The effect of stress on efficacy of dendritic cell therapy for esophageal squamous cell carcinoma.

69 Background: Recently, abscopal effect, by which systemic anti-tumor effect by local radiation therapy (RT) was elicited, has been reported. This phenomenon was thought to be mediated by stress protein gp96, a key molecule in antigen-presenting. We tested the enhancement of dendritic cell (DC) therapy by various stress, such as radiation or modulated electro-hyperthermia (mEHT) in DC therapy for squamous cell carcinoma (SCC). Methods: Mouse SCC cells, SCCVII, were inoculated into the left femur (primary tumor) of C3H/He mice subcutaneously, and also similarly inoculated into non-treated chest subcutaneous tissue (secondary tumor). Only the primary tumor was exposed to 4 or 10 Gy of RT or 5-10 watts of mEHT. Then DCs was injected only into the primary tumor. Following that, tumor volumes of the primary and secondary tumor were measured. Next, the population of immune-related T-cells in tumor-draining lymph nodes (TDLN) and gp96 expression in the primary tumor were evaluated. Results: With intratumoral in...