Institute Of Recherche En Cancerologie Of Montpellier
Institute Of Recherche En Cancerologie Of Montpellier
Chavanieu A.,Montpellier University |
Pugniere M.,Institute Of Recherche En Cancerologie Of Montpellier |
Pugniere M.,Montpellier University |
Pugniere M.,Institute Regional du Cancer
Expert Opinion on Drug Discovery | Year: 2016
Introduction: Fragment-based approaches have played an increasing role alongside high-throughput screening in drug discovery for 15 years. The label-free biosensor technology based on surface plasmon resonance (SPR) is now sensitive and informative enough to serve during primary screens and validation steps.Areas covered: In this review, the authors discuss the role of SPR in fragment screening. After a brief description of the underlying principles of the technique and main device developments, they evaluate the advantages and adaptations of SPR for fragment-based drug discovery. SPR can also be applied to challenging targets such as membrane receptors and enzymes.Expert opinion: The high-level of immobilization of the protein target and its stability are key points for a relevant screening that can be optimized using oriented immobilized proteins and regenerable sensors. Furthermore, to decrease the rate of false negatives, a selectivity test may be performed in parallel on the main target bearing the binding site mutated or blocked with a low-off-rate ligand. Fragment-based drug design, integrated in a rational workflow led by SPR, will thus have a predominant role for the next wave of drug discovery which could be greatly enhanced by new improvements in SPR devices. © 2016 Informa UK Limited, trading as Taylor & Francis Group.
Cosnefroy A.,INERIS |
Brion F.,INERIS |
Maillot-Marechal E.,INERIS |
Porcher J.-M.,INERIS |
And 6 more authors.
Toxicological Sciences | Year: 2012
The number of environmental chemical contaminants suspected to act as endocrine disruptor compounds by interacting with estrogen receptor (ER) signaling pathway has been continuously increasing. To study such interaction, the use of stable reporter gene assays is relevant, but species-specific in vitro screening assays are still lacking to address hazard assessment of estrogenic chemicals in aquatic vertebrates. Here, we describe the development of stable reporter gene assays based on stable expression of subtypes of zebrafish ER (zfERα, zfERβ1, and zfERβ2) coupled to estrogen response element-driven luciferase in a zebrafish liver (ZFL) cell line. The three established cell models, named ZELH-zfERα, ZELH-zfERβ1, and ZELHzfERβ2, expressed stable and significant basal luciferase signal, which was induced by 17β-estradiol (E2) in a sensitive and doseresponse manner at EC 50s of 0.2, 0.03, and 0.05nM, respectively. In addition, E2 significantly altered cell proliferation in ZELHzfERα and ZELH-zfERβ2 cells, but not in parental ZFL and ZELH-zfERβ1 cells, suggesting a functionality of these two receptors to modulate endogenous gene expression in the transfected clones. The screening of various xenoestrogens from different classes in the three models resulted in different luciferase response patterns. Natural and synthetic estrogens and 1,1,1-trichloro-2-(2 chlorophenyl)-2-(4-chlorophenyl)ethane were active at lower concentrations in ZELH-zfERβ1 and ZELH-zfERβ2 than in ZELH-zfERα cells, whereas genistein and zearalenone metabolites as well as three benzophenone derivatives preferentially activated zfERα. Altogether, the newly established models provide specific and convenient in vitro tool for comparative assessment of zfERs selective activation by chemicals within ZFL cell context. © The Author 2011. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved.
Le Maire A.,French Institute of Health and Medical Research |
Le Maire A.,French National Center for Scientific Research |
Teyssier C.,French Institute of Health and Medical Research |
Teyssier C.,French National Center for Scientific Research |
And 18 more authors.
Nature Structural and Molecular Biology | Year: 2010
In the absence of ligand, some nuclear receptors, including retinoic acid receptor (RAR), act as transcriptional repressors by recruiting corepressor complexes to target genes. This constitutive repression is crucial in metazoan reproduction, development and homeostasis. However, its specific molecular determinants had remained obscure. Using structural, biochemical and cell-based assays, we show that the basal repressive activity of RAR is conferred by an extended Β-strand that forms an antiparallel Β-sheet with specific corepressor residues. Agonist binding induces a Β-strand-to-α-helix transition that allows for helix H11 formation, which in turn provokes corepressor release, repositioning of helix H12 and coactivator recruitment. Several lines of evidence suggest that this structural switch could be implicated in the intrinsic repressor function of other nuclear receptors. Finally, we report on the molecular mechanism by which inverse agonists strengthen corepressor interaction and enhance gene silencing by RAR. © 2010 Nature America, Inc. All rights reserved.
