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Autophagy Induction by Endothelial-Monocyte Activating Polypeptide II Contributes to the Inhibition of Malignant Biological Behaviors by the Combination of EMAP II with Rapamycin in Human Glioblastoma.

Ma J, Meng F, Li S, Liu L, Zhao L, Liu Y, Hu Y, Li Z, Yao Y, Xi Z, Teng H, Xue Y - Front Mol Neurosci (2015)

Bottom Line: 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.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.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurobiology, College of Basic Medicine, China Medical University Shenyang, China ; Institute of Pathology and Pathophysiology, China Medical University Shenyang, China.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus

Effect of endothelial-monocyte activating polypeptide II (EMAP II) on human GBM cells and GSCs. (A) Timeline of the research with EMAP II. (B) Effect of EMAP II on the cell viability of U87, U118, and GSCs after treatment with 0.005 nM, 0.05 nM, 0.5 nM, and 5 nM EMAP II for 0.5, 1, 2, 3, and 6 h. (C) Effects of EMAP II, 3-MA and Z-VAD on the cell viability of U87, U118 and GSCs after treatment with 0.05 nM EMAP-II for 0.5 h. (D) Effects of EMAP II, 3-MA, and Z-VAD on MMP of U87, U118, and GSCs by JC-1 staining for flow cytometry. Values represented the means ± SD (n = 5, each). ∗∗P < 0.01 vs. control group, ##P < 0.01 vs. EMAP II group.
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Figure 1: Effect of endothelial-monocyte activating polypeptide II (EMAP II) on human GBM cells and GSCs. (A) Timeline of the research with EMAP II. (B) Effect of EMAP II on the cell viability of U87, U118, and GSCs after treatment with 0.005 nM, 0.05 nM, 0.5 nM, and 5 nM EMAP II for 0.5, 1, 2, 3, and 6 h. (C) Effects of EMAP II, 3-MA and Z-VAD on the cell viability of U87, U118 and GSCs after treatment with 0.05 nM EMAP-II for 0.5 h. (D) Effects of EMAP II, 3-MA, and Z-VAD on MMP of U87, U118, and GSCs by JC-1 staining for flow cytometry. Values represented the means ± SD (n = 5, each). ∗∗P < 0.01 vs. control group, ##P < 0.01 vs. EMAP II group.

Mentions: The effects of EMAP II on the cell viability of human GBM cells and GSCs were evaluated at indicated time and concentration (the time line of experiments was shown in Figure 1A). As shown in Figure 1B, the cell viability of U87, U118, and GSCs were inhibited by EMAP II in time- and dose-dependent patterns. Compared with the control group, the cell viability was significantly decreased at 0.5 h with the treatments of 0.05, 0.5, and 5 nM EMAP II (P < 0.01). The cell viability of U87, U118, and GSCs were inhibited at 0.5, 1, and 2 h in groups of 0.05, 0.5, and 5 nM, respectively (P < 0.01), whereas there was no obvious difference among three groups (P > 0.05). Thus, 0.05 nM at 0.5 h were selected as the optimum concentration and time point in the subsequent experiments, respectively. We further investigated whether the inhibitory effect of EMAP II on cell viability was associated with the induced autophagy and apoptosis. Cells were pretreated with autophagy inhibitor 3-MA or caspase inhibitor Z-VAD alone or in combination. As shown in Figure 1C, the cell viability was inhibited in EMAP II and EMAP II+Z-VAD groups compared with control group (P < 0.01), and there was no significant difference between these groups (P > 0.05). In addition, the cell viability was increased in EMAPII+3-MA group compared with EMAP II group (P < 0.01), suggesting that 3-MA blocked the inhibitory effect of EMAP II on the cell viability.


Autophagy Induction by Endothelial-Monocyte Activating Polypeptide II Contributes to the Inhibition of Malignant Biological Behaviors by the Combination of EMAP II with Rapamycin in Human Glioblastoma.

Ma J, Meng F, Li S, Liu L, Zhao L, Liu Y, Hu Y, Li Z, Yao Y, Xi Z, Teng H, Xue Y - Front Mol Neurosci (2015)

Effect of endothelial-monocyte activating polypeptide II (EMAP II) on human GBM cells and GSCs. (A) Timeline of the research with EMAP II. (B) Effect of EMAP II on the cell viability of U87, U118, and GSCs after treatment with 0.005 nM, 0.05 nM, 0.5 nM, and 5 nM EMAP II for 0.5, 1, 2, 3, and 6 h. (C) Effects of EMAP II, 3-MA and Z-VAD on the cell viability of U87, U118 and GSCs after treatment with 0.05 nM EMAP-II for 0.5 h. (D) Effects of EMAP II, 3-MA, and Z-VAD on MMP of U87, U118, and GSCs by JC-1 staining for flow cytometry. Values represented the means ± SD (n = 5, each). ∗∗P < 0.01 vs. control group, ##P < 0.01 vs. EMAP II group.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4664732&req=5

Figure 1: Effect of endothelial-monocyte activating polypeptide II (EMAP II) on human GBM cells and GSCs. (A) Timeline of the research with EMAP II. (B) Effect of EMAP II on the cell viability of U87, U118, and GSCs after treatment with 0.005 nM, 0.05 nM, 0.5 nM, and 5 nM EMAP II for 0.5, 1, 2, 3, and 6 h. (C) Effects of EMAP II, 3-MA and Z-VAD on the cell viability of U87, U118 and GSCs after treatment with 0.05 nM EMAP-II for 0.5 h. (D) Effects of EMAP II, 3-MA, and Z-VAD on MMP of U87, U118, and GSCs by JC-1 staining for flow cytometry. Values represented the means ± SD (n = 5, each). ∗∗P < 0.01 vs. control group, ##P < 0.01 vs. EMAP II group.
Mentions: The effects of EMAP II on the cell viability of human GBM cells and GSCs were evaluated at indicated time and concentration (the time line of experiments was shown in Figure 1A). As shown in Figure 1B, the cell viability of U87, U118, and GSCs were inhibited by EMAP II in time- and dose-dependent patterns. Compared with the control group, the cell viability was significantly decreased at 0.5 h with the treatments of 0.05, 0.5, and 5 nM EMAP II (P < 0.01). The cell viability of U87, U118, and GSCs were inhibited at 0.5, 1, and 2 h in groups of 0.05, 0.5, and 5 nM, respectively (P < 0.01), whereas there was no obvious difference among three groups (P > 0.05). Thus, 0.05 nM at 0.5 h were selected as the optimum concentration and time point in the subsequent experiments, respectively. We further investigated whether the inhibitory effect of EMAP II on cell viability was associated with the induced autophagy and apoptosis. Cells were pretreated with autophagy inhibitor 3-MA or caspase inhibitor Z-VAD alone or in combination. As shown in Figure 1C, the cell viability was inhibited in EMAP II and EMAP II+Z-VAD groups compared with control group (P < 0.01), and there was no significant difference between these groups (P > 0.05). In addition, the cell viability was increased in EMAPII+3-MA group compared with EMAP II group (P < 0.01), suggesting that 3-MA blocked the inhibitory effect of EMAP II on the cell viability.

Bottom Line: 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.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.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurobiology, College of Basic Medicine, China Medical University Shenyang, China ; Institute of Pathology and Pathophysiology, China Medical University Shenyang, China.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus