Abstract
Small interfering RNAs (siRNAs) and microRNAs (miRNAs) are sequence-specific post-transcriptional regulators of gene expression. Although major components of the RNA interference (RNAi) pathway have been identified, regulatory mechanisms for this pathway remain largely unknown. Here we demonstrate that the RNAi pathway can be modulated intracellularly by small molecules. We have developed a cell-based assay to monitor the activity of the RNAi pathway and find that the small-molecule enoxacin (Penetrex) enhances siRNA-mediated mRNA degradation and promotes the biogenesis of endogenous miRNAs. We show that this RNAi-enhancing activity depends on the trans-activation-responsive region RNA-binding protein. Our results provide a proof-of-principle demonstration that small molecules can be used to modulate the activity of the RNAi pathway. RNAi enhancers may be useful in the development of research tools and therapeutics.
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Acknowledgements
We would like to thank S. Warren, S. Chang, K. Garber and C. Strauss for their helpful discussions and critical reading of the manuscript and H. Ju for technical assistance. We thank I. Verma, J. Belasco and G. Hannon for providing us the plasmids. Q.L. is a Damon Runyon Scholar (DRS-43) and is supported by the Welch Foundation (I-1608). P.J. is supported by NIH grants (NS051630 and MH076090). P.J. is the recipient of a Beckman Young Investigator Award and a Basil O'Connor Scholar Research Award and is an Alfred P. Sloan Research Fellow in Neuroscience.
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P.J. designed the research. G.S. conducted the chemical screen and identified the small molecule presented in this paper. G.S. and Y.L. performed the majority of mechanistic experiments. J.Z., L.L., Z.S. and C.H. performed chemical synthesis. G.S., Y.L., W.L., M.A.F., A.M.K. and C.W. performed additional testing on the compound. K.E.S. and R.D. performed miRNA profiling and developed the reporter system. A.W.S.C., Z.P. and Q.L. provided some reagents used in this paper. G.S., Y.L. and P.J. wrote the paper.
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P.J. is the scientific founder of Effigene Pharmaceuticals, Inc. Effigene is engaged in the development of RNAi modulators.
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Supplementary Figures 1–9, Tables 1–4, Methods (PDF 3440 kb)
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Shan, G., Li, Y., Zhang, J. et al. A small molecule enhances RNA interference and promotes microRNA processing. Nat Biotechnol 26, 933–940 (2008). https://doi.org/10.1038/nbt.1481
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DOI: https://doi.org/10.1038/nbt.1481