Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0376358 (prostate cancer)
 59,338 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Neoplasms have a striking tendency to metastasize or "home" to bone. Hematopoietic cells also home to bone during embryonic development, where evidence points to the chemokine stromal cell-derived factor-1 (SDF-1 or CXCL12; expressed by osteoblasts and endothelial cells) and its receptor (CXCR4) as key elements in these processes. We hypothesized that metastatic prostate carcinomas also use the SDF-1/CXCR4 pathway to localize to the bone. To test this, levels of CXCR4 expression were determined for several human prostate cancer cell lines by reverse transcription-PCR and Western blotting. Positive results were obtained for cell lines derived from malignancies that had spread to bone and marrow. Prostate cancer cells were also observed migrating across bone marrow endothelial cell monolayers in response to SDF-1. In in vitro adhesion assays, pretreatment of the prostate cancer cells with SDF-1 significantly increased their adhesion to osteosarcomas and endothelial cell lines in a dose-dependent manner. Invasion of the cancer cell lines through basement membranes was also supported by SDF-1 and inhibited by antibody to CXCR4. Collectively, these results suggest that prostate cancers and perhaps other neoplasms may use the SDF-1/CXCR4 pathway to spread to bone.
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PMID:Use of the stromal cell-derived factor-1/CXCR4 pathway in prostate cancer metastasis to bone. 1191 62

Prostate cancer is the most commonly diagnosed cancer and the second leading cause of cancer-related death among men in the United States. African American men have a 60% greater incidence of prostate cancer and a twofold higher mortality rate than Caucasian men. The Duffy antigen/receptor for chemokines (DARC) is a receptor expressed on erythrocytes and vascular endothelial cells that binds to and clears angiogenic chemokines. The DARC also functions as the erythrocyte receptor for invasion by malarial parasites. Approximately 70% of African Americans lack erythrocyte expression of the DARC as a genetic mechanism of protection against malaria infection. Given the importance of angiogenic chemokines in the development of tumor vascular networks and the chemokine binding properties of the DARC, the possibility that a lack of DARC expression on erythrocytes may represent an epigenetic factor that predisposes African American men to a greater incidence and mortality of prostate cancer should be considered.
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PMID:The Duffy antigen/receptor for chemokines (DARC) and prostate cancer. A role as clear as black and white? 1208 71

Interleukin-8 (IL-8), a chemokine implicated in the metastasis and angiogenesis of a variety of cancers, has been reported to be overexpressed in prostate cancer. In this study, we ascribe a new role for IL-8 in prostate cancer progression using LNCaP cells. We demonstrate that IL-8 activates the androgen receptor and confers androgen-independent growth, while serving as a potent chemotactic factor. Our evaluation of the possible signal pathways involved in androgen-independence and cell migration shows that the tyrosine kinases Src and FAK (focal adhesion kinase) are involved in IL-8-induced signaling. Pharmacological and genetic inhibitors of Src and FAK interfere with IL-8-induced cell migration, while only the Src inhibitor was able to repress androgen-independent growth. This suggests that both growth and migration depend on the activity of Src, whereas cell migration also requires the activation of FAK. Our evidence that IL-8-induced androgen-independent growth is, at least in part, due to androgen receptor activation includes (1) an inhibitor of androgen receptor activity diminishes cell growth; (2) androgen receptor transactivation potential is augmented by IL-8 and (3) androgen receptor is recruited to the promoter of prostate specific antigen (PSA) upon IL-8 treatment, based on chromatin immunoprecipitation experiments. Taken together, our data suggest that in addition to its role in metastasis and angiogenesis, IL-8 may also serve as a facilitator for androgen-independent transition of prostate cancers. To our knowledge, this is the first report about the tyrosine kinase signals and androgen receptor activation induced by IL-8 in prostate cancer cells. The observation that IL-8 mediates its growth and chemotactic effects via Src and FAK suggests the potential use for tyrosine kinase inhibitors at early stage of prostate cancer development.
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PMID:Interleukin-8 confers androgen-independent growth and migration of LNCaP: differential effects of tyrosine kinases Src and FAK. 1476 70

