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

摘要

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/cm² was delivered to EAT cells. Then we examined the expression of pro-apoptosis proteins(Bax，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 stared 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].