毫米波辐射对人急性早幼粒白血病细胞诱导凋亡的作用

目的 探讨毫米波对人急性早幼粒白血病细胞增殖和凋亡的影响。方法 以波长7.1mm，频率42.2GHz的毫米波辐射体外培养的NB4细胞，光镜及电镜观察细胞形态改变，生长曲线测定细胞生长及增殖情况。流式细胞仪（FCM）检测细胞周期分布。细胞凋亡指数及凋亡相关基因表达的改变。结果 1mW/cm^2的毫米波辐射，每日1次，30min，可明显抑制NB4细胞的生长，辐射第3天细胞生长抑制率为44.1%；光镜及电镜下可见凋亡细胞形态，FCM示G0/G1期细胞及凋亡百分比增加；p21、p53、Bax和Fas表达增加，c-Myc、Bcl-2表达下降，5mW/cm^2的毫米波对细胞增殖及凋亡的影响却不明显，虽然p53、Bax和Fax表达增加，Bcl-2表达下降，但c-Myc和p21的表达却无改变。结论 1mW/cm^2毫米波辐射适当时间后能显著抑制NB4细胞增殖、诱导细胞凋亡；其凋亡诱导机制可能与调控细胞凋亡相关基因的表达有关，其中对c-Myc蛋白表达的下调可能具有关键作用。

Induction of apoptosis of human acute promyelocytic leukemia cells with millimeter wave radiation

Objective To investigate the effect of millimeter wave radiation on proliferation and apoptosis of acute promyelocytic leukemia cell line NB 4 cells. Methods The human acute promyelocytic leukemia cell line NB 4 cells in vitro were radiated with millimeter wave with frequency 42.2 GHz and wavelength 7.1 mm.Then,morphological features of apoptotic cells were observed by light microscope and electron microscope;cell growth and proliferative activity was determined by cell growth curve;distribution of cell cycle,rate of apoptoic cells and change of expression of apoptosis related genes were analysed by the flow cytometry.Results With 1 mW/cm 2 millimeter wave radiation for 30 min/day,the growth of NB 4 cells was obviously inhibited.At the third day after radiation,the inhibition rate was 44.1%.The morphological characteristics of apoptosis were found under the light microscope and electron microscope.Of the flow cytometry test,ratio of G 0/G 1 and percentage of apoptotic cells were increased;It also revealed that the expression of p21?p53?Bax and Fas was up-regulation, while c-Myc and Bcl-2 was down-regulation. But under the 5 mW/cm 2 millimeter wave radiation,there was no obvious effect in proliferation and apoptosis of NB 4 cells;while the expression of c-Myc and p21 was not also changed.Conclusion It shows that the 1 mW/cm 2 millimeter wave radiation can inhibit the NB 4 cells proliferation and induce the cell apoptosis.Its mechanisms might related to modulation of gene expressions associated with proliferation and apoptosis.Which the down-regulation of c-Myc by millimeter wave radiation may play an important role.