Objective: To investigate the effects and mechanism of cytokine-induced killer (CIK) cells in reversing multidrug resistance (MDR) and increasing intracellular concentration of adriamycin (ADR) in the K562/ADR cells.
Methods: Peripheral mononuclear cells (MNCs) were isolated from healthy donors and cultured with combined cytokines to generate CIK. The changes of cell phenotype and cytokines secretion of CIK were determined. K562/ADR cells were divided into three groups: ADR in combination CIK (group I), CIK alone (group II) and ADR alone (group III). The viability and proliferation of K562/ADR cells were assayed by MTT assay, the intracellular concentration of ADR and the expression of P-glycoproteins (P-gp) in K562/ADR cells by FCM.
Results: The cytotoxicity of ADR in group I was higher than that in group II (P < 0.05). The cytotoxicity was increased with the E/T ratio increasing (P < 0.05) but had no relation with the concentration of ADR in group I (P > 0.05). The expression of P-gp was declined in group I and group II (P > 0.05). The intracellular concentration of ADR in group I was higher than that in group II (P < 0.05), and had no relation with the ADR concentration (P > 0.05).
Conclusion: Pre-treatment with CIK can increase the cytotoxicity and the intracellular concentration of ADR and decrease the expression of P-gp in K562/ADR cells in the ADR and CIK combination group. Acute leukemia patients would be most likely to benefit from the combination of chemotherapy and CIK therapy.