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Tsai SC, Farn SS, Lo WL, Ou Yang FY, Kang YC, Chen LC, Chen KT, Liao JW, Kung JY, Chen JT, Huang FYJ. Evaluation of Chelator-to-Antibody Ratio on Development of 89Zr-iPET Tracer for Imaging of PD-L1 Expression on Tumor. Int J Mol Sci 2023; 24:17132. [PMID: 38138961 PMCID: PMC10743313 DOI: 10.3390/ijms242417132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 11/23/2023] [Accepted: 11/29/2023] [Indexed: 12/24/2023] Open
Abstract
89Zr-iPET has been widely used for preclinical and clinical immunotherapy studies to predict patient stratification or evaluate therapeutic efficacy. In this study, we prepared and evaluated 89Zr-DFO-anti-PD-L1-mAb tracers with varying chelator-to-antibody ratios (CARs), including 89Zr-DFO-anti-PD-L1-mAb_3X (tracer_3X), 89Zr-DFO-anti-PD-L1-mAb_10X (tracer_10X), and 89Zr-DFO-anti-PD-L1-mAb_20X (tracer_20X). The DFO-anti-PD-L1-mAb conjugates with varying CARs were prepared using a random conjugation method and then subjected to quality control. The conjugates were radiolabeled with 89Zr and evaluated in a PD-L1-expressing CT26 tumor-bearing mouse model. Next, iPET imaging, biodistribution, pharmacokinetics, and ex vivo pathological and immunohistochemical examinations were conducted. LC-MS analysis revealed that DFO-anti-PD-L1-mAb conjugates were prepared with CARs ranging from 0.4 to 2.0. Radiochemical purity for all tracer groups was >99% after purification. The specific activity levels of tracer_3X, tracer_10X, and tracer_20X were 2.2 ± 0.6, 8.2 ± 0.6, and 10.5 ± 1.6 μCi/μg, respectively. 89Zr-iPET imaging showed evident tumor uptake in all tracer groups and reached the maximum uptake value at 24 h postinjection (p.i.). Biodistribution data at 168 h p.i. revealed that the tumor-to-liver, tumor-to-muscle, and tumor-to-blood uptake ratios for tracer_3X, tracer_10X, and tracer_20X were 0.46 ± 0.14, 0.58 ± 0.33, and 1.54 ± 0.51; 4.7 ± 1.3, 7.1 ± 3.9, and 14.7 ± 1.1; and 13.1 ± 5.8, 19.4 ± 13.8, and 41.3 ± 10.6, respectively. Significant differences were observed between tracer_3X and tracer_20X in the aforementioned uptake ratios at 168 h p.i. The mean residence time and elimination half-life for tracer_3X, tracer_10X, and tracer_20X were 25.4 ± 4.9, 24.2 ± 6.1, and 25.8 ± 3.3 h and 11.8 ± 0.5, 11.1 ± 0.7, and 11.7 ± 0.6 h, respectively. No statistical differences were found between-tracer in the aforementioned pharmacokinetic parameters. In conclusion, 89Zr-DFO-anti-PD-L1-mAb tracers with a CAR of 1.4-2.0 may be better at imaging PD-L1 expression in tumors than are traditional low-CAR 89Zr-iPET tracers.
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Affiliation(s)
- Shih-Chuan Tsai
- Department of Nuclear Medicine, Taichung Veterans General Hospital, Taichung 407219, Taiwan; (S.-C.T.); (J.-Y.K.)
| | - Shiou-Shiow Farn
- National Atomic Research Institute, Taoyuan 325207, Taiwan; (S.-S.F.); (W.-L.L.); (F.-Y.O.Y.); (L.-C.C.); (J.-T.C.)
| | - Wei-Lin Lo
- National Atomic Research Institute, Taoyuan 325207, Taiwan; (S.-S.F.); (W.-L.L.); (F.-Y.O.Y.); (L.-C.C.); (J.-T.C.)
