Search results for "Protein kinase B"
showing 10 items of 191 documents
Mutations and Deregulation of Ras/Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR Cascades Which Alter Therapy Response.
2012
The Ras/Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR cascades are often activated by genetic alterations in upstream signaling molecules such as receptor tyrosine kinases (RTK). Certain components of these pathways, RAS, NF1, BRAF, MEK1, DUSP5, PP2A, PIK3CA, PIK3R1, PIK3R4, PIK3R5, IRS4, AKT, NFKB1, MTOR, PTEN, TSC1, and TSC2 may also be activated/inactivated by mutations or epigenetic silencing. Upstream mutations in one signaling pathway or even in downstream components of the same pathway can alter the sensitivity of the cells to certain small molecule inhibitors. These pathways have profound effects on proliferative, apoptotic and differentiation pathways. Dysregulation of components of these cas…
Different FLT3-ITD Integration Sites Are Associated with Differential Sensitivity to Tyrosine Kinase Inhibitors (TKI) In Vitro.
2010
Abstract Abstract 1709 Introduction: Currently, small molecule FLT3 tyrosine kinase inhibitors (TKIs) are promising therapeutic approaches to overcome the dismal prognosis of AML patients harbouring FLT3-ITD mutations. However, up to 30% of these patients show primary resistance to FLT3-TKIs. Recently, we uncovered a novel mechanism of primary resistance to FLT3 TKIs in a patient displaying an atypical integration site of ITD within the beta2-sheet (ITD_A627E). The data suggested that atypical integration sites of ITDs within the tyrosine kinase domain-1 (TKD1) of FLT3 (beta1-sheet, nucleotide binding loop and beta2-sheet) are associated with rewired signaling and differential responsivenes…
The selective oestrogen receptor modulator, bazedoxifene, mimics the neuroprotective effect of 17β‐oestradiol in diabetic ischaemic stroke by modulat…
2019
Because neuroprotection in stroke should be revisited in the era of recanalisation, the present study analysed the potential neuroprotective effect of the selective oestrogen receptor modulator, bazedoxifene acetate (BZA), in an animal model of diabetic ischaemic stroke that mimics thrombectomy combined with adjuvant administration of a putative neuroprotectant. Four weeks after induction of diabetes (40 mg kg-1 streptozotocin, i.p.), male Wistar rats were subjected to transient middle cerebral artery occlusion (intraluminal thread technique, 60 minutes) and assigned to one of three groups treated with either: vehicle, BZA (3 mg kg-1 day-1 , i.p.) or 17β-oestradiol (E2 ) (100 μg kg-1 day-…
Ras/Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR cascade inhibitors: How mutations can result in therapy resistance and how to overcome resistance
2012
// James A. McCubrey 1 , Linda S. Steelman 1 , William H. Chappell 1 , Stephen L. Abrams 1 , Richard A. Franklin 1 , Giuseppe Montalto 2 , Melchiorre Cervello 3 , Massimo Libra 4 , Saverio Candido 4 , Grazia Malaponte 4 , Maria C. Mazzarino 4 , Paolo Fagone 4 , Ferdinando Nicoletti 4 , Jorg Basecke 5 , Sanja Mijatovic 6 , Danijela Maksimovic-Ivanic 6 , Michele Milella 7 , Agostino Tafuri 8 , Francesca Chiarini 9 , Camilla Evangelisti 9 , Lucio Cocco 10 , Alberto M. Martelli 9,10 1 Department of Microbiology and Immunology, Brody School of Medicine at East Carolina University, Greenville, NC, USA 2 Department of Internal Medicine and Specialties, University of Palermo, Palermo, Italy 3 Consi…
Synergistic Growth Inhibitory Activity of Combined Mek/Mtor Pathway Blockade in Pten-Null Cancers
2014
ABSTRACT Aim: We have recently shown that induction of PTEN expression plays an integral role in MEK inhibitors' antitumor activity. Here we hypothesize that PTEN status critically influences the functional outcome of combined MEK and PI3K/mTOR inhibition. Methods: Single and combined MEK (trametinib, T) and mTOR (everolimus, E) blockade were assessed in a panel of cancer cell lines and in patient-derived lung and colon cancer stem cells (L- or C-CSC). Pharmacologic interactions were analyzed by conservative isobologram analysis. PTEN role was assessed by shRNA-mediated silencing or overexpression by stable transfection. Treatment-induced changes in the phosphoproteome were analyzed by anti…
Colony-stimulating factor-1-induced oscillations in phosphatidylinositol-3 kinase/AKT are required for caspase activation in monocytes undergoing dif…
2009
Abstract The differentiation of human peripheral blood monocytes into resident macrophages is driven by colony-stimulating factor-1 (CSF-1), which upon interaction with CSF-1 receptor (CSF-1R) induces within minutes the phosphorylation of its cytoplasmic tyrosine residues and the activation of multiple signaling complexes. Caspase-8 and -3 are activated at day 2 to 3 and contribute to macrophage differentiation, for example, through cleavage of nucleophosmin. Here, we show that the phosphatidylinositol-3 kinase and the downstream serine/threonine kinase AKT connect CSF-1R activation to caspase-8 cleavage. Most importantly, we demonstrate that successive waves of AKT activation with increasi…
Nose-to-brain delivery of insulin enhanced by a nanogel carrier.
