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)

Although an aggressive phenotype of renal cell carcinoma (RCC) is known to frequently be associated with inflammatory paraneoplastic syndrome including serum C-reactive protein (CRP) elevation, the molecular mechanism underlying this clinical phenomenon as well as what yields the malignant phenotype leading to the progression of RCC has yet to be elucidated. Based on the increased level of inflammatory cytokines such as interleukin-6 in advanced cases of RCC, a cytokine-inducible transcription factor, namely, nuclear factor-kappa B (NF-kappa B), may thus play a role in the progression of RCC. An electrophoretic mobility shift assay (EMSA) was carried out to determine the activity of NF-kappa B. Out of 45 cases of RCC, 15 cases (33%) showed a >200% increase in the NF-kappa B activity in comparison with that seen in normal renal tissue. In locally advanced cases (> or =pT3), 64% (9/14) showed an increased activity whereas it was only observed in 19% (6/31) of localized cases (< or =pT2). All three cases with metastases showed an increased NF-kappa B activity. The NF-kappa B activity determined by EMSA was further confirmed by an immunohistochemical analysis using an antibody recognizing the nuclear localization signal (NLS) in p65 subunit of NF-kappa B. The serum CRP elevation correlated with the increased NF-kappa B activation, and therefore NF-kappa B may be a causative transcription factor of inflammatory paraneoplastic syndrome. A high NF-kappa B activity was associated with an increased expression of both the p65 and p50 subunits of NF-kappa B and a concomitant decreased expression of I kappa B alpha. No functional mutations of the I kappa B alpha gene were detected. The NF-kappa B activity may therefore be a late event in carcinogenesis related to tumor development, thereby representing a possible molecular target in the treatment of RCC.
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PMID:Increased nuclear factor-kappa B activation is related to the tumor development of renal cell carcinoma. 1266 95

We established a new renal carcinoma cell line that produces parathyroid hormone-related protein (PTHrP) and interleukin-6 in culture. The cellular production of PTHrP was confirmed by Northern blot analysis and immunofluorescence examination. Bone and lung metastases occurred simultaneously 3.5 years after surgery. The patient did not show hypercalcemia at this time, despite the presence of multiple osteolytic metastases. About 7 months after bone metastasis was first shown, serum PTHrP was detected by means of an immunoradiometric assay and the calcium level was found to be elevated to 3.29 mmol/l. The hypercalcemia was successfully controlled by i.v. administration of bisphosphonates.
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PMID:Hypercalcemia upon recurrence of renal cell carcinoma producing parathyroid hormone-related protein. 1277 88

Since the growth of prostate cancer is androgen-sensitive, metastatic disease has been treated by hormonal therapy. Almost all prostate cancer patients initially respond to hormonal therapy, but the majority gradually develop resistance. The mechanism of the change in tumors from being androgen-responsive to androgen-unresponsive is generally explained by clonal selection, adaptation, an alternative pathway of signal transduction and androgen receptor (AR) involvement. Since androgen action is mediated by ARs, abnormalities in ARs are believed to play an important role in the progression of prostate cancer. Hyperactivated AR gene mutations have been detected in 20-30% of hormone-refractory tumors and functional analyses have demonstrated a wide responsiveness to estrogens, progesterone and anti-androgens as well as to androgens. The AR is highly amplified in 30% of patients with hormone-refractory prostate cancer that has been treated by castration without anti-androgens. Immunohistochemical studies of ARs in hormone-refractory prostate cancer specimens have shown that AR protein is down-regulated. DNA hypermethylation of the AR promoter region leading to AR down-regulation has been identified in 30% of hormone-refractory prostate cancers. The AR N-terminal domain in the LNCaP cell line model is activated by interleukin-6 via mitogen-activated protein kinase and single transducers and activators of transcription 3. Epidemiological observations have shown that short CAG repeats are more frequently associated with higher transactivational function in the African-American population, which may explain racial differences in the incidence of prostate cancer. Among Japanese, a short CAG repeat appears to predict a response to hormonal therapy, indicating a positive prognostic value and good prognosis at the metastatic stage of prostate cancer. Several co-factors between ARs and the transcriptional complex have been cloned and reports indicate that steroid receptor co-activator 1 is correlated with the hormone-refractory progression of prostate cancer. Thus, ARs plays an important role in the progression of prostate cancer. Based on the findings described above, genetic diagnosis and/or molecular-targeted therapy via AR pathways can be developed for hormone-refractory states.
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PMID:Androgen receptor involvement in the progression of prostate cancer. 1279 Jul 84

Interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-alpha) are important multifunctional cytokines involved in tumour growth and metastasis. In this study, we have measured serial levels of serum IL-6 and TNF-alpha in prostate cancer patients. A total of 80 patients with carcinoma of the prostate and 38 controls were studied. Three patient groups, with small bulk localised, large volume localised and metastatic prostate cancer, were assessed. Serum IL-6 and TNF-alpha levels were measured and correlated with clinicopathological variables and patient survival. Serial changes in these cytokines were also assessed and related to disease progression in 40 patients with recurrent prostate cancer. Serum IL-6 levels in patients with metastatic disease (9.3+/-7.8 pg x ml(-1)) were higher than those in patients with localised disease (1.3+/-0.8 pg x ml(-1), P<0.001). Significantly elevated levels of TNF-alpha were found in metastatic disease (6.3+/-3.6 pg x ml(-1)) compared with localised disease (1.1+/-0.5 pg x ml(-1), P<0.001). The levels of both cytokines were directly correlated with the extent of the disease. Serial analysis in 40 patients with recurrent tumours showed that both cytokines became elevated at the point of prostate-specific antigen progression. In conclusion, these results suggest that IL-6 and TNF-alpha correlate with the extent of disease in patients with prostate cancer and may be monitored in conjunction with other disease markers.
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PMID:Serum levels of IL-6 and TNF-alpha correlate with clinicopathological features and patient survival in patients with prostate cancer. 1515 May 88

The androgen receptor (AR) is implicated in regulation of cellular events in advanced prostate cancer. It is expressed in primary tumours as well as in metastases from patients who failed endocrine therapy. Activation of the AR in metastatic tumours occurs as a result of increased sensitivity of the receptor, point mutations that alter activation spectrum and in response to various nonsteroidal compounds. Peptide growth factors that activate the signalling pathway of mitogen-activated protein kinases (MAPK) stimulate AR activity in ligand-independent or synergistic manner. Outcome of nonsteroidal activation depends on cellular and promoter context. AR activation by Her-2/neu is associated with enhanced tumour growth of the LAPC-4 xenograft. The issue whether MAPK or protein kinase Akt involved in growth factor signalling directly phosphorylate the AR is a matter of debate. AR ligand-independent activation by protein kinase A activators was also demonstrated. Under physiological conditions, potentiation of AR activity by low doses of androgen might be of importance in prostate cancer patients who receive endocrine therapy. Interleukin-6 (IL-6) and related cytokines also activate AR in a ligand-independent and synergistic manner. IL-6 is a pleiotropic regulator of tumour growth, which in some prostate cancers acts as a paracrine growth inhibitor and in other cases as an autocrine growth stimulator. Activation of the AR by IL-6 requires functional pathways of Janus kinases/signal transducers and activators of transcription factors and MAPK. Studies on AR co-activators implicated in ligand-independent activation may further improve understanding of cross-talk between signalling pathways.
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PMID:Androgen receptor cross-talk with cell signalling pathways. 1551 41

