The Research On Effect Of Photodynamic Therapy With Aloe-emodin In Osteosarcoma MG63

ObjectiveTo investigate the effect of Aloe-emodin mediated photodynamictherapy (PDT) on human osteosarcoma MG63cells and the possiblemechanism.MethodsTo assess the cytotoxic effect of PDT, we measured the cell viabilityof MG63after PDT using LED irradiation (0–4.8J/cm2) followingincubation with AE (0–100μM) for6hours. MTT assay was used toassess cell viability after additional24hours incubation. We also observedthe morphological changes and apoptosis rate of the cells after PDT byHoechst nuclear staining, and flow cytometric assay. In addition, wedetected the subcellular localization of AE using Mito-Tracker. ROS wasdetected by DCFH-DA, Mitochondrial membrane potential (MMP) wasmeasured by Rhodamine123and observed by flow cytometry. Caspase-3,-9,-12, Bcl-2, Bax, cytochrome c, Grp-78, CHOP and JNK expressionwas assessed. ResultsAE-mediated PDT significantly inhibited the proliferation of MG63cells in a dose-dependent manner. The apoptotic rate and secondarynecrosis were significantly higher in cells treated with AE-mediated PDTthan those treated with single light irradiation, as well as those in treatedwith AE alone and those treated with the empty control (P <0.05). Nosignificant differences were observed between the latter three groups (P>0.05). After PDT treatment, nuclear condensation and fragmentation withapoptotic bodies were observed in the cells using Hoechst nuclear staining,and mitochondrial membrane potential was substantially decreased.Western blot analysis revealed elevated cytochrome c, caspase-9, andcaspase-3expression. In addition, overexpression of Bax, Grp-78, CHOPand JNK was shown and slightly decreased Bcl-2expression.ConclusionsAE-mediated PDT can effectively suppress the proliferation ofhuman osteosarcoma MG63cells and induce apoptosis. Mitochondrial andendoplasmic reticulum were confirmed to be involved in the AEPDT-induced apoptosis of human osteosarcoma MG63.