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Neurotensin receptor 1 (NTS

International audience; Neurotensin receptor 1 (NTSR1) is overexpressed in most human pancreatic ductal adenocarcinomas. It makes it an attractive target for the development of pancreatic cancer imaging agents. In this study, we sought to develop a bimodal PET-fluorescent imaging agent capable of specifically targeting these receptors. Starting from the structure of a known NTSR1 agonist, a series of tracers was synthesized, radiometalated with gallium-68 and evaluated in vitro and in vivo, in mice bearing an AsPC-1 xenograft. PET imaging allowed us to identify the compound [ 68 Ga]Ga-NODAGA-Lys(Cy5**)-AEEAc-[Me-Arg 8 , Tle 12 ]-NT(7-13) as the one with the most promising biodistribution profile, characterized by high tumor uptake (2.56 ± 0.97 %ID/g, 1 h p.i.) and rapid elimination from non-targeted organs, through urinary excretion. Fluorescence imaging gave similar results. On this basis, fluorescence-guided resection of tumor masses was successfully carried out on a preclinical model.

ObjectiveMacrophage activation by monosodium urate (MSU) and calcium pyrophosphate (CPP) crystals mediates an interleukin (IL)-1β-dependent inflammation during gout and pseudo-gout flare, respectively. Since metabolic reprogramming of macrophages goes along with inflammatory responses dependently on stimuli and tissue environment, we aimed to decipher the role of glycolysis and oxidative phosphorylation in the IL-1β-induced microcrystal response.MethodsBriefly, an in vitro study (metabolomics and real-time extracellular flux analysis) on MSU and CPP crystal-stimulated macrophages was performed to demonstrate the metabolic phenotype of macrophages. Then, the role of aerobic glycolysis in IL-1β production was evaluated, as well in vitro as in vivo using 18F-fluorodeoxyglucose positron emission tomography imaging and glucose uptake assay, and molecular approach of glucose transporter 1 (GLUT1) inhibition.ResultsWe observed that MSU and CPP crystals led to a metabolic rewiring toward the aerobic glycolysis pathway explained by an increase in GLUT1 plasma membrane expression and glucose uptake on macrophages. Also, neutrophils isolated from human synovial fluid during gout flare expressed GLUT1 at their plasma membrane more frequently than neutrophils isolated from bloodstream. Both glucose deprivation and treatment with either 2-deoxyglucose or GLUT1 inhibitor suppressed crystal-induced NLRP3 activation and IL-1β production, and microcrystal inflammation in vivo.ConclusionIn conclusion, we demonstrated that GLUT1-mediated glucose uptake is instrumental during the inflammatory IL-1β response induced by MSU and CPP crystals. These findings open new therapeutic paths to modulate crystal-related inflammation.

Peptide-based imaging agents targeting prostate-specific membrane antigen (PSMA) have revolutionized the evaluation of biochemical recurrence of prostate cancer (PCa) but lacks sensitivity at very low serum prostate specific antigen (PSA) levels. Once recurrence is suspected, other positron emission tomography (PET) radiotracers could be of interest to discriminate between local and distant relapse. We studied [Mice were xenografted with 22Rv1, an androgen-receptor (AR)-positive, PCa cell line that expresses PSMA and PC3, an AR-negative one that does not express PSMA. PET imaging using the different radiotracers was performed sequentially and the uptake characteristics compared to one other. NTSR1 and PSMA expression levels were analysed in tumours by immunohistochemistry.[PET imaging using [Peptide-based imaging agents targeting PSMA represent a major progress in the evaluation of biochemical recurrence of PCa but sometimes yield false negative results in some lesions. Continuing efforts have thus been made to evaluate other radiotracers. Our preclinical results suggest that [

Neurotensin receptor 1 (NTSR1) is overexpressed in human pancreatic ductal adenocarcinoma (PDAC). Specific noninvasive positron-emission tomography (PET) imaging probes may improve the diagnostic accuracy and the monitoring of therapy for patients with PDAC. Here, we report the use of the

