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)

Some murine leukemia viruses (MuLVs), among them Cas-Br-E and ts-1 MuLVs, are neurovirulent, inducing spongiform myeloencephalopathy and hind limb paralysis in susceptible mice. It has been shown that the env gene of these viruses harbors the determinant of neurovirulence. It appears that neuronal loss occurs by an indirect mechanism, since the target motor neurons have not been found to be infected. However, the pathogenesis of the disease remains unclear. Several lymphokines, cytokines, and other cellular effectors have been found to be aberrantly expressed in the brains of infected mice, but whether these are required for the development of the neurodegenerative lesions is not known. In an effort to identify the specific effectors which are indeed required for the initiation and/or development of spongiform myeloencephalopathy, we inoculated gene-deficient (knockout [KO]) mice with ts-1 MuLV. We show here that interleukin-6 (IL-6), inducible nitric oxide synthetase (iNOS), ICE, Fas, Fas ligand (FasL), and TNF-R1 KO mice still develop signs of disease. However, transgenic mice overexpressing Bcl-2 in neurons (NSE/Bcl-2) were largely protected from hind limb paralysis and had less-severe spongiform lesions. These results indicate that motor neuron death occurs in this disease at least in part by a Bcl-2-inhibitable pathway not requiring the ICE, iNOS, Fas/FasL, TNF-R1, and IL-6 gene products.
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PMID:Protection against murine leukemia virus-induced spongiform myeloencephalopathy in mice overexpressing Bcl-2 but not in mice deficient for interleukin-6, inducible nitric oxide synthetase, ICE, Fas, Fas ligand, or TNF-R1 genes. 1464 73

Terminal B-cell differentiation is a multi-step process, from short-lived plasmablasts to mature long-lived plasma cells (PC). The anti-apoptotic Bcl-2 family member Bfl-1/A1 plays a critical role in the survival of mature B cells. However, its potential involvement at the later stages of B-cell development remains highly controversial. Our aim was thus to clarify the place of Bfl-1/A1 in the biology of normal PC and in the pathogenesis of multiple myeloma (MM), the major PC dyscrasia. Using gene expression profiling and quantifiable reverse transcription polymerase chain reaction experiments, we found a similar down-regulation of Bfl-1/A1 in both normal immature plasmablasts and mature PC when compared with B cells. In myeloma cells, the level of Bfl-1/A1 was low and Bfl-1/A1 was not a nuclear factor kappaB-inducible gene. Collectively, these data demonstrate that Bfl-1/A1 is not involved in the prolonged survival of normal mature PC, and that Bfl-1/A1 deregulation is not a common oncogenic event in MM. However, overexpression of Bfl-1/A1 by retroviral transduction promoted autonomous survival of an interleukin-6-dependent myeloma cell line and rendered it less sensitive to dexamethasone. Thus, Bfl-1/A1 transduction could be an interesting tool to obtain myeloma cell lines from primary samples and to favour the in vitro generation of antibody-secreting, long-lived normal PC.
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PMID:The Bcl-2 family member Bfl-1/A1 is strongly repressed in normal and malignant plasma cells but is a potent anti-apoptotic factor for myeloma cells. 1508 20