Belguise K.,Institute Of Recherche En Cancerologie Of Montpellier |
Belguise K.,French Institute of Health and Medical Research |
Belguise K.,Montpellier University |
Milord S.,Institute Of Recherche En Cancerologie Of Montpellier |
And 10 more authors.
Oncogene | Year: 2012
Fra-1 is aberrantly expressed in a large number of cancer cells and tissues, and emerging evidence suggests an important role for this Fos family protein in both oncogenesis and the progression or maintenance of many tumour types. Here, we show that the concentration of Fra-1 is high in invasive oestrogen receptor (ER)-negative (ER) breast cancer cell lines, regardless of their Ras pathway status. All of the ER cells express high levels of activated PKCθ, and the inhibition of PKCθ activity using RNA interference or the expression of a dominant-negative mutant results in a dramatic reduction in Fra-1 abundance. Conversely, the ectopic expression of constitutively active PKCθ leads to Fra-1 phosphorylation and accumulation in poorly invasive ER cells. This accumulation is due to the stabilisation of the Fra-1 protein through PKCθ signalling, whereas other members of the PKC family are ineffective. Both Ste20-related proline-alanine-rich kinase (SPAK) and ERK1/2, whose activities are upregulated by PKCθ, participate in PKCθ-driven Fra-1 stabilisation. Interestingly, their relative contributions appear to be different depending on the cell line studied. ERK1/2 signalling has a major role in ER MDA-MB-231 cells, whereas Fra-1 accumulation occurs mainly through SPAK signalling in ER BT549 cells. Fra-1 mutational analysis shows that the phosphorylation of S265, T223 and T230 is critical for PKCθ-driven Fra-1 stabilisation. Phosphorylation of the protein was confirmed using specific antisera against Fra-1 phosphorylated on T223 or S265. In addition, Fra-1 participates in PKCθ-induced cell invasion and is necessary for PKCθ-induced cell migration. In summary, we identified PKCθ signalling as an important regulator of Fra-1 accumulation in ER breast cancer cells. Moreover, our results suggest that PKCθ could participate in progression of some breast cancers and could be a new therapeutic target. © 2012 Macmillan Publishers Limited. All rights reserved.
Elgqvist J.,Institute Of Recherche En Cancerologie Of Montpellier |
Elgqvist J.,French Institute of Health and Medical Research |
Elgqvist J.,Montpellier University |
Elgqvist J.,Institute Regional Of Cancerologie Of Montpellier |
And 6 more authors.
Frontiers in Oncology | Year: 2014
This article presents a general discussion on what has been achieved so far and on the possible future developments of targeted alpha (a)-particle therapy (TAT). Clinical applications and potential benefits of TAT are addressed as well as the drawbacks, such as the limited availability of relevant radionuclides. Alpha-particles have a particular advantage in targeted therapy because of their high potency and specificity. These features are due to their densely ionizing track structure and short path length. The most important consequence, and the major difference compared with the more widely used ß--particle emitters, is that single targeted cancer cells can be killed by self-irradiation with a-particles. Several clinical trials on TAT have been reported, completed, or are on-going: four using 213Bi, two with 211At, two with 225Ac, and one with 212Pb/212Bi. Important and conceptual proof-of-principle of the therapeutic advantages of a-particle therapy has come from clinical studies with 223Ra-dichloride therapy, showing clear benefits in castration-resistant prostate cancer. © 2014 Elgqvist, Frost, Pouget and Albertsson.
Westover D.,Roswell Park Cancer Institute |
Ling X.,Roswell Park Cancer Institute |
Ling X.,Canget Biotekpharma, Llc |
Lam H.,Roswell Park Cancer Institute |
And 6 more authors.
