Figure 3. Melatonin inhibits malignant properties of NPC cells. (A) Representative images (left panel) and quantification (right upper panel) of cell apoptosis in the indicated cells treated with melatonin (Mel, 48 hr), as determined by AnnexinV/propidium iodide (PI) assay. (B) The cell viability of the indicated cells incubated with melatonin (72 hr) was determined by CCK-8 assay. (C, D) Images and quantification of migrated (C) and invaded (D) NPC cells treated with melatonin (2 mM) for 24 hr were analyzed in transwell assays. Data presented are the mean ± SD; **P < 0.01 compared with control using Student t-test.