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)

Inflammation has been implicated as an etiological factor in several human cancers. Growing evidence suggests that chronic inflammation may also play a role in the etiology of prostate cancer. Considering that genetic susceptibility is a major risk factor for this disease, we hypothesize that sequence variants in genes that regulate inflammation may modify individual susceptibility to prostate cancer. The lipopolysaccharide receptor Toll-like receptor 4 (TLR4) is a central player in the signaling pathways of the innate immune response to infection by Gram-negative bacteria and is an important candidate inflammatory gene. We performed a systematic genetic analysis of TLR4 sequence variants by evaluating eight single-nucleotide polymorphisms that span the entire gene among 1383 newly diagnosed prostate cancer patients and 780 age- and residence-matched controls in Sweden. We found an association between a sequence variant (11381G/C) in the 3'-untranslated region of the TLR4 gene and prostate cancer risk. The frequency of the variant genotypes (CG or CC) was significantly higher in the patients (24.1%) than in the controls (19.7%; P = 0.02). The frequency of risk genotypes among patients diagnosed before the age of 65 years was even higher (26.3%). Compared with men who had the wild-type genotype of this single-nucleotide polymorphism (GG), those with GC or CC genotypes had a 26% increased risk for prostate cancer (odds ratio, 1.26; 95% confidence interval, 1.01-1.57) and 39% increased risk increased risk for early onset prostate cancer (before age 65 years; odds ratio, 1.39; 95% confidence interval, 1.02-1.91). The risk attributable to this variant for prostate cancer in Sweden was estimated to be 4.9%. Although the biological mechanism of the observed association remains to be elucidated, our finding supports a role for a bacteria-associated response pathway, possibly acting via inflammation, in the development of prostate cancer.
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PMID:Sequence variants of toll-like receptor 4 are associated with prostate cancer risk: results from the CAncer Prostate in Sweden Study. 1508 12

Chronic inflammation has been hypothesized to be a risk factor for prostate cancer. The Toll-like receptor 4 (TLR4) presents the bacterial lipopolysaccharide (LPS), which interacts with ligand-binding protein and CD14 (LPS receptor) and activates expression of inflammatory genes through nuclear factor-kappaB and mitogen-activated protein kinase signaling. A previous case-control study found a modest association of a polymorphism in the TLR4 gene [11381G/C, GG versus GC/CC: odds ratio (OR), 1.26] with risk of prostate cancer. We assessed if sequence variants of TLR4 were associated with the risk of prostate cancer. In a nested case-control design within the Health Professionals Follow-up Study, we identified 700 participants with prostate cancer diagnosed after they had provided a blood specimen in 1993 and before January 2000. Controls were 700 age-matched men without prostate cancer who had had a prostate-specific antigen test after providing a blood specimen. We genotyped 16 common (>5%) single nucleotide polymorphisms (SNP) discovered in a resequencing study spanning TLR4 to test for association between sequence variation in TLR4 and prostate cancer. Homozygosity for the variant alleles of eight SNPs was associated with a statistically significantly lower risk of prostate cancer (TLR4_1893, TLR4_2032, TLR4_2437, TLR4_7764, TLR4_11912, TLR4_16649, TLR4_17050, and TLR4_17923), but the TLR4_15844 polymorphism corresponding to 11381G/C was not associated with prostate cancer (GG versus CG/CC: OR, 1.01; 95% confidence interval, 0.79-1.29). Six common haplotypes (cumulative frequency, 81%) were observed; the global test for association between haplotypes and prostate cancer was statistically significant (chi(2) = 14.8 on 6 degrees of freedom; P = 0.02). Two common haplotypes were statistically significantly associated with altered risk of prostate cancer. Inherited polymorphisms of the innate immune gene TLR4 are associated with risk of prostate cancer.
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PMID:Sequence variants of Toll-like receptor 4 and susceptibility to prostate cancer. 1635 90

Toll-like receptor 4 (TLR4) is a key innate immunity receptor that initiates an inflammatory response primarily against Gram-negative bacteria. Two recent publications reported that variants in TLR4 were associated with risk of prostate cancer. To further investigate the role of TLR4 in prostate cancer susceptibility, we identified six tagging single-nucleotide polymorphisms that comprehensively captured the common genetic variation of the locus and tested these polymorphisms in our case-control study of 1,012 men. Two single-nucleotide polymorphisms showed nominally statistically significant associations with prostate cancer risk, with the strongest (rs10759932) associated with a 4-fold increased risk of disease (P = 0.006). We estimated through permutation analysis that a similarly strong result would occur by chance 2.5% of the time. Our findings support previous studies and suggest that inherited differences in TLR4 influence prostate cancer risk.
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PMID:Toll-like receptor 4 genetic variation and advanced prostate cancer risk. 1730 Dec 71