Interactions between the cyclin-dependent kinase inhibitor flavopiridol and the small-molecule Bcl-2 antagonist HA14-1 were examined in human multiple myeloma cells. Whereas individual treatment of U266 myeloma cells with 10 micromol/L HA14-1 or 100 nmol/L flavopiridol had little effect, exposure of cells to flavopiridol (6 hours) followed by HA14-1 (18 hours) resulted in a striking increase in mitochondrial dysfunction (cytochrome c and Smac/DIABLO release; loss of mitochondrial membrane potential), activation of the caspase cascade, apoptosis, and diminished clonogenic survival. Similar findings were noted in other myeloma cell lines (e.g., MM.1S, RPMI8226, and NCI-H929) as well as in those resistant to dexamethasone and cytotoxic agents (e.g., MM.1R, 8226/Dox40, and 8226/LR5). Combined exposure to flavopiridol and HA14-1 was associated with down-regulation of Mcl-1 and Bcl-xL, Bid cleavage, and mitochondrial translocation of Bax. Flavopiridol/HA14-1-treated cells also exhibited a pronounced activation of Jun NH2-terminal kinase, a modest activation of p38 mitogen-activated protein kinase, and down-regulation of cyclin D1. Flavopiridol/HA14-1-induced apoptosis was associated with a marked increase in reactive oxygen species generation; moreover,both events were attenuated by the antioxidant N-acetyl-l-cysteine. Finally, in contrast to dexamethasone, flavopiridol/HA14-1-induced lethality was unaffected by exogenous interleukin-6 or insulin-like growth factor-I. Together, these findings indicate that flavopiridol and the small-molecule Bcl-2 antagonist HA14-1 cooperate to trigger oxidant injury, mitochondrial dysfunction, caspase activation, and apoptosis in human multiple myeloma cells and suggest that this approach may warrant further evaluation as an antimyeloma strategy.
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PMID:The small-molecule Bcl-2 inhibitor HA14-1 interacts synergistically with flavopiridol to induce mitochondrial injury and apoptosis in human myeloma cells through a free radical-dependent and Jun NH2-terminal kinase-dependent mechanism. 1563 44

Interleukin-6 (IL-6) has an essential role in the initial progression of myeloma cell tumours. IL-6 triggers proliferation of these cells via the Ras-mitogen-activated protein kinase (MAPK) cascade and is thought to promote their survival via signal transducer and activator of transcription (STAT) pathway-dependent regulation of Bcl-2 family antiapoptotic members. Using IL-6-dependent murine B9 hybridoma/plasmacytoma cells, we here report that exiting the cell cycle G1 phase is a crucial step contributing to maintain viability. We show that (1) drug-mediated reversible G1 arrest triggered apoptosis despite the presence of IL-6; (2) a short IL-6 pulse to G1-arrested cells was sufficient to induce S phase entry and prevent apoptosis; and (3) phorbol ester and related derivatives promoted S phase entry and survival of IL-6-starved cells without up-regulating bcl-XL expression. Furthermore, that the MAPK kinase (MEK) 1/2 inhibitor, U0126, blocked proliferation and induced death of B9 cells indicate that IL-6 may not exert its survival effect primarily through bcl-XL and emphasizes the key role of Ras-MAPK cascade elements in the regulation of myeloma growth/viability.
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PMID:The survival of IL-6-dependent myeloma cells critically relies on their capability to transit the G1 to S phase interval of the cell cycle. 1568 36

We and others have shown that Mcl-1 was essential for the survival of human myeloma cells in vitro. Furthermore, this antiapoptotic protein is upregulated by interleukin-6, which plays a critical role in multiple myeloma (MM). For these reasons, we have evaluated the expression of Mcl-1 in vivo in normal, reactive and malignant plasma cells (PC), that is, myeloma cells from 51 patients with MM and 21 human myeloma cell lines (HMCL) using flow cytometry. We show that Mcl-1 is overexpressed in MM in comparison with normal bone marrow PC. In total, 52% of patients with MM at diagnosis (P=0.017) and 81% at relapse (P=0.014 for comparison with diagnosis) overexpress Mcl-1. Of note, only HMCL but not reactive plasmacytoses have abnormal Mcl-1 expression, although both PC expansions share similar high proliferation rates. Of interest, Bcl-2 as opposed to Mcl-1, does not discriminate malignant from normal PC. Finally, the level of Mcl-1 expression is related to disease severity, the highest values at diagnosis being associated with the shortest event-free survival (P=0.002). In conclusion, Mcl-1, which has been shown to be essential for the survival of human myeloma cells in vitro, is overexpressed in vivo in MM in relation with relapse and shorter survival. Mcl-1 represents a potential therapeutical target in MM.
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PMID:Mcl-1 is overexpressed in multiple myeloma and associated with relapse and shorter survival. 1590 94

