DQ661

DQ661 is a **novel dimeric quinacrine derivative**—two quinacrine molecules joined by a specialized linker—designed as a chemical tool and potential therapeutic. It functions as a *highly potent and lysosomally selective inhibitor* of **palmitoyl-protein thioesterase 1 (PPT1)**, a lysosomal enzyme. By inhibiting PPT1, DQ661 disrupts key lysosomal functions, including *autophagy* and *macropinocytosis*, and inhibits the activity and localization of the **mechanistic target of rapamycin complex 1 (mTORC1)** at the lysosomal membrane. Unlike parent antimalarial drugs used as autophagy inhibitors, DQ661 targets both degradative and anabolic lysosomal pathways critical for tumor metabolism, making it a multidimensional anti-cancer agent. DQ661 has demonstrated **in vivo anti-tumor activity** in immunocompetent mouse models of melanoma, pancreatic cancer, and colorectal cancer. The compound was developed by medicinal chemistry efforts primarily at the University of Pennsylvania as a *preclinical tool* to investigate lysosomal function and resistance mechanisms in cancer[1][2][3][4].

Other names

dimeric quinacrine (context: description, not approved as synonym)DQ-661DQ661DQ 661