青蒿素对人鼻咽癌CNE细胞的放射增敏作用及机制的研究

Objective To investigate the radiosensitizing effects of artemisinin on CNE human nasopharyngeal carcinoma cells in vitro.Methods CNE human nasopharyngeal carcinoma cell line was used in this study.Cell growth kinetics was determined by MTT assay.Effect of the drug on radiosensitivity of CNE cells was analyzed by clonogenic assay.The change of cell cycle was measured by flow cytometry.Results The inhibition of CNE cells growth by artemisinin was increased with concentrations.Artemisinin (1 μmol/L)could enhance the radiosensitizing effects on CNE cell line,and the sensitizing enhancement ratio(SER)was 1.26.Artemisinin abrogated radiation-induced G2/M arrest of the tested CNE cells.Compared with the radiation alone group,the proportion of G2/M phase cells increased in radiation combined with drug group.Conclusions Artemisinin could reduce radiation-induced G2/M arrest and enhance the cytotoxicity of γ-irradiation on the CNE ceils.     

青蒿素对人鼻咽癌CNE细胞的放射增敏作用及机制的研究

Objective To investigate the radiosensitizing effects of artemisinin on CNE human nasopharyngeal carcinoma cells in vitro.Methods CNE human nasopharyngeal carcinoma cell line was used in this study.Cell growth kinetics was determined by MTT assay.Effect of the drug on radiosensitivity of CNE cells was analyzed by clonogenic assay.The change of cell cycle was measured by flow cytometry.Results The inhibition of CNE cells growth by artemisinin was increased with concentrations.Artemisinin (1 μmol/L)could enhance the radiosensitizing effects on CNE cell line,and the sensitizing enhancement ratio(SER)was 1.26.Artemisinin abrogated radiation-induced G2/M arrest of the tested CNE cells.Compared with the radiation alone group,the proportion of G2/M phase cells increased in radiation combined with drug group.Conclusions Artemisinin could reduce radiation-induced G2/M arrest and enhance the cytotoxicity of γ-irradiation on the CNE ceils.     

青蒿琥酯对人宫颈癌HeLa细胞的放射增敏作用

Objective To investigate the radiosensitizing effects of artesunate on human HeLa cells of cervical cancer in vitro.Methods Hela cells were irradiated with 60Co γ-rays.The dose rate was 0.635 Gy/min and the radiation dose was 0,1,2,4,6 Gy,respectively.The anti-proliferation activities of artesunate on HeLa cells were evaluated with MTT assay,to determine the most appropriate drug concentration.The effect of radiosensitivity was observed by using clonogenic assay.The single-hit multitarget model was used to plot the HeLa cell's dose-survival curve,to calculate mean lethal dose,quasithreshold dose and sensitization enhancement rate,and to evaluate its radiosensitization effect.The apoptosis was analyzed with flow cytometry (FCM) to further test the radiation senseitization of artesunate on HeLa cells.Results The inhibition of artesunate on HeLa cells increased with concentration.In radiation group,the cell cloning efficiency were 91.67% ,82.02% ,58.60% ,25.01%,respectively,and in artesunate (2.0 μ mol/L) + radiation group,the cell cloning efficiency were 74.93% ,60.53% ,22.38% ,5.05%.In radiation group and artesunate (2.0 μmol/L) + radiation group,the mean lethal dose(D0) was 2.95 and 2.07 Gy,respectively,while the qusai-threshold dose (Dq) were 2.01 and 1.24 Gy,respectively,and SER was 1.43.Compared with 2 and 6 Gy radiation group,the apoptosis rate of drug + radiation group increased from 12.26% ,40.08% to 22.71% ,59.92%.Conclusions The inhibiting effect of artesunate on HeLa cells is concentration-dependent.Artesunate has radiosensitizing effect on HeLa cells in vitro.     

低剂量辐射诱导的旁效应及其机制的初步研究

Objective To investigate whether the supernatant (the conditioned fluid) of myeloid cells suspension after low dose radiation (6 cGy) in vitro could resuh in bormesis on the normal or radiation damage cells and its mechanism.Methods Mice myeloid cell suspension was irradiated by 0,2 and 5 Gy,respectively,and cultured in vitro.MTT method was used to measure the reproductive activity of cells.Cytochrome C reduction method was used to determine the concentration of O2-,the immunohistochemical method to test the protein expression of c-fos.Results Co-cultured with the conditioned fluid,the reproductive activity of the myeloid cells after high dose irradiation( P＜0.01 ),while both the concentration of O2- and the protein expression of c-fos were enhanced (P＜0.05 ).Conclusions The conditioned fluid could enhance the proliferation of the myeloid cells after radiation injury.The mechanism of the low dose radiation-induced bystander effect might be correlated with the increase of both the concentration of O2- and the protein expression of c-fos.