Resveratrol synergistically enhances the effect of etoposide in HNSCC cell lines

Conclusion: Resveratrol shows a growth inhibitory effect in head and neck squamous cell carcinoma (HNSCC) cell lines and acts synergistically in combination with etoposide in three cell lines via the induction of apoptotic and necrotic cell death. Objective: In patients with recurrent/distant HNSCC, one of the limited treatment options is etoposide. The aim of this study was to investigate whether resveratrol is able to enhance the antiproliferative effect of etoposide in vitro synergistically. Methods: Dose-response curves of etoposide and resveratrol in three HNSCC cell lines were generated. Drug combinations in a fixed dose ratio were carried out and results were analyzed by the combination index method. Detection of apoptotic cells was performed by flow cytometry. Results: Both compounds show a dose- and time-dependent growth inhibitory effect as single agents after treatment. In combination experiments we observed distinct synergistic effects increasing over time in all three cell lines.