Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P05231 (interleukin-6)
 23,907 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Interleukin-6 (IL-6) has been attributed to induction of osteoclastogenic-precursor cell proliferation and maturation. Estrogens suppress IL-6 production in stromal/osteoblastic cells in vitro. Conversely, estrogen withdrawal is associated with increased IL-6 production. IL-6 is therefore thought to be an important mediator of the increased bone resorption after menopause. However, evidence supporting a rise in the expression of IL-6 or the IL-6 receptor in human bone tissue with menopause is still lacking. To address this question, we established a 5'-nuclease assay to quantitate the expression of human IL-6 and the gp80 subunit of the IL-6 receptor in human bone samples. The number of mRNA copies was normalized to the number of copies of beta actin mRNA. Osteocalcin expression served as an independent control. The study population consisted of 169 women (mean age 52.4 +/- 11.6 years) who underwent surgery for early breast cancer. Serum IL-6 was measured by enzyme-linked immunosorbent assay, serum crosslaps as a marker of bone resorption were measured by electrochemiluminescent assay, and serum osteocalcin was measured by chemoluminescence assays. RNA expression of osteocalcin in bone tissue from early postmenopausal women was higher compared with premenopausal women. Local expression was positively associated with circulating osteocalcin and crosslaps concentrations. Postmenopausal women also had higher circulating IL-6 concentrations. In contrast, bone samples from postmenopausal women lacked an increased expression of either IL-6 or gp80 compared with bone samples from premenopausal women. In conclusion, we failed to detect local increases in IL-6 or IL-6 receptor expression in human bone tissue with menopause. If direct changes in the IL-6 system in bone tissue are involved in postmenopausal bone loss, these changes appear to be below the detection limit of our assay system.
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PMID:Expression of Interleukin-6 (IL-6) and IL-6 receptor mRNA in human bone samples from pre- and postmenopausal women. 1179 88

Oncostatin M (OSM), an interleukin-6 type cytokine, acts via the gp130 signaling receptor to inhibit proliferation and induce differentiation of breast cancer cells. EGF, a mitogen for breast cells, signals via EGFR/ErbB tyrosine kinase receptors which are implicated in breast cancer pathogenesis. Here we show paradoxically that EGF enhanced the OSM-induced inhibition of proliferation and induction of cellular differentiation in both estrogen receptor positive and negative breast cancer cells. This functional synergism was also seen with heregulin but not SCF, PDGF or IGF-1, indicating that it was specific to EGF-related growth factors. Immunoprecipitation experiments revealed that gp130 was constitutively associated with ErbB-2 and ErbB-3. There was a similar association between the OSMRbeta and ErbB-2. Furthermore, EGF unexpectedly induced tyrosine phosphorylation of gp130. We show that OSM induced phosphorylation of STAT3. Both OSM and EGF activated the p42/44 MAP kinases, but while the MEK inhibitor, PD98059, ablated the OSM-induced inhibition, it only partially ablated the inhibitory effects of OSM plus EGF. Thus, we have demonstrated that the receptors and signalling pathways of two apparently unrelated growth factors were intimately linked, resulting in an unexpected biological effect. This provides a new mechanism for generating signalling diversity and has potential clinical implications in breast cancer.
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PMID:An unexpected biochemical and functional interaction between gp130 and the EGF receptor family in breast cancer cells. 1182 58

The cytokine interleukin-6 (IL-6) and its soluble receptor (IL-6sR) can act synergistically to stimulate aromatase activity in cultured stromal fibroblasts derived from breast tissues. In this study, a 16 amino acid peptide, AROHIB, has been used in an attempt to block the ability of IL-6 plus IL-6sR to stimulate aromatase activity in stromal fibroblasts. Pre-incubation of cells with AROHIB for a 3-h period before the addition of IL-6 and IL-6sR resulted in a marked (67%) reduction in the ability of these factors to stimulate aromatase activity. AROHIB was found to be rapidly degraded when exposed to MCF-7 breast cancer cells or fibroblasts. Analysis by FAB-MS was used to identify the site of peptide cleavage. Subsequently, a series of 10 amino acid peptides, DP1-DP4, were designed, synthesised and tested for their ability to resist proteolytic degradation and to inhibit IL-6 plus IL-6sR-stimulated aromatase activity. Peptide DP2, a modified version of the active fragment of AROHIB, had N-acetyl and C-amino terminal protection and an internal D-amino acid (instead of L form) at the site of proteolytic cleavage. Using cells cultured in the presence of 2% stripped foetal calf serum, peptide DP2 resulted in a 74% reduction in cytokine-stimulated aromatase activity. Under serum-free conditions, peptides DP1-DP3 showed modest inhibitory properties. Results from this study suggest that it may be possible to develop small peptides to inhibit cytokine-stimulated aromatase activity in a tissue-specific manner.
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PMID:Peptide inhibition of cytokine-stimulated aromatase activity in breast tissue fibroblasts. 1185 Feb 21

