Inhibition of interleukin 8 attenuates angiogenesis in bronchogenic carcinoma.
ABSTRACT We investigated the role of interleukin 8 (IL-8) in mediating angiogenesis in human bronchogenic carcinoma. Increased quantities of IL-8 were detected in tumor tissue as compared with normal lung tissue. Immunohistochemical staining of tumors revealed primary localization of IL-8 to individual tumor cells and demonstrated the capacity of tumor to elaborate IL-8. Functional studies that used tissue homogenates of tumors demonstrated the induction of both in vitro endothelial cell chemotaxis and in vivo corneal neovascularization. It is important to note that the addition of neutralizing antisera to IL-8 to these assays resulted in the marked and specific attenuation of these responses. Our observations definitively establish IL-8 as a primary mediator of angiogenesis in bronchogenic carcinoma and offer a potential target for immunotherapies against solid malignancies.
Full-textDOI: · Available from: Marie Burdick, May 24, 2015
SourceAvailable from: Kuei-Yang Hsiao[Show abstract] [Hide abstract]
ABSTRACT: STUDY QUESTION How does hypoxia-mediated down-regulation of dual specificity phosphatase-2 (DUSP2) promote endometriotic lesion development?SUMMARY ANSWER Inhibition of DUSP2 by hypoxia enhances endometriotic lesion growth via promoting interleukin-8 (IL-8)-dependent angiogenesis.WHAT IS KNOWN ALREADY Angiogenesis is a prerequisite for the development of endometriosis. DUSP2 is down-regulated in endometriotic stromal cells in a hypoxia inducible factor-1α-dependent manner. Down-regulation of DUSP2 contributes to the pathological process of endometriosis.STUDY DESIGN, SIZE, DURATION A laboratory study recruiting 20 patients of reproductive age with endometriosis and normal menstrual cycles, and an autoimplant-induced mouse model of endometriosis using 13 mice in a 28-day treatment.PARTICIPANTS/MATERIALS, SETTING, METHODS IL-8 mRNA levels were assayed in endometrial stromal cells maintained in normoxic or hypoxic (1% O2) conditions, with or without DUSP2 knockdown. Promoter activity and chromatin immunoprecipitation (ChIP) assays were conducted to characterize the regulation of IL-8 by DUSP2. Conditioned media from cells maintained in normoxic or hypoxic conditions, and cells with/without DUSP2 knockdown were collected to investigate the angiogenic capacity using an in vitro tube formation assay. Reparixin, an IL-8 receptor blocker, was administered to investigate the role of IL-8 in hypoxia-mediated angiogenesis and the development of endometriotic-like lesions in an autotransplanted mouse model.MAIN RESULTS AND THE ROLE OF CHANCE IL-8 mRNA was increased by both hypoxia and DUSP2 knockdown in endometrial stromal cells in an extracellular signal-regulated protein kinase-dependent manner (P < 0.05 versus control). Promoter activity and ChIP assays demonstrated that expression of IL-8 was regulated by CCAAT/enhancer binding protein α (P < 0.05 versus control). Furthermore, conditioned media collected from hypoxia-exposed or DUSP2 knockdown endometrial stromal cells promoted tube formation, which was abolished by co-treatment with reparixin (P < 0.05 versus control). Results from the autotransplanted mouse model demonstrated that number of blood vessels and size of endometriotic-like lesions were markedly reduced in recipient mice treated with reparixin (P < 0.05 versus control).LIMITATIONS, REASONS FOR CAUTION This study was conducted in primary human cell cultures and a mouse model, therefore may not fully reflect the situation in vivo.WIDER IMPLICATIONS OF THE FINDINGS This is the ﬁrst study to highlight the potential application of an IL-8 receptor blocker as a therapeutic target to treat endometriosis. This study demonstrates IL-8 as a key angiogenic factor regulated by hypoxia/DUSP2, which suggests an alternative mechanism through which hypoxia may promote angiogenesis.STUDY FUNDING/COMPETING INTEREST(S) This study was funded by the National Science Council of Taiwan (NSC101-2314-B-006-043-MY2). The author declares that there is no conflict of interest.Human Reproduction 10/2014; 29(12). DOI:10.1093/humrep/deu255 · 4.59 Impact Factor
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ABSTRACT: Oesophageal adenocarcinoma (OA) incidence is rising and prognosis is poor. Understanding the molecular basis of this malignancy is key to finding new prevention and treatment strategies. Gastroesophageal reflux disease (GORD) is the primary cause of OA, usually managed with acid suppression therapy. However, this often does little to control carcinogenic bile acid reflux. The transcription factor nuclear factor kappa B (NF-κB) plays a key role in the pathogenesis of OA and its activity is associated with a poor response to chemotherapy, making it an attractive therapeutic target. We sought to decipher the role of different bile acids in NF-κB activation in oesophageal cell lines using short, physiologically relevant exposure times. The effect of an acidic or neutral extracellular pH was investigated concurrently, to mimic in vivo conditions associated with or without acid suppression. We found that some bile acids activated NF-κB to a greater extent when combined with acid, whereas others did so in its absence, at neutral pH. The precise composition of an individual's reflux, coupled with whether they are taking acid suppressants may therefore dictate the extent of NF-κB activation in the oesophagus, and hence the likelihood of histological progression and chemotherapy success. Regardless of pH, the kinase IKK was pivotal in mediating reflux induced NF-κB activation. Its importance was confirmed further as its increased activation was associated with histological progression in patient samples. We identified further kinases important in acid or bile induced NF-κB signaling in oesophageal cells, which may provide suitable targets for therapeutic intervention. © 2014 Wiley Periodicals, Inc.International Journal of Cancer 06/2014; 136(3). DOI:10.1002/ijc.29029 · 5.01 Impact Factor
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ABSTRACT: The CXC chemokines have recently been identified as a family of molecules which can regulate angiogenesis. Members of this family which contain the amino acid motif Glu–Leu–Arg in their amino terminus (ELR^+) act as angiogenic factors, while ELR^-members act as angiostatic molecules. The balance of these angiogenic versus angiostatic factors is critical in regulating homeostasis. As we detail in this review, there is increasing evidence from a variety of tumor model systems to suggest that the angiogenic members of this family and their receptors may be playing an important role in the neovascular pathology of solid tumors. In contrast, the angiostatic effects of the ELR- family members may provide novel therapeutic strategies for treating many tumors.Angiogenesis 01/1998; 2(2). DOI:10.1023/A:1009284305061 · 4.41 Impact Factor