EMT phenotype induced by acetylation of tumor chromatin shows high BMI-1 levels and is observed in the invasion front of HNSCCs.

<p>(A) Western blot analysis depicting increased BMI-1 expression in HNSCC cells following TSA treatment. (B) Representative images of nuclear BMI-1 (FITC/green) and polarization of the F-actin filaments (TRITC/red) in tumor cells undergoing EMT after TSA treatment. (C) Representative examples of increased tumor cell invasion after treatment with HDAC inhibitors. Note the significant increase in invasiveness of HN6 and HN13 cells (* p<0.05 and *** p<0.001 respectively). (D) Representative examples of human samples of normal oral mucosa and HNSCC (H&E stained). Note acetylated tumor cells (Ac. H3-FITC) that co-express high levels of vimentin (TRICT/green) at the invasion front of HNSCC. Epithelial cells in normal mucosa display acetylated cells distributed throughout the epidermis but do not express vimentin.