Figure 6.
Induction of apoptotic cell death in HNSCC cell lines after afatinib treatment (0 nm, IC 20, IC 40, IC 60, IC 80) under both normoxic and hypoxic conditions. Cells were stained with annexin V‐FITC (AnnV) and PI and measured flow cytometrically. Treatment with afatinib induced an increase in the percentage of AnnV+/PI− and AnnV+/PI+ cells with a corresponding decrease of the percentage viable (AnnV−/PI−) cells in the majority of HPV‐negative (A–C) and HPV‐positive (D, E) intrinsically cetuximab‐resistant HNSCC cell lines under both normal and reduced oxygen conditions. This induction of apoptotic cell death was also observed in cetuximab‐sensitive (F, I) as well as acquired cetuximab‐resistant and PBS‐treated control (G, H, J, and K) HNSCC cell lines. *P‐value effect treatment on the percentage AnnV+/PI− cells ≤ 0.050.