Preparation of tumor-specific CTLs and their therapeutic effects on bone marrow micrometastasis of breast cancer

Objective:To prepare auto-tumor-specific cytotoxicity T lymphocytes(CTLs) of breast cancer patients and to observe their therapeutic effects on bone marrow micrometastasis(BMM) of breast cancer.Methods: BMM in 82 patients with primary breast cancer(stage Ⅰto Ⅲ),who were treated in the Fourth Affiliated Hospital of Hebei Medical University from March to December in 2007(all the patients signed paper of informed consent),was exmined by flow cytometry using CK18 and CK19 as marker.Twenty-three patients with BMM were randomly divided into two groups: 17 patients were treated with tumor-specific CTLs(therapy group),and 6 patients were treated with IL-2(control group).Tumor-specific CTLs were induced in vitro from axillary lymph nodes and peripheral blood of breast cancer patients in therapy group,and were reinfused into the same patient 10-14 days after operation.The therapeutic effects of tumor-specific CTLs on BMM of breast cancer patients were observed.Results: Twenty-three cases(28.05%) in 82 breast cancer patients were BMM positive as detected by FCM.BMM positive rates increased with the increase of clinical TNM stages and histological grades of breast cancer,and decreased with the increase of ER and PR protein expression in cancer tissues.Dendritic cells(DCs) were successfully isolated and induced from the peripheral blood of breast cancer patients.Tumor-specific CTLs were induced by co-culturing lymphocytes from axillarey lymph nodes with auto-tumor antigen-impulsed DCs.Fourteen cases in the therapy group became negative of BMM after treatment with tumor-specific CTLs(14/19,82.35%).Only one case in the control group became negative of BMM after treatment with IL-2(1/6,16.67%,P=0.00028).Conclusion: Tumor-specific CTLs have been successfully prepared and they show a satisfactory therapeutic effect on bone marrow micrometastasis of breast cancer.