The potassium channel Kv1.3 is highly expressed in the mitochondria of various cancerous cells. Here we show that direct inhibition of Kv1.3 using two mitochondria-targeted inhibitors alters mitochondrial function and leads to reactive oxygen species (ROS)-mediated death of even chemoresistant cells independently of p53 status. These inhibitors killed 98% of ex vivo primary chronic B-lymphocytic leukemia tumor cells while sparing healthy B cells. In orthotopic mouse models of melanoma and pancreatic ductal adenocarcinoma, the compounds reduced tumor size by more than 90% and 60%, respectively, while sparing immune and cardiac functions. Our work provides direct evidence that specific pharmacological targeting of a mitochondrial potassium channel can lead to ROS-mediated selective apoptosis of cancer cells in vivo, without causing significant side effects.
Leanza, L., Romio, M., Becker, K. A., Azzolini, M., Trentin, L., Managò, A., … Szabo, I. (2017). Direct Pharmacological Targeting of a Mitochondrial Ion Channel Selectively Kills Tumor Cells In Vivo. Cancer Cell, 31(4), 516-531.e10. https://doi.org/10.1016/j.ccell.2017.03.003