Fig. 4

Alpelisib exerts synergistic effect via suppression of EMT induced by palbociclib. a Heat map showing an unsupervised hierarchical clustering of gene expression after treatment with 1 μM palbociclib, 1 μM alpelisib, a low dosage of combined palbociclib alpelisib (500 nM of each drug), and a high dosage of this combination (1 μM of each drug) in CAL27, FADU, and HN30 cell lines. b Hallmark gene sets are listed. E2F targets genes, EPI_MES_TRANS, and PI3K signaling are marked in bold. c Western blot analyses of EMT markers, TGF-β1/Smad3, and downstream genes were performed in three HNSCC cell lines incubated for 72 h with vehicle (DMSO), 10 ng/ml TGF β1, 1 μmol/L palbociclib, 2 μmol/L SB-431542, or both inhibitors. d Western blot analysis of EMT markers were performed in three HNSCC cell lines incubated for 72 h with vehicle (DMSO), 500 nmol/L palbociclib, 500 nmol/L alpelisib, a low dosage of combination (500 nM of each drug), or a high dosage of combination (1 μM of each drug). e Dose-response curves of relative cell viability with palbociclib monotherapy, palbociclib monotherapy supplemented with 10 ng/ml TGF-β1, and palbociclib monotherapy supplemented with 10 ng/ml TGF-β1 and 500 nM alpelisib for 72 h in three HNSCC cell lines