Plasma levels of D-dimer are elevated in cancer patients. Activation of the extrinsic coagulation system and the fibrinolytic cascade within a tumour is thought to be related with growth, invasion and metastasis. We have investigated the relationship between these markers of fibrin metabolism, standard clinicopathological variables and serum levels of angiogenic cytokines in three cohorts: group A (n=30) consisted of 30 healthy female volunteers, group B (n=23) of consecutive patients with operable breast cancer and group C (n=84) of patients with untreated or progressive metastatic breast cancer. Plasma D-dimers, fibrinogen, IL-6, vascular endothelial growth factor and calculated vascular endothelial growth factor load in platelets are clearly increased in patients with breast cancer. D-dimers were increased in nearly 89% of patients with progressive metastatic disease. The level of D-dimers was positively correlated with tumour load (P<0.0001), number of metastatic sites (P=0.002), progression kinetics (P<0.0001) and the cytokines related to angiogenesis: serum vascular endothelial growth factor (P=0.0016, Spearman correlation=0.285), calculated vascular endothelial growth factor load in platelets (P<0.0001, Spearman correlation=0.37) and serum interleukin-6 (P<0.0001, Spearman correlation=0.59). Similarly increased D-dimer levels were positively correlated with increased fibrinogen levels (P<0.0001, Spearman correlation=0.38). The association between markers of fibrin degradation in patients with progressive breast cancer suggests that the D-dimer level is a clinically important marker for progression and points towards a relation between haemostasis and tumour progression. A role of interleukin-6, by influencing both angiogenesis and haemostasis, is suggested by these observations.
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PMID:Plasma fibrin D-dimer levels correlate with tumour volume, progression rate and survival in patients with metastatic breast cancer. 1187 5

Estrogens play important roles in the development of breast cancer. Inflammatory cytokines such as interleukin-6 (IL-6) and interleukin-1 beta (IL-1 beta) exist at high concentrations in breast cancer tissue. Although these cytokines are thought to exert some effect on cancer growth, their precise mechanism is still unclear. In the present study, we investigated the effects of inflammatory cytokines on aromatase (Arom) and steroid sulfatase (STS), which are estrogen-producing enzymes, and cell proliferation using human breast cancer cell lines (SK-BR-3, MCF-7). IL-6 and IL-1 beta stimulated the activity of Arom and STS. Estrone sulfate (E1-S) had a stimulus effect on cell proliferation of MCF-7. Although IL-6 did not show significant effect on cell proliferation, cell proliferation was significantly increased when IL-6 and E1-S were simultaneously added to the incubation medium. This cell proliferative effect was apparently stronger than the addition of E1-S alone. Addition of IL-1 beta in the presence of E1-S also significantly enhanced cell proliferation though IL-1 beta alone did not show any effect. These results led us to the hypothesis that inflammatory cytokines such as IL-6 and IL-1 beta regulate proliferation of breast cancer cells through estrogen production by steroid-catalyzing enzymes in the tissue.
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PMID:The influence of inflammatory cytokines on estrogen production and cell proliferation in human breast cancer cells. 1220 Dec 23

