Enhancement of the radiation effects by d-allose in head and neck cancer cells

The aim of this study was to investigate the radiosensitizing potential of d-allose in human head and neck cancer cells. HSC-3 cells were treated with or without d-allose for 6 h and then irradiated (2–6 Gy). The combination of d-allose and radiation was more effective than either agent alone. The radiation enhancement ratios at the 37% survival level were 1.61 and 2.11 for 10 mM and 25 mM d-allose treatment, respectively. The combination of d-allose and radiation also reduced the cell proliferation in 3D culture experiments. Although the mRNA expression of TXNIP was not increased by radiation alone, combined use with d-allose markedly elevated TXNIP expression. The combination of d-allose and radiation significantly induced intracellular reactive oxygen species (ROS) and apoptosis compared to that induced by either agent alone. This study shows that d-allose enhances the effect of radiation, suggesting a potential clinical application of combination treatment with d-allose and radiation for head and neck cancer.