Efficacy of a third-generation oncolytic herpes simplex virus in neuroendocrine tumor xenograft models.

Background: Few chemotherapies are available for neuroendocrine tumors, especially for highly malignant neuroendocrine cancers. The third-generation oncolytic herpes simplex virus type 1 (HSV-1) T-01 selectively replicates in tumor cells and shows cytotoxicity against tumor cells without damaging surrounding normal tissues. We examined the antitumor effect of T-01 to explore novel treatments for patients with neuroendocrine tumors.
Methods: The cytotoxicity of T-01 was tested in two human and one murine neuroendocrine tumor cell lines in vitro . Mouse models with subcutaneously implanted human neuroendocrine tumor QGP1 cells were used to investigate T-01 efficacy in vivo .
Results: T-01 showed cytotoxicity against the three cell lines in vitro . In xenograft models, the growth of tumors derived from QGP1 cells was inhibited by T-01 compared with control group. Although weight loss of mice was observed with tumor growth in the control group, it was suppressed by T-01 administration. The antitumor effects of T-01 were dependent on virus concentration and frequency of administration.
Conclusions: T-01 effectively inhibits tumor cell proliferation in a poorly differentiated NEC mouse model. These results suggest that the third-generation oncolytic HSV-1 may serve as a novel treatment for patients with neuroendocrine tumors.
Competing Interests: CONFLICTS OF INTEREST All authors hereby declare that there is no potential or actual personal, financial, or political interest related to this study.