Background/Aim: Somatostatine receptors subtype 2 (SSTR2) are regarded as a potential target in neuroblastoma (NB) for imaging and promising therapeutic approaches. The purpose of this study was to evaluate and compare the SSTR2 status by 68Ga-[tetraxetan-D-Phe1, Tyr3]-octreotide (68Ga-DOTATOC) positron-emission tomography (PET) and the tumour metabolic activity by 18F-fluorodeoxyglucose (FDG) PET in different experimental models of NB. Materials and Methods: Three cell lines of human NB with different levels of expression of SSTR2 were grafted into nude mice. Animals were imaged with FDG and 68Ga-DOTATOC and the maximum standardized uptake value (SUVmax) was determined to quantify tracer uptake. Ex vivo biodistribution of 68Ga-DOTATOC and immunohistochemical analysis of NB xenografts were performed. Results: Compared with FDG, the SUVmax of 68Ga-DOTATOC uptake by the tumour was lower but the ratio to background was higher; there was a strong positive correlation between SUVmax values observed with the two tracers (r2=0.65). Sorting the cell lines according to uptake of FDG or 68Ga-DOTATOC, injected activity per gram of tissue, Ki67 index or expression of SSTR2 assessed visually led to the same classification. Conclusion: 68Ga-DOTATOC allows preclinical imaging of NB according to the intensity of the expression of SSTR2. In contrast with what has been reported for neuroendocrine tumours, in this NB model, the 68Ga-DOTATOC uptake was positively correlated with FDG uptake and with Ki67 index, usual markers of tumour aggressiveness. If confirmed in humans, this result would favour a theranostic application of 68Ga-DOTATOC in NB, even in advanced stages.

International audience; A multi-step procedure has been described which afforded satisfactory yields of N,N 0-disubstituted cinnamamides derived from N-Boc-protected amino acids (Boc-Gly, Boc-Val, Boc-Phe). The key step of this synthesis was a regioselective RedAl reduction of an amide function in presence of a carbamate group. Next, these cinnamamides were evaluated in co-admnistration with ciprofloxacin as efflux pump inhibitors against two S. aureus strains, NorA overexpressing SA1199B and wild type SA1199. In parallel, their intrinsic toxicity was appreciated on human lung fibroblast MRC5 cells. Therefore, the cinnamamide combining both carbamate and indol-3-yl groups, was found to be the most active and one of the less toxic EPI and constituted a promising hit.

Introduction AMBA is a bombesin analogue that binds to GRPr. In a mouse model of estrogen-dependent human breast cancer, we tested whether 68 Ga-AMBA can be used for PET detection of GRPr-expressing tumors and could be more accurate than 18 F-FDG to monitor tumor response to hormone therapy. Methods The radiolabeling of 68 Ga-AMBA was automated using a R&D Synchrom module. ZR75-1, a breast cancer cell line, was xenografted in nude mice. 68 Ga-AMBA tumor uptake was compared with that of 18 F-FDG before and after treatment with tamoxifen. Results AMBA was 68 Ga-radiolabelled in 30 min with 95.3% yield and purity ≥ 98%. Prior to treatment, 68 Ga-AMBA was highly concentrated into tumors (tumor to non-tumor ratio = 2.4 vs. 1.3 with 18 F-FDG). With tamoxifen treatment (n = 6) 68 Ga-AMBA uptake plateaued after 1 week and decreased after 2 weeks, with a significant reduction compared to controls (n = 4). In contrast the effect of tamoxifen treatment could not be appreciated using 18 F-FDG. Conclusions 68 Ga-AMBA appeared better than 18 F-FDG to visualize and monitor the response to hormone treatment in this breast cancer model.

We describe the potentiality of a new liposomal formulation enabling positron emission tomography (PET) and magnetic resonance MR() imaging. The bimodality is achieved by coupling a 68Ga-based radiotracer on the bilayer of magnetic liposomes. In order to enhance the targeting properties obtained under a permanent magnetic field, a sugar moiety was added in the lipid formulation. Two new phospholipids were synthesized, one with a specific chelator of 68Ga (DSPE-PEG-NODAGA) and one with a glucose moiety (DSPE-PEG-glucose). The liposomes were produced according to a fast and safe process, with a high radiolabeling yield. MR and PET imaging were performed on mice bearing human glioblastoma tumors (U87MG) after iv injection. The accumulation of the liposomes in solid tumor is evidenced by MR imaging and the amount is evaluated in vivo and ex vivo according to PET imaging. An efficient magnetic targeting is achieved with these new magnetic liposomes.

