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Yu Z, Ananias HJK, Carlucci G, Hoving HD, Helfrich W, Dierckx RAJO, Wang F, de Jong IJ, Elsinga PH. An update of radiolabeled bombesin analogs for gastrin-releasing peptide receptor targeting. Curr Pharm Des 2013; 19:3329-41. [PMID: 23431995 DOI: 10.2174/1381612811319180015] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 02/15/2013] [Indexed: 11/22/2022]
Abstract
Prostate cancer is a critical public health problem in USA and Europe. New non-invasive imaging methods are urgently needed, due to the low accuracy and specificity of current screen methods and the desire of localizing primary prostate cancer and bone metastasis. Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT) are the non-invasive and sensitive imaging methods which have been widely used for diagnosing diseases in the clinic. Lack of suitable radiotracers is the major issue for nuclear imaging of prostate cancer, although radiolabeled bombesin (BN) peptides targeting the Gastrin-Releasing Peptide Receptor (GRPR) on tumor cells are widely investigated. In this review we discuss the recent trends in the development of GRPR-targeted radiopharmaceuticals based on BN analogs with regard to their potential for imaging and therapy of GRPR-expressing malignancies. Following a brief introduction of GRPR and bombesin peptides, we summarize the properties of prostate cancer specific radiolabeled bombesins. New bombesin tracers published in the last five years are reviewed and compared according to their novelties in biomolecules, radionuclides, labeling methods, bifunctional chelators and linkers. Hot topics such as multimerization, application of agonists and antagonists are highlighted in the review. Lastly, a few clinical trials of cancer nuclear imaging with radiolabeled bombesin have been discussed.
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Rybczynska AA, de Bruyn M, Ramakrishnan NK, de Jong JR, Elsinga PH, Helfrich W, Dierckx RA, van Waarde A. In Vivo Responses of Human A375M Melanoma to a σ Ligand: 18F-FDG PET Imaging. J Nucl Med 2013; 54:1613-20. [DOI: 10.2967/jnumed.113.122655] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Ramakrishnan NK, Rybczynska AA, Visser AKD, Marosi K, Nyakas CJ, Kwizera C, Sijbesma JWA, Elsinga PH, Ishiwata K, Pruim J, Dierckx RAJO, van Waarde A. Small-animal PET with a σ-ligand, 11C-SA4503, detects spontaneous pituitary tumors in aged rats. J Nucl Med 2013; 54:1377-83. [PMID: 23785170 DOI: 10.2967/jnumed.112.115931] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
UNLABELLED Pituitary tumors are often detected only after death or at late stages of the disease when they are macroadenomas with a low surgical cure rate. Spontaneous pituitary tumors occur in rats over 1 y of age. In an ongoing study of changes in σ-1 agonist binding related to aging, several of our rats developed such tumors. The aim of the current study was to assess the kinetics of (11)C-SA4503 ((11)C-labeled 1-[2-(3,4-dimethoxyphenthyl)]-4-(3-phenylpropyl)-piperazine dihydrochloride) in tumor and brain and to evaluate the utility of this tracer in the detection of pituitary tumors. METHODS Small-animal PET scans of the brain region of male Wistar Hannover rats (age, 18-32 mo) were acquired using the σ-1 agonist tracer (11)C-SA4503. The time-dependent uptake of (11)C in the entire brain, tumor or normal pituitary, and thyroid was measured. A 2-tissue-compartment model was fitted to the PET data, using metabolite-corrected plasma radioactivity as the input function. RESULTS Pituitary tumors showed up as bright hot spots in the scans. The total distribution volume (VT) of the tracer was significantly higher in the tumor than in the normal pituitary. Surprisingly, a higher VT was also seen in the brain and thyroid tissue of animals with pituitary tumors than in healthy rats. The increase in VT in the brain and thyroid was not related to a change in nondisplaceable binding potential (BPND) but rather to an increase in the partition coefficient (K1/k2) of (11)C-SA4503. The increase in VT in the tumor on the other hand was accompanied by a significant increase in BPND. Western blotting analysis indicated that pituitary tumors overexpressed σ-1 receptors. CONCLUSION The overexpression of σ-1 receptors in spontaneous pituitary tumors is detected as an increase in uptake and BPND of (11)C-SA4503. Therefore, this tracer may have promise for the detection of pituitary adenomas, using PET.
