IDX enhances the anti-tumor effect of cisplatin in aggressive NPC cancer phenotypes in vitro
(A) Four NPC cell lines (NPC43 EBV-positive, NPC43+ve in blue; NPC43EBV-negative, NPC43-ve in red; C666 in black; C17 in green) were treated with increasing concentrations of IDX and cisplatin (cis) ranging from 1 µM to 40 µM. The viability of cells treated with IDX for 5 days was analyzed by XTT cell proliferation assay. (B) Representative images of cell migration in 8 µm transwell upon IDX treatment, stained with crystal violet, with the migratory cell counts shown next to the images. (C) Representative flow cytometric profiles showing Annexin V and PI staining of NPC cells following IDX treatment. (D) Bar graph represent the percentage of Annexin-V/PI positive NPC cells following IDX treatment. Asterisk to the right of bar indicate statistical difference compare to control DMSO in respective cell lines. (E) Viability of cells treated with cisplatin (Cis) for 5 days was analyzed by XTT assay. (F) Combinatorial treatment of IDX at 1, 2, 4 µM and Cis at 0.6, 1.2, 2.6 µM in four NPC cell lines by XTT assay. (G) Representative images of cell growth following IDX and/or cis treatment, stained with crystal violet. (H) Quantification of cell growth is shown. Results are representative of three independent experiments and presented as the means ±SD *p<0.05, **p<0.01.