ABSTRACT
Purpose@#Temozolomide is used in first-line treatment for glioblastoma. However, chemoresistance to temozolomide is common in glioma patients. In addition, mechanisms for the anti-tumor effects of temozolomide are largely unknown. Ferroptosis is a form of programmed cell death triggered by disturbed redox homeostasis, overloaded iron, and increased lipid peroxidation. The present study was performed to elucidate the involvement of ferroptosis in the anti-tumor mechanisms of temozolomide. @*Materials and Methods@#We utilized the CCK8 assay to evaluate cytotoxicity. Levels of lactate dehydrogenase (LDH), malondialdehyde (MDA), iron, and glutathione (GSH) were measured. Flow cytometry and fluorescence microscope were used to detect the production of reactive oxygen species (ROS). Western blotting, RT-PCR and siRNA transfection were used to investigate molecular mechanisms. @*Results@#Temozolomide increased the levels of LDH, MDA, and iron and reduced GSH levels in TG905 cells. Furthermore, we found that ROS levels and DMT1 expression were elevated in TG905 cells treated with temozolomide and were accompanied by a decrease in the expression of glutathione peroxidase 4, indicating an iron-dependent cell death, ferroptosis. Our results also showed that temozolomide-induced ferroptosis is associated with regulation of the Nrf2/HO-1 pathway. Conversely, DMT1 knockdown by siRNA evidently blocked temozolomide-induced ferroptosis in TG905 cells. @*Conclusion@#Taken together, our findings indicate that temozolomide may suppress cell growth partly by inducing ferroptosis by targeting DMT1 expression in glioblastoma cells.
ABSTRACT
Purpose@#Temozolomide is used in first-line treatment for glioblastoma. However, chemoresistance to temozolomide is common in glioma patients. In addition, mechanisms for the anti-tumor effects of temozolomide are largely unknown. Ferroptosis is a form of programmed cell death triggered by disturbed redox homeostasis, overloaded iron, and increased lipid peroxidation. The present study was performed to elucidate the involvement of ferroptosis in the anti-tumor mechanisms of temozolomide. @*Materials and Methods@#We utilized the CCK8 assay to evaluate cytotoxicity. Levels of lactate dehydrogenase (LDH), malondialdehyde (MDA), iron, and glutathione (GSH) were measured. Flow cytometry and fluorescence microscope were used to detect the production of reactive oxygen species (ROS). Western blotting, RT-PCR and siRNA transfection were used to investigate molecular mechanisms. @*Results@#Temozolomide increased the levels of LDH, MDA, and iron and reduced GSH levels in TG905 cells. Furthermore, we found that ROS levels and DMT1 expression were elevated in TG905 cells treated with temozolomide and were accompanied by a decrease in the expression of glutathione peroxidase 4, indicating an iron-dependent cell death, ferroptosis. Our results also showed that temozolomide-induced ferroptosis is associated with regulation of the Nrf2/HO-1 pathway. Conversely, DMT1 knockdown by siRNA evidently blocked temozolomide-induced ferroptosis in TG905 cells. @*Conclusion@#Taken together, our findings indicate that temozolomide may suppress cell growth partly by inducing ferroptosis by targeting DMT1 expression in glioblastoma cells.
ABSTRACT
Objective To investigate the expression of glutathione S-transferase π (Glutathione S-transferase π, GST-π) protein in peripheral blood and brain of patients with drug-resistant epilepsy and refractory epilepsy rats. Meth?ods From January 2010 to March 2014, the expression of GST-πin the blood and brain of 32 cases of drug-resistant epi?lepsy underwent neurosurgery and 10 cases of cerebral vascular malformation underwent surgery were studied and com?pared. The expression of GST-πin the blood and brain in refractory epilepsy rats and normal rats were studied and com?pared. Results The specimen from 20 temporal, 6 frontal and 6 occipital lobes were obtained from drug-resistant epilep?sy patients. The expression levels of GST-πin the blood and brain in refractory epilepsy rats and normal rats were higher than those of the control groups (P<0.05). Conclusion GST-πmay be involved in the process of drug-resistant epilepsy. The GST-πexpression in blood may be used as a marker for resistance to anti-epileptic agents.