Fig. 3

Palbociclib suppressed the cytotoxicity of cisplatin but potentiated the growth inhibitory effect of SAHA in NPC cells. a. Combined palbociclib + cisplatin treatment did not enhance growth suppression in NPC cells (NPC43 and C17) relative to treatment with cisplatin treatment alone. b. Combined treatment with palbociclib + SAHA strongly suppressed viability in the C666–1, C17 and NPC43 cell lines. c. Combination index (CI) values were calculated using the Chou–Talalay Method to demonstrate the antagonistic, additive, and synergistic effects of drug combinations on the viability of NPC cells. The CI values of palbociclib + cisplatin and palbociclib + SAHA at various doses in the three NPC cell lines are presented as a heatmap. CI values > 1 were observed in all cell lines treated with palbociclib + cisplatin, suggesting an antagonistic effect between these drugs. CI values < 1 were observed in all NPC cell lines treated with palbociclib + SAHA, suggesting a synergistic effect between these drugs