This study investigated the use of 3 different established cell-sorting strategies to isolate and characterize stem cells from head and neck cancer cell lines.

Five low-passage cell lines were subjected to cell sorting based on Hoechst side population, Aldefluor, and CD44 expression. Isolated cell populations were studied for gene expression, radiosensitivity, and chemosensitivity to cisplatin and paclitaxel.

Each sorting method identified a different set of genes associated with different gene ontology categories, with mitosis being the only common category. CD44-associated gene changes were almost exclusively associated with cell cycle and in particular mitosis. There were no significant differences in radiosensitivity or cisplatin sensitivity of stem or non-stem cells, but CD44-isolated stem cells were more resistant to paclitaxel.

This study suggested that CD44 may be the most promising cell-sorting strategy to isolate and investigate the impact of stem cells in head and neck squamous cell cancer (HNSCC).