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

Metastatic renal cell carcinoma (RCC) is notoriously chemoresistant; up until recently, immunotherapy (in particular interferon-alpha) has represented the treatment of choice. The understanding of the biology of RCC has resulted in the development of targeted therapies. In particular, multikinase inhibitors (sunitinib, sorafenib, axitinib, pazopanib), antivascular endothelial growth factor agents (bevacizumab), and mammalian target of rapamycin inhibitors (temsirolimus, everolimus) now have a role in the approach to different subsets of RCC. Sunitinib is indicated for the first-line therapy of metastatic RCC as a consequence of a positive phase III trial versus interferon-alpha; sorafenib is now registered for the second-line treatment of RCC, which was earlier treated with cytokine as a consequence of a positive phase III trial versus placebo. Bevacizumab is also indicated in the first-line treatment of metastatic RCC given in combination with interferon-alpha as a consequence of two positive phase III trials. Temsirolimus, unlike the other agents, has also shown activity in poor-prognosis patients, and is now the treatment of choice in previously untreated poor-prognosis RCC as a single agent. Everolimus can be considered as the best therapeutic option in patients with RCC pretreated with targeted agents as a consequence of a positive phase III study versus best supportive care. Markers for appropriate treatment selection, combined use of targeted agents, treatment of special histologies, and adjuvant and neoadjuvant setting represent important special issues to be dealt with in future studies.
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PMID:New treatment approaches in renal cell carcinoma. 1975 18

The mammalian target of rapamycin (mTOR) pathway regulates translation of key proteins that contribute to the pathogenesis of advanced hematologic malignancies. Inhibitors of mTOR (temsirolimus, everolimus, and deforolimus) constitute a new class of antitumor agents, with potential for treatment of relapsed and/or refractory hematologic malignancies. Mantle cell lymphoma (MCL) was the first hematologic malignancy in which mTOR inhibition was explored as a treatment strategy, owing to its characteristic overexpression of cyclin D1, a G1 cyclin regulated by mTOR signaling. Temsirolimus and everolimus exhibited antitumor activity against relapsed, refractory disease in phase II studies. In a randomized phase III trial, once-weekly intravenous temsirolimus 175 mg for 3 weeks followed by 75 mg once weekly was recently shown to improve progression-free survival (p=0.0009) and objective response rate (p=0.0019) versus investigator's choice of therapy in relapsed or refractory MCL. Evidence of antitumor activity seen in early clinical trials for other non-Hodgkin lymphoma subtypes, multiple myeloma, and myeloid leukemias supports further studies of mTOR inhibitors, alone or in combination strategies, in these diseases. Overall, the clinical findings to date strengthen mTOR inhibition as a novel and promising strategy for the treatment of certain hematologic malignancies, particularly for MCL.
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PMID:Exploring mammalian target of rapamycin (mTOR) inhibition for treatment of mantle cell lymphoma and other hematologic malignancies. 1975 6

Activation of the mTORC1 pathway has been implicated in many types of cancer, and several mTORC1 inhibitors are currently under clinical trials for treating various cancer patients. Notably, Temsirolimus has recently been approved for treatment of advanced renal cell carcinoma. However, the role of mTORC1 pathway in colorectal tumorigenesis remains largely unknown. We have recently found that the mTORC1 pathway is activated in intestinal adenomas of Apc mutant mice, accompanied by an elevated level of mTOR protein, and that treatment with RAD001, an mTORC1 inhibitor, suppresses the growth of these polyps. Our results suggest an important role of mTORC1 pathway in colorectal cancer, as well as a therapeutic possibility for mTORC1 inhibitors in its treatment.
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PMID:The role of mTORC1 pathway in intestinal tumorigenesis. 1985 61

The mammalian target of rapamycin (mTOR) is an intracellular serine/threonine protein kinase positioned at a central point in a variety of cellular signaling cascades. The established involvement of mTOR activity in the cellular processes that contribute to the development and progression of cancer has identified mTOR as a major link in tumorigenesis. Consequently, inhibitors of mTOR, including temsirolimus, everolimus, and ridaforolimus (formerly deforolimus) have been developed and assessed for their safety and efficacy in patients with cancer. Temsirolimus is an intravenously administered agent approved by the US Food and Drug Administration (FDA) and the European Medicines Agency (EMEA) for the treatment of advanced renal cell carcinoma (RCC). Everolimus is an oral agent that has recently obtained US FDA and EMEA approval for the treatment of advanced RCC after failure of treatment with sunitinib or sorafenib. Ridaforolimus is not yet approved for any indication. The use of mTOR inhibitors, either alone or in combination with other anticancer agents, has the potential to provide anticancer activity in numerous tumor types. Cancer types in which these agents are under evaluation include neuroendocrine tumors, breast cancer, leukemia, lymphoma, hepatocellular carcinoma, gastric cancer, pancreatic cancer, sarcoma, endometrial cancer, and non-small-cell lung cancer. The results of ongoing clinical trials with mTOR inhibitors, as single agents and in combination regimens, will better define their activity in cancer.
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PMID:Targeting tumorigenesis: development and use of mTOR inhibitors in cancer therapy. 1986 Sep 3

