Oncolytic Sendai virus‐induced tumor‐specific immunoresponses suppress “simulated metastasis” of squamous cell carcinoma in an immunocompetent mouse model

Abstract Background The objectives of this study were to demonstrate anti‐metastatic effect of BioKnife, uPA activity‐dependent oncolytic Sendai virus, after BioKnife treatment for primary tumor, and analyze its mechanisms in a simulated metastasis mouse model of head and neck squamous cell carcinoma (HNSCC). Methods We established a simulated metastasis mouse model using a murine HNSCC cell line “SCCVII.” We assessed a tumor size and an induction of tumor‐specific immunoresponses using cytotoxic T‐lymphocyte (CTL) assay, flow cytometry (FCM) in spleen and immunohistochemistry (IHC) in secondary tumor. Results Secondary tumors were significantly smaller in BioKnife‐treated group. CTL activities were significantly improved in BioKnife group. FCM revealed that induction of dendritic cells and CD4 + /CD8 + lymphocytes was significantly higher in BioKnife group. IHC showed that CD8 + lymphocytes invaded secondary tumor. Conclusion Tumor‐specific immunoresponses induced by BioKnife has great potential to be a novel, safe, and less invasive option for control and prevention of metastasis.