NSP4 as adjuvant for immunogenicity and design of effective therapeutic HPV16 E6/E7/L1 DNA vaccine in tumor-bearing and healthy C57BL/6 mice.

INTRODUCTION: In humans, approximately 5% of all cancers are attributable to HPV infection. Prophylactic vaccines can inhibit viral migration and persistence. However, further studies are still required to develop such treatments. To achieve this goal, we designed a therapeutic HPV DNA vaccine encoding a construct of E6/E7/L1 and used NSP4 antigen as an adjuvant to assess the efficiency of this construct in generating antigen-specific antitumor immune responses. MATERIALS AND METHODS: Sixty female C57BL/6 mice (6-8 weeks old) were purchased from the Institute Pasteur of Iran. Through a subcutaneous (s.c) injection of a suspension of 100 µl PBS containing 106 TC-1 cells/mouse in the back side, 30 of them became cancerous, while 30 of them were healthy control mice. To amplify E6/E7/L1-pcDNA3 and NSP4-pcDNA3, the competent cells of DH5α and to generate a tumor, TC-1 cell line was used. Mice were then immunized with the HPV DNA vaccine. Cell proliferation was assessed by MTT assay. Finally, cytokine responses (IL-4, IL-12, IFN- γ) were measured in the supernatant of mice spleen cells. RESULT: Mice receiving the NSP4/E6-E7-L1 vaccine had the highest stimulatory index compared to other groups, although it was not statistically significant. Interleukin 4/12 and IFN-γ production were significantly higher in E6-E7-L1 / NSP4 group and E6-E7-L1 group compared to other groups (P < 0.05). Among different groups, E6/E7/L1 + NSP4 group was able to slow down the tumor growth process, but it was not significant (p > 0.05). Among the aforementioned cytokines, IFN-γ and IL-12 are among the cytokines that stimulate the Th1 pathway and IL-4 cytokine stimulates the Th2 pathway and B lymphocytes. CONCLUSION: Our data revealed that the present vaccine can reduce tumor size, and cytokine measurement showed that it stimulates innate and acquired immune responses, thus it can be a therapeutic vaccine in the tumor-bearing mice model.

Live-attenuated poliovirus-induced extrinsic apoptosis through Caspase 8 within breast cancer cell lines expressing CD155.

INTRODUCTION: Breast cancer is one of the most common cancers among women in the world. Different therapeutic strategies such as radiotherapy, chemotherapy and surgery have been used either individually or in combination. Oncolytic virotherapy is a rising treatment methodology, which utilizes replicating viruses to eliminate tumor cells. The aim of this study was to investigate the oncolytic activity of live-attenuated poliovirus in breast cancer cell lines. MATERIALS AND METHODS: The CD155 expression level in two human breast cancer cell lines and a normal breast cell line were evaluated using real-time PCR and flow cytometry. Virus titration was assessed by TCID50. The cytotoxicity of poliovirus on cell line and apoptosis response was investigated by MTT and Caspase 8 and Caspase 9 ELISA kits, respectively. RESULTS: This study showed that CD155 gene was expressed significantly (p = 0.001) higher in both human breast cancer cell lines compared to the normal cell line. The protein expression level of CD155 was 98.1%, 96.7%, in MDA_MB231 and MCF_7 cell lines, respectively, whereas the CD155 expression level was 1.3% in MCF_10A. The cytopathic effect of poliovirus in breast cancer cell lines was significantly higher than normal cells (p < 0.05). Extrinsic apoptosis response was more effective than intrinsic apoptosis in both breast cancer cell lines (p < 0.05). CONCLUSION: In summary, administration of live-attenuated poliovirus can be a promising treatment to breast cancer. However, in vitro and in vivo studies will be required to evaluate the safety of this strategy.