microRNA let-7a (let-7a) (let-7a)

microRNA let-7a is a highly conserved, small non-coding RNA molecule that serves as a master regulator of gene expression by binding to the 3' untranslated regions (UTRs) of target messenger RNAs (Reinhart et al., Nature, 2000). As a founding member of the let-7 family, it is primarily recognized for its role as a potent tumor suppressor, where it negatively regulates several key oncogenes including RAS, MYC, and HMGA2 (Johnson et al., Cell, 2005; Sampson et al., Cancer Res, 2007). In various malignancies, such as lung and breast cancer, let-7a expression is frequently lost or significantly reduced, contributing to uncontrolled cell proliferation and metastasis (Takamizawa et al., Cancer Res, 2004). Beyond its role in oncology, let-7a is essential for proper developmental timing, stem cell differentiation, and the regulation of glucose metabolism (Boyerinas et al., Cancer Res, 2010). Therapeutic approaches currently under investigation involve the use of synthetic let-7a mimics to restore its function in cancer cells and inhibit tumor growth (Trang et al., Mol Ther, 2011). However, challenges remain regarding the efficient delivery of these RNA-based therapeutics and the potential for off-target effects or innate immune system activation (Ling et al., Nat Rev Drug Discov, 2013).

Other names

hsa-let-7a-5pMIRLET7Alet-7a-1let-7a-2let-7a-3Lethal-7a

Post-transcriptional gene silencing via seed-sequence-mediated binding to the 3' UTR of target mRNAs, leading to translational repression or mRNA cleavage (Bartel, Cell, 2004).