Fig. 4

MGMT is required for PA-mediated synergistic effect. A The shRNA-mediated knockdown of MGMT was validated by western blot. Right panel represents the quantification of the MGMT protein levels in A. B Knockdown of MGMT increased the DTIC sensitivities in A375 and SK-MEL-28 cells. C Dose-response curves for MGMT-depleted melanoma cells treated with PA, DTIC or their combinations. The selected concentrations for treatment are identical with those in Fig. 1B. D Synergy scores were obtained from the data represented in C. The synergy scores were calculated by ZIP model and Bliss model, respectively. *p < 0.05, **p < 0.01 and **** p < 0.0001