EFFECT OF REACTIVE OXYGEN SPECIES ON APOPTOSIS INDUCED BY Na2SeO3 IN SW480 CELLS
亚硒酸钠诱导SW480细胞凋亡过程中活性氧的作用

To investigate the mechanism of apoptosis induced by sodium selenite in a human colonic cancer cell line SW480. SW480 cells were loaded with fluorescent probes 2′,7′- DCFH-DA, and rhodamine123, respectively. The changes of intracellular ROS, and mitochondrial transmembrane potential (ΔΨm) was detected by using multiphoton imaging system. The results showed that (1) Na2SeO3 elevated SW480 cells apoptotic rate and intracellular ROS; SOD, catalase evidently suppressed ROS increase and reduced apoptotic rate, (2) Inhibition of mitochondrial electron transport with NaCN or rotenone almost blocked selenite-induced ROS production,(3) Na2SeO3 induced disruption of the mitochondrial transmembrane potential (ΔΨm). The data suggest that Na2SeO3 results in the increase intracellular ROS which origitesfrom mitochondia and mediates Na2SeO3-induced apoptosis.