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

Figure 3 Effects of melatonin on endoplasmic reticulum stress and glutamine metabolism pathways in human pancreatic cancer. A: The expression levels of protein kinase R-like endoplasmic reticulum kinase-eukaryotic initiation factor 2α-activating transcription factor 4 axis proteins in Panc-1 and AsPC-1 cells treated with different melatonin concentrations were measured using western blotting (n = 3); B: The expression of activating transcription factor 4 in Panc-1 and AsPC-1 cells treated with different melatonin concentrations was assessed using immunofluorescence; C: The expression levels of glutamine metabolism-related proteins (alanine-serine-cysteine transporter 2, glutaminase 1, X-cysteine transporter, glutamate-cysteine ligase catalytic subunit, glutathione synthetase, and glutathione peroxidase 4) in Panc-1 and AsPC-1 cells treated with different melatonin concentrations were measured through western blotting (n = 3); D: The expression of glutathione peroxidase 4 in Panc-1 and AsPC-1 cells treated with different concentrations of melatonin was analyzed using immunofluorescence. 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.