Targeted systematic evolution of an RNA platform neutralizing DNMT1 function and controlling DNA methylation

DNA methylation is a fundamental epigenetic modification regulating gene expression. Aberrant DNA methylation is the most common molecular lesion in cancer cells. However, medical intervention has been limited to the use of toxic, unspecific demethylating drugs. Aptamers are novel high affinity targeting ligand molecules. By conjugating the inherent DNMT1 inhibiting capabilities of RNA to an aptamer platform, we generated a first-of-its kind aptamer approach that can target and neutralize DNMT1 function-the aptaDiR. Molecular modelling of RNA-DNMT1 complexes coupled with biochemical and cellular assays enabled the identification and characterization of aptaDiR. This novel RNA bio-drug blocks DNA methylation and impairs cancer cell viability. Collectively, we present an innovative RNA-based approach to modulate DNMT1 activity in cancer or diseases characterized by aberrant DNA methylation and suggest the first alternative strategy to overcome the limitations of currently approved hypomethylating protocols, which will greatly improve clinical intervention on DNA methylation.