The Anti-tumor Study Of Dentritic Cells Vaccine Targeting On Breast Cancer Stem Cells

Objectives: We established a method to enrich the breast cancer stem cells via in serum-free medium and identified its biological characteristics.Then we studied the specific immunoresponse effect of DCs in vitro,which modified by breast cancer stem cells mRNA.Methods:The human breast cancer MCF-7 were cultured in adherent and suspension culture methods .The expression of CD44~+/CD24~- was measured by flow cytometry. We observed their growing character in RPMI-1640 medium , capability of clone in soft agar and the ability of tumorigenisis of two kind cells which were injected into NOD/SCID mice. Getting mRNA from human breast cancer cells of MCF-7 by amplification and transcription in vitro, and then transfecting MCF-7 mRNA into DCs by lipofectamine. Co-culturing DCs test surface markers on DCs on flow cytometry .The ability of DCs inducing the anti-tumor immunoresponse was analysised by measuring the exosomatic specific cytolytic againstMCF-7tumor cells by MTT in vitro.Results:We successfully cultured mammospheres which enriched the stem cell phenotype of CD44~+/CD24_in serum-free medium;the expression of CD44~+/CD24_ in suspension culture was 90.16%,while in adherent culture the expression was only 10.19%. The growth curve displayed that suspension cells has the stronger proliferative capacity than the adherent cells and the suspension cells showed stronger ability of forming clonies in soft agar assay comparing with the adherent cells ; the tumor-initiating capability experiments in NOD/SCID displayed that we had to inject at least 106 adherent cells to form tumors while only 103 suspension cells can attain the same results. We successfully cultured DCs; isolated and amplified the mRNA of breast cancer stem cells ; The specific cytolytic in vitro of T lymphocyte induced by breast cancer stem cells- mRNA -DCs were significantly raised compared with control group (P<0.01). Conclusions: 1. The mammosphere had the properties of cancer stem-like cells, which possessed the ability of self-renewal.Furthermore, they had stronger ability of proliferation,forming clonies and tumorigenic in xenotransplantation.2. The effective and broad application of DCs which was limited by tumor tissue for antigen preparation could be solved by this study. And it could be offer a new strategy to tumor immunotherapy to eradicate the cancer .In this case , we could improve the long-time survival and life quality of the patients but also got the specific antigen target on the cancer stem cells to provide a new treatment for a fundamental treatment.