Fig. 3

TSA downregulates EGFR through the proteasomal degradation pathway in HNSCC cells. a The suppressive effects of TSA on EGFR family proteins confirmed by Western blotting. b The effects of TSA and PXD101 on regulation of EGFR-meditated signaling pathways determined by Western blotting. c, d The dose- and time-dependent effect of TSA on EGFR determined by Western blotting. In c, representative images and quantitative data from three independent experiments were shown in the left and right panels, respectively. e The protein levels of EGFR in the presence of 5 μM TSA alone, 10 μM MG132 alone, or in combination. f The effect of TSA on EGFR ubiquitination. Cells were pretreated with 10 μM MG132 for 4 h before TSA treatment. The cell lysates were IP with anti-EGFR antibody and immunoblotted with anti-Ubiquitin antibody. In these assays, TSA and PXD101 were used to treat HN12 and HN31 cells. *p < 0.05; **p < 0.01