PUMA: a puzzle piece in chloroquine’s antimelanoma activity

Chloroquine can induce cell death in a subset of cancer cell lines, and some melanoma cell lines are quite susceptible. While it is well known that chloroquine impairs lysosomal function and can serve as an autophagy inhibitor, the molecular target of chloroquine and the subsequent cascade of events that leads to cell death are not fully understood. Recent evidence indicates that in melanoma cell lines, chloroquine induces apoptosis by preventing degradation of the pro-apoptotic BH3-only protein PUMA. This finding adds to the unfolding story of chloroquine’s mechanism of action as a cancer therapeutic agent.