Temsirolimus, a highly specific inhibitor of mammalian target of rapamycin (mTOR), is a novel anticancer targeted therapy with a new mechanism of action. The prototype mTOR inhibitor, oral rapamycin, is poorly soluble and undergoes extensive first-pass metabolism, leading to low and potentially variable absorption and exposure. For some tumors, maximizing the bioavailability and dose intensity via intravenous (IV) administration may provide optimal clinical benefit. Temsirolimus is an ester analog of rapamycin that retains its potent intrinsic mTOR inhibitory activity while exhibiting better solubility for IV formulation. In the treatment of advanced renal cell carcinoma, temsirolimus is administered as a 30- to 60-minute IV infusion once weekly at a flat dose of 25 mg. This dosage results in high peak temsirolimus concentrations and limited immunosuppressive activity. Because temsirolimus is active and well tolerated, different dosages and schedules are being explored for other solid and hematologic malignancies, including mantle cell lymphoma. Temsirolimus exhibits a high volume of distribution that, together with IV administration, leads to extensive distribution into peripheral tissues. In addition, significant and protracted exposures are attained with sirolimus (rapamycin), the major equipotent metabolite of temsirolimus. Whereas temsirolimus and sirolimus are both metabolized by cytochrome P450 (CYP) 3A4, drug interaction studies with agents that induce or inhibit CYP3A4 activity indicate that exposure to the sirolimus metabolite is somewhat sensitive to pharmacokinetic (PK) drug interaction. Therefore, temsirolimus dose adjustments are warranted if coadministration cannot be avoided. Despite its complexity, the PK profile of IV temsirolimus is well characterized in cancer patients and provides a strong basis for its future study as a monotherapy or in combination with other anticancer agents.
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PMID:Intravenous temsirolimus in cancer patients: clinical pharmacology and dosing considerations. 1996 96

Clinical trials have validated the importance of mammalian target of rapamycin (mTOR) as a therapeutic target in patients with advanced renal cell carcinoma (RCC). The TORC1 complex controls translation of key proteins involved in cell proliferation and regulates the expression and stability of hypoxia-inducible factor (HIF)-1alpha. Temsirolimus, the first mTOR inhibitor approved for treatment of advanced RCC, has demonstrated significantly longer overall survival (hazard ratio for death, 0.73; 95% confidence interval, 0.58-0.92, P = .008) and progression-free survival (P <.001) compared with interferon alfa (IFN) for patients with poor prognostic features. Median progression-free survival durations were 3.8 and 1.9 months, respectively, for patients treated with temsirolimus or IFN, and median overall survivals were 10.9 and 7.3 months, respectively. Exploratory analyses indicate that temsirolimus benefits those patients with metastatic RCC and multiple adverse prognostic factors regardless of tumor histology or nephrectomy status. Most adverse events that occur in patients receiving temsirolimus can be managed medically (eg, hyperglycemia, hyperlipidemia) or addressed by supportive measures (eg, stomatitis, rash). Although development of symptomatic pneumonitis is rare, monitoring is recommended. Temsirolimus is now considered an important first-line treatment option for patients with advanced RCC and multiple factors predictive of short survival. Current trials are investigating the use of temsirolimus in sequence or in combination with other targeted agents to further improve outcomes.
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PMID:Clinical trial experience with temsirolimus in patients with advanced renal cell carcinoma. 1996 97