Human androgen receptor (AR) associates with coactivator or corepressor proteins that modulate its activation in the presence of ligand. Early studies on AR coactivators in carcinoma of the prostate were hampered because of lack of respective antibodies. Investigations at mRNA level revealed that most benign and malignant prostate cells express common coactivators. AR coactivators SRC-1 and TIF-2 are up-regulated in tissue specimens obtained from patients who failed prostate cancer endocrine therapy. Increased expression of these coactivators is associated with enhanced activation of the AR by the adrenal androgen dehydroepiandrosterone. Similar association between AR coactivator expression and high prostate cancer grade and stage was reported for RAC-3 (SRC-3). The transcriptional integrator CBP was detected in clinical specimens representing organ-confined prostate cancer, lymph node metastases and tumour cell lines. Agonistic effect of the nonsteroidal antiandrogen hydroxyflutamide was strongly potentiated in prostate cells transfected with CBP cDNA. A functional homologue of CBP, p300, is implicated in ligand-independent AR activation by interleukin-6. The AR coactivator Tip60, which is up-regulated by androgen ablation, is recruited to the promoter of the prostate-specific antigen gene in the absence of androgen in androgen-independent prostate cancer sublines. It was proposed that the cofactor ARA70 is a specific enhancer of AR action. However, research from other laboratories has demonstrated interaction between ARA70 and other steroid receptors. Although in some cases dominant-negative coactivator mutants inhibited proliferation of prostate cancer cells in vitro, confirmation from in vivo tumour models is missing. In summary, several abnormalities in AR coactivator expression and function are associated with prostate cancer progression.
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PMID:Expression and function of androgen receptor coactivators in prostate cancer. 1566 89

Prostate cancer (CaP) metastases selectively develop in bone as opposed to other sites through unknown mechanisms. Interleukin-6 (IL-6) is considered to contribute to CaP progression and is produced at high levels in osteoblasts. We hypothesized that osteoblast-derived IL-6 in the bone microenvironment contributes to the fertile soil for CaP growth. Accordingly, human CaP cells, LNCaP, C4-2B and VCaP, were treated with conditioned medium (CM) collected from human osteoblast-like HOBIT cells grown in androgen-depleted medium. We found that CM induced proliferation, prostate-specific antigen (PSA) protein and mRNA expression in a dose-dependent manner in these cell lines as determined by ELISA and real-time PCR, respectively. CM also activated the PSA promoter in these cells. Both HOBIT and primary osteoblast (POB) cells produced high levels of IL-6 measured by bioassay. LNCaP, C4-2B and VCaP cells expressed IL-6, but at much lower levels then the HOBIT and POB and they also expressed the IL-6 receptor mRNA, indicating they can respond to IL-6. Anti-IL-6 antibody added to HOBIT or POB CM dose-dependently inhibited the CM-induced cell proliferation and PSA expression in these CaP cell lines. HOBIT CM induced nuclear translocation of the AR and this was inhibited by anti-IL-6 antibody. Additionally, the antiandrogen bicalutamide inhibited HOBIT CM-induced cell proliferation. These results demonstrate that osteoblasts promote CaP growth through IL-6-mediated activation of the AR. Furthermore, these data underscore the importance of cross-talk between tumor and the bone microenvironment in the development of CaP bone metastases.
Clin Exp Metastasis 2004
PMID:Osteoblasts induce prostate cancer proliferation and PSA expression through interleukin-6-mediated activation of the androgen receptor. 1567 64