Overexpression of the high affinity neurotensin receptor 1 (NTSR1), demonstrated in several human cancers, has been proposed as a new marker for human ductal pancreatic carcinoma and as an independent factor for poor prognosis for ductal breast cancer, head and neck squamous cell carcinoma, and non-small cell lung cancer. The aim of the present study was to develop new DOTA-neurotensin analogues for positron emission tomography (PET) imaging with (68)Ga and for targeted radiotherapy with (90)Y or (177)Lu. We synthesized a DOTA-neurotensin analogue series. Two of these peptides bear two sequence modifications for metabolic stability: DOTA-NT-20.3 shares the same peptide sequence as the previously described DTPA-NT-20.3. In the sequence of DOTA-NT-20.4, the Arg(8)-Arg(9) bond was N-methylated instead of the Pro(7)-Arg(8) bond in DOTA-NT-20.3. An additional sequence modification was introduced in DOTA-LB119 to increase stability. A spacer was added between DOTA and the peptide sequence to increase affinity. Binding to HT29 cells, which express NTSR1, in vivo stability, and biodistribution of the various analogues were compared, and the best candidate was used to image tumors of various sizes with the microPET in mice. (111)In-DOTA-NT-20.3, in spite of a relatively high uptake in kidneys, showed specific tumor uptake and elevated tumor to other organ uptake ratios. High contrast images were obtained at early time points after injection that allowed tumor detection at a time interval postinjection appropriate for imaging with the short-lived radionuclide (68)Ga. (111)In-DOTA-NT-20.4 displayed inferior binding to HT29 cells and reduced tumor uptake. (111)In-DOTA-LB119 displayed at early time points a significantly lower renal uptake but also a lower tumor uptake than (111)In-DOTA-NT-20.3, although binding to HT29 cells was similar. (68)Ga-DOTA-NT-20.3 displayed higher tumor uptake than (68)Ga-DOTA-LB119 and allowed the detection of very small tumors by PET. In conclusion, DOTA-NT-20.3 is a promising candidate for (68)Ga-PET imaging of neurotensin receptor-positive tumors. DOTA-NT-20.3 may also be considered for therapy, as the yttrium-labeled peptide has higher affinity than that of the indium-labeled one. A prerequisite for therapeutic application of this neurotensin analogue would be to lower kidney uptake, for example, by infusion of basic amino acids, gelofusin, or albumin fragments, to prevent nephrotoxicity, as with radiolabeled somatostatin analogues.

// Alex Cazes 1,2 , Lucille Lopez-Delisle 1,2 , Konstantina Tsarovina 3 , Cecile Pierre-Eugene 1,2 , Katleen De Preter 4 , Michel Peuchmaur 5,6 , Andre Nicolas 7 , Claire Provost 8 , Caroline Louis-Brennetot 1,2 , Romain Daveau 1,2 , Candy Kumps 4 , Ilaria Cascone 9 , Gudrun Schleiermacher 1,2,10 , Aurelie Prignon 8 , Frank Speleman 4 , Hermann Rohrer 3 , Olivier Delattre 1,2 and Isabelle Janoueix-Lerosey 1,2 1 Inserm U830, 26 rue d’Ulm, 75005 Paris, France. 2 Institut Curie, Centre de Recherche, 26 rue d’Ulm, 75005 Paris, France. 3 Research Group Developmental Neurobiology, Max Planck Institute for Brain Research, Max-von-Laue-Str. 4, 60438 Frankfurt/M, Germany. 4 Center for Medical Genetics, Ghent University Hospital, De Pintelaan 185, B-9000 Ghent, Belgium. 5 Departement of Pathology, AP-HP, Hopital Universitaire Robert Debre, 48 boulevard Serurier, 75019 Paris, France. 6 Universite Diderot Paris 7, Paris Sorbonne Cite, Paris, France. 7 Platform of Experimental Pathology, Institut Curie, 26 rue d’Ulm, 75005 Paris, France. 8 LIMP (Laboratoire d’Imagerie Moleculaire Positonique), Hopital Tenon, 4 rue de la Chine, 75020 Paris, France. 9 Laboratoire CRRET, EAC CNRS 7149, Universite Paris 12-Val de Marne, 61, avenue du General de Gaulle, 94010 Creteil, France. 10 Institut Curie, Departement de Pediatrie, 26 rue d’Ulm, 75005 Paris, France. Correspondence: Isabelle Janoueix-Lerosey, email: // Keywords : Neuroblastoma, ALK, neurogenesis, therapeutic target, RET Received : March 24, 2014 Accepted : April 01, 2014 Published : April 02, 2014 Abstract Activating mutations of the ALK (Anaplastic lymphoma Kinase) gene have been identified in sporadic and familial cases of neuroblastoma, a cancer of early childhood arising from the sympathetic nervous system (SNS). To decipher ALK function in neuroblastoma predisposition and oncogenesis, we have characterized knock-in (KI) mice bearing the two most frequent mutations observed in neuroblastoma patients. A dramatic enlargement of sympathetic ganglia is observed in Alk F1178L mice from embryonic to adult stages associated with an increased proliferation of sympathetic neuroblasts from E14.5 to birth. In a MYCN transgenic context, the F1178L mutation displays a higher oncogenic potential than the R1279Q mutation as evident from a shorter latency of tumor onset. We show that tumors expressing the R1279Q mutation are sensitive to ALK inhibition upon crizotinib treatment. Furthermore, our data provide evidence that activated ALK triggers RET upregulation in mouse sympathetic ganglia at birth as well as in murine and human neuroblastoma. Using vandetanib, we show that RET inhibition strongly impairs tumor growth in vivo in both MYCN /KI Alk R1279Q and MYCN /KI Alk F1178L mice. Altogether, our findings demonstrate the critical role of activated ALK in SNS development and pathogenesis and identify RET as a therapeutic target in ALK mutated neuroblastoma.

