Anti-cancer efficacy of combined vaccine-strain measles and mumps viruses against colorectal cancer: an experimental study.

OBJECTIVES: This study aimed to evaluate the oncolytic efficacy of a combination of vaccine-strain measles virus (MeV) and mumps virus (MuV) against colorectal cancer (CRC) cells in vitro and in a nude mouse xenograft model. MATERIALS AND METHODS: HT-29 cells were cultured in Dulbecco's Modified Eagle Medium (DMEM) and infected with MeV, MuV, or a combination of MeV and MuV (MM; MeV: MuV = 1:1, v/v). Cell viability, synergistic effects, and apoptosis were assessed using MTT and flow cytometry assays, respectively, in vitro. A nude mouse xenograft model was established to evaluate the in vivo oncolytic efficacy of the MM against CRC xenograft tumors. RESULTS: The MM demonstrated synergistic effects at 48, 72, and 96 h (CI = 0.473, 0.692, and 0.633, respectively). The MM-treated group showed significantly lower cell viability (p < 0.05) and a markedly higher apoptotic rate (p < 0.01) compared with single-virus-infected groups in vitro. In the xenograft model, the MM-treated group exhibited significantly slower tumor growth (p ≤ 0.001), significantly prolonged survival (p < 0.05), reduced mortality, and increased proportions of innate immune cell populations in the spleen compared with single-virus-treated groups. CONCLUSIONS: The MM demonstrated synergistic and superior oncolytic efficacy against HT-29 colorectal cancer cells compared with single-virus therapies in both in vitro and in vivo xenograft models.