| | - Fang-Yu Ou Yang
- National Atomic Research Institute, Taoyuan 325207, Taiwan; (S.-S.F.); (W.-L.L.); (F.-Y.O.Y.); (L.-C.C.); (J.-T.C.)
| | - Yong-Ching Kang
- Department of Medical Imaging and Radiological Sciences, Central Taiwan University of Science and Technology, Taichung 406053, Taiwan;
| | - Liang-Cheng Chen
- National Atomic Research Institute, Taoyuan 325207, Taiwan; (S.-S.F.); (W.-L.L.); (F.-Y.O.Y.); (L.-C.C.); (J.-T.C.)
| | - Kuo-Ting Chen
- Department of Chemistry, National Dong Hwa University, Hualien 974301, Taiwan;
| | - Jiunn-Wang Liao
- Graduate Institute of Veterinary Pathobiology, National Chung-Hsing University, Taichung 402202, Taiwan;
| | - Jui-Yin Kung
- Department of Nuclear Medicine, Taichung Veterans General Hospital, Taichung 407219, Taiwan; (S.-C.T.); (J.-Y.K.)
| | - Jenn-Tzong Chen
- National Atomic Research Institute, Taoyuan 325207, Taiwan; (S.-S.F.); (W.-L.L.); (F.-Y.O.Y.); (L.-C.C.); (J.-T.C.)
| | - Feng-Yun J. Huang
- Department of Medical Imaging and Radiological Sciences, Central Taiwan University of Science and Technology, Taichung 406053, Taiwan;
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Wang X, Wang T, Fan X, Zhang Z, Wang Y, Li Z. A Molecular Toolbox of Positron Emission Tomography Tracers for General Anesthesia Mechanism Research. J Med Chem 2023; 66:6463-6497. [PMID: 37145921 DOI: 10.1021/acs.jmedchem.2c01965] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
With appropriate radiotracers, positron emission tomography (PET) allows direct or indirect monitoring of the spatial and temporal distribution of anesthetics, neurotransmitters, and biomarkers, making it an indispensable tool for studying the general anesthesia mechanism. In this Perspective, PET tracers that have been recruited in general anesthesia research are introduced in the following order: 1) 11C/18F-labeled anesthetics, i.e., PET tracers made from inhaled and intravenous anesthetics; 2) PET tracers targeting anesthesia-related receptors, e.g., neurotransmitters and voltage-gated ion channels; and 3) PET tracers for studying anesthesia-related neurophysiological effects and neurotoxicity. The radiosynthesis, pharmacodynamics, and pharmacokinetics of the above PET tracers are mainly discussed to provide a practical molecular toolbox for radiochemists, anesthesiologists, and those who are interested in general anesthesia.
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Affiliation(s)
- Xiaoxiao Wang
- Center for Molecular Imaging and Translational Medicine, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen, Fujian 361102, China
| | - Tao Wang
- Center for Molecular Imaging and Translational Medicine, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen, Fujian 361102, China
| | - Xiaowei Fan
- Center for Molecular Imaging and Translational Medicine, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen, Fujian 361102, China
| | - Zhao Zhang
- Department of Anesthesiology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Yingwei Wang
- Department of Anesthesiology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Zijing Li
- Center for Molecular Imaging and Translational Medicine, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen, Fujian 361102, China
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Wong AAWL, Lozada J, Lepage ML, Zhang C, Merkens H, Zeisler J, Lin KS, Bénard F, Perrin DM. Synthesis and 18F-radiolabeling of thymidine AMBF 3 conjugates. RSC Med Chem 2020; 11:569-576. [PMID: 33479658 PMCID: PMC7578706 DOI: 10.1039/d0md00054j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 04/09/2020] [Indexed: 01/08/2023] Open
Abstract
In pursuit of 18F-labeled nucleosides for positron emission tomography (PET) imaging, we report on the chemical and radiochemical synthesis of two thymidine (dT) analogs, dT-C5-AMBF3 and dT-N3-AMBF3, that are radiofluorinated by isotope exchange (IEX) and studied as PET imaging agents in mice with tumor xenografts. dT-C5-AMBF3 shows preferential, and tumor-specific, uptake over dT-N3-AMBF3. This work provides a new synthetic method in order to access new nucleoside tracers for PET imaging.