Genetic susceptibility to prostate cancer has been consistently observed by a large number of studies. Recently, several pieces of evidence obtained from epidemiological and pathological studies support that chronic inflammation in prostate tissues may play a role in prostate cancer development. Multiple genes that play critical roles in inflammatory pathways have been associated with prostate cancer risk. In this article we review the key genetic findings of the associated genes. This includes 2 genes identified through family studies, ribonuclease L (RNASEL) and macrophage scavenger receptor 1 (MSR1), as well as a number of genes suggested by case-control studies, such as macrophage inhibitory cytokine-1 (MIC-1), interleukins (IL-8, IL-10), vascular endothelial growth factor (VEGF), intercellular adhesion molecule (ICAM), and Toll-like receptors (TLR-4, TLR-1-6-10 gene cluster). Overall, recent studies seem to suggest multiple genes work together to increase prostate risk, and this is consistent with the reality that inflammation is a very complex process. Thus, future studies are expected to place an emphasis on the study of gene-gene interactions. Advances in high throughput genotyping, data mining, and algorithm development are needed in order to produce interpretable results.
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PMID:Genetic variability in inflammation pathways and prostate cancer risk. 1748 24

Although an eruption of information on the role of Toll-like receptor 4 (TLR4), the main receptor for bacterial lipopolysaccharide, in activating macrophages and dendritic cells has emerged, very little is known about the role of TLR4 present on epithelial cells from sterile environments like tumors. The main goal of this work was to investigate the consequences of TLR4 activation present on tumor cells in two different animal models of cancer: the Dunning rat prostate cancer and the B16 murine melanoma models. We show that (a) activating TLR4 signaling in two different tumor cell lines in vitro modifies the tumor outgrowth in vivo; (b) this effect is not due to a direct consequence of TLR4 signaling on the proliferation/apoptosis balance of the tumor cells; (c) the T-cell compartment is somehow involved in the described phenomenon because the inhibitory effect observed is not seen in athymic nude mice; and (d) tumor-infiltrating lymphocytes purified from tumors induced by TLR4-activated cells show strong induction of IFN gamma transcript in detriment of interleukin-10 transcript, suggesting a change in their functionality. We hypothesize that TLR4 signaling in tumor cells in vitro induces the expression of proinflammatory mediators, which could dramatically alter the maturation state of dendritic cells present at the site of inoculation, switching the type of immune response elicited against the tumor. These results open up new avenues for understanding the role of TLR4 in tumor cells and for identifying potential new therapy strategies for cancer.
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PMID:Activation of Toll-like receptor 4 on tumor cells in vitro inhibits subsequent tumor growth in vivo. 1797 96

Chronic inflammation promotes tumor development and progression, and Toll-like receptors (TLRs) may play an important role in this process. In this study, we found that human prostate epithelial PC3 cells constitutively express TLR4 in mRNA and protein level. lipopolysaccharide (LPS) promotes the expression and secretion of immunosuppressive cytokine TGFbeta(1) and proangiogenic factor VEGF in human prostate epithelial PC3 cells. We further elucidated that functionally activation of TLR4 is essential for the increased VEGF and TGFbeta(1) mRNA expression in the cells. In addition, after LPS stimulation, the increased expression of NF-(K)B p65 protein was also detected in human PC3 cells. Our results demonstrate that TLR4 expressed on human PC3 cells is functionally active, and may play important roles in promoting prostate cancer immune escape, survival, progression, and metastasis by inducing immunosuppressive and proangiogenic cytokines.
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PMID:TLR4 signaling promotes the expression of VEGF and TGFbeta1 in human prostate epithelial PC3 cells induced by lipopolysaccharide. 1864 75

The Toll-like receptor 4 (TLR4) has a wide spectrum of bacteria recognition receptors that may be involved in the signaling of the immune responses in the prostate. A few association studies have assessed the relationship between the risk of prostate cancer (PC) and the polymorphism in the TLR4 gene in European-ancestry populations. To evaluate the association of TLR4 polymorphisms and the risk for PC in Korean men, we genotyped five single-nucleotide polymorphisms (SNPs) of the TRL4 gene (rs11536858, rs1927914, 1927911, rs11536891, and rs11536897) by PCR-restriction fragment length polymorphism from unrelated 157 PC patients and 143 age-matched controls. The rs1927911 SNP increased the risk of PC (adjusted odds ratio ORadj=2.73, 95% CI=1.54-4.87 for the TC genotype; ORadj=6.68, 95% CI=3.27-13.66 for the CC genotype). The GG genotype of the rs11536858 SNP also carried increased risk (ORadj=2.296, 95% CI=1.07-4.93). There was no statistically significant correlation between any of the SNPs of TRL4 and such PC prognostic factors as Gleason grade, initial prostate-specific antigen level, or tumor stage. In conclusion, inherited differences in the TLR4 gene influence the risk of PC in Korean men.
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PMID:The association between Toll-like receptor 4 (TLR4) polymorphisms and the risk of prostate cancer in Korean men. 1938 25