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Ananias HJK, Yu Z, Hoving HD, Rosati S, Dierckx RA, Wang F, Yan Y, Chen X, Pruim J, Lub-de Hooge MN, Helfrich W, Elsinga PH, de Jong IJ. Application of (99m)Technetium-HYNIC(tricine/TPPTS)-Aca-Bombesin(7-14) SPECT/CT in prostate cancer patients: a first-in-man study. Nucl Med Biol 2013; 40:933-8. [PMID: 23891351 DOI: 10.1016/j.nucmedbio.2013.05.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2012] [Revised: 05/20/2013] [Accepted: 05/27/2013] [Indexed: 12/31/2022]
Abstract
RATIONALE The peptide bombesin (BBN) and its derivatives exhibit high binding affinity for the gastrin-releasing peptide receptor (GRPR), which is highly expressed in prostate cancer. We used the BBN-based radiopharmaceutical (99m)Technetium-HYNIC(tricine/TPPTS)-Aca-Bombesin(7-14) ((99m)Tc-HABBN) to perform a first-in-man clinical pilot study to evaluate the feasibility of (99m)Tc-HABBN SPECT/CT for detection of prostate cancer in patients. METHODS Eight patients with biopsy-proven prostate cancer who were scheduled for either radical prostatectomy or external beam radiotherapy underwent (99m)Tc-HABBN scintigraphy and SPECT/CT prior to treatment. Serial blood samples were taken to assess blood radioactivity and to determine in vivo metabolic stability. Clinical parameters were measured and reported side effects, if present, were recorded. Prostate cancer specimens of all patients were immunohistochemically stained for GRPR. RESULTS (99m)Tc-HABBN was synthesized with high radiochemical yield, purity and specific activity. There were no significant changes in clinical parameters, and there were no adverse or subjective side effects. Low metabolic stability was observed, as less than 20% of (99m)Tc-HABBN was intact after 30 min. Immunohistochemical staining for GRPR was observed in the prostate cancer specimens in all patients. (99m)Tc-HABBN scintigraphy and SPECT/CT did not detect prostate cancer in patients with proven disease. CONCLUSIONS (99m)Tc-HABBN SPECT/CT for visualization of prostate cancer is safe but hampered by an unexpected low in vivo metabolic stability in man. The difference between the excellent in vitro stability of (99m)Tc-HABBN in human serum samples determined in our previous study regarding (99m)Tc-HABBN and the low in vivo metabolic stability determined in this study, is striking. This issue warrants further study of peptide-based radiopharmaceuticals.
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Carlucci G, Ananias HJK, Yu Z, Hoving HD, Helfrich W, Dierckx RAJO, Liu S, de Jong IJ, Elsinga PH. Preclinical evaluation of a novel ¹¹¹In-labeled bombesin homodimer for improved imaging of GRPR-positive prostate cancer. Mol Pharm 2013; 10:1716-24. [PMID: 23590837 DOI: 10.1021/mp3005462] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Rational-designed multimerization of targeting ligands can be used to improve kinetic and thermodynamic properties. Multimeric targeting ligands may be produced by tethering multiple identical or two or more monomeric ligands of different binding specificities. Consequently, multimeric ligands may simultaneously bind to multiple receptor molecules. Previously, multimerization has been successfully applied on radiolabeled RGD peptides, which resulted in an improved tumor targeting activity in animal models. Multimerization of peptide-based ligands may improve the binding characteristics by increasing local ligand concentration and by improving dissociation kinetics. Here, we present a preclinical study on a novel radiolabeled bombesin (BN) homodimer, designated (111)In-DOTA-[(Aca-BN(7-14)]2, that was designed for enhanced targeting of gastrin-releasing peptide receptor (GRPR)-positive prostate cancer cells. A BN homodimer was conjugated with DOTA-NHS and labeled with (111)In. After HPLC purification, the GRPR targeting ability of (111)In-DOTA-[Aca-BN(7-14)]2 was assessed by microSPECT imaging in SCID mice xenografted with the human prostate cancer cell line PC-3. (111)In labeling of DOTA-[(Aca-BN(7-14)]2 was achieved within 30 min at 85 °C with a labeling yield of >40%. High radiochemical purity (>95%) was achieved by HPLC purification. (111)InDOTA-[Aca-BN(7-14)]2 specifically bound to GRPR-positive PC-3 prostate cancer cells with favorable binding characteristics because uptake of 111In-DOTA-[Aca-BN(7-14)]2 in GRPR-positive PC-3 cells increased over time. A maximum peak with 30% radioactivity was observed after 2 h of incubation. The log D value was -1.8 ± 0.1. (111)In-DOTA-[Aca-BN(7-14)]2 was stable in vitro both in PBS and human serum for at least 4 days. In vivo biodistribution analysis and microSPECT/CT scans performed after 1, 4, and 24 h of injection showed favorable binding characteristics and tumor-to-normal tissue ratios. This study identifies (111)In-DOTA-[(Aca-BN(7-14)]2 as a promising radiotracer for nuclear imaging of GRPR in prostate cancer.
