Study of As_2O_3 induced pancreatic tumor cells apoptosis

Objective: To study the effects of As_2O_3 on the growth of human pancreatic cancer cell line, AsPC-1 cells, and the mechanism. Methods: AsPC-1 cells were treated with various concentrations of As_2O_3. The effect of As_2O_3 on AsPC-1 cells survival and apoptosis was determined by MTT assay, light microscope, electronmicroscope and flow cytometry, and cellular ROS was measured by fluorometer. Results: After being treated with 1 μmol/L As_2O_3 for 24 h, the growth of AsPC-1 cells was significantly inhibited and a marked apoptosis characteristic was observed. When we measured the cellular hydrogen peroxide (H_2O_2) level we found that the!H_2O_2 level in AsPC-1 cells started to rise(10 μmol/L group increased by 79%) after being incubated with 1-10 μmol/L As_2O_3 for 2h, and sustained increased, reached the peak point of H_2O_2 level at 5h(10 μmol/L group increased by 169% ), and maintained a few hour, after about 12h it began to decrease. At 24h, the H_2O_2 level of treatment group equals to that of control group. The fluctuation of the H_2O_2 level in cells showed dose dependent manners. Conclusiln: As_2O_3 could induce the apoptosis on AsPC-1 cells, derived from the solid tumors, the molecular mechanisms of which may be related to the intracellular ROS(H_2O_2) level. Accumulation of H_2O_2 is the earlier event in the way of As_2O_3 induced AsPC-1 cells apoptosis, which performs a very important role.