极低频磁场联合X线对人肝癌细胞株BEL-7402作用的机制研究

Mechanism with extremely low frequency electromagnetic field and X-ray irradiation on liver carcinoma BEL-7402 cell lines

目的研究极低频磁场联合X线对人肝癌细胞株BEL-7402的作用机制。方法人肝癌细胞株BEL-7402经0、2、4、6、8、10GyX线照射后，用极低频磁场处理（100Hz、0．7mT、30min、3d）后，利用扫描电镜作形态观察，流式细胞仪、基因芯片研究细胞凋亡机制。结果扫描电镜形态显示，极低频磁场联合X线组肝癌细胞株BEL-7402发生凋亡改变。流式细胞仪观察结果显示，当X线剂量是2、4、6、8、10Gy，极低频磁场联合X线凋亡率为10．0％、14．5％、4．3％、5．1％、7．1％，X线组凋亡率是0．1％、8．10％、0．1％、0．4％、2．2％（P〈0．05）。基因芯片结果显示，极低频磁场联合X线组共有1465条出现上调，1108条出现下调。其中比值≥2倍的基因共有336条，上调262条，下调74条。与凋亡相关基因共110条，上调基因71条，下调基因39条。涉及CDC25、CHK1、ATM、D38、PTEN、p53、G．／S、Fas、G2／M、CellCycle、Apoptosis、Caspase基因通路中的基因。极低频磁场加X线组差异表达结果中有13条同时出现在极低频磁场组。42条同时出现在X线组。结论极低频磁场与X线通过不同的基因通路影响细胞凋亡。极低频磁场与X线对人肝癌细胞株BEL-7402凋亡有协同作用。

Objective To investigate the mechanism of extremely low frequency electromagnetic field （ELF-EMF） and X-ray irradiation on liver carcinoma cell lines BEL-7402. Methods Liver carcinoma cell lines BEL-7402 had been incubated with ELF-EMF （100 Hz,0.7 mT, 30 min, 3 days） after X-ray irradiation at different doses （0, 2, 4, 6, 8,10 Gy） . The cells were observed on morphologic changes with scanning electron microscope. Flow cytometry and gene microarray were used to investigate the mechanism of cell apoptosis. Results ELF-EMF plus X-ray induced apoptosis on BEL-7402 was observed under scanning electron microscope. When X-irradiation was 2, 4, 6, 8 and 10 Gy, the apoptosis ratios of combined group and only X- irradiation group were 10.0%, 14.5%, 4.3%, 5.1%, 7.1% and 0.1%, 8.1%, 0.1%, 0.4%, 2.2% （P 〈 0.05） on flow cytometry. The result of microarray indicated that 1465 genes were up-regulated and 1108 down-regulated in the ELF-EMF plus X-ray group in comparison with the control group. The change rates of 110 apoptosis related genes were above 2 times, which including 71 up-regulated and 39 down-regulated. Gene microarray showed that ELF-EMF and X-ray irradiation had a mainly effect on different gene of apoptosis paths （CDC25 and CHK1, ATM, p38, PTEN, p53, G1/S, Fas, G2/M, Cell Cycle, Apoptosis and Caspase）. The same genes of ELF-EMF plus X-ray group were showed 13 in ELF-EMF group and 42 in X-ray group. Conclusions Apoptosis paths were significantly different between ELF-EMF and X-irradiation. ELF-EMF cooperates with X-irradiation on inducing BEL-7402 cell apoptosis.