AQ1, an anthraquinone derivative, is a potent stabilizer of c-KIT G-quadruplexes (G4) that downregulates c-KIT mRNA and protein expression in human and canine cell lines. Also, AQ1 causes inhibition BCL2 gene expression in HGC27 and MCF7 cells. AQ1 inhibits proliferation of in varies human tumor cell lines including HCG27, MCF7 and imatinib resistant HMC1.2 cells.