Establishment and biological characterization of radiation-resistant lung carcinoma cell lines / 中华放射肿瘤学杂志

ABSTRACT

Objective To establish radiation?resistant lung carcinoma cell lines, and to investigate the changes in morphology, apoptosis, invasive migration, and epithelial?mesenchymal transition ( EMT) in cells. Methods The radiation?resistant lung carcinoma cell lines were obtained by exposure of lung carcinoma cell lines, A549 and H1299, to radiation with a low dose in fractions, a sublethal dose, or a gradually increasing dose. The morphological changes in cells, radiosensitivity, survival rates after exposure, apoptosis rates, changes in invasive migration, and expression of EMT marker proteins were evaluated using microscopy, colony formation assay, CCK?8 assay, flow cytometry, transwell migration assay, and Western blot, respectively. Results Radiation with a gradually increasing dose successfully induced the radiation?resistant cell lines, A549R and H1299R. The morphological study showed that the morphology of radiation?resistant cells was converted to the morphology of mesenchymal cells. Compared with A549 and H1299 cells, the values of D0 , Dq , and SF2 were significantly increased in A549R ( P=0.017,P=0.001,P=0.000) and H1299R (P=0.033,P=0.000,P=0.008) cells, respectively;the values of α and α/β were significantly reduced in A549R (P=0.018;P=0.007) and H1299R (P=0.001;P=0.009) cells, respectively. The survival rates in A549R and H1299R cells after exposure to radiation with various doses were significantly higher than those in the control groups (all P<0.05). After exposure, the apoptosis rates were significantly reduced in A549R and H1299R cells ( P=0.02,P=0.01);the invasion and migration rates were significantly increased in A549R (P=0.000;P=0.001) and H1299R (P=0.001,P=0.002) cells;the expression of E?cadherin was significantly down?regulated in A549R and H1299R cells (P=0.00,P=0.01), while the expression of vimentin was significantly elevated in A549R and H1299R cells ( P= 0. 02, P= 0. 01 ) . Conclusions The radiation?resistant lung carcinoma cell lines are successfully established. Both cell lines show enhanced invasion and migration, which may be associated with EMT.