Impact of X-ray radiation on cell cycle and cell apoptosis of diffuse large B-cell lymphoma

Background The malignant degree of the diffuse large B-cell lymphoma (DLBCL) is high.Radiation therapy is sensitive,but the therapeutic schedule can not be unified,reasonable and effective therapeutic schedule is important in clinic treatment of the DLBCL.Objective This study was to access the effect of X-ray on the cell cycle and cell apoptosis of the DLBCL.Methods DLBCL cell line was cultured and the cell suspension was inoculated to 12-well cultured plate.The cells exposed to X-ray for 6,12,24,48 hours with the irradiation doses of 2,4,6,8 Gy respectively.The cell proportions of different cycles were assayed by flow cytometer,and cell apoptosis index was evaluated and calculated.Non-irradiation cells served as controls.Results The cells grew well with a good cell vitality and round-like shape,and the growth was stable in generation 2 or 3.With the increase of X-ray doses and the lapse of irradiation time,the cell proportions in G0-G1 phase gradually reduced (Fdose =45.58,P=0.00; Ftime =43.11,P=0.00).However,cell proportions in G2-M phase were gradually increased as the increase of X-ray doses and lapse of irradiation time (Fdose =40.77,P =0.00 ; Ftime =91.91,P =0.00).In addition,the apoptotic proportion of the cells was significantly elevated with the increase of X-ray dose and irradiation time (Fdose =87.36,P =0.00; Ftime =37.31,P =0.00).Conclusions X-ray irradiation retards DLBCL in the G2-M phase and causes cell apoptosis in dose-and time-dependent manner. Key words: Diffuse large B-cell lymphoma/treatment;  Cell culture;  Radiotherapy;  X-ray;  Cell cycle; Apoptosis