Effect of radiotherapy combined with hyperthermia on rhabdomyosarcoma RD cells in vitro

　　热疗化疗对人横纹肌肉瘤RD细胞的影响

　　Abstract：Objective To observe the effect of radiotherapy in combination with hyperthermia on rhabdomyosarcoma RD cells and compare the effects of hyperthermia and radiotherapy with different orders.Methods The rhabdomyosarcoma RD cells were divided into five groups according to different treatment methods,such as radiotherapy alone,hyperthermia alone,hyperthermia followed by radiotherapy,radiotherapy followed by hyperthermia and control.Each group included 21 bottles and each bottle was seeded with 5000 cells separately.For radiotherapy,4 Gy radiation dose with a source interval of 80 cm was carfied out and the irradiation area was 12 mm × 8 mm.For hyperthermia,electrical heating thermostat box was performed with 42.5℃ for 1 h,5 min for thermal equilibrium.

　　Direct counting was taken to draw the growth curve and calculate the colony formation rate of each group on the 14th day.Flow cytometry was used to analyze the cell cycle and apoptosis.Results The growth inhibitory rate of radiotherapy combined with hyperthermia (1.4％,and 4.7％ ) was significantly higher than radiation or hyperthermia alone ( 13.0％,6.7％ ),and hyperthermia followed by radiotherapy group achieved the highest growth inhibitory rate (P ＜ 0.05 ).The rate of the colony formation in radiotherapy combined with hyperthermia was significantly lower than radiation or hyperthermia alone ( P ＜ 0.05 ) and that in radiotherapy after hyperthermia was the lowest (P ＜0.05 ).The proportion of cells in G2/M-phase in hyperthermia alone was significantly higher than other groups (P ＜ 0.05 ).The apoptosis rate in radiotherapy after hyperthermia was the highest ( P ＜ 0.05).Conclusion Hyperthermia alone caused G2/M-phase arrest of RD cells.The effect of radiotherapy combined with hyperthermia was significantly better than radiation or hyperthermia alone,and hyperthermia followed by radiotherapy had a better effect than radiotherapy followed by hyperthermia treatment strategy.

　　目的：观察热疗结合化疗对人横纹肌肉瘤RD细胞的影响及比较它们次序不同产生的的效果。方法 根据治疗方法把横纹肌肉瘤RD细胞分为5组，放射疗法单独一组，冷疗一组，放疗后热疗一组，热疗后放疗一组及对照组。每组21瓶5000细胞。放疗来说，44Gy辐射剂量，间隔80厘米，辐照面积是12毫米×8毫米。热疗，电加热恒温箱进行1 h,，42.5℃，5分钟。计算出数据绘画出增长曲线及计算14天菌群率。根据细胞计数分析细胞周期分布及死亡率。结果 热疗结合化疗(1.4%,1.4%)增长抑制比其他组高(P ＜ 0.05 ).结论 热疗可以使RD细胞积聚于G2/M期.放疗联合热疗组对RD细胞的杀伤作用强于单一治疗组.热疗后放疗对RD细胞的杀伤效果强于放疗后热疗.