Regulation of IL-8 Expression in IL-1beta-stimulated Prostate Cancer Cells by Glucosamine

• Main Authors: Cheng-Yen Tsai, 蔡政諺
• Other Authors: Yuh-Lin Wu
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/18160960141065892198

碩士 === 國立陽明大學 === 生理學研究所 === 96 === Inflammation is a complex event in response to pathogenic stimuli in various tissues and it involves numerous cytokine production, which is critical to the host immune functions. Cytokines are often secreted by immune cells to recruit more function-related cells to further enhance the host defense to the pathogens. Besides, inflammation also has been demonstrated to be related to cancer procession. For example, inflammation state is related to prostate cancer initiation and progression, and indeed elevation of several cytokines, such as IL-1b, IL-6, IL-8, and IL-10 was noted in prostate cancer. Among them, IL-8 was shown to be highly expressed in prostate cancer cells and it was able to induce prostate cancer cell proliferation and migration in vitro. However, it was not clear whether IL-1b would regulate IL-8 expression. In the other hand, glucosamine, an amino-monosaccharide, was reported to act as an anti-inflammatory player to inhibit IL-1b-induced inflammation and production of cytokines. Therefore, we hypothesized that IL-1b can induce IL-8 expression in prostate cancer cells to promote prostate cancer cell proliferation and/or migration and glucosamine would blunt such effects. Three prostate cancer cell lines (PC-3, DU-145, and LNCaP) were used in this project to evaluate the effects of IL-1b and glucosamine on IL-8 expression by ELISA and RT-PCR analysis. Meanwhile, MTT and alamarBlue assay were adopted to determine whether glucosamine would affect prostate cancer cell proliferation. In addition, cell migration using wound-healing model and co-culture transwell migration were also utilized to examine the effects of IL-8 and glucosamine in prostate cancer cell migration. To delineate how glucosamine regulates IL-1beta-mediated IL-8 expression, MAP kinase and NFkB inhibitors were used to identify the downstream signaling pathways in IL-1b-mediated IL-8 expression. Surprisingly, MAPK pathways but not NFkB pathway are involved in IL-1b-induced IL-8 production. We also observed that glucosamine could downregulate IL-1b-induced ERK phosphorylation. Putting together, in prostate cancer cells, IL-1b can induce IL-8 expression via MAPK pathways to regulate cell proliferation and/or migration. Glucosamine appears to inhibit IL-1b-mediated MAP kinase phosphorylation to reduce IL-8 expression, and therefore to retard prostate cancer cell proliferation and migration.