超声激活血卟啉对小鼠Hepatoma22腹水瘤细胞抗氧化酶活性的影响

Effect of Ultrasound Activating Hematoporphyrin on the Activities of Antioxidative Enzymes in Mouse Hepatoma 22

研究超声激活血卟啉对小鼠hepatoma22(H-22)肿瘤细胞抗氧化酶活性的影响,初步探讨其杀伤细胞的生物学机制。采用频率为1.43MHz、强度为2.0W/cm2的聚焦超声,结合100μg/ml的血卟啉作用于肿瘤细胞,通过台盼蓝拒染法检测细胞存活率;2′,7′-二氯荧光黄双乙酸盐(Dichlorofluorescein diacetata,DCFH-DA)活性氧检测试剂盒检测细胞内活性氧水平;酶化学方法检测细胞内几种抗氧化酶活性的变化。发现同等处理条件下,超声结合血卟啉对细胞的损伤显著高于单纯超声组,单纯血卟啉无明显的细胞毒作用;超声激活血卟啉后细胞悬液中活性氧的生成量明显升高,而细胞内超氧化物歧化酶(Superoxide dismutase,SOD)、谷胱甘肽过氧化物酶(Glutathi-one peroxidase,GSH-PX)、过氧化氢酶(Catalase,CAT)活性均显著下降。推测超声激活血卟啉对小鼠H-22腹水瘤细胞的杀伤作用可能与肿瘤细胞中抗氧化物酶活性降低有关。

This investigation was made with regard to the influences of ultrasound combined with hematoporphyrin on the activities of antioxidative enzyme in ascites hepatoma 22 （H-22） tumor cells, and to a better understanding of the potential biological mechanism of sonodynamic therapy which involved the damage to cells. Combined with 100 μg/ml hematoporphyrin, high intensity focused ultrasound sonieation at a frequency of 1.43 MHz and an intensity level of 2.0 W/cm^2 was delivered to H-22 tumor cells for 1 min. The viability of cells was evaluated by typan-blue blue exclusion test. The intracellular reactive oxygen species （ROS） levels were determined by 2＇, 7 ＇-dichlorofluo- rescein diacetata （DCFH-DA）. Enzymatic chemical methods were used to measure the activities of key antioxidative enzymes. The results indicated that the cell damage rate of ultrasound combined with hematoporphyrin was significantly higher than that of the treatment with ultrasound alone, and hematoporphyrin alone had no killing effect on H- 22 cells. The level of ROS in cell suspension was significantly increased, and the key antioxidative enzyme activities were obviously decreased after treatment with the combined use of ultrasound and hematoporphyrin. We speculated that the decreased activities of key antioxidative enzymes in cells might be involved in mediating the killing effect on H22 cells in sonodynamic therapy.