Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P42345 (mTOR)
 26,049 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A limited number of therapeutic strategies are currently available for patients with inflammatory bowel disease (IBD). In particular, the maintenance therapy after remission in Crohn's disease (CD) is not satisfactory and new approaches are needed. Interleukin-10 gene-deficient (IL-10-/-) mice, a well-characterized experimental model of CD, develop severe chronic colitis due to an aberrant Th1 immune response. Everolimus, an inhibitor of the mammalian target of rapamycin (mTOR), a new immunosuppressive reagent, has been used successfully in animal models for heart, liver, lung and kidney transplantation. In the present study, we examined the efficacy of everolimus in the treatment of chronic colitis in an IL-10-/- mouse model. Everolimus was administered orally for a period of 4 weeks to IL-10-/- mice with clinical signs of colitis. The gross and histological appearances of the colon and the numbers, phenotype and cytokine production of lymphocytes were compared with these characteristics in a control group. The 4-week administration of everolimus resulted in a significant decrease in the severity of colitis, together with a significant reduction in the number of CD4+ T cells in the colonic lamina propria as well as IFN-gamma production in colonic lymphocytes. Everolimus treatment of established colitis in IL-10-/- mice ameliorated the colitis, probably as a result of decreasing the number of CD4+ T cells in the colonic mucosa and an associated reduction in IFN-gamma production.
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PMID:Therapeutic effect of a new immunosuppressive agent, everolimus, on interleukin-10 gene-deficient mice with colitis. 1743 23

Everolimus (40-O-(2-hydroxyethyl)rapamycin, Certican) is a 31-membered macrolide lactone. In lymphocytes, it inhibits the mammalian target of rapamycin (mTOR) and is used as an immunosuppressant after organ transplantation. Due to its instability in pure organic solvents and insufficient HPLC separation, NMR spectroscopy analysis of its metabolite structures is nearly impossible. Therefore, structural identification based on tandem mass spectrometry (MS/MS) and MS(n) fragmentation patterns is critical. Here, we have systematically assessed the fragmentation pattern of everolimus during liquid chromatography (LC)-electrospray ionization (ESI)-MS/MS and validated the fragment structures by (1) comparison with structurally identified derivatives (sirolimus), (2) high-resolution mass spectrometry, (3) elucidation of fragmentation pathways using ion trap mass spectrometry (up to MS(5)) and (4) H/D exchange. In comparison with the structurally related immunosuppressants tacrolimus and sirolimus, our study was complicated by the low ionization efficiency of everolimus. Detection of positive ions gave the best sensitivity, and everolimus and its fragments were mainly detected as sodium adducts. LC-ESI-MS/MS of everolimus in combination with collision-induced dissociation (CID) resulted in a complex fragmentation pattern and the structures of 53 fragments were identified. These detailed fragmentation pathways of everolimus provided the basis for structural elucidation of all everolimus metabolites generated in vivo und in vitro.
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PMID:Assessment and validation of the MS/MS fragmentation patterns of the macrolide immunosuppressant everolimus. 1751 Oct 17

Patient survival after heart transplantation has improved dramatically since the availability of calcineurine inhibitor (CNIs); the number of long-term patients is progressively increasing. However, in these patients, nephrotoxicity of CNIs has been largely responsible for the progressive development of renal dysfunction. Since impaired renal function is an important issue that reduces long-term patient survival, it is important to develop strategies to improve renal function while maintaining immunologic safety to preserve graft function. Everolimus is an mTOR inhibitor sirolimus analogue, that has proved, to be highly efficacious to prevent acute myocardial rejection and reduce the severity of cardiac allograft vasculopathy in de novo HTx patients. There is reasonable evidence that, in long term heart transplanted patients, renal function may improve when everolimus is administered associated with a progressive reduction of CNIs. So far there is no evidence to identify which patient may benefit from this therapeutic approach. Indeed everolimus alone may be equally effective to prevent rejection and improve renal function when CNIs are completely discontinued, but data are still lacking on the risks, dosages and side effects of this type of immunosuppression. Ongoing clinical studies will provide further guidance about the possibility to halt or reduce the progression of renal impairment in long term heart transplant patients.
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PMID:Possible role of everolimus in improving renal function in long-term heart transplantation. 1769 67

