Melatonin Enhances Cisplatin and Radiation Cytotoxicity in Head and Neck Squamous Cell Carcinoma by Stimulating Mitochondrial ROS Generation, Apoptosis, and Autophagy

Figure 1

Melatonin increases the cytotoxic effects of irradiation (IR) and CDDP in HNSCC cell lines Cal-27 and SCC-9. Clonogenic assay of cells exposed to IR (a–c) or CDDP (f–h) and viability of cells exposed to IR (d, e) or CDDP (i, j). Treatment groups include the control (vehicle), IR (8 Gy), CDDP 10 μM, melatonin (aMT) 1000 or 1500 μM, and CDDP or IR plus aMT 100, 500, 1000, or 1500 μM. per group. Data are presented as . and vs. the control, ^# and ^### vs. the IR- or CDDP-treated group, ^δ and ^δδδ vs. IR+aMT 100, and ^$ and ^$$$ vs. IR+aMT 500.