Intrahepatic cholangiocarcinoma (CCA) is characterized by an abundant desmoplastic environment. Poor prognosis of CCA has been associated with the presence of alpha-smooth muscle actin (α-SMA)-positive myofibroblasts (MFs) in the stroma and with the sustained activation of the epidermal growth factor receptor (EGFR) in tumor cells. Among EGFR ligands, heparin-binding epidermal growth factor (HB-EGF) has emerged as a paracrine factor that contributes to intercellular communications between MFs and tumor cells in several cancers. This study was designed to test whether hepatic MFs contributed to CCA progression through EGFR signaling. The interplay between CCA cells and hepatic MFs was examined first in vivo, using subcutaneous xenografts into immunocompromised mice. In these experiments, cotransplantation of CCA cells with human liver myofibroblasts (HLMFs) increased tumor incidence, size, and metastatic dissemination of tumors. These effects were abolished by gefitinib, an EGFR tyrosine kinase inhibitor. Immunohistochemical analyses of human CCA tissues showed that stromal MFs expressed HB-EGF, whereas EGFR was detected in cancer cells. In vitro, HLMFs produced HB-EGF and their conditioned media induced EGFR activation and promoted disruption of adherens junctions, migratory and invasive properties in CCA cells. These effects were abolished in the presence of gefitinib or HB-EGF-neutralizing antibody. We also showed that CCA cells produced transforming growth factor beta 1, which, in turn, induced HB-EGF expression in HLMFs.A reciprocal cross-talk between CCA cells and myofibroblasts through the HB-EGF/EGFR axis contributes to CCA progression.

PET with fluoroethylthyrosine (FET), amino-acid analogue, has been performed in Germany since the beginning of the decade for molecular and metabolic imaging of brain tumours, since FDG, the glucose analogue which is the reference tracer for clinical PET, has this drawback to be taken-up intensely by cerebral cortex. We report on our preliminary results on the comparison of PET/CT with FET and FDG in 10 evaluable patients presenting with a brain lesion either at diagnosis or after treatment. In an attempt to optimise specificity, FET PET/CT has been acquired as a static image 1h after injection, while the most current practice is a dynamic 40 min acquisition starting at FET injection. With our acquisition protocol, diagnostic performance of FET was 88% sensitivity and 80% accuracy vs 13% and 30% respectively for FDG.FET is a radiopharmaceutical with clinical usefulness for the diagnosis, delineation and monitoring of brain tumours. Association with FDG allows identification of high-grade lesions or components, but it could be avoided providing that acquisition and quantification procedures of FET PET/CT would have been better optimised and standardised.

Aim Bronchioloalveolar (BAC) cancer is a source of false-negative F-fluorodeoxyglucose (FDG) PET/computed tomography (CT) results. A few studies reported better diagnostic performances with PET tracers of lipid metabolism, C-choline, or C-acetate, for the detection of well-differentiated adenocarcinoma or BAC. F-fluorocholine (FCH) is a lipid analogue for PET imaging, with advantages in terms of logistics and image resolution. We carried out this prospective pilot study to evaluate whether FCH PET/CT could detect lung cancer with a BAC component and could be more sensitive than FDG in this aim. Methods Fifteen patients with a lung nodule or lesion suspected for BAC on CT and/or with a history of BAC had PET/CT 60-90 min after 5 MBq FDG/kg body mass and, on a separate day, 10-20 min after 4 MBq FCH/kg body mass. The standard of truth was histology and a 6-month follow-up. Results Nine patients (12 lesions) presented BAC or adenocarcinoma with BAC features, two patients presented adenocarcinoma without BAC features (five lesions) and four patients presented benign lesions (15 non-malignant sites). For both FCH and FDG, patient-based sensitivity was 78% for detecting cancer with a BAC component and 82% for detecting malignancy. Site-based sensitivity for detecting malignancy was 76 and 75% for detecting cancer with BAC features, for both radiopharmaceuticals. Specificity was similar for FCH and FDG (site-based 93 vs. 81%, NS). In these early-stage cancers, only one adrenal metastasis was observed that took up FCH and FDG. Conclusion In this population of patients with ground-glass opacities selected on CT suggestive of BAC or with a history of BAC and a recent lung anomaly on CT, FCH detected all malignant lesions with at least a 2.0 cm short axis. However, FDG had similar performance.