Chemokines and their receptors might be involved in the selection of specific organs by metastatic cancer cells. For instance, the CXCR4-SDF-1alpha pair regulates adhesion and migration of breast as well as prostate cancer cells to metastatic sites. In this study, we present the first evidence for the expression of CX3CR1--the specific receptor for the chemokine fractalkine--by human prostate cancer cells, whereas human bone marrow endothelial cells and differentiated osteoblasts express fractalkine. The adhesion of prostate cancer cells to human bone marrow endothelial cells in flow conditions is significantly reduced by a neutralizing antibody against fractalkine, and they migrate toward a medium conditioned by osteoblasts, which secrete the soluble form of the chemokine. Finally, fractalkine activates the PI3K/Akt survival pathway in human prostate cancer cells.
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PMID:CX3CR1-fractalkine expression regulates cellular mechanisms involved in adhesion, migration, and survival of human prostate cancer cells. 1525 32

Chemokines have been implicated in tumor growth, angiogenesis, metastasis and the host immune response to malignant cells. Infection and autoimmune disorders can reduce androgen production by Leydig cells and adversely affect spermatogenesis. Cytokine-responsive gene-2 (crg-2) (systematic name CXCL10, also known as interferon-gamma-inducible protein 10 (IP-10)) is a potent chemokine expressed predominantly by macrophages and Leydig cells in the testis. CXCL10 binds to CXCR3 receptor (a G-protein-coupled receptor) and acts via Gialpha protein. We have shown previously that CXCL10 is differentially expressed in normal Leydig cells, inhibited by human chorionic gonadotropin and induced by interferon-gamma, interleukin-1alpha and tumor necrosis factor-alpha. The purpose of the present study was to determine the effects of overexpression of CXCL10 by transfection experiments in MA-10 cells on cell growth, CXCR3 expression, progesterone synthesis and steroidogenic acute regulatory protein (StAR D1, a key regulatory factor in steroidogenesis) gene expression. We cloned the complete CXCL10 cDNA in a mammalian expression vector with the CMV promoter, pcDNA3.1D/V5-His-TOPO, and confirmed its expression with rat CXCL10 antibody and V5 antibody. Results showed large amounts of CXCL10 protein secreted in the medium in the CXCL10 transfectants by Western blotting. The production of CXCL10 mRNA ranged from 30-50-fold more (n=6) in the transfected cells than the control cells, as determined by semiquantitative and real-time RT-PCR. 8-Br-cAMP downregulated CXCL10 mRNA expression and stimulated CXCR3 mRNA expression. Transfection of MA-10 cells with CXCL10 decreased cAMP-induced progesterone synthesis from 38.5+/-1.7 ng/ml (1.5 x 10(5) cells/ml) in control cells to 23.2+/-1.5 ng in transfected cells (P<0.01). 8-Br-cAMP (0.2 mM)-induced StAR D1 mRNA was decreased 30-40% by transfection with CXCL10. Interestingly, overexpression of CXCL10 induced the expression of its receptor CXCR3 gene, as determined by RT-PCR and fluorescence-activated cell sorter (FACS) analysis. Transfection of CXCL10 also significantly decreased insulin-like growth factor-I (IGF-I, 100 ng/ ml)-induced [3H]thymidine incorporation into DNA. These data suggest that CXCL10 also inhibits MA-10 tumor cell proliferation. In conclusion, CXCL10 inhibits StAR D1 expression, decreases progesterone synthesis and inhibits cell proliferation. CXCL10 has the potential to be used in gene therapy for prostate cancer due to its antiangiogenic effect and its inhibitory effect on steroidogenesis.
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PMID:Effects of overexpression of CXCL10 (cytokine-responsive gene-2) on MA-10 mouse Leydig tumor cell steroidogenesis and proliferation. 1559 Sep 84

