Fig. 4

MEK inhibitors downregulate HDAC inhibitor-induced p-ERK and EGFR expression. a AsPC-1 cells were treated with indicated concentrations of MPT0E028 or SAHA for 24, 48, and 72 h. The protein expression of p-ERK and EGFR was determined by western blotting. Actin was used as an internal control. b AsPC-1 cells were treated with indicated concentrations of MPT0E028 or SAHA combined with or without 10 and 20 μM PD98059 (PD) for 72 h. c AsPC-1 and BxPC-3 cells were treated with indicated concentrations of MPT0E028 or combined with or without trametinib (Tra) for 72 h. p-ERK and EGFR protein expressions were analyzed. t-ERK was used as an internal control. d AsPC-1 cells were treated with indicated conditions for 48 h to determine EGFR mRNA expression. *P < 0.05 and ***P < 0.001 compared with the indicated group