SnapShot: MicroRNAs in Cancer

let-7 family (various) Downregulated in lung, breast, gastric, ovary, prostate and colon cancers, CLL, leiomyomas; miR-98 downregulated in head and neck cancer. Point mutation in let-7e transcript affects miRNA maturation. Repress cell proliferation and growth. let-7f promotes angiogenesis. Targets: CCND1, CDC25a, CDC34, CDK6, CRDBP, DICER, HMGA2, HOXA9, IMP-1, ITGB3, MYC, RAS, TLR4. SNP in K-RAS 3′ UTR (let-7a binding site) increases NSCLC risk (cancer predisposition). Low expression of let-7a-2 in lung and ovarian cancer and of let-7b in uveal melanoma (poor prognosis). let-7i affects chemotherapy potency. Intranasal delivery of let-7a reduces growth of Ras-induced mouse lung tumors.