L-carnitine Sensitizes Human Glioblastoma Cells To TRAIL-induced Apoptosis

Aim: In this study,the enhancing effect of L-carnitine as a sensitizer was investigated on TRAIL(tumor necrosis factor-related apoptosis inducing ligand)-induced apoptosis in Glioma cells.Methods: Glioma cells U87 MG was used as model cell line.Cell viability was determined by CCK-8,apoptosis was assessed by Annexin V-FITC/PI staining,caspase-3 activity and expression.The expression and transcription of NF-κB(nuclear factor kappa B)and c-FLIP(FLICE inhibiting protein)was measured by realtime-PCR and western.In addition,NF-κB was knockdown to analyze its regulating effect on c-FLIP expression.Results: The combination treatment with TRAIL and L-carnitine significantly inhibited cell proliferation and induced apoptosis.Compared with control,combinational treatment significantly suppressed the transcription and expression of c-FLIP as well as translocation of NF-κB.Through silencing NF-κB,NF-κB was found to act as upstream signaling to regulate c-FLIP.Conclusion: L-carnitine sensitizes TRAIL-induced tumor cell apoptosis via suppression of NF-κB-dependent c-FLIP expression.