Search results for "iNOS"
showing 10 items of 2075 documents
The novel dual PI3K/mTOR inhibitor GDC-0941 synergizes with the MEK inhibitor U0126 in non-small cell lung cancer cells.
2011
Lung cancer is a malignant disease with poor outcome, which has led to a search for new therapeutics. The PI3K/Akt/mTOR and Ras/raf/Erk pathways are key regulators of tumor growth and survival. In the present study, their roles were evaluated by MTT assay, flow cytometry and Western blotting in lung cancer cells. We found that a high efficacy of antitumor activity was shown with GDC-0941 treatment in two gefitinib-resistant non-small cell lung cancer (NSCLC) cell lines, A549 and H460. In addition, H460 cells with activating mutations of PIK3CA were relatively more sensitive to GDC-0941 than A549 cells with wild-type PIK3CA. Furthermore, GDC-0941 was highly efficacious in combination with U0…
Increased radioresistance via G12S K-Ras by compensatory upregulation of MAPK and PI3K pathways in epithelial cancer
2011
Background Irradiation-induced signaling via the 2 pathways, Raf-MEK-ERK and PI3K-Akt, is known to be closely associated with a limited response to radiotherapy. In the present study we analyzed the relevance of constitutively active K-Ras for postradiogenic pathway stimulation and the option of coordinated inhibition to overcome these rescue mechanisms. Methods We used 2 epithelial tumor cell lines as a model system, one of them harboring a G12S K-Ras mutation. Cells were irradiated and the effect of combined treatment with ionizing radiation and inhibitors on the expression of pERK and pAkt was determined by Western blotting. Additionally, clonogenic assays were performed to functionally …
Influences of TP53 and the anti-aging DDR1 receptor in controlling Raf/MEK/ERK and PI3K/Akt expression and chemotherapeutic drug sensitivity in prost…
2020
Background TP53 plays critical roles in sensitivity to chemotherapy, and aging. Collagen is very important in aging. The molecular structure and biochemical properties of collagen changes during aging. The discoidin domain receptor (DDR1) is regulated in part by collagen. Elucidating the links between TP53 and DDR1 in chemosensitivity and aging could improve therapies against cancer and aging. Results Restoration of WT-TP53 activity resulted in increased sensitivity to chemotherapeutic drugs and elevated expression of key components of the Raf/MEK/ERK, PI3K/Akt and DDR1 pathways. DDR1 could modulate the levels of Raf/MEK/ERK and PI3K/Akt pathways as well as sensitize the cells to chemothera…
Therapeutic resistance resulting from mutations in Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR signaling pathways.
2011
Chemotherapy remains a commonly used therapeutic approach for many cancers. Indeed chemotherapy is relatively effective for treatment of certain cancers and it may be the only therapy (besides radiotherapy) that is appropriate for certain cancers. However, a common problem with chemotherapy is the development of drug resistance. Many studies on the mechanisms of drug resistance concentrated on the expression of membrane transporters and how they could be aberrantly regulated in drug resistant cells. Attempts were made to isolate specific inhibitors which could be used to treat drug resistant patients. Unfortunately most of these drug transporter inhibitors have not proven effective for ther…
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…
a1D-Adrenoceptors are responsible for the high sensitivity and the slow time-course of noradrenaline-mediated contraction in conductance arteries.
2013
The objective of this study was to determine whether the different time-course characteristics of α1-adrenoceptor-mediated contraction in arteries can be related to the subtypes involved. Contractile responses to noradrenaline (NA) were compared with inositol phosphate accumulation and extracellular signal-regulated kinase (ERK)1/2 phosphorylation after α1-agonist stimuli in the same vessels in the presence or absence of α1-antagonists in rat or in α1-subtype knockout (KO) mice. Aorta, where α1D-AR is the main functional subtype, had higher sensitivity to NA (in respect of inositol phosphate [IP], pERK1/2, and contractile response) than tail artery, where the α1A-adrenoceptor subtype is pre…
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…
Multimessenger search for sources of gravitational waves and high-energy neutrinos: Initial results for LIGO-Virgo and IceCube
2014
Made available in DSpace on 2022-04-29T07:21:49Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-11-17 We report the results of a multimessenger search for coincident signals from the LIGO and Virgo gravitational-wave observatories and the partially completed IceCube high-energy neutrino detector, including periods of joint operation between 2007-2010. These include parts of the 2005-2007 run and the 2009-2010 run for LIGO-Virgo, and IceCube's observation periods with 22, 59 and 79 strings. We find no significant coincident events, and use the search results to derive upper limits on the rate of joint sources for a range of source emission parameters. For the optimistic assumption of …
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…
Enhanced proinflammatory response to the Candida albicans gpi7 null mutant by murine cells.
2008
International audience; The Candida albicans gpi7/gpi7 null mutant strain (Deltagpi7), which is affected in glycosylphosphatidylinositol (GPI) anchor biosynthesis, showed a reduced virulence following systemic infection of C57BL/6 mice. In vitro production of TNF-alpha, IL-6 and IL-1beta by macrophages in response to Deltagpi7 cells was significantly increased as compared to control (wild type GPI7/GPI7 and revertant gpi7/GPI7) cells; this probably contributes to the enhanced recruitment of neutrophils to the peritoneal cavity in response to Deltagpi7 cells. Survival of knockout mice for Toll-like receptor (TLR) 2 and TLR4 following intravenous injection of Deltagpi7 cells showed no signifi…