Multiple myeloma (MM) accounts for 1 % of all cancer deaths. Although treated aggressively, almost all myelomas eventually recur and become resistant to treatment. Atiprimod (2-(3-Diethylaminopropyl)-8,8-dipropyl-2-azaspiro[4,5] decane dimaleate) has exerted anti-inflammatory activities and inhibited oeteoclast-induced bone resorption in animal models and been well tolerated in patients with rheumatoid arthritis in phase I clinical trials. Therefore, we investigated its activity in MM cells and its mechanism of action. We found that Atiprimod inhibited proliferation of the myeloma cell lines U266-B1, OCI-MY5, MM-1, and MM-1R in a time- and dose-dependent manner. Atiprimod blocked U266-B1 myeloma cells in the G(0)/G(1) phase, preventing cell cycle progression. Furthermore, Atiprimod inhibited signal transducer and activator of transcription (STAT) 3 activation, blocking the signalling pathway of interleukin-6, which contributes to myeloma cell proliferation and survival, and downregulated the antiapoptotic proteins Bcl-2, Bcl-X(L), and Mcl-1. Incubation of U266-B1 myeloma cells with Atiprimod induced apoptosis through the activation of caspase 3 and subsequent cleavage of the DNA repair enzyme poly(adenosine diphosphate-ribose) polymerase. Finally, Atiprimod suppressed myeloma colony-forming cell proliferation in fresh marrow cells from five patients with newly diagnosed MM in a dose-dependent fashion. These data suggest that Atiprimod has a role in future therapies for MM.
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PMID:Atiprimod blocks STAT3 phosphorylation and induces apoptosis in multiple myeloma cells. 1597 Sep 28

We report a 75-year-old Japanese woman with classic Kaposi's sarcoma. PCR amplified human herpesvirus 8 (HHV-8) DNA sequences from her skin lesions and peripheral blood mononuclear cells (PBMC), but not her plasma, saliva or urine. An antibody test against HHV-8 lytic antigens was positive. Immunohistochemical staining detected latent antigen. There was no evidence of HHV-8 infection in her husband, sister or daughter. Genes coding for HHV-8-encoded viral interleukin-6, viral macrophage inflammatory protein I, viral G protein-coupled receptor, viral cyclin D and viral Bcl-2 were expressed to the same degree in both her skin lesion and PBMC. Latency-associated T0.7 mRNA and HHV-8-encoded viral tegument protein genes were expressed in her PBMC at levels lower than in the skin lesions. Based on the gene expression profile, we concluded that lytic HHV-8 infection was present in her skin lesions and PBMC.
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PMID:Transcripts of the human herpesvirus 8 genome in skin lesions and peripheral blood mononuclear cells of a patient with classic Kaposi's sarcoma. 1630 2

Failure of severed adult CNS axons to regenerate could be attributed to both a reduced intrinsic capacity to grow and an heightened susceptibility to inhibitory factors of the CNS extracellular environment. A particularly interesting and useful paradigm for investigating CNS axonal regeneration is its enhancement at the CNS branch of dorsal root ganglion (DRG) neurons after conditional lesioning of their peripheral branch. Recent reports have implicated the involvement of two well-known signaling pathways utilizing separate transcription factors; the Cyclic AMP (cAMP) response element binding protein (CREB) and signal transducer and activator of transcription 3 (STAT3), in conditional lesioning. The former appears to be the pathway activated by neurotrophic factors and Bcl-2, while the latter is responsible for the neurogenic effect of cytokines [such as the leukemia inhibitory factor (LIF) and interleukin-6 (IL-6) elevated at lesion sites]. Recent findings also augmented earlier notions that modulations of the activity of another class of cellular signaling intermediate, the conventional protein kinase C (PKC), could result in a contrasting growth response by CNS neurons to myelin-associated inhibitors. We discuss these signaling pathways and mechanisms, in conjunction with other recent reports of regeneration enhancement and also within the context of what is known about aiding regeneration of injured CNS axons.
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PMID:Axonal regeneration in adult CNS neurons--signaling molecules and pathways. 1647 81

