Effect of down-regulation NEK-2 level on radio-sensitibity of A549 cells / 中华放射肿瘤学杂志

ABSTRACT

Objective To investigate the influence of down-regulation NEK-2 level on the radiosensitivity of A549 cells.Methods NEK-2 siRNA was transfected to A549 cells with liposome and NEK-2 expression level was inspected by Western blot.The radiosensitivity was detected by clone formation experiment.Cell cycle and cell apoptosis were analyzed by flow cytometry.Immunofluorescence experiment was used to detect the DNA double strand break and repair.Results NEK-2 siRNA successfully suppressed NEK-2 expression in A549 cells and resuced the cell proliferation ability after irradiation compared to the blank control group and the negative control group.It can improve the radiosensitivity of A549 cells (The radiosensitivity of A549 cells enhanced significantly.).The D0 values declined form 1.80 Gy to 1.40 Gy,and the sensitizing enhancement ratio was 1.32.After irradiation,compared to negative control group,the apoptosis rate was significantly improved (7.85％ to 17.17％),cells in G2/M phase were obviously increased (9.23％ to 30.16％),the DNA double strand break rate was increased (100％ to 165％) and the DNA damage repair rate was reduced (100％ to 48％) in NEK-2 siRNA group.The comparisons among the groups wer statistically significant (P＜0.05).Conclusions NEK-2 siRNA reduced the proliferation and increased the radiosensitivity of A549 cell line,probably by affecting the cell cycle,promoting cell apoptosis and suppressing DNA damage repair.