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F. Antunes I, Haisma HJ, Elsinga PH, Di Gialleonardo V, Waarde AV, Willemsen ATM, Dierckx RA, de Vries EFJ. Induction of β-Glucuronidase Release by Cytostatic Agents in Small Tumors. Mol Pharm 2012; 9:3277-85. [DOI: 10.1021/mp300327w] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Carlucci G, Ananias HJK, Yu Z, Van de Wiele C, Dierckx RA, de Jong IJ, Elsinga PH. Multimerization improves targeting of peptide radio-pharmaceuticals. Curr Pharm Des 2012; 18:2501-16. [PMID: 22475514 DOI: 10.2174/13816128112092501] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 02/24/2012] [Indexed: 11/22/2022]
Abstract
Multimerization offers unique kinetic and thermodynamic properties to molecules. Multimeric ligands, characterized by multiple similar or different monomeric molecules tethered together, can bind several receptors simultaneously. Multimerization occurs also in nature. This process can be used to develop molecules with high diagnostic and therapeutic value. By altering parameters as linkers` length and flexibility, scaffold and backbones insertion, and ligands-receptors recognition, it is possible to provide high selectivity and binding affinity. The resultant multimeric ligand has a more favorable binding affinity than corresponding monomeric ligands.
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Antunes IF, Haisma HJ, Elsinga PH, Sijbesma JWA, Waarde AV, Willemsen ATM, Dierckx RA, de Vries EFJ. In vivo evaluation of [18F]FEAnGA-Me: a PET tracer for imaging β-glucuronidase (β-GUS) activity in a tumor/inflammation rodent model. Nucl Med Biol 2012; 39:854-63. [PMID: 22445742 DOI: 10.1016/j.nucmedbio.2012.02.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Revised: 01/02/2012] [Accepted: 02/11/2012] [Indexed: 01/08/2023]
Abstract
INTRODUCTION The PET tracer, 1-O-(4-(2-fluoroethyl-carbamoyloxymethyl)-2-nitrophenyl)-O-β-d-glucopyronuronate ([(18)F]FEAnGA), was recently developed for PET imaging of extracellular β-glucuronidase (β-GUS). However, [(18)F]FEAnGA exhibited rapid renal clearance, which resulted in a relatively low tracer uptake in the tumor. To improve the pharmacokinetics of [(18)F]FEAnGA, we developed its more lipophilic methyl ester analog, [(18)F]FEAnGA-Me. METHODS [(18)F]FEAnGA-Me was obtained by alkylation of the O-protected glucuronide methyl ester precursor with [(18)F]-fluoroethylamine ([(18)F]FEA), followed by removal of the acetate protecting groups with NaOMe/MeOH. The PET tracer was evaluated by in vitro and in vivo studies. RESULTS [(18)F]FEAnGA-Me was obtained in 5%-10% overall radiochemical yield. It is 10-fold less hydrophilic than [(18)F]FEAnGA and it is stable in PBS and in the presence of β-GUS for 1 h. However, in the presence of esterase or plasma [(18)F]FEAnGA-Me is converted to [(18)F]FEAnGA, and subsequently converted to [(18)F]FEA by β-GUS. MicroPET studies in Wistar rats bearing a C6 glioma and a sterile inflammation showed similar uptake in tumors after injection of either [(18)F]FEAnGA-Me or [(18)F]FEAnGA. Both tracers had a rapid two-phase clearance of total plasma radioactivity with a half-life of 1 and 8 min. The [(18)F]FEAnGA fraction generated from [(18)F]FEAnGA-Me by in vivo hydrolysis had a circulation half-life of 1 and 11 min in plasma. Similar distribution volume in the viable part of the tumor was found after injection of either [(18)F]FEAnGA-Me or [(18)F]FEAnGA. CONCLUSION The imaging properties of [(18)F]FEAnGA-Me were not significantly better than those of [(18)F]FEAnGA. Therefore, other strategies should be applied in order to improve the kinetics of these tracers.