Cancer-derived heat shock protein gp96 induces a tumor-specific protective immune response primarily mediated by cytotoxic T lymphocytes (CTL) directed toward cancer-associated peptides associated with gp96. Both innate and adaptive immune responses have been demonstrated using a cell culture-based signaling mechanism. When used as an extraneous vaccine, one critical interaction which must occur for an immune response to be generated is the interaction between gp96 and the antigen presenting cell (APC) surface receptors (CD91, SR-A, TLR-2, and TLR-4). Our previous study concluded that gp96 purified from various rat and human prostate cancers is differentially glycosylated based on the amino and neutral monosaccharide content, and it was postulated that the monosaccharides may play a role in its biological activity. In this report, we report differences in the cancer-specific sialic acid content of gp96 purified from normal rat prostate compared to two rat prostate cancers, MAT-LyLu and Dunning G, as well as between two human prostate cancer cells, LnCaP and DU145. We also examined the modulatory effect of sialic acid residues on the binding of gp96 to APCs and its subsequent activation. Our results supported the contention that significant differences in the sialic acid content exist between Dunning G, MAT-LyLu, and normal rat prostate gp96, which affected its binding and biochemical activity to APCs. We therefore postulate that varied glycans of HPS96, a hitherto neglected structural component, may play a pivotal role in its anticancer activity. We suggest that construction of the glycan tree is a key to identification of the necessary and sufficient elements in the structure-function activity of HSP96.
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PMID:Sialic acid content of tissue-specific gp96 and its potential role in modulating gp96-macrophage interactions. 1957 60

A major cause of tumor treatment failure is cancer cell metastasis. Toll-like receptor 4 (TLR4)-mediated signaling has been implicated in tumor cell invasion, survival, and metastasis in a variety of cancers. In this study, we investigated the biological roles of TLR4 in prostate metastatic cell invasion and survival, and the potential of gene silencing of TLR4 using small interfering RNA (siRNA) for treatment of cancer. In cultured human prostate cancer cell lines, TLR4 were higher PC3 and DU145 as compared with the poorly metastatic LNCaP indicating that up-regulation of TLR4 was positively correlated with metastasis of tumor cell. In the highly metastatic cancer cell PC3, gene silencing of TLR4 using siRNA significantly inhibited TLR4 mRNA expression and protein level. Knockdown of TLR4 in PC3 cells resulted in a dramatic reduction of tumor cell migration and invasion as indicated by a Matrigel invasion assay. Furthermore, TLR4 siRNA suppressed cell viability and ultimately caused the induction of apoptotic cell death. The effects were associated with abrogating TLR4-mediated signaling to downstream target molecules such as myeloid differentiation factor 88 (MyD88), adaptor-inducing IFN-beta (TRIF), and interferon regulatory factor-1 (IRF-1). In a mouse prostate cancer model, administration with the plasmid construct expressing siRNA for TLR4 obviously inhibited established tumor growth and survival. These studies revealed evidence of a multifaceted signaling network operating downstream of TLR4-mediated tumor cell invasion, proliferation, and survival. Thus, RNA interference-directed targeting of TLR4 may raise the potential of its application for cancer therapy.
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PMID:Small interfering RNA-directed targeting of Toll-like receptor 4 inhibits human prostate cancer cell invasion, survival, and tumorigenicity. 1964 79

Lipopolysaccharide (LPS)-induced TLR4-NF-(K)B signaling plays an important role in the development of prostatic tumors from chronic bacterial prostatic infection. Although many studies support the role of selenium in protecting against the development of prostate cancer secondary to chronic prostatitis, the mechanism of action remains unclear. The aim of our study was to investigate whether selenium inhibits the LPS-induced TLR4 signaling pathway in human prostate cancer PC3 cells. Using real-time quantitative PCR and ELISA analysis, we found that pretreatment with selenium (0.5-5uM) inhibited the LPS-induced expression of TGFbeta(1) and VEGF and production of these cytokines and IL-6 by PC3 cells, but did not alter the expression of TLR4 mRNA. Further experiments using Western blot showed that selenium at 3 and 5uM significantly inhibited the translocation of the NF-(K)B p65 subunit to the nucleus in LPS-stimulated PC3 cells. Our results suggest that low doses of selenium may protect the prostate from prostatitis-induced cancer by inhibiting nuclear translocation of the NF-(K)B and the subsequent production of the immunosuppressive cytokine TGFbeta(1), proangiogenic factor VEGF and pro-inflammatory factor IL-6.
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PMID:Sodium selenite inhibits the expression of VEGF, TGFbeta(1) and IL-6 induced by LPS in human PC3 cells via TLR4-NF-(K)B signaling blockage. 1981 70


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