Cisplatin pretreatment enhances anti-tumor activity of cytokine-induced killer cells

AIM:To investigate whether cisplatin (DDP) enhances the anti-tumor activity of cytokine-induced killer (CIK) cells in a murine colon adenocarcinoma model.METHODS:Tumor size and weight served as indicators of therapeutic response.Immunohistochemistry was performed to observe intratumoral lymphocyte infiltration and tumor microvessel density.Changes in the percentage of regulatory T (Treg) cells within the spleens of tumor-bearing mice preconditioned with DDP were monitored using flow cytometry.RESULTS:A marked T cell-dependent,synergistic antitumor effect of the combined therapy was observed (1968 ± 491 mm 3 vs 3872 ± 216 mm 3 ;P=0.003).Preconditioning chemotherapy with DDP augmented the infiltration of CD3+ T lymphocytes into the tumor mass and reduced the percentage of both intratumoral and splenic Treg cells.CONCLUSION:Preconditioning with DDP markedly enhances the efficacy of adoptively transferred CIK cells,providing a potential clinical modality for the treatment of patients with colorectal cancer.