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Antunes IF, Doorduin J, Haisma HJ, Elsinga PH, van Waarde A, Willemsen ATM, Dierckx RA, de Vries EFJ. 18F-FEAnGA for PET of β-glucuronidase activity in neuroinflammation. J Nucl Med 2012; 53:451-8. [PMID: 22323774 DOI: 10.2967/jnumed.111.096388] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED Activation of microglia is a hallmark of inflammatory, infectious, and degenerative diseases of the central nervous system. Several studies have indicated that there is an increase in release of β-glucuronidase by activated microglia into the extracellular space at the site of neuroinflammation. β-glucuronidase is involved in the hydrolysis of glycosaminoglycans on the cell surface and the degradation of the extracellular matrix. Therefore, β-glucuronidase might be a biomarker for ongoing neurodegeneration induced by neuroinflammation. In this study, we investigated whether the PET tracer (18)F-FEAnGA was able to detect β-glucuronidase release during neuroinflammation in a rat model of herpes encephalitis. METHODS Male Wistar rats were intranasally inoculated with herpes simplex virus 1 (HSV-1) or phosphate-buffered saline as a control. (11)C-(R)-PK11195 and (18)F-FEAnGA small-animal PET scans were acquired for 60 min. Logan graphical analysis was used to calculate (18)F-FEAnGA distribution volumes (DV(Logan)) in various brain areas. RESULTS After administration of (18)F-FEAnGA, the area under the activity concentration-versus-time curve of the whole brain was 2 times higher in HSV-1-infected rats than in control rats. In addition, the DV(Logan) of (18)F-FEAnGA was most increased in the frontopolar cortex, frontal cortex, bulbus olfactorius, cerebral cortex, cerebellum, and brainstem of HSV-1-infected rats, when compared with control rats. The conversion of (18)F-FEAnGA to 4-hydroxy-3-nitrobenzyl alcohol was found to be 1.6 times higher in HSV-1-infected rats than in control rats and correlated with the DV(Logan) of (18)F-FEAnGA in the same areas of the brain. Furthermore, the DV(Logan) of (18)F-FEAnGA also correlated with β-glucuronidase activity in the same brain regions. In addition, DV(Logan) of (18)F-FEAnGA showed a tendency to correlate with (11)C-(R)-PK11195 uptake (marker for activated microglia) in the same brain regions. CONCLUSION Despite relatively low brain uptake, (18)F-FEAnGA was able to detect an increased release of β-glucuronidase during neuroinflammation.
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Toyohara J, Elsinga PH, Ishiwata K, Sijbesma JWA, Dierckx RAJO, van Waarde A. Evaluation of 4'-[methyl-11C]thiothymidine in a rodent tumor and inflammation model. J Nucl Med 2012; 53:488-94. [PMID: 22315439 DOI: 10.2967/jnumed.111.098426] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
UNLABELLED 4'-[methyl-(11)C]thiothymidine ((11)C-4DST) is a novel radiopharmaceutical that can be used for tumor imaging because of its rapid incorporation into DNA as a substrate for DNA synthesis. The in vivo stability of (11)C-4DST is much greater than that of natural thymidine, because of the presence of a sulfur atom in the 4'-position. Here, we evaluated the tissue kinetics and biodistribution of (11)C-4DST in a rodent tumor and acute sterile inflammation model in comparison with the previously published biodistribution data of 3'-deoxy-3'-(18)F-fluorothymidine ((18)F-FLT), (18)F-FDG, (11)C-choline, (11)C-methionine, and 2 σ-receptor ligands in the same animal model. METHODS C6 tumor cells were implanted subcutaneously into the right shoulder and turpentine (0.1 mL) was injected intramuscularly into the left hind leg of male Wistar rats 11 d and 24 h, respectively, before the scanning day. The animals were anesthetized with isoflurane, and (11)C-4DST (20-50 MBq) was injected intravenously. A dynamic PET scan was performed for 60 min with either the shoulder or hind leg region in the field of view. The animals were sacrificed, and a biodistribution study was performed. RESULTS (11)C-4DST showed the highest tumor uptake (standardized uptake value, 4.93) of all radiopharmaceuticals tested. Its tumor-to-muscle concentration ratio (12.7) was similar to that of (18)F-FDG (13.2). The selectivity of (11)C-4DST for tumor as compared with acute inflammation was high (37.7), comparable to that of the σ-ligand (18)F-FE-SA5845 and much higher than that of (18)F-FDG (3.5). Rapidly proliferating tissues (tumor and bone marrow) showed a steadily increasing uptake. In inflamed muscle, (11)C-4DST showed relatively rapid washout, and tracer concentrations in inflamed and noninflamed muscle were not significantly different at intervals greater than 40 min. Competition of endogenous thymidine for (11)C-4DST uptake in target tissues was negligible, in contrast to competition for (18)F-FLT uptake. Thus, pretreatment of animals with thymidine phosphorylase was not required before PET with (11)C-4DST. CONCLUSION In our rodent model, (11)C-4DST showed high tumor uptake (sensitivity) and high tumor selectivity. The different kinetics of (11)C-4DST in rapidly proliferating and inflammatory tissue may allow distinction between tumor and acute inflammation in a clinical setting. These promising results for (11)C-4DST warrant further investigation in PET studies in patients with various types of tumors.
