Fig. 1

a Western blot analysis of the three major anti-apoptotic BCL-2 family proteins in SCCHN cell lines. Sites of primary tumors are indicated in brackets: OC oral cavity, LX larynx, OP oropharynx. b BH3 profiling with increasing concentrations of BIM peptide revealed that the indicated SCCHN cell lines were primed to undergo apoptosis. c SCCHN cell lines exposed to the indicated BH3 mimetics (100 nM) for 24 h failed to undergo apoptosis, as assessed by phosphatidylserine (PS) externalization. d–f Representative IHC images of oral cavity (OC) normal tissue, primary tumor core and advancing front (AF), stained using antibodies against d BCL-2 e BCL-X_L, and f MCL-1 (clone D5V5L) and counterstained with hematoxylin. Scale bars 50 μm. Dot plots depict the relative staining intensities (H-scores) of the specified antibody. Each dot represents the data from an individual patient. The IHC images shown correspond to the yellow circles in the graph. b, c One-way ANOVAs with Dunnett’s multiple comparisons tests, with a single pooled variance. Error bars = mean ± SEM of at least three independent experiments. d–f Normality tests were performed, followed by Kruskal Wallis tests with Dunn’s multiple comparisons tests. Error bars = mean ± SD. *P < 0.05, **P < 0.01, ***P < 0.001.