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)

Several proangiogenic/proinflammatory factors involved in endometrial cancer are regulated by leptin, but the signaling mechanisms responsible for these leptin-induced actions are largely unknown. Here, we report that in benign (primary and HES) and cancerous-endometrial epithelial cells (EEC) (An3Ca, SK-UT2 and Ishikawa), leptin in a dose-dependent manner regulates vascular endothelial growth factor, (VEGF); interleukin-1 beta, (IL-1beta); leukemia inhibitory factor, (LIF) and their respective receptors, VEGFR2, IL-1R tI and LIFR. Remarkably, leptin induces a greater increase in VEGF/VEGFR2 and LIF levels in cancer than in benign cells. However, IL-1beta was only increased by leptin in benign primary-EEC. Cancer-EEC expressed higher levels of leptin receptor (full-length OB-Rb and short isoforms) in contrast to benign primary-EEC. Leptin-mediated activation of JAK2 (janus kinase 2) was upstream to the activation of PI-3K (phosphatidylinositol-3 kinase) and/or MAPK (mitogen-activated protein kinase) signaling pathways. Leptin induction of cytokines/receptors generally involved JAK2 and MAPK activation, but PI-3K phosphorylation was required for leptin increase of LIF, IL-1/IL-1R tI. Leptin-mediated activation of mTOR (mammalian target of Rapamycin), mainly linked to MAPK, played a central role in leptin regulation of all cytokines and receptors. These results suggest that leptin's effects are cell-specific and could confer a proliferative or cell survival advantage or possibly promote endometrial thickness. Leptin's effects on proangiogenic molecules were more evident in malignant versus benign cells and may imply that there is an underlying shift in leptin-induced cell signaling pathways in endometrial cancer cells.
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PMID:Leptin regulation of proangiogenic molecules in benign and cancerous endometrial cells. 1879 54

Bone and soft tissue sarcomas are an infrequent and heterogeneous group of mesenchymal tumors, including more than a hundred different entities attending to histological patterns. Sarcomas are quite resistant to conventional chemotherapy (anthracycline and ifosfamide) with the exception of some subtypes, such as Ewing's sarcoma (ES). New drugs with proved efficacy against sarcomas include taxanes, gemcitabine, and ET-743. Preclinical studies have also identified key molecular events leading to the progression and development of sarcomas which are good candidates to targeted therapy. Inhibitors of the tyrosine kinase receptors, such as IGF-1R, c-kit, PDGFR, VEGFR, or the mTOR signaling pathway, proteasome, angiogenesis, and stress response proteins are under clinical evaluation against sarcomas. ES, a tumor characterized by chromosomal translocations that originate gene fusions (EWS-FLI1, EWS-ERG), is an example of a good chemotherapy responder tumor whose survival rate shows a plateau in recent years. Preclinical studies have identified that new targets such as HSP90 are of relevance to ES. On the other hand, recent studies showed the role of cancer stem cells (CSCs) in sarcomas and the relevance of the identification of reliable molecular markers and possible therapeutic targets. New therapeutic approaches could be directed against CSCs. This review describes more recent targeted therapy in sarcomas, with special emphasis on ES and the role of CSCs. We also emphasize the role of high throughput proteomic techniques in identifying new therapeutic targets.
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PMID:Targeting sarcomas: therapeutic targets and their rational. 1901 96

Molecularly targeted therapies hold the promise of providing new anticancer treatments that are more effective and less toxic than traditional cytotoxic chemotherapy. Unfortunately, results of first generation targeted therapy trials for malignant gliomas (glioblastomas and anaplastic forms of astrocytomas, oligodendrogliomas and oligoastrocytomas) have been disappointing. While combination strategies targeting angiogenesis through inhibition of the VEGFR pathway (eg, bevacizumab combined with irinotecan) have demonstrated promising activity, single-agent drugs have been largely unsuccessful when tested in recurrent disease clinical trials. These single agents include EGF receptor tyrosine kinase inhibitors (gefitinib and erlotinib), PDGF receptor inhibitors (imatinib), mTOR inhibitors (temsirolimus and everolimus), and VEGFR, protein kinase C-beta and other angiogenesis pathway inhibitors (vatalanib and enzastaurin). A new generation of trials is seeking to define whether inhibiting multiple targets simultaneously through utilization of less specific, multi-targeting drugs, or through combination of two or more single-targeted drugs, can overcome tumor resistance. In this review, the rationale and challenges of developing such multi-targeted strategies in gliomas are presented.
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PMID:Exploring multi-targeting strategies for the treatment of gliomas. 1903 35

