声化学诱导艾氏腹水瘤细胞凋亡机制初探

Preliminary study on the mechanism of apoptosis in Ehrlich ascites tumor cells by sonochemical-activated hematoporphyrin

本研究采用频率1.43MHz,声强3W/cm2的高频聚焦超声处理艾氏腹水肿瘤细胞,研究超声激活血卟啉诱导艾氏腹水肿瘤细胞凋亡的途径及其与癌细胞内的氧自由基之间的关系。通过细胞免疫组织化学方法检测与癌细胞凋亡相关的Bax,细胞色素c和caspase-3蛋白的动态表达,黄嘌呤氧化酶法检测超氧化物歧化酶活性变化,硫代巴比妥酸法检测膜脂质过氧化物的含量。结果发现超声加血卟啉处理1h,癌细胞胞浆中的三种促凋亡蛋白表达增多,3h时表现为高表达;处理1h的癌细胞,超氧化物歧化酶活性下降,膜脂质过氧化物增多。研究结果表明超声激活血卟啉诱导艾氏腹水肿瘤细胞凋亡可能通过线粒体途径,且与癌细胞受损后产生的氧自由基有关。

We investigated the mechanism of apoptosis in Ehrlich ascites tumor （EAT） cells treated by ultrasound activating hematoporphyrin, and whether the apoptosis was associated with oxygen free radicals produced in cells. Combined with hematoporphyrin, high intensity focused ultrasound sonication at a frequency of 1.43 MHz and an intensity level of 3 W/cm^2 was delivered to EAT cells. Then we examined the expression of pro-apoptosis proteins （gax, cytochrome c and caspase-3）, the activity of superoxide dismutase and the content of lipid peroxides in EAT cells by immunohistochemistry, xanthine oxidase method and thiobarbituric acid reaction method respectively. The expressions of three pro-apoptosis proteins started one hour after ultrasound activating hematoporphyrin, and more expressions were also detected after three hours of the treatment. However, there were no detectable expressions of three pro-apoptosis proteins immediately after the treatment, compared with untreated groups. In groups treated by ultrasound alone, three pro-apoptosis proteins started expressing after three hours of sonication. On the other hand, the activity of superoxide dismutase remarkably decreased and the content of lipid peroxides notably increased one hour following the treatment, comparing to groups untreated and treated by ultrasound alone. These results suggest that the apoptosis in EAT cells induced by ultrasound activating hematoporphyrin may occur through a mitochondria dependent way, in which oxygen free radicals probably play an important role [Acta Zoologica Sinica 51 （6） ： 1073-1079, 2005].