Oncolytic Sendai virus-induced tumor-specific immunoresponses suppress "simulated metastasis" of squamous cell carcinoma in an immunocompetent mouse model.

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.