This study aims to investigate the effect of
endothelial-monocyte activating polypeptide II (
EMAP II) on human
glioblastoma (GBM) cells and
glioblastoma stem cells (GSCs) as well as its possible mechanisms. In this study,
EMAP II inhibited the cell viability and decreased the mitochondrial membrane potential in human GBM cells and GSCs, and autophagy inhibitor 3-methyl
adenine (3-MA) blocked these effects. Autophagic vacuoles were formed in these cells after
EMAP II treatment and this phenomenon was blocked by 3-MA. In addition, the up-regulation of microtubule-associated protein-1 light chain-3 (LC3)-II and the down-regulation of autophagic degraded substrate p62/SQSTM1 caused by
EMAP II were observed. Cells treated with
EMAP-II inhibited the PI3K/Akt/mTOR signal pathway, and PI3K/Akt agonist
insulin-like growth factor-1 (IGF-1) blocked the effect of
EMAP II on the expression of LC3-II and p62/SQSTM1. Cells exposed to
EMAP-II experienced mitophagy and ER stress. Furthermore, the inhibition of cell proliferation, migration and invasion of GBM cells and GSCs were more remarkable by the combination of
EMAP II and
rapamycin than either agent alone in vitro and in vivo. The current study demonstrated that the cytotoxicity of
EMAP II in human GBM cells and GSCs was induced by autophagy, accompanied by the inhibition of PI3K/Akt/mTOR signal pathway, mitophagy and ER stress. The combination of
EMAP II with
rapamycin demonstrated the inhibitory effect on the malignant
biological behaviors of human GBM cells and GSCs in vitro and in vivo.