The protective effect of Cu/Zn-SOD against oxidative stress after PTEN deletion.

Reactive oxygen species (ROS), antioxidant enzyme, and cancerization are related to each other. To investigate whether these factors are involved in the mechanism by which phosphatase and tensin homolog deleted on chromosome ten (PTEN) suppresses tumors. Fluorescent probes and molecular hybridizations were performed to measure ROS and antioxidant enzyme levels in cells lacking PTEN. After induction of oxidative stress by PTEN deletion, we observed an increase in the expression of the antioxidant enzyme Cu/Zn-SOD. In addition, the overall antioxidative capability of the cells was attenuated. These results suggest that negative regulation occurs through interactions among ROS, Cu/Zn-SOD, and PTEN, and such a disequilibrium between oxidation and antioxidation could contribute to the reduced antioxidative capacity in PTEN null cells. These studies will guide further investigations into the biological function of PTEN.