Metastasis is a multistep process involving a variety of direct cell-cell, cell-matrix and paracrine interactions. In the present study, we examined some consequences of direct interaction between tumour cells and endothelial cells in vitro. When multicellular spheroids of two human tumour cell lines (HeLa and Hep-2) were transferred onto a human umbilical vein endothelial cell (HUVEC) monolayer, a peri-spheroidal zone of damaged endothelial cells was observed after 24h co-culture. To determine the cause of this damage, the production levels of superoxide anion (O2-), interleukin-6 (IL-6) and metalloproteinase-2 (MMP-2) were measured both in co-culture and in monocultures of the tumour cell spheroids and endothelial cells. Attachment of HeLa and Hep-2 cellular spheroids to the HUVEC monolayer resulted in 1.6-fold and 2.1-fold increases in O2- release, respectively. Also, the MMP-2 level was five times greater in the co-culture than in the tumour spheroid monoculture. The increase of IL-6 in the co-culture model, on the other hand, was only slight. However, a 2h preincubation of endothelial cells with LPS (10 microg/ml) prior to the transfer of spheroids induced a significant increase in the production of this cytokine compared to an appropriate control (an LPS-activated endothelial cell monolayer). These results strongly suggest that both ROS and MMP-2 are involved in endothelial cell injury when tumour cells cross the endothelial barrier. Moreover, IL-6, which participates in the inflammatory response, may also be involved in the extravasation of tumour cells.
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PMID:Role of reactive oxygen species (ROS), metalloproteinase-2 (MMP-2) and interleukin-6 (IL-6) in direct interactions between tumour cell spheroids and endothelial cell monolayer. 1589 83

Prostate cancer has a propensity to metastasize to the bone. Currently the only effective systemic treatment for these patients is androgen ablation therapy. However, the tumor will invariably progress to an androgen-independent stage and the patient will succumb to his disease within approximately 2 years. The earliest indication of hormonal progression is the rising titer of serum prostate specific antigen. Current evidence implicates the androgen receptor (AR) as a key factor in maintaining the growth of prostate cancer cells in an androgen-depleted state. Under normal conditions, binding of ligand activates the receptor, allowing it to effectively bind to its respective DNA element. However, AR is also transformed in the absence of androgen (ligand-independent activation) in prostate cells via multiple protein kinase pathways and the interleukin-6 (IL-6) pathway that converge upon the N-terminal domain of the AR. This domain is the main region for phosphorylation and is also critical for normal coregulator recruitment. Here we discuss evidence supporting the role of the AR, IL-6 and other protein kinase pathways in the hormonal progression of prostate cancer to androgen independence and the mechanisms involved in activation of the AR by these pathways. Receptor-targeted therapy, especially potential drugs targeting the N-terminal domain, may effectively prevent or delay the hormonal progression of AR-dependent prostate cancer.
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PMID:Amino-terminus domain of the androgen receptor as a molecular target to prevent the hormonal progression of prostate cancer. 1644 Mar

Endocrine therapy for advanced prostate cancer is based on androgen ablation or blockade of the androgen receptor (AR). AR action in prostate cancer has been investigated in a number of cell lines, their derivatives, and transgenic animals. AR expression is heterogenous in prostate cancer in vivo; it could be detected in most primary tumors and their metastases. However, some cells lack the AR because of epigenetic changes in the gene promoter. AR expression increases after chronic androgen ablation in vitro. In several xenografts, AR upregulation is the most consistent change identified during progression towards therapy resistance. In contrast, the AR pathway may be by-passed during chronic treatment with a nonsteroidal anti-androgen. AR sensitivity in prostate cancer increases as a result of activation of the Ras/mitogen-activated protein kinase pathway. One of the major difficulties in endocrine therapy for prostate cancer is acquisition of agonistic properties of AR antagonists observed in the presence of mutated AR. Enhancement of AR function by associated coactivator proteins has been extensively investigated. Cofactors SRC-1, RAC3, p300/CBP, TIF-2, and Tip60 are upregulated in advanced prostate cancer. Most studies on ligand-independent activation of the AR are focused on Her-2/neu and interleukin-6 (IL-6). On the basis of studies that showed overexpression and activation of the AR in advanced prostate cancer, it was suggested that novel therapies that reduce AR expression will provide a benefit to patients. There is experimental evidence showing that prostate tumor growth in vitro and in vivo is inhibited following administration of chemopreventive drugs or antisense oligonucleotides that downregulate AR mRNA and protein expression.
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PMID:Androgen axis in prostate cancer. 1659 69


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