Everolimus inhibits the mammalian target of rapamycin (mTOR) in proliferating cells. It is widely used in transplant patients and has also been exploited by drug-eluting stents for the treatment of cardiovascular disease. However, there is only limited data on the pathophysiological effects of mTOR-inhibitors on the vascular wall. We aimed to unravel the effects of everolimus on cholesterol-induced atherosclerosis and on circulating cell mediators in LDL-receptor-deficient (LDLR(-/-)) mice. Male hypercholesterolemic LDLR(-/-) mice received either solvent (group A; n=28) or everolimus at 0.05 mg/kg (group B, n=22) and 1.5 mg/kg (group C, n=29) per body weight per day by subcutaneously implanted osmotic minipumps for the study period of 12 weeks. Group B showed 44% reduction of atherosclerotic lesions at the brachiocephalic artery (BCA). In group C atherosclerotic lesions were reduced by 85% in the BCA and by 60% at the aortic root. This was associated with a significantly lower complexity of lesions in both treated groups (p<0.001) and despite a 40% increase of plasma cholesterol. Everolimus caused a significant reduction of circulating cell mediators such as interleukin-1alpha, interleukin-5, GM-CSF and interleukin-12p40. Everolimus increased the plasma levels of KC but had no effect on eighteen other circulating cell mediators studied. Everolimus strongly inhibits atherosclerosis development in LDL-receptor(-/-) mice despite severe hypercholesterolemia. Everolimus application had only small effects on circulating cell mediators. The significant reduction of atherosclerotic lesions was associated with a delayed transition from early macrophages enriched lesions to advanced atherosclerotic plaques.
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PMID:Prevention of atherosclerosis by the mTOR inhibitor everolimus in LDLR-/- mice despite severe hypercholesterolemia. 1798 Mar 69

Inhibition of a single transduction pathway is often inefficient due to activation of alternative signalling. The mammalian target of rapamycin (mTOR) is a key intracellular kinase integrating proliferation, survival and angiogenic pathways and has been implicated in the resistance to EGFR inhibitors. Thus, mTOR blockade is pursued to interfere at multiple levels with tumour growth. We used everolimus (RAD001) to inhibit mTOR, alone or in combination with anti-EGFR drugs gefitinib or cetuximab, on human cancer cell lines sensitive and resistant to EGFR inhibitors, both in vitro and in vivo. We demonstrated that everolimus is active against EGFR-resistant cancer cell lines and partially restores the ability of EGFR inhibitors to inhibit growth and survival. Everolimus reduces the expression of EGFR-related signalling effectors and VEGF production, inhibiting proliferation and capillary tube formation of endothelial cells, both alone and in combination with gefitinib. Finally, combination of everolimus and gefitinib inhibits growth of GEO and GEO-GR (gefitinib resistant) colon cancer xenografts, activation of signalling proteins and VEGF secretion. Targeting mTOR pathway with everolimus overcomes resistance to EGFR inhibitors and produces a cooperative effect with EGFR inhibitors, providing a valid therapeutic strategy to be tested in a clinical setting.
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PMID:Inhibition of mTOR pathway by everolimus cooperates with EGFR inhibitors in human tumours sensitive and resistant to anti-EGFR drugs. 1831 15

Malignant peripheral nerve sheath tumors (MPNST) are chemoresistant sarcomas with poor 5-year survival that arise in patients with neurofibromatosis type 1 (NF1) or sporadically. We tested three drugs for single and combinatorial effects on collected MPNST cell lines and in MPNST xenografts. The mammalian target of rapamycin complex 1 inhibitor RAD001 (Everolimus) decreased growth 19% to 60% after 4 days of treatment in NF1 and sporadic-derived MPNST cell lines. Treatment of subcutaneous sporadic MPNST cell xenografts with RAD001 significantly, but transiently, delayed tumor growth, and decreased vessel permeability within xenografts. RAD001 combined with the epidermal growth factor receptor tyrosine kinase inhibitor erlotinib caused additional inhibitory effects on growth and apoptosis in vitro, and a small but significant additional inhibitory effect on MPNST growth in vivo that were larger than the effects of RAD001 with doxorubicin. RAD001 plus erlotinib, in vitro and in vivo, reduced phosphorylation of AKT and total AKT levels, possibly accounting for their additive effect. The results support the consideration of RAD001 therapy in NF1 patient and sporadic MPNST. The preclinical tests described allow rapid screening strata for drugs that block MPNST growth, prior to tests in more complex models, and should be useful to identify drugs that synergize with RAD001.
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PMID:Effective in vivo targeting of the mammalian target of rapamycin pathway in malignant peripheral nerve sheath tumors. 1848 11