The decrease in ovarian estrogen production that occurs at the menopause may lead to an increase in peripheral aromatase activity. While estrogens can have beneficial effects on some body tissues, such as bone and the cardiovascular system, they also have a crucial role in supporting the growth and development of breast tumors. A number of factors, including interleukin-6 (IL-6), tumor necrosis factor alpha (TNFalpha), and prostaglandin E(2) (PGE(2)), which can stimulate aromatase activity, have now been identified. As plasma concentrations of some cytokines increase at the menopause, this may account for the increased peripheral aromatase activity that is detected in older women. Macrophages and lymphocytes which infiltrate breast tissue are now thought to be an important source of cytokines that can stimulate aromatase activity in this tissue. Studies, we have recently carried out, have suggested that the endogenous estrogen metabolite, 2-methoxy-estradiol, may be able to modulate the ability of cytokines and PGE(2) to stimulate aromatase activity. Understanding the role of endogenous estrogen metabolites in regulating estrogen synthesis may give rise to new strategies for the prevention or treatment of breast cancer.
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PMID:Regulation of estrogen synthesis in postmenopausal women. 1239 94

Interleukin-6 (IL-6) is a multifunctional cytokine produced by macrophages, T cells, B cells, endothelial cells and tumour cells. Interleukin-6 is able to promote tumour growth by upregulating anti-apoptotic and angiogenic proteins in tumour cells. In murine models it has been demonstrated that antibodies against IL-6 diminish tumour growth. Several reports have highlighted the prognostic importance of IL-6 in e.g., prostate and colon cancer. We addressed prospectively the prognostic significance of serum IL-6 (sIL-6), measured at diagnosis of metastasis, in 96 unselected and consecutive patients with progressive metastatic breast cancer before the initiation of systemic therapy. The median sIL-6 value for the breast cancer population was 6.6 +/- 2.1 pg/ml. Patients with 2 or more metastatic sites had higher sIL-6 values compared to those with only 1 metastatic site (respectively 8.15 +/- 1.7 pg/ml and 3.06 +/- 6.6 pg/ml; p < 0.001). Patients with liver metastasis (8.3 +/- 2.4 pg/ml), with pleural effusions (10.65 +/- 9.9 pg/ml) and with dominant visceral disease (8.15 +/- 3.3 pg/ml) had significantly higher values compared to those without liver metastases (4.5 +/- 3.4 pg/ml; p = 0.001), without pleural effusions (5.45 +/- 1.5 pg/ml; p = 0.0077) and with dominant bone disease (4.5 +/- 1.4 pg/ml; p = 0.007) respectively. No correlation between sIL-6 and age, menopausal status, performance status, tumour grade, body-mass index, histology and hormone receptor status was found. Multivariate analysis showed that high levels of serum IL-6 have independent prognostic value. We conclude that circulating IL-6 is associated with worse survival in patients with metastatic breast cancer and is correlated with the extent of disease.
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PMID:Circulating interleukin-6 predicts survival in patients with metastatic breast cancer. 1249 72

Metastasis of prostate cancer to bone is a common complication of progressive prostate cancer. Skeletal metastases are often associated with severe pain and thus demand therapeutic interventions. Although often characterized as osteoblastic, prostate cancer skeletal metastases usually have an underlying osteoclastic component. Advances in osteoclast biology and pathophysiology have led toward defining putative therapeutic targets to attack tumor-induced osteolysis. Several factors have been found to be important in tumor-induced promotion of osteoclast activity. One key factor is the protein receptor activator of nuclear factor-kappa B ligand (RANKL), which is required to induce osteoclastogenesis. RANKL is produced by prostate cancer bone metastases, enabling these metastases to induce osteolysis through osteoclast activation. Another factor, osteoprotegerin, is a soluble decoy receptor for RANKL and inhibits RANKL-induced osteoclastogenesis. Osteoprotegerin has been shown in murine models to inhibit tumor-induced osteolysis. In addition to RANKL, parathyroid hormone-related protein and interleukin-6 are produced by prostate cancer cells and can promote osteoclastogenesis. Finally, matrix metalloproteinases (MMPs) are secreted by prostate cancer cells and promote osteolysis primarily through degradation of the nonmineralized bone matrix. MMP inhibitors have been shown to diminish tumor establishment in bone in murine models. Thus, many factors derived from prostate cancer metastases can promote osteolysis, and these factors may serve as therapeutic targets. The importance of osteoclasts in the establishment and progression of skeletal metastases has led to clinical evaluation of therapeutic agents to target them for slowing metastatic progression. Bisphosphonates are a class of compounds that decrease osteoclast life span by promoting their apoptosis. The bisphosphonate pamidronate has proven clinical efficacy for relieving bone pain associated with breast cancer metastases and has a promising outlook for prostate cancer metastases. Another bisphosphonate, zoledronic acid, appears to directly target prostate cancer cells in addition to diminishing osteoclast activity at the metastatic site. In addition to bisphosphonates, other novel therapies based on studies that delineate mechanisms of skeletal metastases establishment and progression will be developed in the near future.
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PMID:The role of osteoclastic activity in prostate cancer skeletal metastases. 1253 87