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Antunes IF, Haisma HJ, Elsinga PH, van Waarde A, Willemsen ATM, Dierckx RA, de Vries EFJ. In vivo evaluation of 1-O-(4-(2-fluoroethyl-carbamoyloxymethyl)-2-nitrophenyl)-O-β-D-glucopyronuronate: a positron emission tomographic tracer for imaging β-glucuronidase activity in a tumor/inflammation rodent model. Mol Imaging 2012; 11:77-E1. [PMID: 22418030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023] Open
Abstract
β-Glucuronidase (β-GUS) plays an important role in inflammation and degenerative processes. The enzyme has also been investigated as a target in prodrug therapy for cancer. To investigate the role of β-GUS in pathologies and to optimize β-GUS-based prodrug therapies, we recently developed a positron emission tomographic (PET) tracer, 1-O-(4-(2-fluoroethyl-carbamoyloxymethyl)-2-nitrophenyl)-O-β-D-glucopyronuronate ([18F]FEAnGA), which proved to be selectively cleaved by β-GUS. Here we present the in vivo evaluation of [18F]FEAnGA for imaging of β-GUS in a tumor/inflammation model. Ex vivo biodistribution of [18F]FEAnGA was conducted in healthy rats. PET imaging and pharmacokinetic modeling were performed in Wistar rats bearing C6 tumors of different sizes and sterile inflammation. The biodistribution studies of [18F]FEAnGA indicated low uptake in major organs and rapid excretion through the renal pathway. MicroPET studies revealed three times higher uptake in the viable part of larger C6 gliomas than in smaller C6 gliomas. Uptake in inflamed muscle was significantly higher than in control muscle. The distribution volume of [18F]FEAnGA in the viable part of the tumor correlated well with the cleavage of the tracer to [18F]fluoroethylamine and the spacer 4-hydroxy-3-nitrobenzyl alcohol. [18F]FEAnGA is a PET tracer able to detect increased activity of β-GUS in large solid tumors and in inflamed tissues.
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Antunes IF, Haisma HJ, Elsinga PH, van Waarde A, Willemsen AT, Dierckx RA, de Vries EF. In Vivo Evaluation of 1-O-(4-(2-Fluoroethyl-Carbamoyloxymethyl)-2-Nitrophenyl)-O-β-D-Glucopyronuronate: A Positron Emission Tomographic Tracer for Imaging β-Glucuronidase Activity in a Tumor/Inflammation Rodent Model. Mol Imaging 2012. [DOI: 10.2310/7290.2011.00029s1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Antunes IF, Haisma HJ, Elsinga PH, van Waarde A, Willemsen AT, Dierckx RA, de Vries EF. In Vivo Evaluation of 1-O-(4-(2-Fluoroethyl-Carbamoyloxymethyl)-2-Nitrophenyl)-O-β-D-Glucopyronuronate: A Positron Emission Tomographic Tracer for Imaging β-Glucuronidase Activity in a Tumor/Inflammation Rodent Model. Mol Imaging 2012. [DOI: 10.2310/7290.2011.00029] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Campbell-Verduyn LS, Mirfeizi L, Schoonen AK, Dierckx RA, Elsinga PH, Feringa BL. Strain-Promoted Copper-Free “Click” Chemistry for 18F Radiolabeling of Bombesin. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201105547] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Campbell-Verduyn LS, Mirfeizi L, Schoonen AK, Dierckx RA, Elsinga PH, Feringa BL. Strain-promoted copper-free "click" chemistry for 18F radiolabeling of bombesin. Angew Chem Int Ed Engl 2011; 50:11117-20. [PMID: 21956935 DOI: 10.1002/anie.201105547] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Indexed: 01/02/2023]
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van Waarde A, Ramakrishnan NK, Rybczynska AA, Elsinga PH, Ishiwata K, Nijholt IM, Luiten PGM, Dierckx RA. The cholinergic system, sigma-1 receptors and cognition. Behav Brain Res 2011; 221:543-54. [PMID: 20060423 DOI: 10.1016/j.bbr.2009.12.043] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Accepted: 12/26/2009] [Indexed: 12/31/2022]
Abstract