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Affiliation(s)
- Antonio A W L Wong
- Department of Chemistry , University of British Columbia (UBC) , 2036 Main Mall , Vancouver , BC , V6T 1Z1 Canada .
| | - Jerome Lozada
- Department of Chemistry , University of British Columbia (UBC) , 2036 Main Mall , Vancouver , BC , V6T 1Z1 Canada .
| | - Mathieu L Lepage
- Department of Chemistry , University of British Columbia (UBC) , 2036 Main Mall , Vancouver , BC , V6T 1Z1 Canada .
| | - Chengcheng Zhang
- Department of Molecular Oncology , B.C. Cancer Research Centre (BCCRC) , 675 West 10th Avenue , Vancouver , BC , V5Z 1L3 Canada
| | - Helen Merkens
- Department of Molecular Oncology , B.C. Cancer Research Centre (BCCRC) , 675 West 10th Avenue , Vancouver , BC , V5Z 1L3 Canada
| | - Jutta Zeisler
- Department of Molecular Oncology , B.C. Cancer Research Centre (BCCRC) , 675 West 10th Avenue , Vancouver , BC , V5Z 1L3 Canada
| | - Kuo-Shyan Lin
- Department of Molecular Oncology , B.C. Cancer Research Centre (BCCRC) , 675 West 10th Avenue , Vancouver , BC , V5Z 1L3 Canada
| | - François Bénard
- Department of Molecular Oncology , B.C. Cancer Research Centre (BCCRC) , 675 West 10th Avenue , Vancouver , BC , V5Z 1L3 Canada
| | - David M Perrin
- Department of Chemistry , University of British Columbia (UBC) , 2036 Main Mall , Vancouver , BC , V6T 1Z1 Canada .
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Pelin A, Wang J, Bell J, Le Boeuf F. The importance of imaging strategies for pre-clinical and clinical in vivo distribution of oncolytic viruses. Oncolytic Virother 2018; 7:25-35. [PMID: 29637059 PMCID: PMC5880516 DOI: 10.2147/ov.s137159] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Oncolytic viruses (OVs) are an emergent and unique therapy for cancer patients. Similar to chemo- and radiation therapy, OV can lyse (kill) cancer cell directly. In general, the advantages of OVs over other treatments are primarily: a higher safety profile (as shown by less adverse effects), ability to replicate, transgene(s) delivery, and stimulation of a host’s immune system against cancer. The latter has prompted successful use of OVs with other immunotherapeutic strategies in a synergistic manner. In spite of extended testing in pre-clinical and clinical setting, using biologically derived therapeutics like virus always raises potential concerns about safety (replication at non-intended locations) and bio-availability of the product. Recent advent in in vivo imaging techniques dramatically improves the convenience of use, quality of pictures, and amount of information acquired. Easy assessing of safety/localization of the biotherapeutics like OVs became a new potential weapon in the physician’s arsenal to improve treatment outcome. Given that OVs are typically replicating, in vivo imaging can also track virus replication and persistence as well as precisely mapping tumor tissues presence. This review discusses the importance of imaging in vivo in evaluating OV efficacy, as well as currently available tools and techniques.