Parathyroid hormone-related protein (PTHrP) is expressed in the mammary gland and appears to be critical to the morphogenesis of this structure. PTHrP production in the breast is generally attributed to epithelial cells. Because the stromal component of the breast produces factors implicated in proliferation and differentiation of mammary epithelial tissue and tumors, the aim of this study was to investigate the PTHrP expression by mammary fibroblasts from breast cancer tumors and normal breast. PTHrP antibodies labeled intralobular fibroblasts in normal breast and stromal fibroblasts that surround tumor cells. PTHrP was constitutively produced by the cultured mammary fibroblasts, independent of serum stimulation. Normal (15.83 +/- 1.72 fmol/10(6) cells) and pathological breast fibroblasts (19.87 +/- 5.76) secreted similar amounts of PTHrP. PTH/PTHrP receptor mRNA was detected by RT-PCR in all the samples tested. Fibroblasts from normal breast were both PTH and PTHrP-cAMP responsive (453 +/- 133% and 513 +/- 133%, respectively, from basal stimulation), whereas pathological breast fibroblasts were minimally PTHrP-cAMP responsive (183 +/- 36%). The production of other fibroblastic factors implicated in tumor growth and invasiveness was also examined. Interleukin-6 (IL-6), tumor necrosis factor-alpha (INF-alpha), and pro-matrix metalloproteinase (MMP)-1 were not affected by the status of the tissue. In contrast, increased levels of pro-MMP-2 were produced in fibroblasts that originated from pathological (290 +/- 62 ng/10(6) cells) samples compared with those from normal donors (125 +/- 41 ng/10(6) cells). PTHrP production was correlated with TNF-alpha and pro-MMP-2 production. However, inhibition with specific neutralizing antibodies against TNF-alpha or PTHrP, or with a PTHrP antagonist, showed that these factors did not regulate each other. In conclusion, breast fibroblasts are constitutive PTHrP-producing cells with the potential for autocrine signaling through the PTH/PTHrP receptor.
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PMID:Constitutive production of parathyroid hormone-related protein (PTHrP) by fibroblasts derived from normal and pathological human breast tissue. 1254 23

Interleukin-6 (IL-6) and interleukin-11 (IL-11) are frequently produced by breast cancer cells. These interleukins promote osteoclast formation and may mediate osteolysis at the site of breast cancer bone metastases. Transforming growth factor-beta (TGF-beta), tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) up-regulate IL-6 and IL-11 production in a cytokine-dependent fashion in breast cancer cells, but very little is known about their intracellular signaling pathways in breast cancer cells. To study TGF-beta, TNF-alpha and IL-1beta regulation of IL-6 and IL-11 production in human MDA-MB-231 breast cancer cells, we established single cell clones stably expressing dominant negative (DN) forms of the mitogen-activated protein kinases p38 (p38/AF) or ERK1 (ERK1K71R). We show here, that while basal, TGF-beta and IL-1beta induced IL-6 production was similar in parental cells and in pcDNA3 control, ERK1K71R and p38/AF clones, TNF-alpha induced IL-6 production was blunted in the ERK1K71R clones. TGF-beta and IL-1beta, but not TNF-alpha, induced IL-11 production in parental MDA-MB-231 cells. Similar findings were detected in clones stably expressing p38/AF and ERK1K71R, which did not change basal IL-11 production either. In conclusion, TNF-alpha induced IL-6 production is mediated via ERK1 activation in MDA-MB-231 cells. These observations may be helpful in designing new anti-osteolytic therapies.
Breast Cancer Res Treat 2003 Jul
PMID:Tumor necrosis factor-alpha induces interleukin-6 production via extracellular-regulated kinase 1 activation in breast cancer cells. 1288


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