title: A matrix metalloproteinase inhibitor enhances anti-cytotoxic T lymphocyte antigen-4 antibody immunotherapy in breast cancer by reprogramming the tumor microenvironment.
abstract: Anti-cytotoxic T lymphocyte antigen-4 (CTLA-4) treatment is effective for the treatment of primary tumors, but not sufficient for the treatment of metastatic tumors, likely owing to the effects of the tumor microenvironment. In this study, we aimed to determine the therapeutic effects of combined treatment with a matrix metalloproteinase (MMP) inhibitor (MMPI) and anti-CTLA-4 antibody in a breast cancer model in mice. Interestingly, combined treatment with MMPI and anti-CTLA-4 antibody delayed tumor growth and reduced lung and liver metastases compared with anti-CTLA-4 alone or vehicle treatment. The functions of the liver and kidney in mice in the different groups did not differ significantly compared with that in normal mice. The CD8+/CD4+ ratio in T cells in the spleen and tumor were increased after monotherapy or combined anti-CTLA-4 antibody plus MMPI therapy compared with that in vehicle-treated mice. Anti-CTLA-4 antibody plus MMPI therapy reduced the percentage of regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) and decreased the Treg/Th17 cell ratio in the spleen compared with those in the vehicle-treated group. Additionally, anti-CTLA-4 antibody plus MMPI therapy reduced the percentages of regulatory T cells (Tregs), myeloid-derived suppressor cells (MDSCs), and Th17 cells in tumors compared with that in the vehicle-treated group. Moreover, combined treatment with MMPI and anti-CTLA-4 antibody reduced the microvessel density (MVD) in tumors compared with that in vehicle or MMPI-treated mice. There was a negative correlation between MVD and the CD8+ T cell percentage, CD4+ T cell percentage, and CD8+/CD4+ T cell ratio, but a positive correlation with Tregs, Th17 cells, Treg/Th17 cell ratio, and MDSCs. Thus, these data demonstrated that addition of MMPI enhanced the effects of anti-CTLA-4 antibody treatment in a mouse model of breast cancer by delaying tumor growth and reducing metastases.
authors.affiliation: The Key Laboratory of Pathobiology, Ministry of Education, The College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China.
authors.forename: Mingyue
authors.initials: M
authors.lastname: Li
authors.affiliation: The Key Laboratory of Pathobiology, Ministry of Education, The College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China.
authors.forename: Shugang
authors.initials: S
authors.lastname: Xing
authors.affiliation: The Key Laboratory of Pathobiology, Ministry of Education, The College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China.
authors.forename: Haiying
authors.initials: H
authors.lastname: Zhang
authors.affiliation: The Key Laboratory of Pathobiology, Ministry of Education, The College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China.
authors.forename: Siqi
authors.initials: S
authors.lastname: Shang
authors.affiliation: The Key Laboratory of Pathobiology, Ministry of Education, The College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China.
authors.forename: Xiangxiang
authors.initials: X
authors.lastname: Li
authors.affiliation: The Key Laboratory of Pathobiology, Ministry of Education, The College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China.
authors.forename: Bo
authors.initials: B
authors.lastname: Ren
authors.affiliation: The Key Laboratory of Pathobiology, Ministry of Education, The College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China.
authors.forename: Gaiyun
authors.initials: G
authors.lastname: Li
authors.affiliation: The Key Laboratory of Pathobiology, Ministry of Education, The College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China.
authors.forename: Xiaona
authors.initials: X
authors.lastname: Chang
authors.affiliation: The Key Laboratory of Pathobiology, Ministry of Education, The College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China.
authors.forename: Yilei
authors.initials: Y
authors.lastname: Li
authors.affiliation: The Key Laboratory of Pathobiology, Ministry of Education, The College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
mesh_terms: D000818:Animals; D000906:Antibodies / Q000008:administration & dosage; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes; D060908:CTLA-4 Antigen / Q000276:immunology / Q000627:therapeutic use*; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D007167:Immunotherapy; D061965:Matrix Metalloproteinase Inhibitors / Q000008:administration & dosage*; D051379:Mice; D009362:Neoplasm Metastasis; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D058504:Th17 Cells / Q000276:immunology / Q000473:pathology; D059016:Tumor Microenvironment / Q000276:immunology*
chemical_list: D000906:Antibodies; D060908:CTLA-4 Antigen; D061965:Matrix Metalloproteinase Inhibitors