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Affiliation(s)
- Adrian Pelin
- Department of Biochemistry, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.,Ottawa Hospital Research Institute, Center for Cancer Therapeutics, Ottawa, ON, Canada
| | - Jiahu Wang
- Ottawa Hospital Research Institute, Center for Cancer Therapeutics, Ottawa, ON, Canada.,Genvira Biosciences, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - John Bell
- Department of Biochemistry, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.,Ottawa Hospital Research Institute, Center for Cancer Therapeutics, Ottawa, ON, Canada
| | - Fabrice Le Boeuf
- Ottawa Hospital Research Institute, Center for Cancer Therapeutics, Ottawa, ON, Canada
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Monitoring Tumor Response after Liposomal Doxorubicin in Combination with Liposomal Vinorelbine Treatment Using 3'-Deoxy-3'-[ 18F]Fluorothymidine PET. Mol Imaging Biol 2018; 19:408-420. [PMID: 27730471 DOI: 10.1007/s11307-016-1005-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
PURPOSE Surgical resection is the standard treatment for localized colorectal cancer, which is the most common type of gastrointestinal cancer. However, over 40 % cases are diagnosed metastasized and apparently inoperable. Systemic chemotherapy provides an alternative to these patients. This study aims to evaluate the therapeutic potential of liposomal doxorubicin (lipoDox) in combination with liposomal vinorelbine (lipoVNB) in a CT-26 colon carcinoma-bearing mouse model. PROCEDURES The in vitro cytotoxicity of Dox and VNB on CT-26 cancer cells was determined by MTT and colony formation assays. Mice were subcutaneously inoculated with 2 × 105 of CT-26 cells in the right hind flank. When tumor size reached 200 ± 50 mm3, mice were assigned to receive different treatment protocols. The pharmacokinetics, micro single-photon emission computed tomography/x-ray computed tomography imaging, biodistribution, and immunohistochemical staining studies were performed to survey the therapeutic efficacy of each regimen. RESULTS Based on the results of pharmacokinetic study, co-administration of lipoDox and lipoVNB did not affect their individual systemic distribution, while lipoDox retained longer in blood than lipoVNB did. Superior tumor growth retardation was observed in the group received lipoDox plus lipoVNB administration (1 mg/kg each, namely D1V1) than those injected with lipoDox plus VNB (1 mg/kg each, namely D1fV1). No severe side effects were detected in each group. The tumor-to-muscle ratio (T/M) derived from 3'-dexoy-3'-[18F]fluorothymidine ([18F]FLT) micro positron emission tomography (PET) images of D1V1- and D1fV1-treated mice and the controls on day 7 was 6.88 ± 0.54, 7.50 ± 0.84, and 9.87 ± 0.73, respectively, suggesting that D1V1 is a more efficacious regimen against CT-26 xenografts. The results of proliferating cell nuclear antigen (PCNA) immunohistochemical staining were consistent with those findings obtained from [18F]FLT microPET imaging. CONCLUSION This study demonstrated that lipoDox in combination with lipoVNB was more efficacious than clinically used regimen, lipoDox plus VNB, in the treatment of colon carcinoma and [18F]FLT-PET is a promising approach in monitoring the treatment outcome at early stage.
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Rapic S, Vangestel C, Verhaeghe J, Thomae D, Pauwels P, Van den Wyngaert T, Staelens S, Stroobants S. Evaluation of [ 18F]Fluorothymidine as a Biomarker for Early Therapy Response in a Mouse Model of Colorectal Cancer. Mol Imaging Biol 2017; 19:109-119. [PMID: 27324368 DOI: 10.1007/s11307-016-0974-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
PURPOSE In oncology, positron emission tomography imaging using dedicated tracers as biomarkers may assist in early evaluation of therapy efficacy. Using 3'-deoxy-3'-[18F]fluorothymidine ([18F]FLT), we investigated the early effects of chemotherapeutic treatment on cancer cell proliferation in a BRAF-mutated colorectal cancer xenograft model. PROCEDURES Colo205 subcutaneously inoculated animals underwent 90-min dynamic imaging before and 24 h after treatment with vehicle (control), cetuximab (resistant) or irinotecan (sensitive). Total distribution volume was quantified from dynamic data, and standardized uptake values as well as tumor-to-blood ratios were calculated from static images averaged over the last 20 min. In vivo imaging data was correlated with ex vivo proliferation and thymidine metabolism proteins. RESULTS All imaging parameters showed a significant post-treatment decrease from [18F]FLT baseline uptake for the irinotecan group (p ≤ 0.001) as compared with the cetuximab and vehicle group and correlated strongly with each other (p ≤ 0.0001). In vivo data were in agreement with Ki67 staining, showing a significantly lower percentage of Ki67-positive cells in the irinotecan group as compared with other groups (p ≤ 0.0001). Tumor expression of thymidine kinase 1 phosphorylated on serine 13, thymidylate synthase, and thymidine phosphorylase remained unaffected, while thymidine kinase 1 expression was, surprisingly, significantly higher in irinotecan-treated animals (p ≤ 0.01). In contrast, tumor ATP levels were lowest in this group. CONCLUSIONS [18F]FLT positron emission tomography was found to be a suitable biomarker of early tumor response to anti-proliferative treatment, with static imaging not being inferior to full compartmental analysis in our xenograft model. The dynamics of thymidine kinase 1 protein expression and protein activity in low ATP environments merits further investigation.
