Abstract: Objective To investigate the effects of carboxyamidotriazole-orotate (CTO) on the proliferation and apoptosis of mouse glioma cell line GL261. Methods The proliferation of GL261 cells was detected by live cell counting. Cell cycle of GL261 cells was detected by PI staining and flow cytometry. Apoptosis of GL261 cells was detected by annexinⅤ/PI double staining and flow cytometry; DCFH-DA staining and flow cytometry were used to detect the content of intracellular reactive oxygen species (ROS) of GL261 cells. The oxygen consumption rate (OCR) of GL261 cells was measured in Seahorse bioenergy assay. The ATP content in GL261 cells was detected by ATP detection kit. Results Compared to the control group, the proliferation of GL261 cells in CTO treatment group was significantly inhibited in a time- and dose-dependent way, the proportion of GL261 cells in S phase was significantly increased (P＜0.05) in 20 μmol/L CTO group. Compared with the control group, more apoptosis occurred in GL261 cells of CTO group, and ROS content in GL261 cells of 20 μmol/L CTO group was also significantly increased (P＜0.01). Compared with the control group, the contents of OCR and ATP in GL261 cells was signifi- cantly reduced in the CTO group(P＜0.01). Conclusions CTO inhibits proliferation of GL261 cells and promotes their apoptosis by increased production of ROS. In addition, CTO inhibits the mitochondrial respiration of GL261 cells and the production of ATP in mitochondria, thus inhibits growth of glioma cells.

Key words: carboxyamidotriazole-orotate, cell line GL261, proliferation, apoptosis, mitochondrial respiration