Cetuximab enhances radiosensitivity by inhibiting the radiation-induced ERS chaperone GRP78.

<p>(A) Western blot results showed that irradiation (5 Gy) induced the activation of GRP78 in oropharyngeal carcinoma cells in a time-dependent manner. (B) Western blot results showed that silencing GRP78 inhibited the expression of GRP78 protein in oropharyngeal carcinoma cells. (C) Silencing GRP78 reduced the colony formation rate of oropharyngeal carcinoma cells. Additionally, radiation parameters were fitted to a classic multitarget single hit model as shown in the table. For (A) and (B), bands were quantified using ImageJ software and were normalized to a loading control. Fold changes are shown compared with the control lane. N/A = not applicable.