Role of endoplasmic reticulum stress in human brain gliomas cell apoptosis induced by proteasome inhibitor MG-132

Objective To investigate the role of endoplasmic reticulum stress ( ERS) in human brain gliomas cell(SHG-44) apoptosis induced by proteasome inhibitor MG-132. Methods Human glioma cells were passage cultured. Glioma cells were treated by MG-132 with varying concentration(5, 10, 15 and 50 μmol/L) for 24 h. Compared with cells prior to the treatment (control group), cell viability was detected by MTT assay and the expression of ERS associated proteins GRP78 and apoptosis associated proteins Caspsse-12 was examined by PCR and Western-blotting. Results After MG-132 treatment for 24 h, SHG-44 cell viability was decreased significantly (39 %) (P <0.05), and continued to show a significant decline with the increasing concentration of MG-132 (P <0.05). RT-PCR results showed that the expression of ERS associated proteins GRP78 in SHG-44 cells were significantly increased after 5, 10, 15 and 50 μmol/L MG-132 treatment, and the expression of Caspase-12 was significantly increased after 5 μmol/L MG-132 treatment, slightly increased after 10 and 15 μmol/L treatment compared with that after 5 μmol/L treatment and reached the peak after 50 μmol/L treatment. Western-blotting results of GRP78 in SHG-44 cells were same as results of RT-PCR. Conclusion ERS may be involved in the apoptosis of gliomas cells induced by proteasome inhibitor MG-132. Key words: MG-132; SHG-44; Endoplasmic reticulum stress; Apoptosis