脉冲电场对胰腺癌细胞活性氧生成的影响

Objective To investigate the changes of reactive oxygen species (ROS) in pancreatic cancer cells under the effect of pulsed electric fields (PEF). Methods Murine-derived pancreatic cancer cells Panc02 were treated with PEF at electric field strengths of 0, 250, 500, 750, and 1000 V/cm, respectively. The intracellular ROS generation pa注ems under the different field strengths and at different times after the PEF were investigated in vitro by flow cytometry and immunofluorescence, meanwhile exploring the apoptosis of murine and human pancreatic cancer cells under different field strengths. Twenty 6- to 8-week-old male C57BL/6 SPF mice were prepared as orthotopic pancreatic cancer models and divided into five groups of four mice each : 250 V/cm PEF group, 500 V/cm PEF group, 750 V/cm PEF group, 1000 V/cm PEF group, and sham operation group. ROS expression in the residual tumor tissues of mice in each group was detected by immunofluorescence. Results Under the 500 V/cm, 750 V/cm and 1000 V/cm electric field strength, the proportion of cells with intracellular ROS expression was decreased after 6 h, 12 h, 24 h and 48 h of the PEF compared with 2 h after the PEF, and the differences were statistically significant (all P < 0.05). Compared with 0 V/cm PEF group, ROS expression increased in Panc02 cells treated with 500 V/cm and 750 V/cm PEF groups, and the differences were statistically significant (all P < 0.05). Compared with 250 V/cm PEF group under the same time, ROS in Panc02 cells treated with 500 V/cm and 750 V/cm electric field strengths increased, and the differences were statistically significant (all P < 0.05). The proportions of apoptosis of both Panc02 cells and MIA-PaCa-2 cells increased with rising field strength and peaked at the field strength of 750 V/cm. Compared with the sham-operated group, the expression of ROS was increased in pancreatic cancer tissues of mice in the 500 V/cm PEF-treated group (16.65 ±6.01 vs. 2.38 ± 1.21, £ = - 6.53) and 750 V/cm PEF-treated group (16.54 ±4.41 vs. 2.38 ± 1.21, 力二-6.48), and the differences were statistically significant in both cases (both P <Q. 001). Conclusion PEF treatment was able to increase the level of ROS in both pancreatic cancer cells and tissues, and more ROS were produced when the electric field strength was 500 and 750 V/cm.