Reduced tumor invasiveness and angiogenesis was observed in Matrigel plugs in mice deficient in IL-1 expression, as compared to control mice. In contrast, mice deficient in IL-1Ra, where there is overexpression of IL-1, show the most intensive angiogenic response. CD34-positive hemopoietic

stem cells were the earliest and most abundant infiltrating population; in control mice, their levels in Matrigel plugs were higher than in mice deficient in IL-1 expression. CD34-positive cells are probably key players in tumor-mediated angiogenesis in this model. Reconstitution of the bone marrow of IL-1 deficient mice by cells from control mice leads to an increased number of CD34-positive cells, as well as increased tumor invasiveness and angiogenesis, comparable to control mice. We found that several populations of CD34-positive cells invaded the Matrigel after injection of melanoma cells RAD001 molecular weight to different KO mice. Both IL-1α Napabucasin mw and IL-1β are probably involved in the induction of CD11b+,

CD34+ and VEGFR1+ cells, designated as hematopoietic precursor cells, whereas IL-1β is mostly involved in CD34+, VEGFR2+, CD31- cells, known as endothelial precursor cells. It was found that both cell types can produce VEGF and thus promote tumor induced angiogenesis. At the same time, only inhibition of IL-1β reduces the angiogenic response induced by injection of B16 melanoma cells in control mice. Thus, inhibition of IL-1β at early stages of tumor development may prove to be effective Dynein for use in anti-tumor therapy. O163 VEGF-A165A and IL-6 in Human Colon Cancer: A Microenvironment Cooperation

Leading to Cell Death Escape through microRNAS Dysregulation Sabina Pucci 1 , Paola Mazzarelli1, Maria J. Zonetti1, Luigi G. Spagnoli1 1 Department of Biopathology, University of Rome Tor Vergata, Rome, Italy Cooperation through the sharing of diffusible factors of tumor microenvinoment and the redirection of some specific guardian pathways raises new questions about tumorigenesis and has implication on designing new therapeutic approaches.Tissue microenvironment strongly influences tumorigenesis and neovascularization, redirecting some pathways versus a persisting pro-survival state. Recent studies suggest a potential role of IL-6-sIL6R in the pathogenesis of colon cancer, although data on the possible relationship between IL-6 production and tumour progression are still conflicting. Increased formation of IL-6-sIL-6R complexes that interact with gp130 on the cell membrane leads to increased expression and nuclear translocation of STAT3, which can cause the induction of anti-apoptotic genes, such Bcl-xL. Moreover, as it has been observed in critical conditions (hypoxia,oxidative stress), STAT 3 activation influences the preferential expression of VEGF-A165a, leading to the inhibition of programmed cell death inducing Bcl-2.