Identification of Trovafloxacin, Ozanimod, and Ozenoxacin as Potent c‐Myc G‐Quadruplex Stabilizers to Suppress c‐Myc Transcription and Myeloma Growth

Abstract c‐Myc is a major oncogene that is estimated to result in almost all human cancers and the c‐Myc downregulation has become an attractive strategy for cancer treatment. For it is hard to design compounds that can directly interact with the c‐Myc protein, the DNA G‐quadruplex (G4) was discovered in its promoter region which was referred to as a potential drug target for controlling c‐Myc expression. In this study, a combined strategy of molecular docking‐based virtual screening, molecular dynamics (MD) simulation, and molecular mechanics/generalized Born surface area (MM/GBSA) free energy calculation was conducted on the existing FDA‐Approved Drugs Library, eight compounds were selected for further experimental assay. Among them, five compounds exhibited dose‐dependently anticancer activities against RPMI‐8226 cells with IC 50 values less than 18.4 μM. Further experiments showed that Trovafloxacin, Ozanimod, and Ozenoxacin decreased c‐Myc mRNA level obviously and downregulated c‐Myc expression significantly. In summary, compounds Trovafloxacin, Ozanimod, and Ozenoxacin might be regarded as new c‐Myc G4 stabilizers for the treatment of c‐Myc related cancers in the future.