2018
Recent evidences suggest that insulin delivery to the brain can be an important pharmacological therapy for some neurodegenerative pathologies, including Alzheimer disease (AD). Due to the presence of the Blood Brain Barrier, a suitable carrier and an appropriate route of administration are required to increase the efficacy and safety of the treatment. Here, poly(N-vinyl pyrrolidone)-based nanogels (NG), synthetized by e-beam irradiation, alone and with covalently attached insulin (NG-In) were characterized for biocompatibility and brain delivery features in a mouse model. Preliminarily, the biodistribution of the "empty" nanocarrier after intraperitoneal (i.p.) injection was investigated b…
Molecular mechanisms mediating the neuroprotective role of the selective estrogen receptor modulator, bazedoxifene, in acute ischemic stroke: A compa…
2017
As the knowledge on the estrogenic system in the brain grows, the possibilities to modulate it in order to afford further neuroprotection in brain damaging disorders so do it. We have previously demonstrated the ability of the selective estrogen receptor modulator, bazedoxifene (BZA), to reduce experimental ischemic brain damage. The present study has been designed to gain insight into the molecular mechanisms involved in such a neuroprotective action by investigating: 1) stroke-induced apoptotic cell death; 2) expression of estrogen receptors (ER) ERα, ERβ and the G-protein coupled estrogen receptor (GPER); and 3) modulation of MAPK/ ERK1/2 and PI3K/Akt signaling pathways. For comparison, …
Faim2 contributes to neuroprotection by erythropoietin in transient brain ischemia.
2018
Delayed cell death in the penumbra region of acute ischemic stroke occurs through apoptotic mechanisms, making it amenable to therapeutic interventions. Fas/CD95 mediates apoptotic cell death in response to external stimuli. In mature neurons, Fas/CD95 signaling is modulated by Fas-apoptotic inhibitory molecule 2 (Faim2), which reduces cell death in animal models of stroke, meningitis, and Parkinson disease. Erythropoietin (EPO) has been studied as a therapeutic strategy in ischemic stroke. Erythropoietin stimulates the phosphatidylinositol-3 kinase/Akt (PI3K/Akt) pathway, which regulates Faim2 expression. Therefore, up-regulation of Faim2 may contribute to neuroprotection by EPO. Male Faim…
Pterostilbene Prevents Early Diabetic Retinopathy Alterations in a Rabbit Experimental Model
2019
Oxidative stress generated by diabetes plays a key role in the development of diabetic retinopathy (DR), a common diabetic complication. DR remains asymptomatic until it reaches advanced stages, which complicate its treatment. Although it is known that good metabolic control is essential for preventing DR, knowledge of the disease is incomplete and an effective treatment with no side effects is lacking. Pterostilbene (Pter), a natural stilbene with good antioxidant activity, has proved to beneficially affect different pathologies, including diabetes. Therefore, our study aimed to analyse the protective and/or therapeutic capacity of Pter against oxidant damage by characterising early retina…