Identification of HuR–RNA Interfering Compounds by Dynamic Combinatorial Chemistry and Fluorescence Polarization

[Image: see text] The RNA binding protein HuR regulates the post-transcriptional process of different oncogenes and tumor suppressor genes, and its dysregulation is linked with cancer. Thus, modulating the complex HuR–RNA represents a promising anticancer strategy. To search for novel HuR ligands able to interfere with the HuR–RNA complex, the protein-templated dynamic combinatorial chemistry (pt-DCC) method was utilized. The recombinant RRM1+2 protein construct, which contains essential domains for ligand–HuR binding and exhibits enhanced solubility and stability compared to the native protein, was used for pt-DCC. Seven acylhydrazones with over 80% amplification were identified. The binding of the fragments to HuR extracted from DCC was validated using STD-NMR, and molecular modeling studies revealed the ability of the compounds to bind HuR at the mRNA binding pocket. Notably, three compounds effectively interfered with HuR–RNA binding in fluorescence polarization studies, suggesting their potential as foundational compounds for developing anticancer HuR–RNA interfering agents.