Resveratrol has been proposed to act as a chemopreventive agent in numerous epidemiologic studies and has been shown to inhibit proliferation of various tumor cells in vitro. In the present study, we investigated the antitumor effects of resveratrol on multiple myeloma (MM) cells and the mechanisms involved. Our findings indicated that resveratrol inhibited proliferation of tumor cells in a dose- [corrected] dependent manner by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and [3H]thymidine incorporation assay. Resveratrol also enhanced the inhibitory effect of dexamethasone on the growth of MM cells by MTT assay. Flow cytometric analysis demonstrated that resveratrol arrested the cells at the G1 and S phases of the cell cycle. Because nuclear factor-kappaB (NF-kappaB) plays a key role in cell survival and proliferation of human MM cells, we tested the effect of resveratrol on NF-kappaB expression by Western blot analysis and immunofluorescence. NF-kappaB was constitutively active in all human MM cell lines examined, and resveratrol down-regulated NF-kappaB expression in all cell lines. Resveratrol also down-regulated the expression of NF-kappaB-regulated gene products by Western blot analysis, gelatin zymography, and enzyme-linked immunosorbent assay, including interleukin-6, Bcl-2, Bcl-xL, XIAP, c-IAP, vascular endothelial growth factor (VEGF), and matrix metalloproteinase-9 (MMP-9), which modulates an array of signals controlling cellular survival and proliferation and tumor promotion. Indeed, annexin V-fluoroisothyocyanate and Transwell invasion analyses revealed that incubation of MM cells with resveratrol resulted in apoptotic cell death and inhibition of invasion. In conclusion, these data suggest that resveratrol is an effective in vitro inhibitor of NF-kappaB in human MM cells. Resveratrol plays a role in suppressing the proliferation of MM cells and induces apoptosis, thus providing the molecular basis for the treatment of MM patients with this compound.
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PMID:Resveratrol downregulates the constitutional activation of nuclear factor-kappaB in multiple myeloma cells, leading to suppression of proliferation and invasion, arrest of cell cycle, and induction of apoptosis. 1649 May 92

Interleukin-6 (IL-6) is an important mediator of liver regeneration and repair that is also elevated in chronic liver diseases, including fatty liver of obesity and cirrhosis. IL-6 has been reported both to delay and accelerate liver regeneration. We examined the effects on liver injury and regeneration of a continuous administration of exogenous IL-6 to mice by injection of an IL-6-expressing CHO-cell line in athymic nude mice and by osmotic mini-pump delivery of recombinant murine IL-6. Short-term IL-6 administration (1-2 days) accelerated early recovery of liver mass, whereas more long-term administration (5-7 days) markedly impaired liver regeneration. Similarly, short-term IL-6 treatment increased hepatic resistance to the lethal effects of the Fas agonist Jo-2, but on more prolonged IL-6 exposure the Jo-2 resistance vanished. IL-6 administration initially induced expression of the anti-apoptotic proteins Bcl-2 and Bcl-xL, correlating with protection against Fas-mediated cell death. More prolonged IL-6 administration, however, resulted in marked induction of the pro-apoptotic protein Bax. This result coincided with increased activation of the type II or intrinsic, mitochondrial path to cell death, manifested by increased caspase-9 activation and increased cytochrome c release after Jo-2 exposure. These data demonstrate that IL-6 can function acutely to improve hepatic regeneration and repair, but that more chronic exposure not only abolishes the protective effects of IL-6, but actually sensitizes the liver to injury and death. In conclusion, elevated IL-6 in certain chronic liver diseases contributes to an increased likelihood of liver failure after injury.
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PMID:Paradoxical effects of short- and long-term interleukin-6 exposure on liver injury and repair. 1649 6


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