. let-7a-3 is a tumor suppressor; its decreased expression is linked to poor prognosis in cancer, and its restoration (using mimics) inhibits tumor cell growth and chemotherapy-induced cell death. As a microRNA, it does not encode protein but acts as a regulatory RNA molecule influencing multiple RNA and protein networks. Its core biological effects are exerted via sequence-specific binding to target mRNAs, especially those encoding oncogenes, and inhibiting their translation or stability.

Other names

hsa-let-7a-3LET7A3MIRNLET7A3let-7a-3

Drugs (mimics) increase let-7a-3 levels, leading to repression of oncogenic mRNA targets and inhibition of cell growth, proliferation, and cell death pathways let-7a-3 binds to 3'UTR (and occasionally the coding regions) of target mRNAs, inducing translational repression and triggering mRNA decay