The establishment of metastatic bone lesions in prostate cancer (CaP) is a process partially dependent on angiogenesis. Previously we demonstrated that the stromal-derived factor-1 (SDF-1 or CXCL12)/CXCR4 chemokine axis is critical for CaP cell metastasis. In this investigation, cell lines were established in which CXCR4 expression was knocked down using siRNA technology. When CaP cells were co-transplanted with human vascular endothelial cells into SCID mice, significantly fewer human blood vessels were observed paralleling the reductions in CXCR4 levels. Likewise, the invasive behaviors of the CaP cells were inhibited in vitro. From these functional observations we explored angiogenic and signaling mechanisms generated following SDF-1 binding to CXCR4. Differential activation of the MEK/ERK and PI3K/AKT pathways that result in differential secretion IL-6, IL-8, TIMP-2 and VEGF were seen contingent on the cell type examined; VEGF and TIMP-2 expression in PC3 cells are dependent on AKT activation and ERK activation in LNCaP and LNCaP C4-2B cells leads to IL-6 or IL-8 secretion. At the same time, expression of angiostatin levels were inversely related to CXCR4 levels, and inhibited by SDF-1 stimulation. These data link the SDF-1/CXCR4 pathway to changes in angiogenic cytokines by different signaling mechanisms and, suggest that the delicate equilibrium between proangiogenic and antiangiogenic factors may be achieved by different signal transduction pathways to regulate the angiogenic phenotype of prostate cancers. Taken together, our results provide new information regarding expression of functional CXCR4 receptor-an essential role and potential mechanism of angiogenesis upon SDF-1 stimulation.
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PMID:Diverse signaling pathways through the SDF-1/CXCR4 chemokine axis in prostate cancer cell lines leads to altered patterns of cytokine secretion and angiogenesis. 1600 85

G protein-coupled receptors (GPCRs) play important roles in a variety of biological and pathological processes. They are considered among the most desirable targets for drug development. Recent studies have demonstrated that many GPCRs, such as endothelin receptors, chemokine receptors and lysophosphatidic acid receptors have been implicated in the tumorigenesis and metastasis of multiple human cancers. In this study, we conducted an in silico analysis of GPCR gene expression in primary human tumors by analyzing some publicly available gene expression profiling data. Statistical analysis was performed on eight microarray data sets of non-small cell lung cancer, breast cancer, prostate cancer, melanoma, gastric cancer and diffused large B cell lymphoma to identify GPCRs that are up-regulated in primary or metastatic cancer cells. Our analysis has demonstrated overexpression of several GPCRs in primary tumor cells, including chemokine receptors and protease-activated receptors that were shown to be important for tumorigenesis by previous studies. In addition, we have uncovered several GPCRs, such as neuropeptide receptors, adenosine A2B receptor, P2Y purinoceptor, calcium-sensing receptor and metabotropic glutamate receptors, that are expressed at a significantly higher level in some cancer tissue and may play a role in cancer progression. Analysis of cancer samples in different disease stages also suggests that some GPCRs, such as endothelin receptor A, may be involved in early tumor progression and others, such as CXCR4, may play a critical role in tumor invasion and metastasis. The present study demonstrates the value of publicly available microarray data as a resource to gain more understanding of cancer biology, to validate previous findings from in vitro experiments, and to identify potential novel anticancer targets and biomarkers.
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PMID:Overexpression of G protein-coupled receptors in cancer cells: involvement in tumor progression. 1621 Dec 29

Though chemokines of the CXC family are thought to play key roles in neoplastic transformation and tumor invasion, information about CXC chemokines in prostate cancer is sparse. To evaluate the involvement of CXC chemokines in prostate cancer, we analyzed the CXC coding mRNA of both chemokine ligands (CXCL) and chemokine receptors (CXCR), using the prostate carcinoma cell lines PC-3, DU-145 and LNCaP. CXCR proteins were further evaluated by Western blot, CXCR surface expression by flow cytometry and confocal microscopy. The expression pattern was correlated to adherence of the tumor cells to an endothelial cell monolayer or to extracellular matrix components. Based on growth and adhesion capacity, PC-3 and DU-145 were identified to be highly aggressive tumor cells (PC-3>DU-145), whereas LNCaP belonged to the low aggressive phenotype. CXCL1, CXCL3, CXCL5 and CXCL6 mRNA, chemokines with pro-angiogenic activity, were strongly expressed in DU-145 and PC-3, but not in LNCaP. CXCR3 and CXCR4 surface level differed in the following order: LNCaP>DU-145>PC-3. The differentiation factor, fatty acid valproic acid, induced intracellular CXCR accumulation. Therefore, prostate tumor malignancy might be accompanied by enhanced synthesis of angiogenesis stimulating CXC chemokines. Further, shifting CXCR3 and CXCR4 from the cell surface to the cytoplasm might activate pro-tumoral signalling events and indicate progression from a low to a highly aggressive phenotype.
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PMID:Prostate tumor CXC-chemokine profile correlates with cell adhesion to endothelium and extracellular matrix. 1626 40

