Abstract: 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 gene- rated 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×l0⁵ MS⁺B16 cells. Compared with that of the negative control immunized with phosphate-buffered saline(PBS), a signi- ficant 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.

Key words: Survivin, MUC1 variable-number tandem repeat(MUC1 VNTR), Tumor antigen, Tumor model, Tumor vaccine