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Affiliation(s)
- Sara Rapic
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Christel Vangestel
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
- Department of Nuclear Medicine, Antwerp University Hospital, Wilrijkstraat 10, 2650, Edegem, Belgium
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - David Thomae
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
- Department of Nuclear Medicine, Antwerp University Hospital, Wilrijkstraat 10, 2650, Edegem, Belgium
| | - Patrick Pauwels
- Center for Oncological Research (CORE), University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
- Department of Pathology, Antwerp University Hospital, Wilrijkstraat 10, 2650, Edegem, Belgium
| | - Tim Van den Wyngaert
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
- Department of Nuclear Medicine, Antwerp University Hospital, Wilrijkstraat 10, 2650, Edegem, Belgium
| | - Steven Staelens
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Sigrid Stroobants
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium.
- Department of Nuclear Medicine, Antwerp University Hospital, Wilrijkstraat 10, 2650, Edegem, Belgium.
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Zhang X, Liu F, Slikker W, Wang C, Paule MG. Minimally invasive biomarkers of general anesthetic-induced developmental neurotoxicity. Neurotoxicol Teratol 2016; 60:95-101. [PMID: 27784630 DOI: 10.1016/j.ntt.2016.10.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 08/29/2016] [Accepted: 10/21/2016] [Indexed: 12/22/2022]
Abstract
The association of general anesthesia with developmental neurotoxicity, while nearly impossible to study in pediatric populations, is clearly demonstrable in a variety of animal models from rodents to nonhuman primates. Nearly all general anesthetics tested have been shown to cause abnormal brain cell death in animals when administered during periods of rapid brain growth. The ability to repeatedly assess in the same subjects adverse effects induced by general anesthetics provides significant power to address the time course of important events associated with exposures. Minimally-invasive procedures provide the opportunity to bridge the preclinical/clinical gap by providing the means to more easily translate findings from the animal laboratory to the human clinic. Positron Emission Tomography or PET is a tool with great promise for realizing this goal. PET for small animals (microPET) is providing valuable data on the life cycle of general anesthetic induced neurotoxicity. PET radioligands (annexin V and DFNSH) targeting apoptotic processes have demonstrated that a single bout of general anesthesia effected during a vulnerable period of CNS development can result in prolonged apoptotic signals lasting for several weeks in the rat. A marker of cellular proliferation (FLT) has demonstrated in rodents that general anesthesia-induced inhibition of neural progenitor cell proliferation is evident when assessed a full 2weeks after exposure. Activated glia express Translocator Protein (TSPO) which can be used as a marker of presumed neuroinflammatory processes and a PET ligand for the TSPO (FEPPA) has been used to track this process in both rat and nonhuman primate models. It has been shown that single bouts of general anesthesia can result in elevated TSPO expression lasting for over a week. These examples demonstrate the utility of specific PET tracers to inform, in a minimally-invasive fashion, processes associated with general anesthesia-induced developmental neurotoxicity. The fact that PET procedures are also used clinically suggests an opportunity to confirm in humans what has been repeatedly observed in animals.
