Melatonin-induced ferroptosis in pancreatic cancer cells by stimulating endoplasmic reticulum stress and inhibiting alanine-serine-cysteine transporter 2-driven glutamine metabolism

Figure 5 Melatonin + CCT020312 exacerbates activating transcription factor 4-mediated endoplasmic reticulum stress and increases ferroptosis in pancreatic cancer cells. A: The expression levels of protein kinase R-like endoplasmic reticulum kinase (PERK)-eukaryotic initiation factor 2α-activating transcription factor 4 axis proteins in Panc-1 and AsPC-1 cells treated with high melatonin concentrations combined with the PERK agonist CCT020312 for 24 hours were analyzed using western blotting (n = 3); B: The expression levels of glutamine metabolism-related proteins in Panc-1 and AsPC-1 cells treated with high melatonin concentrations combined with the PERK agonist CCT020312 for 24 hours were analyzed using western blotting (n = 3); C: Malondialdehyde levels in Panc-1 and AsPC-1 cells were measured using a commercial assay kit (n = 3); D: Lipid reactive oxygen species levels in Panc-1 and AsPC-1 cells were detected in situ using a reactive oxygen species assay kit. MLT: Melatonin; DMSO: Dimethyl sulfoxide; PERK: Protein kinase R-like endoplasmic reticulum kinase; p-PERK: Phosphorylated-protein kinase R-like endoplasmic reticulum kinase; ElF2α: Eukaryotic initiation factor 2α; p-ElF2α: Phosphorylated-eukaryotic initiation factor 2α; ATF4: Activating transcription factor 4; ASCT2: Alanine-serine-cysteine transporter 2; GLS1: Glutaminase 1; Xct: X-cysteine transporter; GCLC: Glutamate-cysteine ligase catalytic subunit; GSS: Glutathione synthetase; GPX4: Glutathione peroxidase 4. ^bP < 0.01, and ^dP < 0.0001.