Molecular Cancer | Year: 2015
Background: Irinotecan is a camptothecin analogue currently used in clinical practice to treat advanced colorectal cancer. However, acquired resistance mediated by the drug efflux pump ABCG2 is a recognized problem. We reported on a novel camptothecin analogue, FL118, which shows anticancer activity superior to irinotecan. In this study, we sought to investigate the potency of FL118 versus irinotecan or its active metabolite, SN-38, in both in vitro and in vivo models of human cancer with high ABCG2 activity. We also sought to assess the potency and ABCG2 affinity of several FL118 analogues with B-ring substitutions. Methods: Colon and lung cancer cells with and without ABCG2 overexpression were treated with FL118 in the presence and absence of Ko143, an ABCG2-selective inhibitor, or alternatively by genetically modulating ABCG2 expression. Using two distinct in vivo human tumor animal models, we further assessed whether FL118 could extend time to progression in comparison with irinotecan. Lastly, we investigated a series of FL118 analogues with B-ring substitutions for ABCG2 sensitivity. Results: Both pharmacological inhibition and genetic modulation of ABCG2 demonstrated that, in contrast to SN-38, FL118 was able to bypass ABCG2-mediated drug resistance. FL118 also extended time to progression in both in vivo models by more than 50% compared with irinotecan. Lastly, we observed that FL118 analogues with polar substitutions had higher affinity for ABCG2, suggesting that the nonpolar nature of FL118 plays a role in bypassing ABCG2-mediated resistance. Conclusions: Our results suggest that in contrast to SN-38 and topotecan, FL118 is a poor substrate for ABCG2 and can effectively overcome ABCG2-mediated drug resistance. Our findings expand the uniqueness of FL118 and support continued development of FL118 as an attractive therapeutic option for patients with drug-refractory cancers resulting from high expression of ABCG2. © Westover et al.; licensee BioMed Central.
Freiss G.,Institute Of Recherche En Cancerologie Of Montpellier |
Freiss G.,French Institute of Health and Medical Research |
Freiss G.,Montpellier University |
Chalbos D.,Institute Of Recherche En Cancerologie Of Montpellier |
And 2 more authors.
Anti-Cancer Agents in Medicinal Chemistry | Year: 2011
Protein tyrosine phosphorylation plays a major role in many cellular functions implicated in cancer development and progression, but only a few of the known protein tyrosine phosphatases have yet been clearly classified as oncogenes or tumor suppressors. PTPL1 interacts with tumor-associated proteins, suggesting a link between PTPL1, the PTPN13 gene product, and tumorigenesis or cancer progression. However, the impact of PTPL1 on cancer is divided between its capacity to counteract the activity of oncogenic tyrosine kinases and its inhibitory interaction with the death receptor, Fas. In this manuscript, we review the PTPL1-interacting proteins implicated in cancer. In addition, we examine the phenotypic arguments concerning both the PTPL1/Fas interaction and the ability of PTPL1 to inhibit signaling from growth factor receptors or oncogenes with tyrosine kinase activity. Finally, we compare the alterations in expression and the genetic and epigenetic arguments supporting an oncogenic or an anti-oncogenic impact of PTPL1. © 2011 Bentham Science Publishers Ltd.