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Jensen MM, Kjaer A. Monitoring of anti-cancer treatment with (18)F-FDG and (18)F-FLT PET: a comprehensive review of pre-clinical studies. AMERICAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 2015; 5:431-456. [PMID: 26550536 PMCID: PMC4620172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 09/10/2015] [Indexed: 06/05/2023]
Abstract
Functional imaging of solid tumors with positron emission tomography (PET) imaging is an evolving field with continuous development of new PET tracers and discovery of new applications for already implemented PET tracers. During treatment of cancer patients, a general challenge is to measure treatment effect early in a treatment course and by that to stratify patients into responders and non-responders. With 2-deoxy-2-[(18)F]fluoro-D-glucose ((18)F-FDG) and 3'-deoxy-3'-[(18)F]fluorothymidine((18)F-FLT) two of the cancer hallmarks, altered energy metabolism and increased cell proliferation, can be visualized and quantified non-invasively by PET. With (18)F-FDG and (18)F-FLT PET changes in energy metabolism and cell proliferation can thereby be determined after initiation of cancer treatment in both clinical and pre-clinical studies in order to predict, at an early time-point, treatment response. It is hypothesized that decreases in glycolysis and cell proliferation may occur in tumors that are sensitive to the applied cancer therapeutics and that tumors that are resistant to treatment will show unchanged glucose metabolism and cell proliferation. Whether (18)F-FDG and/or (18)F-FLT PET can be used for prediction of treatment response has been analyzed in many studies both following treatment with conventional chemotherapeutic agents but also following treatment with different targeted therapies, e.g. monoclonal antibodies and small molecules inhibitors. The results from these studies have been most variable; in some studies early changes in (18)F-FDG and (18)F-FLT uptake predicted later tumor regression whereas in other studies no change in tracer uptake was observed despite the treatment being effective. The present review gives an overview of pre-clinical studies that have used (18)F-FDG and/or (18)F-FLT PET for response monitoring of cancer therapeutics.
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Affiliation(s)
- Mette Munk Jensen
- Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Rigshospitalet and University of Copenhagen Denmark
| | - Andreas Kjaer
- Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Rigshospitalet and University of Copenhagen Denmark
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Wu CY, Chou LS, Chan PC, Ho CH, Lin MH, Shen CC, Liu RS, Lin WJ, Wang HE. Monitoring tumor response with radiolabeled nucleoside analogs in a hepatoma-bearing mouse model early after doxisome(®) treatment. Mol Imaging Biol 2014; 15:326-35. [PMID: 23247923 DOI: 10.1007/s11307-012-0604-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE This study aims to demonstrate that 3'-deoxy-3'-(18)F-fluorothymidine ((18)F-FLT) positron emission tomography (PET) is a promising modality for noninvasively monitoring the therapeutic efficacy of Doxisome(®) in a subcutaneous hepatoma mouse model. PROCEDURES Male BALB/c nu/nu mice were inoculated with HepG2 hepatoma xenograft in the right flank. Doxisome(®) (5 mg/kg, three times a week for 2 weeks) was intravenously administrated for treatment. (18)F-FLT-microPET, biodistribution studies, and immunohistochemistry of Ki-67 were performed. RESULTS A significant difference (p < 0.05) in tumor volume was observed on day 5 between treated and control groups. The tumor-to-muscle ratio derived from (18)F-FLT-PET and (123)I-ICdR-microSPECT images of Doxisome(®)-treated mice dropped from 12.55 ± 0.76 to 3.81 ± 0.31 and from 2.48 ± 0.42 to 1.59 ± 0.08 after a three-dose treatment, respectively, while that of the control group remained steady. The retarded proliferation rate of treated xenograft was confirmed by Ki-67 immunohistochemistry staining. CONCLUSIONS This study clearly demonstrated that Doxisome(®) is an effective anti-cancer drug against the growth of HepG2 hepatoma and that (18)F-FLT-PET could provide early information of tumor response during treatment.
