Entity

Time filter

Source Type

London, United Kingdom

Dry J.R.,Cancer Bioscience | Pavey S.,Queensland Institute of Medical Research | Pavey S.,University of Queensland | Pratilas C.A.,Sloan Kettering Cancer Center | And 27 more authors.
Cancer Research | Year: 2010

Selumetinib (AZD6244, ARRY-142886) is a selective, non-ATP-competitive inhibitor of mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK)-1/2. The range of antitumor activity seen preclinically and in patients highlights the importance of identifying determinants of response to this drug. In large tumor cell panels of diverse lineage, we show that MEK inhibitor response does not have an absolute correlation with mutational or phospho-protein markers of BRAF/MEK, RAS, or phosphoinositide 3-kinase (PI3K) activity. We aimed to enhance predictivity by measuring pathway output through coregulated gene networks displaying differential mRNA expression exclusive to resistant cell subsets and correlated to mutational or dynamic pathway activity. We discovered an 18-gene signature enabling measurement of MEK functional output independent of tumor genotype. Where the MEK pathway is activated but the cells remain resistant to selumetinib, we identified a 13-gene signature that implicates the existence of compensatory signaling from RAS effectors other than PI3K. The ability of these signatures to stratify samples according to functional activation of MEK and/or selumetinib sensitivity was shown in multiple independent melanoma, colon, breast, and lung tumor cell lines and in xenograft models. Furthermore, we were able to measure these signatures in fixed archival melanoma tumor samples using a single RT-qPCR-based test and found intergene correlations and associations with genetic markers of pathway activity to be preserved. These signatures offer useful tools for the study of MEK biology and clinical application of MEK inhibitors, and the novel approaches taken may benefit other targeted therapies. ©2010 AACR. Source


Seth R.,Royal Marsden Hospital | Khan A.A.,Chester Beatty Laboratories | Pencavel T.D.,Royal Marsden Hospital | Wilkinson M.J.,Royal Marsden Hospital | And 7 more authors.
Plastic and Reconstructive Surgery | Year: 2015

Introduction: Free flap gene therapy exploits a novel therapeutic window when viral vectors can be delivered into a flap ex vivo. The authors investigated the therapeutic potential of an adenovirally-delivered thymidine kinase/ganciclovir prodrug system expressed following vector delivery into a free flap. Methods: The authors demonstrated direct in vitro cytotoxicity by treating a panel of malignant cell lines with the thymidine kinase/ganciclovir system and demonstrated significant cell kill proportional to the multiplicity of infection of adenoviral vector expressing thymidine kinase. Bystander cytotoxicity was demonstrated using conditioned media from producer cells (expressing adenovirally-delivered thymidine kinase and treated with ganciclovir) to demonstrate cytotoxicity in naive tumor cells. The authors investigated the effect of adenoviral vector expressing thymidine kinase/ganciclovir therapy in vivo, using models of microscopic and macroscopic residual disease in a rodent superficial inferior epigastric artery flap model. Results: The authors observed retardation of tumor volume growth in both microscopic (p = 0.0004) and macroscopic (p = 0.0005) residual disease models and prolongation of animal survival. Gene expression studies demonstrated that viral genomic material was found predominantly in flap tissues but declined over time. Conclusions: The authors describe the utility of virally delivered enzyme/prodrug therapy, using a free flap as a vehicle for delivery. They discuss the merits and limitations of this approach and the unique role of therapeutic free flaps among reconstructive techniques available to the plastic surgeon. Copyright © 2015 by the American Society of Plastic Surgeons. Source


Williams C.K.O.,University of Ibadan | Williams C.K.O.,Port of Los Angeles | Williams C.K.O.,Center for AIDS Research CFAR | Foroni L.,Royal Postgraduate Medicine School | And 5 more authors.
ecancermedicalscience | Year: 2014

