Abstract 4665: Sensitization of head and neck cancer cells toward cisplatin by inhibition of autophagy

Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL Cisplatin is a commonly used chemotherapeutics but its efficacy is limited by the resistance presented by some tumor cells. Autophagy is a form of cell death by self-digesting organelles. The present study was undertaken to examine whether cisplatin can induce autophagy and whether autophagy modulates the efficacy of cisplatin against head and neck squamous cancer cells (HNSCC). In responses to increasing doses of cisplatin, there was a steady increase in autophagy, as indicated by LC3 punctate staining, in a cisplatin resistant UMSCC-15S cell line, whereas induction of autophagy was rapidly peaked at low doses of cisplatin in the UMSCC-10B cell line which was more sensitive toward cisplatin. Further studies found that there were increased autophagic fluxes at basal level in the cisplatin sensitive UMSCC-10B cells when compared to cisplatin resistant UMSCC-15S cells. Inhibition of autophagy by chloroquine significantly reduced colony formation of both cell lines, and sensitized UMSCC-15S cells toward cisplatin treatment. Our studies suggest that autophagy responses can be modulated to augment the efficacy of cisplatin against HNSCCs. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4665. doi:1538-7445.AM2012-4665