Fig. 5

EMT signaling mechanistic analysis of selected drug combinations in HNSCC in vitro. a ExcessHSA scores of palbociclib-alpelisib, palbociclib-cetuximab, and palbociclib cisplatin combined therapy in 13 HNSCC cell lines mentioned in Fig. 1a. b ExcessHSA scores of palbociclib-alpelisib combined therapy in PIK3CA WT and mut/amp cell lines. c Gene expression of epithelial and mesenchymal signatures after three distinct treatments (palbociclib plus alpelisib, palbociclib plus cetuximab, palbociclib plus cisplatin) compared to palbociclib monotherapy in HNSCC cell lines. Significantly up- and downregulated genes were marked with red and blue dotted lines, respectively. d Protein expressions of canonical EMT markers in FADU cells treated with palbociclib, palbociclib plus alpelisib (low dosage), palbociclib plus alpelisib (high dosage), palbociclib plus cisplatin, and palbociclib plus cetuximab. e RRM2 and canonical EMT marker expressions in RRM2-overexpressing FADU cells. f ExcessHSA scores were determined in order to observe the effects of palbociclib combined with alpelisib or cetuximab for 72 h in the presence of RRM2 overexpression and the corresponding inhibitor osalmid. g Canonical EMT markers expressions were detected in both EV- and RRM2-expressing FADU cells after palbociclib monotherapy and combination treatments in the presence/absence of the RRM2 inhibitor. The data are shown as the mean ± SD. n.s., not significant; * P < 0.05, *** P < 0.001, **** P < 0.0001, as estimated using unpaired two-tailed Student’s t tests, one- or two-way ANOVA analysis