Van Der Pas M.H.G.M.,VU University Amsterdam |
Van Dongen G.A.M.S.,VU University Amsterdam |
Cailler F.,Institute Of Recherche En Cancerologie Of Montpellier |
Pelegrin A.,Institute Of Recherche En Cancerologie Of Montpellier |
Meijerink W.J.H.J.,VU University Amsterdam
Surgical Endoscopy and Other Interventional Techniques | Year: 2010
Background: The sentinel lymph node (SLN) procedure alter the strategy for the treatment of patients with colon cancer. New techniques emerge that may provide the surgeon with a tool for accurate intraoperative detection of the SLNs. Methods: An SLN procedure of the sigmoid was used in six goats. During laparoscopy, the near-infrared dye indocyanine green (ICG) was injected into the subserosa of the sigmoid via a percutaneously inserted needle during four experiments and in the submucosa during colonoscopy in two experiments. After injection, the near-infrared features of a newly developed laparoscope were used to detect the lymph vessels and SLNs. At the end of the procedure, 2 h after injection, all the goats were killed, and autopsy was performed. During postmortem laparotomy, the sigmoid was removed and used for confirmation of ICG node uptake. Results: In all the procedures, the lymph vessels were easily detected by their bright fluorescent emission. In the first two experiments, no lymph nodes were detected. In the subsequent four experiments, human serum albumin was added to the ICG solution before injection to enable better lymph node entrapment. In all four experiments, at least one bright fluorescent lymph node was found after the lymph vessels had been tracked by their fluorescent guidance. The mean time between injection and SLN identification was 10 min. In two cases, the SLNs were located up to 5 mm into the fat tissue of the mesentery and were not seen by regular vision of the laparoscope. By switching on the near-infrared features of the scope, a clear bright dot became visible, which increased in intensity after opening of the mesentery. Conclusion: The SLN procedure for the sigmoid using near-infrared laparoscopy in the goat is a very promising technique. Achievements described in this report justify a clinical trial on the feasibility of ICG-guided SLN detection in humans. © 2010 The Author(s).
Fritz V.,Institute Of Recherche En Cancerologie Of Montpellier |
Fritz V.,Montpellier University |
Fajas L.,Institute Of Recherche En Cancerologie Of Montpellier |
Fajas L.,Montpellier University
Oncogene | Year: 2010
Cancer development involves major alterations in cells metabolism. Enhanced glycolysis and de novo fatty acids synthesis are indeed characteristic features of cancer. Cell proliferation and metabolism are tightly linked cellular processes. Others and we have previously shown a close relationship between metabolic responses and proliferative stimuli. In addition to trigger proliferative and survival signaling pathways, most oncoproteins also trigger metabolic changes to transform the cell. We present herein the view that participation of cell-cycle regulators and oncogenic proteins to cancer development extend beyond the control of cell proliferation, and discuss how these new functions may be implicated in metabolic alterations concomitant to the pathogenesis of human cancers. © 2010 Macmillan Publishers Limited All rights reserved.
Menez C.,National Polytechnic Institute of Toulouse |
Mselli-Lakhal L.,National Polytechnic Institute of Toulouse |
Foucaud-Vignault M.,National Polytechnic Institute of Toulouse |
Balaguer P.,Institute Of Recherche En Cancerologie Of Montpellier |
And 4 more authors.
Biochemical Pharmacology | Year: 2012
Ivermectin is widely used in human and veterinary medicine for the control of helminth infections. Ivermectin is known to interact with P-glycoprotein (P-gp/MDR1), being a good substrate and a potent inhibitor, however, the influence of ivermectin on the expression of the transporter has not been investigated. Expression of P-glycoprotein was investigated in cultured mouse hepatocytes acutely exposed to ivermectin. The two P-glycoprotein murine isoforms, Mdr1a and Mdr1b, mRNA levels were assessed by real-time RT-PCR. Ivermectin induced a clear time- and concentration-dependent up-regulation of Mdr1a and Mdr1b mRNA levels (as early as a 12-h exposure and up to 2.5-fold at 10 μM). Moreover, ivermectin-treated cells displayed enhanced cellular efflux of the P-glycoprotein substrate calcein that was inhibited by the P-glycoprotein blocker valspodar, providing evidence that the ivermectin-induced P-glycoprotein was functional. The mechanisms underlying these effects were investigated. Ivermectin-mediated Mdr1 mRNA induction was independent of the two nuclear receptors CAR and PXR, which are known to be involved in drug transporters regulation. Moreover, by using reporter cell lines that detects specific ligand-activated transcription factors, we showed that ivermectin did not displayed CAR, PXR or AhR ligand activities. However, studies with actinomycin D revealed that the half-life of Mdr1a and Mdr1b mRNA were significantly prolonged by two-fold in ivermectin-treated cells suggesting a post-transcriptional mode of ivermectin regulation. This study demonstrates for the first time that ivermectin induces P-glycoprotein overexpression through post-transcriptional mRNA stabilization, thus offering insight into the mechanism of reduced therapeutic efficacy and development of ivermectin-resistant parasites. © 2011 Elsevier Inc. All rights reserved.