Combination effects of pulsed electric field and low temperature plasma on H22 mouse liver cancer cell / 中华肝胆外科杂志

ABSTRACT

Objective:To investigate the effect of pulsed electric field (PEF) combined with low temperature plasma (LTP) on mouse liver cancer cell.Methods:H22 mouse liver cancer cells were divided into liver cancer group, PEF treatment group, LTP treatment group, combined group A (first PEF treatment immediately after LTP treatment), combined group B (first LTP treatment immediately after PEF treatment), combined group C (same as combined group A, but 20 minutes interval) and combined group D (same as combined group B, but 20 minutes interval). Cell viability was detected by cell counting, apoptosis was detected by flow cytometry, intracellular reative oxygen species (ROS) was marked by fluorescence and counted. Twenty healthy female Kunming mouse aged 4-6 weeks without specific pathogens were subcutaneous injected with liver cancer cells, and then were randomly divided into model group, PBS control group, PEF experimental group, LTP experimental group and combined group (LTP+ PEF, no interval) ( n=4). Tumor relative volume and tumor inhibition rate were measured. Results:The survival rates were liver cancer cell group (98.3±0.9)%, PEF treatment group (66.8±4.4)%, LTP treatment group (62.1±3.9)%, combined group A (43.7±3.7)%, combined group B (31.0±1.4)%, combined group C (46.8±2.9)%, combined group D (39.0±2.3)%. Compared with liver cancer cell group, the cell survival rate of all treatment groups was decreased, and the cell survival rate of the four combined treatment group was lower than that of PEF treatment group and LTP treatment group, the differences were statistically significant (all P<0.05). The survival rate of combined B group was the lowest. The results of apoptosis detection were consistent with those of cell survival rate. Under fluorescence microscope, the ROS fluorescence of cells in the combined group B was significantly increased, and the ROS fluorescence of cells in the LTP treatment group was more than that in the PEF treatment group, and the percentage of ROS positive cells in the combined group B was higher than that in the LTP treatment group and the PEF treatment group, with statistical significance (all P<0.05). Tumor relative volume and tumor inhibition rate in the combined group were better than those in the PEF and LTP groups, and the differences were statistically significant (all P<0.05). Conclusion:LTP combined with PEF has a better killing effect on H22 cells than PEF or LTP treatment, which is expected to be a new tumor therapy.