The most serious complication of peritoneal dialysis is encapsulating peritoneal sclerosis (EPS). The prolonged inflammatory stimuli, fibrogenic cytokine overexpression, and angiogenesis that underlie EPS ultimately result in increased production of fibrous tissue, encapsulating the bowel loops. In recent years, inhibitors of mammalian target of rapamycin (mTOR) as an alternative agent for calcineurin inhibitor toxicity have been widely used in organ transplantation. These agents have also been used since the 1990s in endovascular medicine for drug-eluting stents because of antiproliferative effects on vascular smooth muscle cells and potent anti-inflammatory properties by direct action on human immune cells. Because of the shared characteristics of EPS and other fibrotic processes, we hypothesized that everolimus, an mTOR inhibitor can reverse the process responsible for the eventual development of EPS. We allocated 32 non-uremic albino Wistar rats to 4 groups: control group, 2 mL isotonic saline injected intraperitoneally (IP) daily for 3 weeks; CG group, 2 mL/200 g (0.1%) chlorhexidine gluconate (CG) injected IP daily and ethanol (15%) dissolved in saline, for 3 weeks; resting group, CG (weeks 0 - 3), plus peritoneal rest (weeks 3 - 6); and Evo-R, CG (weeks 0 - 3), plus 0.3 mg/L everolimus in drinking water (weeks 3 - 6). At the end of the study, we performed a 1-hour peritoneal equilibration test with 25 mL 3.86% PD solution, and examined the dialysate-to-plasma ratio of urea (D/P urea), dialysate white blood cell count, ultrafiltration (UF) volume, and morphologic change in the parietal peritoneum. Exposure to CG for 3 weeks resulted in alterations in peritoneal transport (increased D/P urea, decreased UF volume, p < 0.05) and morphology (increased inflammation, neovascularization, fibrosis, and peritoneal thickness, p < 0.05). Peritoneal rest has some beneficial effect only on UF failure and dialysate cell count (p < 0.05). However; everolimus was more effective than peritoneal rest with regard to vascularity and peritoneal thickness (p < 0.05). Everolimus has beneficial effects on UF failure, inflammation, and fibrosis. Everolimus may have therapeutic value in the management of EPS.
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PMID:Effects of everolimus as an antiproliferative agent on regression of encapsulating peritoneal sclerosis in a rat model. 1898 12

Everolimus (EVL), an antagonist of mammalian target of rapamycin, has been recently introduced into solid organ transplantation either associated with low dose of anticalcineurins (CNI) or replacing them in an attempt to avoid nephrotoxicity and chronic allograft nephropathy. Due to the molecular similarities with sirolimus, it has been expected that there would be the same incidence of metabolic changes and adverse events. We retrospectively studied kidney allograft recipients converted from CNI to EVL during a 12-month period. Patients received a standard dose of EVL starting at 1.5 mg/d and thereafter titrating to achieve trough levels in the range of 3 to 5 ng/mL. Patients achieved mean EVL trough levels of 5.2, 4.0 and 4.5 ng/mL at 1, 6, and 12 months, respectively. One year following conversion, the calculated creatinine clearance increased from 57 to 63 mL/min and proteinuria did not change. Fasting blood glucose levels decreased significantly following conversion to EVL. During the same time, no significant changes were observed in body weight, body mass index, albumin, cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, lipid-lowering medication requirements, blood magnesium, and uric acid. We concluded that EVL did not negatively influence various nutritional parameters.
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PMID:Metabolic changes following conversion from an anticalcineurin-based therapy to an everolimus-based one: a single-center experience. 1901 Feb 49

Monocytes/macrophages recruited into the arterial wall during atherogenesis are crucial in the initiation and progression of atherosclerosis and play a fundamental role in the destabilization process that is the main causal event of acute coronary syndromes. In the present study, we investigated the effect of the mammalian target of rapamycin inhibitor everolimus on macrophage accumulation within carotid lesions elicited by perivascular collar placement in cholesterol-fed rabbits. Everolimus (1.5 mg/kg given 1 day before collaring followed by 1 mg/kg/day for 14 days, administered by oral gavage) markedly decreased lesion macrophage content as compared with vehicle control (-65%; p < 0.01). This effect was associated with a reduction in intimal thickening and occurred in the absence of changes in plasma cholesterol concentrations. To gain insights on the potential mechanism(s) underlying this effect, we investigated the influence of everolimus on chemoattractant-induced migration of human monocytes in vitro. Pretreatment with therapeutic concentrations of everolimus (10 nM) significantly lowered monocyte chemotaxis in response to various chemotactic factors (i.e., monocyte chemoattractant protein-1/CCL2, fractalkine/CX3CL1, interleukin-8/CXCL8, complement fragment 5a, or N-formyl-Met-Leu-Phe) without inducing monocyte cell death. These results suggest that everolimus may favorably influence the atherosclerotic process by affecting the recruitment of monocytes into early lesions.
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PMID:Everolimus inhibits monocyte/macrophage migration in vitro and their accumulation in carotid lesions of cholesterol-fed rabbits. 1902 42

Mammalian target of rapamycin (mTOR), a serine/threonine kinase, is a mediator in the downstream signalling pathway phosphatidylinositol 3-kinase/Akt, playing a key role in regulation of basic cellular functions including growth and cell proliferation. The inhibitor of mTOR RAD001, or everolimus (Novartis Pharma AG), is a hydroxyethyl ether rapamycin derivative administered orally. Everolimus showed an important anti-angiogenic and antiproliferative activity on cell lines derived from human tumours and on xenograft models of human tumours. This molecule appears well tolerated, with skin reactions, stomatitis, myelosupression and metabolic abnormalities transient and reversible with interruption of treatment. Clear data suggest antitumor activity, including tumour regression and prolonged stable disease, which has been reported in patients with a variety of malignancies, especially those with metastatic renal cell cancer. Here, we review the preclinical data of this compound with current clinical results and future developments.
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PMID:[Everolimus (RAD001) and solid tumours: a 2008 summary]. 1909 55


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