[Show abstract][Hide abstract] ABSTRACT: IL-17F does not affect cell apoptosis, cell cycle and cell growth in vitro. FACS analysis of IL-17F-transfected, mock-transfected and wild-type HCT116 cells cultured in 10%FBS medium (A) or 0.1%FBS medium (B). (C) MTT analysis of IL-17F-transfected, mock-transfected and wild-type HCT116 cells.
[Show abstract][Hide abstract] ABSTRACT: Interleukin-17F (IL-17F), produced by Th17 cells and other immune cells, is a member of IL-17 cytokine family with highest homology to IL-17A. IL-17F has been shown to have multiple functions in inflammatory responses. While IL-17A plays important roles in cancer development, the function of IL-17F in tumorigenesis has not yet been elucidated. In the current study, we found that IL-17F is expressed in normal human colonic epithelial cells, but this expression is greatly decreased in colon cancer tissues. To examine the roles of IL-17F in colon cancer, we have used IL-17F over-expressing colon cancer cell lines and IL-17F-deficient mice. Our data showed decreased tumor growth of IL-17F-transfected HCT116 cells comparing to mock transfectants when transplanted in nude mice. Conversely, there were increased colonic tumor numbers and tumor areas in Il-17f(-/-) mice than those from wild-type controls after colon cancer induction. These results indicate that IL-17F plays an inhibitory role in colon tumorigenesis in vivo. In IL-17F over-expressing tumors, there was no significant change in leukocyte infiltration; instead, we found decreased VEGF levels and CD31(+) cells. While the VEGF levels were increased in the colon tissues of Il-17f(-/-) mice with colon cancer. Together, our findings demonstrate a protective role for IL-17F in colon cancer development, possibly via inhibiting tumor angiogenesis.
[Show abstract][Hide abstract] ABSTRACT: IL-17F does not change immune cell subsets in vivo. (A) FACS analysis of CD11b, Gr-1, and CD49b in transplanted tumors of IL-17F- and mock-transfected HCT116 cells. (B) IFNγ+CD4+, IFNγ+CD8+ and NK1.1+ cell frequencies in mesenteric lymph node cells from AOM-DSS treated WT, Il-17a−/− and Il-17f−/− mice.
[Show abstract][Hide abstract] ABSTRACT: IL-17F does not influence cell growth and cell cycle of HUVEC cells in vitro. (A) Elisa analysis of VEGF levels in supernatants of IL-17F-transfected, mock-transfected and wild-type HCT116 cells. MTT analysis (B) and FACS analysis (C) of HUVEC cells cultured in conditioned medium (from IL-17F-transfected, mock-transfected or wild-type HCT116 cells) or normal medium.