Identification of Potential Therapeutic Targets Among CXC Chemokines in Breast Tumor Microenvironment Using Integrative Bioinformatics Analysis.

BACKGROUND/AIMS: Breast cancer is a common cause of cancer mortality throughout the world. The cross-talk between cancer cells and interstitial cells exerts significant effects on neoplasia and tumor development and is modulated in part by chemokines. CXC is one of four chemokine families involved in mediating survival, angiogenesis, and immunosensitization by chemoattracting leukocytes, and it incentivizes tumor cell growth, invasion and metastasis in the tumor microenvironment. However, the differential expression profiles and prognostic values of these chemokines remains to be elucidated. METHODS: In this study, we compared transcriptional CXC chemokines and survival data of patients with breast carcinoma (BC) using the ONCOMINE dataset, Kaplan-Meier Plotter, TCGA and cBioPortal. RESULTS: We discovered increased mRNA levels for CXCL8/10/11/16/17, whereas mRNA expression of CXCL1/2/3/4/5/6/7/12/14 was lower in BC patients compared to non-tumor tissues. Kaplan-Meier plots revealed that high mRNA levels of CXCL1/2/3/4/5/6/7/12/14 correlate with relapse-free survival (RFS) in all types of BC patients. Conversely, high CXCL8/10/11 predicted worse RFS in BC patients. Significantly, high transcription levels of CXCL9/12/13/14 conferred an overall survival (OS) advantage in BC patients, while high levels of CXCL8 demonstrated shorter OS in all BC sufferers. CONCLUSIONS: Integrative bioinformatics analysis suggests that CXCL8/12/14 are potential suitable targets for precision therapy in BC patients compared to other CXC chemokines.

Pro-inflammatory properties of stromal cell-derived factor-1 (CXCL12) in collagen-induced arthritis.

CXCL12 (stromal cell-derived factor 1) is a unique biological ligand for the chemokine receptor CXCR4. We previously reported that treatment with a specific CXCR4 antagonist, AMD3100, exerts a beneficial effect on the development of collagen-induced arthritis (CIA) in the highly susceptible IFN-gamma receptor-deficient (IFN-gammaR KO) mouse. We concluded that CXCL12 plays a central role in the pathogenesis of CIA in IFN-gammaR KO mice by promoting delayed type hypersensitivity against the auto-antigen and by interfering with chemotaxis of CXCR4+ cells to the inflamed joints. Here, we investigated whether AMD3100 can likewise inhibit CIA in wild-type mice and analysed the underlying mechanism. Parenteral treatment with the drug at the time of onset of arthritis reduced disease incidence and modestly inhibited severity in affected mice. This beneficial effect was associated with reduced serum concentrations of IL-6. AMD3100 did not affect anti-collagen type II antibodies and, in contrast with its action in IFN-gammaR KO mice, did not inhibit the delayed type hypersensitivity response against collagen type II, suggesting that the beneficial effect cannot be explained by inhibition of humoral or cellular autoimmune responses. AMD3100 inhibited the in vitro chemotactic effect of CXCL12 on splenocytes, as well as in vivo leukocyte infiltration in CXCL12-containing subcutaneous air pouches. We also demonstrate that, in addition to its effect on cell infiltration, CXCL12 potentiates receptor activator of NF-kappaB ligand-induced osteoclast differentiation from splenocytes and increases the calcium phosphate-resorbing capacity of these osteoclasts, both processes being potently counteracted by AMD3100. Our observations indicate that CXCL12 acts as a pro-inflammatory factor in the pathogenesis of autoimmune arthritis by attracting inflammatory cells to joints and by stimulating the differentiation and activation of osteoclasts.

Topical antisense oligonucleotide therapy against LIX, an enterocyte-expressed CXC chemokine, reduces murine colitis.