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Affiliation(s)
- Chun-Yi Wu
- Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, No.155, Sec.2, Li-Nong St., Taipei, Taiwan 11217
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Lin AL, Pulliam DA, Deepa SS, Halloran JJ, Hussong SA, Burbank RR, Bresnen A, Liu Y, Podlutskaya N, Soundararajan A, Muir E, Duong TQ, Bokov AF, Viscomi C, Zeviani M, Richardson AG, Van Remmen H, Fox PT, Galvan V. Decreased in vitro mitochondrial function is associated with enhanced brain metabolism, blood flow, and memory in Surf1-deficient mice. J Cereb Blood Flow Metab 2013; 33:1605-11. [PMID: 23838831 PMCID: PMC3790931 DOI: 10.1038/jcbfm.2013.116] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Revised: 06/03/2013] [Accepted: 06/06/2013] [Indexed: 11/09/2022]
Abstract
Recent studies have challenged the prevailing view that reduced mitochondrial function and increased oxidative stress are correlated with reduced longevity. Mice carrying a homozygous knockout (KO) of the Surf1 gene showed a significant decrease in mitochondrial electron transport chain Complex IV activity, yet displayed increased lifespan and reduced brain damage after excitotoxic insults. In the present study, we examined brain metabolism, brain hemodynamics, and memory of Surf1 KO mice using in vitro measures of mitochondrial function, in vivo neuroimaging, and behavioral testing. We show that decreased respiration and increased generation of hydrogen peroxide in isolated Surf1 KO brain mitochondria are associated with increased brain glucose metabolism, cerebral blood flow, and lactate levels, and with enhanced memory in Surf1 KO mice. These metabolic and functional changes in Surf1 KO brains were accompanied by higher levels of hypoxia-inducible factor 1 alpha, and by increases in the activated form of cyclic AMP response element-binding factor, which is integral to memory formation. These findings suggest that Surf1 deficiency-induced metabolic alterations may have positive effects on brain function. Exploring the relationship between mitochondrial activity, oxidative stress, and brain function will enhance our understanding of cognitive aging and of age-related neurologic disorders.
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Affiliation(s)
- Ai-Ling Lin
- 1] Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA [2] Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA [3] Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
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Lin AL, Zheng W, Halloran JJ, Burbank RR, Hussong SA, Hart MJ, Javors M, Shih YYI, Muir E, Solano Fonseca R, Strong R, Richardson AG, Lechleiter JD, Fox PT, Galvan V. Chronic rapamycin restores brain vascular integrity and function through NO synthase activation and improves memory in symptomatic mice modeling Alzheimer's disease. J Cereb Blood Flow Metab 2013; 33:1412-21. [PMID: 23801246 PMCID: PMC3764385 DOI: 10.1038/jcbfm.2013.82] [Citation(s) in RCA: 160] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 04/04/2013] [Accepted: 04/23/2013] [Indexed: 12/14/2022]
Abstract
Vascular pathology is a major feature of Alzheimer's disease (AD) and other dementias. We recently showed that chronic administration of the target-of-rapamycin (TOR) inhibitor rapamycin, which extends lifespan and delays aging, halts the progression of AD-like disease in transgenic human (h)APP mice modeling AD when administered before disease onset. Here we demonstrate that chronic reduction of TOR activity by rapamycin treatment started after disease onset restored cerebral blood flow (CBF) and brain vascular density, reduced cerebral amyloid angiopathy and microhemorrhages, decreased amyloid burden, and improved cognitive function in symptomatic hAPP (AD) mice. Like acetylcholine (ACh), a potent vasodilator, acute rapamycin treatment induced the phosphorylation of endothelial nitric oxide (NO) synthase (eNOS) and NO release in brain endothelium. Administration of the NOS inhibitor L-NG-Nitroarginine methyl ester reversed vasodilation as well as the protective effects of rapamycin on CBF and vasculature integrity, indicating that rapamycin preserves vascular density and CBF in AD mouse brains through NOS activation. Taken together, our data suggest that chronic reduction of TOR activity by rapamycin blocked the progression of AD-like cognitive and histopathological deficits by preserving brain vascular integrity and function. Drugs that inhibit the TOR pathway may have promise as a therapy for AD and possibly for vascular dementias.
