Fig. 5

ETS-1 is not controlled by the MEK/ERK pathway and inhibition of the MEK/ERK pathway does not re-sensitize cisplatin-resistant HNSCC cells to cisplatin treatment. a. Cell lysates were prepared from SCC25/SCC25CP, Cal27/Cal27CP, and FaDu/FaDu-CP cell pairs, as well as UMSCC74B cells. Phosphorylation and total levels of ERK and ETS-1, as well as β-actin, were detected by Western blot. b. Cells were treated with different doses of PD0325901 for 24 h, lysed, and phosphorylation of ERK and ETS-1-T38 and total levels of ERK, ETS-1, and β-actin were detected by Western blot. c. Cal27CP cells were treated with different doses of cisplatin alone or in combination with PD0321901 (5 μM) for 24 h, and phosphorylation of ERK and ETS-1-T38 and total levels of ERK, ETS-1 and β-actin were detected by Western blot. d. Cal27CP cells were treated with DMSO control, cisplatin, PD0325901, or a combination for 72 h. Cell proliferation was measured by MTS assay