This article provides an overview of present knowledge regarding the relationship between the cholinergic system and sigma-1 receptors, and discusses potential applications of sigma-1 receptor agonists in the treatment of memory deficits and cognitive disorders. Sigma-1 receptors, initially considered as a subtype of the opioid family, are unique ligand-regulated molecular chaperones in the endoplasmatic reticulum playing a modulatory role in intracellular calcium signaling and in the activity of several neurotransmitter systems, particularly the cholinergic and glutamatergic pathways. Several central nervous system (CNS) drugs show high to moderate affinities for sigma-1 receptors, including acetylcholinesterase inhibitors (donepezil), antipsychotics (haloperidol, rimcazole), selective serotonin reuptake inhibitors (fluvoxamine, sertraline) and monoamine oxidase inhibitors (clorgyline). These compounds can influence cognitive functions both via their primary targets and by activating sigma-1 receptors in the CNS. Sigma-1 agonists show powerful anti-amnesic and neuroprotective effects in a large variety of animal models of cognitive dysfunction involving, among others (i) pharmacologic target blockade (with muscarinic or NMDA receptor antagonists or p-chloroamphetamine); (ii) selective lesioning of cholinergic neurons; (iii) CNS administration of β-amyloid peptides; (iv) aging-induced memory loss, both in normal and senescent-accelerated rodents; (v) neurodegeneration induced by toxic compounds (CO, trimethyltin, cocaine), and (vi) prenatal restraint stress.
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Paul S, Khanapur S, Rybczynska AA, Kwizera C, Sijbesma JW, Ishiwata K, Willemsen AT, Elsinga PH, Dierckx RA, van Waarde A. Small-Animal PET Study of Adenosine A1 Receptors in Rat Brain: Blocking Receptors and Raising Extracellular Adenosine. J Nucl Med 2011; 52:1293-300. [DOI: 10.2967/jnumed.111.088005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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Ananias HJK, Yu Z, Dierckx RA, van der Wiele C, Helfrich W, Wang F, Yan Y, Chen X, de Jong IJ, Elsinga PH. 99mTechnetium-HYNIC(tricine/TPPTS)-Aca-Bombesin(7–14) as a Targeted Imaging Agent with MicroSPECT in a PC-3 Prostate Cancer Xenograft Model. Mol Pharm 2011; 8:1165-73. [DOI: 10.1021/mp200014h] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Fiebrich HB, van Asselt SJ, Brouwers AH, van Dullemen HM, Pijl MEJ, Elsinga PH, Links TP, de Vries EGE. Tailored imaging of islet cell tumors of the pancreas amidst increasing options. Crit Rev Oncol Hematol 2011; 82:213-26. [PMID: 21704529 DOI: 10.1016/j.critrevonc.2011.05.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Revised: 04/10/2011] [Accepted: 05/19/2011] [Indexed: 02/07/2023] Open
Abstract
Pancreatic islet cell tumors are neuroendocrine tumors, which can produce hormones and can arise as part of multiple endocrine neoplasia type 1 or von-Hippel-Lindau-disease, two genetically well-defined hereditary cancer syndromes. Currently, technical innovation improves conventional and specific molecular imaging techniques. To organize the heterogeneous results described for the imaging of these tumors, we distinguished three indications (1) imaging of a patient with hormone hypersecretion, (2) search for a pancreatic primary in case of proven neuroendocrine cancer of unknown primary, and (3) screening of asymptomatic mutation carriers. We searched for publications on imaging of islet cell tumors between 1995 and January 2010 and defined a Level of Evidence (LOE) for the applicability of each technique. For each technique, data were analyzed in a Forest plot and arranged per imaging indication and tumor subtype. LOEs are weak for all imaging techniques. Analyses indicate a prominent role for endoscopic ultrasound for all three indications.