Vascular endothelial growth factor (VEGF)-A inhibitors exhibit unseen high responses and toxicity in recurrent epithelial ovarian cancer suggesting an important role for the VEGF/VEGFR pathway. We studied the correlation of VEGF signalling and AKT/mTOR signalling. Using a tissue microarray of clinical samples (N=86), tumour cell immunohistochemical staining of AKT/mTOR downstream targets, pS6 and p4E-BP1, together with tumour cell staining of VEGF-A and pVEGFR2 were semi-quantified. A correlation was found between the marker for VEGFR2 activation (pVEGFR2) and a downstream target of AKT/mTOR signalling (pS6) (R=0.29; P=0.002). Additional gene expression analysis in an independent cDNA microarray dataset (N=24) showed a negative correlation (R=-0.73, P<0.0001) between the RPS6 and the VEGFR2 gene, which is consistent as the gene expression and phosphorylation of S6 is inversely regulated. An activated tumour cell VEGFR2/AKT/mTOR pathway was associated with increased incidence of ascites (chi(2), P=0.002) and reduced overall survival of cisplatin-taxane-based patients with serous histology (N=32, log-rank test, P=0.04). These data propose that VEGF-A signalling acts on tumour cells as a stimulator of the AKT/mTOR pathway. Although VEGF-A inhibitors are classified as anti-angiogenic drugs, these data suggest that the working mechanism has an important additional modality of targeting the tumour cells directly.
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PMID:The VEGF pathway and the AKT/mTOR/p70S6K1 signalling pathway in human epithelial ovarian cancer. 1924 Jul 22

Neuroblastoma (NB) is one of the most common pediatric solid tumors originating from the neural crest lineage. Despite intensive treatment protocols including megatherapy with hematopoietic stem cell transplantation, the prognosis of NB patients remains poor. More effective therapeutics are required. High vascularity has been described as a feature of aggressive, widely disseminated NB. Our previous work demonstrated the overexpression of vascular endothelial growth factor (VEGF) in NB, and we showed that an anti-VEGF receptor (VEGFR-2) antibody could induce sustained NB tumor suppression and regression. Sunitinib is a kinase inhibitor targeting platelet-derived growth factor receptors and VEGFRs and, therefore, a promising antiangiogenic agent. In this study, we investigated the antitumor activity of sunitinib and its synergistic cytotoxicity with conventional (cyclophosphamide) and novel (rapamycin) therapies. Both NB cell lines and tumor-initiating cells from patient tumor samples were used in our in vitro and in vivo models for these drug testing. We show that sunitinib inhibits tumor cell proliferation and phosphorylation of VEGFRs. It also inhibits tumor growth, angiogenesis, and metastasis in tumor xenograft models. Low-dose sunitinib (20 mg/kg) demonstrates synergistic cytotoxicity with an mTOR inhibitor, rapamycin, which is more effective than the traditional chemotherapeutic drug, cyclophosphamide. These preclinical studies provide the evidence of antitumor activity of sunitinib both in the early stage of tumor formation and in the progressive metastatic disease. These studies also provide the framework for clinical trial of sunitinib, alone and in combination with conventional and novel therapies to increase efficacy and improve patient outcome in NB.
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PMID:In vivo antitumor and antimetastatic activity of sunitinib in preclinical neuroblastoma mouse model. 1941 27

Notable advances have been achieved in head and neck cancer and in lung cancer as regards oncogenesis knowledge and treatment optimization. Multimodal management including molecular targeted therapies have provided a clear benefit in some circumstances. This review provides information on these two primary sites. Some issues are specific (non-tobacco-related carcinogenesis, antiangogenic agents) while some others are shared by both primary sites (oncogenesis, EGFR pathway targeting). Molecular targeted therapies have shifted some treatment algorithms in head and neck cancer (monoclonal antibodies targeting EGFR and radiotherapy in advanced diseases) and in lung cancer as well (1st line anti VEGFR antibodies, EGFR pathway tyrosin-kinase inhibitors as 2nd line treatment for metastatic diseases). Many new prospects are under evaluation (anti-EGFR antibodies, mTOR inhibitors, multi-targets agents, anti-IGFR1 antibodies). Molecular targeted therapies have also generated new protocols for disease evaluation, imaging and bio-clinical monitoring in order to better select patients and improve the outcome.
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PMID:[Information on head, neck and lung cancers]. 1943 69

