Abstract
Glioma is one of the most common types of primary brain tumors. Ivermectin (IVM), a broad-spectrum antiparasitic drug, has been identified as a novel anticancer agent due to its inhibitory effects on the proliferation of glioma cells in vitro and in vivo. However, the ability of IVM to induce autophagy and its role in glioma cell death remains unclear. The main objective of the present study was to explore autophagy induced by IVM in glioma U251 and C6 cells, and the deep underlying molecular mechanisms. In addition, we examined the effects of autophagy on apoptosis in glioma cells. In the present study, transmission electron microscopy (TEM), immunofluorescence, Western blot and immunohistochemistry were used to evaluate autophagy activated by IVM. Cell viability was measured by 3-(4,5-dimethylthiazol2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and colony formation assay. The apoptosis rate was detected by flow cytometry and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL). Meanwhile, autophagy inhibition was achieved by using chloroquine (CQ). U251-derived xenografts were established for examination of IVM-induced autophagy on glioma in vivo. Taken together, the results of the present study showed that autophagy induced by IVM has a protective effect on cell apoptosis in vitro and in vivo. Mechanistically, IVM induced autophagy through AKT/mTOR signaling and induced energy impairment. Our findings show that IVM is a promising anticancer agent and may be a potential effective treatment for glioma cancers.