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Vangestel C, Peeters M, Mees G, Oltenfreiter R, Boersma HH, Elsinga PH, Reutelingsperger C, Van Damme N, De Spiegeleer B, Van de Wiele C. In vivo imaging of apoptosis in oncology: an update. Mol Imaging 2011; 10:340-58. [PMID: 21521554 DOI: 10.2310/7290.2010.00058] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Accepted: 08/05/2010] [Indexed: 01/09/2023] Open
Abstract
In this review, data on noninvasive imaging of apoptosis in oncology are reviewed. Imaging data available are presented in order of occurrence in time of enzymatic and morphologic events occurring during apoptosis. Available studies suggest that various radiopharmaceutical probes bear great potential for apoptosis imaging by means of positron emission tomography and single-photon emission computed tomography (SPECT). However, for several of these probes, thorough toxicologic studies are required before they can be applied in clinical studies. Both preclinical and clinical studies support the notion that 99mTc-hydrazinonicotinamide-annexin A5 and SPECT allow for noninvasive, repetitive, quantitative apoptosis imaging and for assessing tumor response as early as 24 hours following treatment instigation. Bioluminescence imaging and near-infrared fluorescence imaging have shown great potential in small-animal imaging, but their usefulness for in vivo imaging in humans is limited to structures superficially located in the human body. Although preclinical tumor-based data using high-frequency-ultrasonography (US) are promising, whether or not US will become a routinely clinically useful tool in the assessment of therapy response in oncology remains to be proven. The potential of magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) for imaging late apoptotic processes is currently unclear. Neither 31P MRS nor 1H MRS signals seems to be a unique identifier for apoptosis. Although MRI-measured apparent diffusion coefficients are altered in response to therapies that induce apoptosis, they are also altered by nonapoptotic cell death, including necrosis and mitotic catastrophe. In the future, rapid progress in the field of apoptosis imaging in oncology is expected.
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van Waarde A, Rybczynska AA, Ramakrishnan N, Ishiwata K, Elsinga PH, Dierckx RAJO. Sigma receptors in oncology: therapeutic and diagnostic applications of sigma ligands. Curr Pharm Des 2011; 16:3519-37. [PMID: 21050178 DOI: 10.2174/138161210793563365] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2010] [Accepted: 10/13/2010] [Indexed: 11/22/2022]
Abstract
Sigma receptors (subtypes sigma-1 and sigma-2) are a unique class of binding sites expressed throughout the mammalian body. The endogenous ligand for these sites has not been identified, but steroid hormones (particularly progesterone), sphingolipid-derived amines and N,N-dimethyltryptamine can bind with fairly high affinity. Sigma receptors are overexpressed in rapidly proliferating cells, like cancer cells. Particularly the sigma-2 subtype is upregulate when cells divide and down regulated when they become quiescent. Sigma ligands, especially sigma-2 agonists, can inhibit proliferation and induce apoptosis by a mechanism involving changes in cytosolic Ca(2+), ceramide and sphingolipid levels. Tumor cells are much more sensitive to such treatment than cells from their tissue of origin. Sigma ligands induce apoptosis not only in drug-sensitive but also in drug-resistant cancer cells (e.g., cells with p53 mutations, or caspase dysfunction). Moreover, sigma ligands may abrogate P-glycoprotein-mediated drug resistance and at subtoxic doses, they can potentiate the effect of conventional cytostatics. Thus, sigma-2 agonists may be developed as antineoplastic agents for the treatment of drug-resistant tumors. A large number of radiolabeled sigma ligands has been prepared for SPECT (single-photon emission computed tomography) and PET (positron emission tomography) imaging. Such radiopharmaceuticals can be used for tumor detection, tumor staging, and evaluation of anti-tumor therapy. There is still a need for the development of ligands with (1) high selectivity for the sigma-2 subtype, (2) defined action (agonist or antagonist) and (3) optimal pharmacokinetics (low affinity for P-glycoprotein, high and specific tumor uptake, and rapid washout from non-target tissues).
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Nagengast WB, Lub-de Hooge MN, Oosting SF, den Dunnen WFA, Warnders FJ, Brouwers AH, de Jong JR, Price PM, Hollema H, Hospers GAP, Elsinga PH, Hesselink JW, Gietema JA, de Vries EGE. VEGF-PET imaging is a noninvasive biomarker showing differential changes in the tumor during sunitinib treatment. Cancer Res 2010; 71:143-53. [PMID: 21084271 DOI: 10.1158/0008-5472.can-10-1088] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Non-invasive imaging of angiogenesis could ease the optimization of antiangiogenesis treatments for cancer. In this study, we evaluated the role of VEGF-PET as a biomarker of dynamic angiogenic changes in tumors following treatment with the kinase inhibitor sunitinib. The effects of sunitinib treatment and withdrawal on the tumor was investigated using the new VEGF-PET tracer (89)Zr-ranibizumab as well as (18)F-FDG PET, and (15)O-water PET in mouse xenograft models of human cancer. The obtained imaging results were compared with tumor growth, VEGF plasma levels and immunohistologic analyzes. In contrast to (18)F-FDG and (15)O-water PET, VEGF-PET demonstrated dynamic changes during sunitinib treatment within the tumor with a strong decline in signal in the tumor center and only minimal reduction in tumor rim, with a pronounced rebound after sunitinib discontinuation. VEGF-PET results corresponded with tumor growth and immunohistochemical vascular- and tumor- markers. Our findings highlight the strengths of VEGF-PET imaging to allow serial analysis of angiogenic changes in different areas within a tumor.
