Targeting the Mitochondrial Protease ClpP for Anticancer Therapy.

Cancer cells depend on mitochondrial reprogramming for growth, but this raises reactive oxygen species (ROS), increasing reliance on protein quality control (PQC) repair mechanisms. The mitochondrial proteome is maintained through a robust PQC composed of chaperones and proteases, including the mitochondrial matrix protease caseinolytic protease P (ClpP). ClpP has recently emerged as a potential therapeutic target against cancer. Notably, imipridones act as ClpP agonists and have shown potent anticancer activity by inhibiting mitochondrial Electron Transport Chain (ETC) function. In this study, we developed a new generation ClpP agonist, compound 9 (MS6076), which exhibits enhanced ClpP binding, more potent disruption of mitochondrial ETC and lethality in breast cancer models compared to the imipridone ONC212. Furthermore, we show that compound 9 induced cell death in cancer cells resistant to ONC212. The discovery and characterization of compound 9 therefore add to the expanding arsenal of imipridones to target ClpP in cancer.