The anticancer effect of
curcumin has been widely reported. However, whether
curcumin can enhance the radiosensitivity of human
oral squamous cell carcinoma (OSCC) remains to be elucidated. The aim of the present study was to evaluate the efficacy of
curcumin combined with radiation against OSCC. SAS cells were transfected with the
luciferase gene (luc) and named SAS/luc. NF-κB/
DNA binding activity, the surviving fraction and NF-κB-regulated effector
protein expression were determined by electrophoretic mobility shift assay, clonogenic survival assay and western blotting, respectively. The therapeutic efficacy was evaluated in SAS/luc
tumor-bearing mice by caliper measurement and bioluminescence imaging.
Curcumin enhanced SAS/luc radiosensitivity through the inhibition of radiation-induced NF-κB activity and expression of effector
proteins both in vitro and in vivo. With 4 Gy or greater radiation doses, synergistic effects of
curcumin were observed. The combination group (
curcumin plus radiation) had significantly better
tumor control compared with that of
curcumin or radiation alone. No significant
body weight change of mice was found throughout the entire study. In conclusion,
curcumin is a radiosensitizer against OSCC with negligible toxicity.