Example 5
To determine whether cytotoxicity of OTS-412 was maintained despite the inhibition of OTS-412 virus replication by GCV, the cytotoxicity between the following groups was compared: groups treated with the wild type HSV1-TK-expressing vaccinia virus, alone or in combination with GCV, and groups treated with OTS-412, alone or in combination with GCV. Specifically, HCT-116 cancer cells were treated with 0.05 MOI (0.05 pfu/cell) of wild type HSV1-TK-expressing vaccinia virus or OTS-412, alone or in combination with GCV (50 μg). The resulting cells were cultured for 72 hours and analyzed for cytotoxicity using CCK8 (Cell Counting Kit 8).
As a result, the cytotoxicity of OTS-412 and GCV combined treatment was maintained at 95% or more of OTS-412 single treated group whereas the vaccinia virus expressing wild-type HSV1-TK showed almost no cytotoxicity (