Temsirolimus, an inhibitor of mammalian target of rapamycin (mTOR), has anti-tumor activity in patients with relapsed or refractory mantle cell lymphoma (MCL) and other mature lymphoid neoplasms. mTOR is an intracellular kinase that controls the mRNA translation of many proteins (eg, cyclin D1) that can act as oncogenes and contribute to lymphomagenesis. Characterized by overexpression of cyclin D1, MCL was identified as a disease that might be susceptible to mTOR inhibition. When single-agent temsirolimus was explored in two phase II studies for treatment of patients with relapsed or refractory MCL, it demonstrated anti-tumor activity, with overall response rates of 38% and 41%. Subsequently, a three-arm, randomized phase III trial was conducted to compare two dosing regimens of temsirolimus with investigator's choice of therapy for heavily pretreated patients with relapsed or refractory MCL (N = 162; randomized 1:1:1). Once-weekly intravenous temsirolimus 175 mg for 3 weeks followed by 75 mg once weekly (175/75) significantly improved progression-free survival (hazard ratio = 0.44; P = .0009) versus investigator's choice therapy. Median progression-free survival durations were 4.8 and 1.9 months, respectively. The objective response rates were 22% in the 175/75 group and 2% in the investigator's choice group (P = .0019). For patients receiving temsirolimus, the most frequent grade 3 or 4 adverse events were thrombocytopenia, anemia, neutropenia, and asthenia. The results of this trial established a recommended clinical dose for temsirolimus monotherapy in patients with relapsed or refractory MCL and validated the importance of mTOR in the pathogenesis of advanced MCL. Objective responses also have been reported for other mature B-cell neoplasms (eg, diffuse large B-cell lymphoma or follicular lymphoma) in the phase II setting. Temsirolimus as monotherapy or in combination with other active agents warrants further investigation for treatment of MCL and other non-Hodgkin lymphomas.
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PMID:Temsirolimus in mantle cell lymphoma and other non-Hodgkin lymphoma subtypes. 1996 99

Activation of mammalian target of rapamycin (mTOR) signaling occurs in a wide variety of human tumors and can lead to increased susceptibility to mTOR inhibitors. Temsirolimus, a novel analog of rapamycin, has shown promising preclinical and early clinical anti-tumor activity in various solid and hematologic tumor types, either alone or in combination with chemotherapy or other targeted agents. Randomized phase III trials have already demonstrated significant clinical benefits of treatment with single-agent temsirolimus in advanced renal cell carcinoma and relapsed and/or refractory mantle cell lymphoma. Other malignancies studied in the phase I and II trial settings include glioblastoma, breast cancer, endometrial cancer, non-Hodgkin lymphomas, and multiple myeloma. This article reviews a comprehensive collection of the clinical trial results reported to date for temsirolimus in various solid and hematologic malignancies, as well as current strategies being tested in ongoing trials. The findings with temsirolimus in multiple tumors provide a valuable framework for future development of temsirolimus and other mTOR inhibitors.
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PMID:Evaluating temsirolimus activity in multiple tumors: a review of clinical trials. 1996

Spinocerebellar ataxia type 3 is a neurodegenerative disorder caused by the expansion of the polyglutamine repeat region within the ataxin-3 protein. The mutant protein forms intracellular aggregates in the brain. However, the cellular mechanisms causing toxicity are still poorly understood and there are currently no effective treatments. In this study we show that administration of a rapamycin ester (cell cycle inhibitor-779, temsirolimus) improves motor performance in a transgenic mouse model of spinocerebellar ataxia type 3. Temsirolimus inhibits mammalian target of rapamycin and hence upregulates protein degradation by autophagy. Temsirolimus reduces the number of aggregates seen in the brains of transgenic mice and decreases levels of cytosolic soluble mutant ataxin-3, while endogenous wild-type protein levels remain unaffected. Temsirolimus is designed for long-term use in patients and therefore represents a possible therapeutic strategy for the treatment of spinocerebellar ataxia type 3. Using this disease model and treatment paradigm, we employed a microarray approach to investigate transcriptional changes that might be important in the pathogenesis of spinocerebellar ataxia type 3. This identified ubiquitin specific peptidase-15, which showed expression changes at both the messenger ribonucleic acid and protein level. Ubiquitin specific peptidase-15 levels were also changed in mice expressing another mutant polyglutamine protein, huntingtin. In total we identified 16 transcripts that were decreased in transgenic ataxin-3 mice that were normalized following temsirolimus treatment. In this mouse model with relatively mild disease progression, the number of transcripts changed was low and the magnitude of these changes was small. However, the importance of these transcriptional alterations in the pathogenesis of spinocerebellar ataxia type 3 remains unclear.
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PMID:Autophagy induction reduces mutant ataxin-3 levels and toxicity in a mouse model of spinocerebellar ataxia type 3. 2000 18

Temsirolimus, an ester of sirolimus (rapamycin), selectively inhibits the kinase mammalian target of rapamycin and consequently blocks the translation of cell cycle regulatory proteins and prevents overexpression of angiogenic growth factors. Patients with advanced renal cell carcinoma (RCC) and a poor prognosis who received a once-weekly intravenous (IV) infusion of temsirolimus 25 mg, experienced significant survival benefits when compared with patients receiving standard interferon-alpha (IFNalpha) therapy in a large phase III clinical study. In this study, median overall survival was 10.9 vs. 7.3 months and objective response rates were 8.6% in temsirolimus recipients vs. 4.8% IFNalpha recipient group.Temsirolimus monotherapy recipients experienced significantly fewer grade 3 or 4 adverse events and had fewer withdrawals for adverse events than patients receiving IFNalpha.
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PMID:Temsirolimus. 2007 39


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