Objective: To investigate the activities of cytokine induced killer cells (CIK cells) and specific cytotoxic T lymphocytes (CTL) in killing CD55(high) subgroup in MCF-7 breast cancer cell line.
Methods: The killing effects of CIK cells, and specific CTLs in diminishing CD55(high) subgroup cells were analyzed and compared with those of three chemotherapy drugs. First, the MCF-7 breast cancer cells were treated with different concentrations of three chemotherapeutic drugs, docetaxel, epirubicin and fluorouracil. Then immune cells were isolated from human peripheral blood and were induced to become CIK cells. They were then used to treat CD55(high) and CD55(low) subpopulations in MCF-7 cells. Finally, lymphocytes were isolated from surgical specimens of human axially lymph nodes, and were induced to become tumor-specific CTL in vitro. Their activities in killing CD55(high) and CD55(low) subpopulations in MCF-7 cells were measured as well.
Results: The killing rates of docetaxel, epirubicin and fluorouracil on CD55(high) subgroup MCF-7 cells were much lower than on total MCF-7 cells. The killing rate of CIK cells on CD55(high) subgroup cells was(42.72 ± 4.36)%. The killing rates of specific CTLs on CD55(high), CD55(low), and total MCF-7 cells were(52.86 ± 4.45)%, (22.41 ± 2.83)%, and(21.67 ± 4.15)%, respectively.
Conclusion: Specific CTL possessed more effective killing effects on CD55(high) cells.