Abstract: The invention provides compounds, compositions and therapeutic methods. The compounds and compositions can be used for the treatment of myotonic dystrophy. The compounds can selectively bind to CUG repeats in RNA, or to CTG repeats in DNA, and inhibit replication of the nucleic acids. RNA-targeted therapeutic agents for the treatment of myotonic dystrophy type 1 (DM1) are described. In one embodiment, two bisamidinium ligands are linked using “click” chemistry to form a heterodimer that is a potent inhibitor of the MBNL1-rCUGexp complex (KI=25±8 nM), is relatively non-toxic to HeLa cells, dissolves nuclear foci, corrects >80% of the IR misregulated alternative splicing in DM1 model cells (1 ?M), and shows improvement of disease phenotypes in a DM1 Drosophila model.

Abstract: The invention provides rationally designed multi-targeting therapeutic agents for myotonic dystrophy type 1 (DM1), an incurable neuromuscular disease that originates in an abnormal expansion of CTG repeats (CTGexp) in the DMPK gene. The rationally designed small molecules target the DM1 pathobiology in three distinct ways: (1) binding the expanded trinucleotide repeat, CTGexp, and inhibiting its transcription to the toxic CUGexp RNA, (2) binding the CUGexp RNA and releasing sequestered muscleblind-like protein (MBNL1), and (3) cleaving the toxic CUGexp in an RNase-like manner. Importantly, the compounds can reduce the levels of CUGexp in DM1 model cells and reverse two separate CUGexp-induced phenotypes of DM1.