/Yuan Shifang(袁時芳，Dept Vascul Endocr Surg，Xijing Hosp，4 th Mil Med Univ，Xi’an 710032)…∥Chin J Gen Surg.-2011，26(8).-677 ～682

ObjectiveTo construct a recombinant bacillus Calmette-Guérin(BCG)vaccines based on different tandem repeats of MUC1 and GM-CSF，rBCG-MVNTR1/4/8-CSF，and to observe the ability of three recombinant BCG vaccines in the inhibition of breast cancer.MethodsAfter MUC1 variable-number tandem repeats(MVNTR1/4/8)were cloned in a stepwise manner，the E.coli-Mycobacteria shuttle expression vector pDE22-MVNTR1/4/8-CSF were constructed by fusing MVNTR1/4/8 and GM-CSF，and then used to transform competent BCG by electroporation after identification by restriction endonuclease digestion analysis and DNA sequencing.A novel breast cancer vaccines，rBCG-MVNTR1/4/8-CSF was constructed.The expression of fused MVNTR1/4/8-CSF protiens was analyzed by SDS-PAGE and Western blot.The ability of rBCG vaccines inhibiting the growth of breast cancer was observed in hu-PBL-SCID mice.The specific T cell responses in mice were assessed by immunohistochemistry.ResultsThe expression of recombinant MVNTR1/4/8-CSF fusion proteins were detected by SDS-PAGE and Western Blot in rBCG-MVNTR1/4/8-CSF vaccines，respectively.Tumor incidence in mice prophylactic immunized with rBCG-MVNTR4-CSF(37.5%)or rBCG-MVNTR8-CSF(25%)significantly decreased compared with PBS and BCG-pDE22 control(100%)at 42 days after tumor implantation(P ＜0.05).MCF-7 tumor growth inhibition in rBCG-MVNTR4/8-CSF-immunized mice was more significant than that in controls(P ＜0.01).The inhibition effect of three rBCG vaccines on breast rumor growth appeared to rise with increase of numbers of the tandem repeats of MUC1.Survival rate was 75%of mice in the rBCG-MVNTR4-CSF-treated group and 87.5%of mice in the rBCG-MVNTR8-CSF-treated groups at 70 days after tumor implantation;however，survival rate was only 12.5%in control group(P ＜ 0.05).The CD4-positive and CD8-positive lymphocytes were detected only in rBCG-MVNTR4/8-CSF-immunized mice.ConclusionConclusions rBCGMVNTR4/8-CSF immunization inhibits breast cancer growth in mice.10 refs，5 figs.