Figure 1

OBP-301 synergistically enhances the cytotoxic effect of chemotherapeutic agents in human osteosarcoma cells.

(a) Four human osteosarcoma cell lines (SaOS-2, MNNG/HOS, HOS and 143B) were treated with cisplatin (CDDP) or doxorubicin (DOX) at the indicated doses for 24 hours. In combined chemotherapy, cells were treated with CDDP and DOX at the clinically used ratio (CDDP:DOX = 4:1) for 24 hours. Cells were infected with OBP-301 at the indicated MOIs for 3 days. Cell viability was quantified using the XTT assay. Cell viability was calculated relative to that of the mock-infected group, which was set at 1.0. Cell viability data are expressed as mean values ± SD (n = 5). (b) In combination therapy with chemotherapy and OBP-301, cells were infected with OBP-301 at the indicated MOIs. Two days after viral infection, cells were further treated with CDDP and DOX (CDDP:DOX = 4:1) for 24 hours. (c) The combination index was calculated with the CalcuSyn software (BioSoft, Inc.). Synergism and antagonism were defined as interaction indices of <1 or >1, respectively.