The Study Of Low-temperature Plasma’s Radiosensitizing Effects On The Different Human Malignant Cell Lines

Objective: To evaluate the effect of low-temperature plasma in enhancing theradiosensitivity of human malignant cells lines and the possible mechanisms.Methods: The proliferation of theHepG2cell lines、the A549cell lines and theHela cell lines were measured by MTT assay; Cell survival was detected by cloning Assay;The HepG2、A549cell cycle distribution、apoptosis and ROS content were tested by flowcytometry.Results:1、Low-temperature plasma obviously inhibited the viability of HepG2、A549、Helacells in time dependent manner.2、Low-temperature plasma showed radiosensitization effects to the two differenthuman malignant cell lines.In HepG2cells, D0and Dq were2.86and2.50in group R, but2.22and1.02in group P+R, sensitivity enhancement ratio（SERD0）were1.28; In A549cells, D0and Dq were2.94and2.21in group R, but2.22and1.13in group P+R, SERD0were1.32.3、The outcome of cell cycle distribution analyzed by flow cytometry showed: inHepG2cells, G2/M phase proportion of group C, group P, group R and the group P+Rwere18.06±2.39%、35.58±2.96%、31.60±2.01%和55.37±2.54%; in A549cells,G2/Mphase proportion of group C, group P, group R and the group P+R were17.02±2.46%、31.65±3.05%、27.71±2.51%和51.28±2.44%; In two different human malignant cell lines,compared with group C, the prolongation of G2/M arrest of group R、group P and thegroup P+R were enhanced (P<0.05); Compared with group R, the prolongation of G2/Marrest of group P+R were enhanced (P<0.05).4、The outcome of apoptosis rate analyzed by flow cytometry showed: in HepG2cells, the apoptosis rate of group C, group P, group R and the group P+R were4.33±0.21%、53.22±2.84%、14.63±2.91%and69.64±6.16%; in A549cells, the apoptosis rate ofgroup C, group P, group R and the group P+R were3.87±0.45%、33.16±3.11%、21.14±2.81%and57.15±3.03%; In two different human malignant cell lines, compared withgroup C, the apoptosis rate of group R、group P and the group P+R were enhanced(P<0.05); Compared with group R, the apoptosis rate of group P+R were enhanced(P<0.05).5、The outcome of ROS content analyzed by flow cytometry showed：in HepG2cells,ROS content of group C, group P, group R and the group P+R were16.80±1.30、54.00±1.50、26.50±3.72and79.1±8.28; in A549cells, ROS content of group C, group P,group R and the group P+R were10.47±2.64、25.00±2.00、17.37±1.25及33.82±3.51;In two different human malignant cell lines, compared with group C, ROS content ofgroup R、group P and the group P+R were enhanced (P<0.05); Compared with group R,ROS content of group P+R were enhanced (P<0.05).Conclusions:1、The proliferation inhibited by low-temperature plasma was universal in HepG2cells、A549cells and Hela cells.2、The radiosensitivition of low-temperature plasma was in HepG2cells andA549cells.3、Low-temperature plasma had radiosensitization and its mechanism might be relatedto enhance G2/M phase arrest and induce apoptosis by increasing ROS content.