Major differences exist in the nature of leukaemia and lymphoma in low-income African children compared to those in the high-income countries. These include the absence of the peak incidence of acute lymphoblastic leukaemia (ALL) in under-five-year olds that characterizes the disease in high-income countries. Conversely, chloroma association with acute myelogenous leukaemia (CA-AML/AMML) and Burkitt's lymphoma (BL) are rare in the high-income countries. This report describes clinical and laboratory as well as epidemiological features of childhood leukaemia and lymphoma reported betwen 1982 and 1984 in the city of Ibadan, Nigeria. The observed pattern of distribution of childhood haematological malignancies in the city is more consistent with the observations of Ludwik Gross's experiments on environmental influences, such as malnutrition and infections, animal leukaemogenesis, and mirroring the consequences of the primordial pressures that have shaped human genetics and pathophysiology. Copyright: © the authors. Source


Suire S.,Babraham Institute | Lecureuil C.,Babraham Institute | Lecureuil C.,CNRS Research Institute of Insect Biology | Anderson K.E.,Babraham Institute | And 10 more authors.
EMBO Journal | Year: 2012

The molecular mechanisms by which receptors regulate the Ras Binding Domains of the PIP 3-generating, class I PI3Ks remain poorly understood, despite their importance in a range of biological settings, including tumorigenesis, activation of neutrophils by pro-inflammatory mediators, chemotaxis of Dictyostelium and cell growth in Drosophila. We provide evidence that G protein-coupled receptors (GPCRs) can stimulate PLCβ2/β3 and diacylglycerol-dependent activation of the RasGEF, RasGRP4 in neutrophils. The genetic loss of RasGRP4 phenocopies knock-in of a Ras-insensitive version of PI3Kγ in its effects on PI3Kγ-dependent PIP 3 accumulation, PKB activation, chemokinesis and reactive oxygen species (ROS) formation. These results establish a new mechanism by which GPCRs can stimulate Ras, and the broadly important principle that PLCs can control activation of class I PI3Ks. © 2012 European Molecular Biology Organization | All Rights Reserved. Source


Luangdilok S.,Cancer Research UK Research Institute | Box C.,Cancer Research UK Research Institute | Harrington K.,Chester Beatty Laboratories | Rhys-Evans P.,Head and Neck Unit | Eccles S.,Cancer Research UK Research Institute
European Journal of Cancer | Year: 2011

Vascular endothelial growth factors (VEGF-C and VEGF-A) play important roles in tumour-induced lymphangiogenesis and angiogenesis, respectively, key processes implicated in promoting tumour growth and metastatic spread. Previous work from our laboratory has shown that EGFR overexpression in squamous carcinomas of the head and neck (SCCHN) is linked to high levels of VEGF-A and VEGF-C (but low levels of VEGF-D) and is associated with poor prognosis. The present study explored the signalling pathways regulating the induction of VEGF-C and VEGF-A in the SCCHN cell lines CAL 27 and Detroit 562. The addition of exogenous EGF induced the expression of VEGF-C and VEGF-A in a concentration-dependent manner and this was blocked by a selective EGFR inhibitor, gefitinib. In both cell lines stimulated with endogenous or exogenous ligand, inhibition of MEK1/2 (with U0126 or PD98059) or PI3K (with PI-103 or LY294002) resulted in a marked reduction of EGFR-induced VEGF-A expression, whereas exogenous EGF-induced VEGF-C upregulation was blocked by inhibitors of MEK but not PI3K. Inhibition of p38 MAPK suppressed EGF-induced VEGF-C upregulation in CAL 27 cells, but inhibited EGF-induced VEGF-A upregulation in Detroit 562. Taken together, our evidence suggests that both endogenous and exogenous EGFR activation induces VEGF-A expression requiring both PI3K and MAPK signalling whereas VEGF-C expression is dependent on MAPK, but not the PI3K or mTOR pathways in SCCHN cell lines. p38 MAPK appears to be differentially linked to either VEGF-A or VEGF-C regulation in different cellular contexts. © 2011 Published by Elsevier Ltd. Source

Discover hidden collaborations