Effect Of IL-8 On Malignant Phenotype Of Tumor In Microenvironment Of Ovarian Tumors And Its Mechanism

Objectives In this study, we detected IL-8expression in ovarian tumor microenvironment; we used three-dimensional Cell Culture and in vivo experiment to detect whether treatment of IL-8could promote tumor growth and malignant phenotype; we further studied the possible mechanism involved in IL-8play important part in tumor microenvironment.Methods1. Immunohistochemical staining was used to detect IL-8expression in the mesenchymal of ovarian tumor tissue; ELISA was used to detect IL-8expression in NOF and CAOF, RT-PCR was used to detect expression of IL-8receptors CXCR1/CXCR2.2. β-Galactosidase was used to detect cell senescence of normal ovarian fibroblast after treatment of IL-8. Western blot was used to analyze the probable mechanism and the detailed signal pathway.3. Three-dimensional Cell Culture was divided to five groups according to different medium:Blank control, IL-8treatment, CAOFcm (condition medium), CAFcm+IgGIL-8and Senescence cm, in order to detect colony spherite number and size, and invasive ability.4. We established an orthotopic xenograft tumor model in BALB/c nude mice using the HEY and SKOV3cell lines. Every cell line (eg. HEY) was divided into6groups: HEY alone, HEY+NOF, HEY+NOF (after IL-8treatment), HEY+NOF (after CAOFcm treatment), HEY+NOF (after CAOFcm+IL-8antibody treatment) and HEY+CAOF, in order to detect tumor growth curve.Results1. IL-8expression is much more in ovarian tumor mesenchymal tissue than in normal mesenchymal tissue. Conditional medium of ovarian tumor-associated fibroblast contained more IL-8expression than normal fibroblast. And IL-8receptor CXCR1/CXCR2in ovarian tumor-associated fibroblast is also over-expressed.2. After treatment of IL-8in normal ovarian fibroblast, we can detect obvious senescence. There are many signal pathway involving in the role of IL-8in tumor environment, mainly through PI3K/AKT pathway, and increasing levels of vascular endothelial growth factor.3. In three-dimensional heterotypic culture models also demonstrate senescent fibroblasts enhance epithelial proliferation and invasion, as shown in below.4. HEY or SKOV3cells at the same time mixed with NOFs which were treated with different conditioned mediums were injected to mice. The NOF+IL-8group and NOF/IL-8group promote tumor growth compared with the NOF group and the group only containingHEY or SKOV3cells. CAFcm group could obviously facilitate tumor growth and the function can be inhibited by anti-IL-8 antibody in some extents.Conclusions Our results provide strong evidence that IL-8is rich in in ovarian tumor microenvironment and IL-8induces ovarian stroma fibroblast senescence, and then promote tumor growth and invasion inthis process different signal pathway are involved in.