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Affiliation(s)
- Ai-Ling Lin
- Research Imaging Institute, San Antonio, TX, USA
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Methylene blue as a cerebral metabolic and hemodynamic enhancer. PLoS One 2012; 7:e46585. [PMID: 23056355 PMCID: PMC3467226 DOI: 10.1371/journal.pone.0046585] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 09/03/2012] [Indexed: 12/04/2022] Open
Abstract
By restoring mitochondrial function, methylene blue (MB) is an effective neuroprotectant in many neurological disorders (e.g., Parkinson’s and Alzheimer’s diseases). MB has also been proposed as a brain metabolic enhancer because of its action on mitochondrial cytochrome c oxidase. We used in vitro and in vivo approaches to determine how MB affects brain metabolism and hemodynamics. For in vitro, we evaluated the effect of MB on brain mitochondrial function, oxygen consumption, and glucose uptake. For in vivo, we applied neuroimaging and intravenous measurements to determine MB’s effect on glucose uptake, cerebral blood flow (CBF), and cerebral metabolic rate of oxygen (CMRO2) under normoxic and hypoxic conditions in rats. MB significantly increases mitochondrial complex I–III activity in isolated mitochondria and enhances oxygen consumption and glucose uptake in HT-22 cells. Using positron emission tomography and magnetic resonance imaging (MRI), we observed significant increases in brain glucose uptake, CBF, and CMRO2 under both normoxic and hypoxic conditions. Further, MRI revealed that MB dramatically increased CBF in the hippocampus and in the cingulate, motor, and frontoparietal cortices, areas of the brain affected by Alzheimer’s and Parkinson’s diseases. Our results suggest that MB can enhance brain metabolism and hemodynamics, and multimetric neuroimaging systems offer a noninvasive, nondestructive way to evaluate treatment efficacy.
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Ekshyyan O, Sibley D, Caldito GC, Sunderland J, Vascoe C, Nathan CAO. 18F-fluorodeoxythymidine micro-positron-emission tomography versus 18F-fluorodeoxyglucose micro-positron-emission tomography for in vivo minimal residual disease imaging. Laryngoscope 2012; 123:107-11. [PMID: 23018799 DOI: 10.1002/lary.23600] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Revised: 05/17/2012] [Accepted: 06/25/2012] [Indexed: 11/09/2022]
Abstract
OBJECTIVES/HYPOTHESIS The early detection of persistent/recurrent disease of head and neck squamous cell carcinoma (HNSCC) after treatment can be challenging. The currently used radioisotope (18)F-fluorodeoxyglucose (FDG) is a nonspecific tracer for cancer cells as it detects all metabolically active cells including inflammation. (18)F-fluorodeoxythymidine (FLT) is a radioactive tracer for rapidly proliferating cells, and therefore is more specific for detecting cancer. Our aim was to compare FLT and FDG microPET (positron-emission tomography) to the gold standard in vivo bioluminescence imaging for serial assessment of neoplastic growth in a minimal residual disease in vivo model. STUDY DESIGN Prospective outcomes research. METHODS In order to mimic the postsurgical environment of HNSCC patients FaDu cells transfected with a luciferase-expressing retrovirus were inoculated into the skin flap of Balb/c nu/nu mice. Three days later before tumors formed, mice were randomized into (18)F-FLT or (18) F-FDG groups, and microPET imaging was performed on days 3, 6, 10, 18, and 24 after tumor cell inoculation. RESULTS (18)F-FLT detected tumors as early as day 3 even before tumors were palpable, whereas (18)F-FDG only detected palpable tumors. The average overall normalized radioactivity in the FLT group was significantly higher than the FDG group (P = .025). CONCLUSIONS (18)F-FLT identified tumor cells before tumors were palpable and can potentially be used for early detection of persistence/recurrence of HNSCC. In addition, this radioisotope can be used to monitor adjuvant therapy with novel targeted therapeutics in preclinical models of persistent disease.
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Affiliation(s)
- Oleksandr Ekshyyan
- Department of Otolaryngology-Head and Neck Surgery, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71130-3932, USA
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