Fig. 4: Deprivation of the EGFR signal synergizes with CDK4/6 inhibition.
From: Deprivation of EGFR signal causes senolysis in PDAC with CDK4/6 inhibition
A IB of the indicated proteins in MIA PaCa-2 cells pre-treated with or without 10 µM palbociclib for 48 h, thereafter with the indicated doses of gefitinib for 48 h. B IHC of Ki-67 in MIA PaCa-2 cells pre-treated with or without 10 µM palbociclib for 48 h, thereafter with the indicated doses of gefitinib or cetuximab for 48 h. Scale bars, 20 µm. C IB of the indicated proteins in MIA PaCa-2 cells pre-treated with or without 10 µM palbociclib for 48 h, thereafter with the indicated doses of gefitinib for 0-48 h. D IB of the indicated proteins in the MIA PaCa-2 cells simultaneously treated with or without 10 µM palbociclib and 5 µM gefitinib for 0-72 h. E Representative images of SA-β-gal staining in the indicated cells pre-treated with or without 10 µM palbociclib for 48 h, thereafter with 5 µM gefitinib for 48 h. Scale bars, 100 µm. Quantitation of SA-β-gal positive cells from 3 or more randomly chosen fields. F Representative flow cytometry profiles of annexin V/PI double staining in MIA PaCa-2 cells pre-treated with or without 10 μM palbociclib for 48 h, thereafter with 20 µM gefitinib for 48 h (P → G). Quantitation of apoptotic cells (% = early apoptotic cells in Q2 + late apoptotic cells in Q3). G Representative images of SA-β-gal staining in MIA PaCa-2 cells pre-treated with or without 10 µM palbociclib for 48 h, thereafter with 200 µg/mL cetuximab for 48 h. Scale bars, 100 µm. Quantitation of SA-β-gal positive cells from 3 or more randomly chosen fields. H Representative flow cytometry profiles of annexin V/PI double staining in MIA PaCa-2 cells pre-treated with or without 10 μM palbociclib for 48 h, thereafter with 350 µg/mL cetuximab for 48 h. Quantitation of apoptotic cells (% = early apoptotic cells in Q2 + late apoptotic cells in Q3). α-tubulin was used as a loading control. DMSO was used as a vehicle. All data are shown as mean ± SD of three independent experiments. One-way ANOVA followed by Tukey’s post-hoc test was performed in E-H. *p < 0.05, **p < 0.01, ***p < 0.001.