Epithelial neutrophil-activating peptide-78 (ENA-78), a member of the CXC chemokine subfamily, is induced by inflammatory cytokines in human colonic enterocyte cell lines and increased in the colon of patients with inflammatory bowel disease (IBD). Lipopolysaccharide-induced CXC-chemokine (LIX) was recently identified as the murine homolog of ENA-78. Here we show that, similar to ENA-78, inflammatory cytokine stimulation of a murine colonic epithelial cell line, MODE-K, results in increased LIX expression. Consistent with the expression pattern of ENA-78 in IBD, LIX expression is significantly increased in mice with colitis induced by the ingestion of dextran sodium sulfate (DSS). Treating mice with antisense oligonucleotides to LIX via rectal enema delivery before DSS treatment results in colonic enterocyte uptake and a significant reduction in neutrophil infiltration and severity of colitis. These findings indicate that LIX plays an integral role in the pathogenesis of DSS-induced colitis. Similarly, enterocyte-derived CXC chemokines may play a key role in regulating neutrophil recruitment and intestinal injury in IBD. The intracolonic administration of ENA-78 antisense oligonucleotides may be effective in treating distal ulcerative colitis in humans.

Ginger extract inhibits beta-amyloid peptide-induced cytokine and chemokine expression in cultured THP-1 monocytes.

INTRODUCTION: Neuritic plaques, a neuropathologic hallmark of Alzheimer's disease, are extracellular deposits of beta-amyloid peptides (Abeta). In the central nervous system neuritic plaques are surrounded by activated microglial cells expressing proinflammatory cytokines, chemokines, and neurotoxic mediators. Long-term activation of microglial cells is suspected to contribute to the neuron loss in Alzheimer's disease. OBJECTIVE: This study was conducted to determine whether a ginger (Zingiber officinale and Alpinia galanga) extract (GE) can dampen the activation of THP-1 cells by lipopolysaccharide, proinflammatory cytokines, and fibrillar amyloid peptide Abeta(1-42), a major component of neuritic plaques. METHODS: THP-1 cells, a human monocytic cell line with properties similar to human microglial cells, were incubated with GE or control medium alone for 1 hour, and then with reincubated lipopolysaccharide (LPS), tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta) or fibrillar Abeta(1-42) for an additional hour. The extent of THP-1 cell activation was determined by measuring mRNA levels of TNF-alpha and IL-1beta, cyclooxygenase-2 (COX-2), macrophage inflammatory protein 1alpha (MIP-1alpha), monocyte chemoattractant protein-1 (MCP-1), and interferon-gamma inducible protein 10 (IP-10). RESULTS: The results document that the GE used in this study inhibits LPS, cytokine, and amyloid Abeta peptide-induced expression of the proinflammatory genes TNF-alpha, IL-1beta, COX-2, MIP-alpha, MCP-1, and IP-10. The data provide experimental evidence that ginger can inhibit the activation of human monocytic THP-1 cells by different proinflammatory stimuli and reduce the expression of a wide range of inflammation-related genes in these microglial-like cells. CONCLUSIONS: The findings suggest that GE may be useful in delaying the onset and the progression of neurodegenerative disorders involving chronically activated microglial cells in the central nervous system.

Tannic acid is an inhibitor of CXCL12 (SDF-1alpha)/CXCR4 with antiangiogenic activity.