The chemokine stromal-derived factor-1alpha (SDF-1alpha/CXCL-12) and its receptor, CXCR4, play a crucial role in adhesion and transendothelium migration (TEM) of prostate cancer cells. We tested the hypothesis that enhanced expression of CXCR4 in prostate cancer cells is dependent upon SDF-1alpha-mediated activation of nuclear factor-kappaB (NF-kappaB). SDF-1alpha increased the CXCR4 mRNA and protein expression in PC-3 cells but not in LNCaP cells. Similarly, SDF-1alpha enhanced the NF-kappaB-dependent transcriptional activity in PC-3 cells but not in LNCaP cells. SDF-1alpha increased PC-3 cell adhesion to the human umbilical vein endothelial cell monolayer and enhanced TEM, which was abrogated with anti-CXCR4 monoclonal antibody (mAb). Suppression of NF-kappaB activity in PC-3 cells by a mutant IkappaBalpha super-repressor adenoviral vector decreased the CXCR4 mRNA expression and inhibited adhesion and TEM. Transient overexpression of p65 subunit of NF-kappaB in PC-3 cells up-regulated CXCR4 receptor expression and increased the adhesion and TEM of these cells in response to SDF-1alpha gradient. Treatment of PC-3 cells with SDF-1alpha leads to nuclear translocation of NF-kappaB protein within 15 to 30 minutes, which correlated with IkappaBalpha phosphorylation. A p42/44 mitogen-activated protein kinase [MAPK, extracellular signal regulated kinase-1/2 (ERK-1/2)] biphasic activation pattern was observed in these cells at 15 minutes and 3 hours after SDF-1alpha treatment. Phosphorylation of IkappaB kinase alpha was observed within 30 minutes, which was blocked by PD98059 [MAPK kinase (MEK) inhibitor]. PD98059 cotreatment significantly inhibited SDF-1alpha-induced NF-kappaB reporter activity and CXCR4 receptor expression as shown by flow cytometry. These data suggest that SDF-1alpha-induced expression of CXCR4 in PC-3 cells is dependent on MEK/ERK signaling cascade and NF-kappaB activation.
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PMID:Up-regulation of CXCR4 expression in PC-3 cells by stromal-derived factor-1alpha (CXCL12) increases endothelial adhesion and transendothelial migration: role of MEK/ERK signaling pathway-dependent NF-kappaB activation. 1626 13

The direct relationship between the aging process and the incidence and prevalence of both benign prostatic hyperplasia (BPH) and prostate cancer (PCa) implies that certain risk factors associated with the development of both diseases increase with the aging process. In particular, both diseases share an overly proliferative phenotype, suggesting that mechanisms that normally act to suppress cellular proliferation are disrupted or rendered dysfunctional as a consequence of the aging process. We propose that one such mechanism involves changes in the prostate microenvironment, which 'evolves' during the aging process and disrupts paracrine interactions between epithelial and associated stromal fibroblasts. We show that stromal fibroblasts isolated from the prostates of men 63-81 years of age at the time of surgery express and secrete higher levels of the CXCL12 chemokine compared with those isolated from younger men, and stimulate CXCR4-mediated signaling pathways that induce cellular proliferation. These studies represent an important first step towards a mechanistic elucidation of the role of aging in the etiology of benign and malignant prostatic diseases.
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PMID:CXCL12 overexpression and secretion by aging fibroblasts enhance human prostate epithelial proliferation in vitro. 1630 Apr 81


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