Chemotherapy, biological agents or combinations of both have had little impact on survival of patients with metastatic melanoma. Advances in understanding the genetic changes associated with the development of melanoma resulted in availability of promising new agents that inhibit specific proteins up-regulated in signal cell pathways or inhibit anti-apoptotic proteins. Sorafenib, a multikinase inhibitor of the RAF/RAS/MEK pathway, elesclomol (STA-4783) and oblimersen (G3139), an antisense oligonucleotide targeting anti-apoptotic BCl-2, are in phase III clinical studies in combination with chemotherapy. Agents targeting mutant B-Raf (RAF265 and PLX4032), MEK (PD0325901, AZD6244), heat-shock protein 90 (tanespimycin), mTOR (everolimus, deforolimus, temsirolimus) and VEGFR (axitinib) showed some promise in earlier stages of clinical development. Receptor tyrosine-kinase inhibitors (imatinib, dasatinib, sunitinib) may have a role in treatment of patients with melanoma harbouring c-Kit mutations. Although often studied as single agents with disappointing results, new targeted drugs should be more thoroughly evaluated in combination therapies. The future of rational use of new targeted agents also depends on successful application of analytical techniques enabling molecular profiling of patients and leading to selection of likely therapy responders.
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PMID:Small molecules and targeted therapies in distant metastatic disease. 1961 96

The mammalian target of rapamycin(mTOR)and its molecular pathways are supposed to be activated frequently in human renal cell carcinoma as well as other cancers. It has a kinase activity for 40S ribosomal protein kinase and eukaryotic translation initiation factor 4E-binding protein 1. These proteins, when phosphorylated, promote protein translation and RNA transcription in the nutrient-rich condition. mTOR inhibitors such as Temsirolimus (CCI779) and Everolimus (RAD001) are effective for suppressing cell growth with inhibiting mTOR kinase activity. Rapamycin and its related analogs such as Temsirolimus and Everolimus are less toxic for humans compared with other anti-VEGFR inhibitors and has been used as an immunosuppressive agent. These agents have an inhibitory activity against the mTORC1 complex. Since they do not have inhibitory activity against mTORC2 complex, the ability of mTOR inhibition by Temsirolimus is supposed to be 40 to 50% of full inhibition in mTOR kinase. Temsirolimus has modest anticancer activity against advanced clinical RCC patients with poor risk. The objective response rate was only 7%, 26% of patients experienced minor responses and another 17% of patients had stable disease that lasted 6 months. The median time to tumor progression and median survival for the study patients were 5.8 and 15.0 months, respectively. The overall survival of patients treated with Temsirolimus alone was statistically longer than in those treated with IFN alone in the 626 cases in phase II study. Combinations of mTOR with other anti- VEGFR agents were not effective. Vertical therapies of mTOR inhibitor in combination with AKT inhibitors, or newly development of stronger mTOR kinase which can suppress both mTORC1 and mTORC2 are planned at present.
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PMID:[Mammalian target of rapamycin, its mode of action and clinical response in metastatic clear cell carcinoma]. 1962 Jul 95

Sunitinib demonstrating efficacy in pancreatic islet cell carcinomas will pave the way for further trials in other neuroendocrine tumor types such as carcinoid, poorly differentiated neuroendocrine disease, and several other endocrine tumors that are dependent on VEGF/VEGFR for angiogenesis. In addition, other drugs with distinct mechanisms of action, such as mTOR inhibitors, currently investigated in phase III trials, may also supply novel options in those diseases to control tumor growth and metastasis.
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PMID:Sunitinib paves the way for targeted therapies in neuroendocrine tumors. 1991 Nov 11

Advanced renal cell carcinoma is associated with a poor prognosis and is refractory to standard chemotherapy. Recent progress in the understanding of molecular biology and pathogenesis of renal cell cancer has been translated into the development of new therapeutic strategies. The management of metastatic RCC has been revolutionized with the development of targeted molecular therapies against VEGF-VEGFR and mTOR. Randomized phase III clinical trials demonstrated clinical benefit for patients with advanced RCC in overall survival and progression free survival. At the moment, six molecules have been approves in advanced RCC: cytokines (IL-2 and IFN), antiangiogenic therapies (sunitinib, sorafenib, bevacizumab) and mTOR inhibitors (Temsirolimus, everolimus). Nephrectomy is an important component of the multimodality treatment of mRCC. Prospective trials will be assessed the value of nephrectomy in patients treated by antiangiogenic therapies. Large randomized trial are ongoing to evaluate these new therapies in adjuvant setting.
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PMID:[Renal cell carcinoma management and therapies in 2010]. 2041 1


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