PURPOSE: Increasing evidence suggests that interaction between the chemoattractant CXCL12/stromal cell-derived factor-1alpha and its receptor CXCR4 plays a pivotal role in the metastasis of various tumors. Our previous studies showed that multi-component Chinese herbal medicines inhibited the effects of CXCL12/CXCR4. As a result of sequential chromatographic fractionation of one herbal medicine ingredient, Lianqiao (fruit of Forsythia suspensa), we observed that tannins were, at least in part, responsible for this activity. The aim of this study was to assess the anti-CXCL12/CXCR4 activity of a commercial tannic acid and evaluate its potential to inhibit tumor cell migration and angiogenesis in vitro. EXPERIMENTAL DESIGN: The inhibitory effect of tannic acid on CXCL12/CXCR4 was measured by chemotaxis assay, ligand binding assay, and fluorescence-activated cell sorter analysis. The antiangiogenic effect of tannic acid was assessed by in vitro endothelial cell tube formation. RESULTS: Tannic acid, at nontoxic concentrations, specifically inhibited CXCL12-induced human monocyte migration (IC(50), 7.5 micro g/ml) but did not inhibit CCL2-, CCL3-, CCL5-, formylmethionylleucylphenylalanine (fMLP)-, or C5a-induced migration. The compound markedly blocked CXCL12 binding to THP-1 cells (IC(50), 0.36 micro g/ml). Tannic acid also inhibited CXCL12-induced, but not epidermal growth factor-induced, migration of MDA 231 breast tumor cells. Additionally, 0.5 micro g/ml of tannic acid selectively inhibited CXCL12-mediated, but not basic fibroblast growth factor- or endothelial cell growth supplement-mediated, bovine aorta endothelial cell capillary tube formation. CONCLUSION: These studies indicate that tannic acid is a novel selective CXCL12/CXCR4 antagonist and consequently may provide a mechanistic basis for the reported antitumor and anti-inflammatory properties of tannic acid.

CXC chemokine receptor 4 expression and function in human astroglioma cells.

Chemokines constitute a superfamily of proteins that function as chemoattractants and activators of leukocytes. Astrocytes, the major glial cell type in the CNS, are a source of chemokines within the diseased brain. Specifically, we have shown that primary human astrocytes and human astroglioma cell lines produce the CXC chemokines IFN-gamma-inducible protein-10 and IL-8 and the CC chemokines monocyte chemoattractant protein-1 and RANTES in response to stimuli such as TNF-alpha, IL-1beta, and IFN-gamma. In this study, we investigated chemokine receptor expression and function on human astroglioma cells. Enhancement of CXC chemokine receptor 4 (CXCR4) mRNA expression was observed upon treatment with the cytokines TNF-alpha and IL-1beta. The peak of CXCR4 expression in response to TNF-alpha and IL-1beta was 8 and 4 h, respectively. CXCR4 protein expression was also enhanced upon treatment with TNF-alpha and IL-1beta (2- to 3-fold). To study the functional relevance of CXCR4 expression, stable astroglioma transfectants expressing high levels of CXCR4 were generated. Stimulation of cells with the ligand for CXCR4, stromal cell-derived factor-1alpha (SDF-1alpha), resulted in an elevation in intracellular Ca(2+) concentration and activation of the mitogen-activated protein kinase cascade, specifically, extracellular signal-regulated kinase 2 (ERK2) mitogen-activated protein kinase. Of most interest, SDF-1alpha treatment induced expression of the chemokines monocyte chemoattractant protein-1, IL-8, and IFN-gamma-inducible protein-10. SDF-1alpha-induced chemokine expression was abrogated upon inclusion of U0126, a pharmacological inhibitor of ERK1/2, indicating that the ERK signaling cascade is involved in this response. Collectively, these data suggest that CXCR4-mediated signaling pathways in astroglioma cells may be another mechanism for these cells to express chemokines involved in angiogenesis and inflammation.

Reynosin from Sassurea lappa as inhibitor on CINC-1 induction in LPS-stimulated NRK-52E cells.

An inhibitor on CINC-1 (cytokine-induced neutrophil chemoattractant-1) induction in LPS-stimulated rat kidney epithelioid NRK-52E cells was purified from the roots of Sassurea lappa Clarke, a herbal medicine used in Korean traditional prescriptions for gastric intestinal diseases by a variety of column chromatographic procedures. The inhibitor was identified as reynosin, a sesquiterpene lactone isolated and characterized previously from Ambrosia confertiflora DC., and Magnolia grandiflora L. Reynosin exhibited a dose-dependent inhibition on CINC-1 induction in LPS-stimulated NRK-52E cells, where 50% of inhibitory effect was shown at the concentration of about 1 microM.