Figure 5.

Melatonin treatment neither induces cell death nor death receptor/ligand regulation in neuroblastoma cells. (A) Increase in cell death does not occur in neuroblastoma cell lines as evaluated by the release of LDH into the extracellular medium, after 72 h of incubation with 1 mM melatonin. (B) SK-N-SH, SK-N-AS and SK-N-SY5Y neuroblastoma cells were treated with or without 1 mM melatonin for 8 or 24 h, and TNFR1, TNF-α, Fas, Fas-L, DR4, DR5 and TRAIL expression were determined by quantitative PCR to assess mRNA expression levels. GAPDH was used as a housekeeping gene. Relative gene expressions are represented as the n-fold increase compared with basal level (dotted lines represent vehicle-treated cells).