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Antunes IF, Haisma HJ, Elsinga PH, Dierckx RA, de Vries EFJ. Synthesis and Evaluation of [18F]-FEAnGA as a PET Tracer for β-Glucuronidase Activity. Bioconjug Chem 2010; 21:911-20. [DOI: 10.1021/bc9004602] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Campbell-Verduyn LS, Szymański W, Postema CP, Dierckx RA, Elsinga PH, Janssen DB, Feringa BL. One pot 'click' reactions: tandem enantioselective biocatalytic epoxide ring opening and [3+2] azide alkyne cycloaddition. Chem Commun (Camb) 2010; 46:898-900. [PMID: 20107643 DOI: 10.1039/b919434g] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Halohydrin dehalogenase (HheC) can perform enantioselective azidolysis of aromatic epoxides to 1,2-azido alcohols which are subsequently ligated to alkynes producing chiral hydroxy triazoles in a one-pot procedure with excellent enantiomeric excess.
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Fiebrich HB, Brouwers AH, Kerstens MN, Pijl MEJ, Kema IP, de Jong JR, Jager PL, Elsinga PH, Dierckx RAJO, van der Wal JE, Sluiter WJ, de Vries EGE, Links TP. 6-[F-18]Fluoro-L-dihydroxyphenylalanine positron emission tomography is superior to conventional imaging with (123)I-metaiodobenzylguanidine scintigraphy, computer tomography, and magnetic resonance imaging in localizing tumors causing catecholamine excess. J Clin Endocrinol Metab 2009; 94:3922-30. [PMID: 19622618 DOI: 10.1210/jc.2009-1054] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
CONTEXT Catecholamine excess is rare, but symptoms may be life threatening. OBJECTIVE The objective of the study was to investigate the sensitivity of 6-[F-18]fluoro-l-dihydroxyphenylalanine positron emission tomography ((18)F-DOPA PET), compared with (123)I-metaiodobenzylguanidine ((123)I-MIBG) scintigraphy and computer tomography (CT)/magnetic resonance imaging (MRI) for tumor localization in patients with catecholamine excess. DESIGN AND SETTING All consecutive patients with catecholamine excess visiting the University Medical Center Groningen, Groningen, The Netherlands, between March 2003 and January 2008 were eligible. PATIENTS Forty-eight patients were included. The final diagnosis was pheochromocytoma in 40, adrenal hyperplasia in two, paraganglioma in two, ganglioneuroma in one, and unknown in three. MAIN OUTCOME MEASURES Sensitivities and discordancy between (18)F-DOPA PET, (123)I-MIBG, and CT or MRI were analyzed for individual patients and lesions. Metanephrines and 3-methoxytyramine in plasma and urine and uptake of (18)F-DOPA with PET were measured to determine the whole-body metabolic burden and correlated with biochemical tumor activity. The gold standard was a composite reference standard. RESULTS (18)F-DOPA PET showed lesions in 43 patients, (123)I-MIBG in 31, and CT/MRI in 32. Patient-based sensitivity for (18)F-DOPA PET, (123)I-MIBG, and CT/MRI was 90, 65, and 67% (P < 0.01 for (18)F-DOPA PET vs. both (123)I-MIBG and CT/MRI, P = 1.0 (123)I-MIBG vs. CT/MRI). Lesion-based sensitivities were 73, 48, and 44% (P < 0.001 for (18)F-DOPA PET vs. both (123)I-MIBG and CT/MRI, P = 0.51 (123)I-MIBG vs. CT/MRI). The combination of (18)F-DOPA PET with CT/MRI was superior to (123)I-MIBG with CT/MRI (93 vs. 76%, P < 0.001). Whole-body metabolic burden measured with (18)F-DOPA PET correlated with plasma normetanephrine (r = 0.82), urinary normetanephrine (r = 0.84), and metanephrine (r = 0.57). CONCLUSION To localize tumors causing catecholamine excess, (18)F-DOPA PET is superior to (123)I-MIBG scintigraphy and CT/MRI.
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