Establishment of a Tumor-bearing Mouse Model Stably Expressing Human Tumor Antigens Survivin and MUC1 VNTRs

摘要

The eukaryotic vectors VR1012 expressing survivin or 33 tandem repeats of human mucin 1(MUC1)(VNTRs),namely,VR1012-S and VR1012-VNTR(VNTR=variable number of tandem repeat),were constructed by cloning survivin and VNTR genes into VR1012,respectively.The eukaryotic vector pEGFP expressing survivin and MUC1 VNTRs fusion gene pEGFP-MS was also constructed.Mouse melanoma cell line(B16)stably expressing survivin and MUC1 VNTRs(MS+B16)was established by Lipofectamine-mediated transfection of pEGFP-MS into B16 cells.EGFP expression in MS+B16 cells was observed using a fluorescent microscope and survivin and MUC1 VNTRs(MS)expression was confirmed by means of Western blot analysis.A syngenic graft tumor model was generated by subcutaneous injection of MS+B16 cells into C57/BL6 mice and tumor size increased rapidly with time in a cell number dependent manner.After the third immunization,mice were challenged subcutaneously with 5×105 MS+B16 cells.Compared with that of the negative control immunized with phosphate-buffered saline(PBS),a significant reduction of tumor growth was observed in groups immunized with survivin plasmid DNA and MUC1 VNTRs plasmid DNA.Thus,the suppression of subcutaneous tumor was antigen-specific.This model is useful for the development of tumor vaccines targeting survivin and MUCI VNTRs.