title: Interleukin-17, produced by lymphocytes, promotes tumor growth and angiogenesis             in a mouse model of breast cancer.
abstract: Previous studies have suggested that interleukin-17 (IL-17), an inflammatory             cytokine expressed predominantly by Th17 cells, is highly expressed in tumor tissue             and may help tumors to evade immune surveillance. In this study, the significance             of IL-17 expression in the tumors of murine models of breast cancer was explored.             BALB/c mice were injected with MA782/5S28102 or 4T1 breast cancer cell lines to             establish breast tumors. The expression of IL-17 in tumor tissue was detected             by western blotting 1 and 4 weeks later, which revealed that it increased with             tumor progression (P<0.05). Additionally, tumor cells and tumor-infiltrating             lymphocytes were isolated from tumor tissues and cultured for 5 days with stimulation             by phorbol-12-myristate-13-acetate (PMA), anti‑CD3 antibody and anti-CD28 antibody.             Culture media from stimulated tumor cells or tumor-infiltrating lymphocytes were             harvested and their concentrations of IL-17 were tested by ELISA. Tumor cells             secreted low levels of IL-17 into the media; however, lymphocytes from tumor tissues             secreted high levels of IL-17, with 4T1 tumors secreting higher levels of IL-17             than MA782 tumors (P<0.05). To evaluate the effect of IL-17 on the proliferation             of tumor cells, 4T1 cells were cultured in the presence or absence of recombinant             IL-17 and cell numbers were counted on day 5 of culturing. Ectopic IL-17 did not             promote the proliferation of tumor cells in vitro. To further understand the effect             of IL-17 expression within tumors, 4T1 tumor-bearing mice were injected with recombinant             IL-17 or saline via the tail vein. Tumor size was measured up to 21 days following             the initial infusion of IL-17. IL-17 infusion resulted in an increased tumor volume             and microvascular density (as measured by the immunohistochemical detection of             CD34 expression in microvessels; P<0.05). Therefore, IL-17 expression within             tumor tissues appears to originate from tumor-infiltrating lymphocytes and is             likely to promote tumor growth by enhancing angiogenesis.
authors.affiliation: School of Medicine, Anhui University of Science and Technology, Huainan, Anhui 232001, PR China. djwdxswy@126.com
authors.forename: Jiu-Wei
authors.initials: JW
authors.lastname: Du
authors.forename: Ke-Yi
authors.initials: KY
authors.lastname: Xu
authors.forename: Li-Yi
authors.initials: LY
authors.lastname: Fang
authors.forename: Xin-Lan
authors.initials: XL
authors.lastname: Qi
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000494:pharmacology; D018952:Antigens, CD34 / Q000378:metabolism; D001943:Breast Neoplasms / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology; D018106:CD28 Antigens / Q000276:immunology; D017252:CD3 Complex / Q000276:immunology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004195:Disease Models, Animal; D005260:Female; D020381:Interleukin-17 / Q000235:genetics / Q000378:metabolism*; D016246:Lymphocytes, Tumor-Infiltrating / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D055806:Microvessels / Q000378:metabolism; D009389:Neovascularization, Pathologic; D010703:Phorbol Esters / Q000494:pharmacology; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology
chemical_list: D000911:Antibodies, Monoclonal; D018952:Antigens, CD34; D018106:CD28 Antigens; D017252:CD3 Complex; D020381:Interleukin-17; D010703:Phorbol Esters; D011994:Recombinant Proteins; C119222:phorbol-12-myristate