Els F Halff, Sridhar Natesan, David R Bonsall, Mattia Veronese, Anna Garcia-Hidalgo, Michelle Kokkinou, Sac-Pham Tang, Laura J Riggall, Roger N Gunn, Elaine E Irvine, Dominic J Withers, Lisa A Wells, Oliver D Howes
Positron emission tomography (PET) using the radiotracer [18F]-FDOPA provides a tool for studying brain dopamine synthesis capacity in animals and humans. We have previously standardised a micro-PET methodology in mice by intravenously administering [18F]-FDOPA via jugular vein cannulation and assessment of striatal dopamine synthesis capacity, indexed as the influx rate constant KiMod of [18F]-FDOPA, using an extended graphical Patlak analysis with the cerebellum as a reference region. This enables a direct comparison between preclinical and clinical output values. However, chronic intravenous catheters are technically difficult to maintain for longitudinal studies. Hence, in this study, intraperitoneal administration of [18F]-FDOPA was evaluated as a less-invasive alternative that facilitates longitudinal imaging. Our experiments comprised the following assessments: (i) comparison of [18F]-FDOPA uptake between intravenous and intraperitoneal radiotracer administration and optimisation of the time window used for extended Patlak analysis, (ii) comparison of KiMod in a within-subject design of both administration routes, (iii) test-retest evaluation of KiMod in a within-subject design of intraperitoneal radiotracer administration, and (iv) validation of KiMod estimates by comparing the two administration routes in a mouse model of hyperdopaminergia induced by subchronic ketamine. Our results demonstrate that intraperitoneal [18F]-FDOPA administration resulted in good brain uptake, with no significant effect of administration route on KiMod estimates (intraperitoneal: 0.024 ± 0.0047 min-1, intravenous: 0.022 ± 0.0041 min-1, p = 0.42) and similar coefficient of variation (intraperitoneal: 19.6%; intravenous: 18.4%). The technique had a moderate test-retest validity (intraclass correlation coefficient (ICC) = 0.52, N = 6) and thus supports longitudinal studies. Following subchronic ketamine administration, elevated KiMod as compared to control condition was measured with a large effect size for both methods (intraperitoneal: Cohen's d = 1.3; intravenous: Cohen's d = 0.9), providing further evidence that ketamine has lasting effects on the dopamine system, which could contribute to its therapeutic actions and/or abuse liability.
使用放射性示踪剂[18F]-FDOPA的正电子发射断层扫描(PET)为研究动物和人类大脑多巴胺合成能力提供了一种工具。我们之前已经标准化了一种微型pet方法,通过颈静脉静脉注射[18F]-FDOPA,并评估纹状体多巴胺合成能力,以[18F]-FDOPA的流入速率常数K i Mod为指标,使用扩展的图形Patlak分析,以小脑作为参考区域。这样可以直接比较临床前和临床输出值。然而,在纵向研究中,长期静脉导管在技术上难以维持。因此,在本研究中,腹腔注射[18F]-FDOPA被认为是一种微创的替代方法,有助于纵向成像。我们的实验包括以下评估:(i)比较静脉注射和腹腔注射放射性示踪剂对[18F]-FDOPA的摄取,并优化用于扩展Patlak分析的时间窗口,(ii)比较两种给药途径的受试者内设计Ki Mod, (iii)腹腔注射放射性示踪剂的受试者内设计Ki Mod的测试-重测评估,(iv)通过比较两种给药途径在亚慢性氯胺酮诱导的高多巴胺能小鼠模型中验证Ki Mod的估计。我们的研究结果表明,腹腔注射[18F]-FDOPA导致了良好的脑摄取,给药途径对Ki Mod估计值没有显著影响(腹腔注射:0.024±0.0047 min-1,静脉注射:0.022±0.0041 min-1, p = 0.42),相似的变异系数(腹腔注射:19.6%;静脉注射:18.4%)。该技术具有中等的重测效度(类内相关系数(ICC) = 0.52, N = 6),因此支持纵向研究。亚慢性氯胺酮给药后,与对照组相比,两种方法的K i Mod升高均具有较大的效应量(腹腔:Cohen's d = 1.3;静脉注射:科恩d = 0.9),进一步证明氯胺酮对多巴胺系统有持久的影响,这可能有助于其治疗作用和/或滥用风险。
{"title":"Evaluation of Intraperitoneal [<sup>18</sup>F]-FDOPA Administration for Micro-PET Imaging in Mice and Assessment of the Effect of Subchronic Ketamine Dosing on Dopamine Synthesis Capacity.","authors":"Els F Halff, Sridhar Natesan, David R Bonsall, Mattia Veronese, Anna Garcia-Hidalgo, Michelle Kokkinou, Sac-Pham Tang, Laura J Riggall, Roger N Gunn, Elaine E Irvine, Dominic J Withers, Lisa A Wells, Oliver D Howes","doi":"10.1155/2022/4419221","DOIUrl":"https://doi.org/10.1155/2022/4419221","url":null,"abstract":"<p><p>Positron emission tomography (PET) using the radiotracer [<sup>18</sup>F]-FDOPA provides a tool for studying brain dopamine synthesis capacity in animals and humans. We have previously standardised a micro-PET methodology in mice by intravenously administering [<sup>18</sup>F]-FDOPA via jugular vein cannulation and assessment of striatal dopamine synthesis capacity, indexed as the influx rate constant <i>K</i> <sub><i>i</i></sub> <sup>Mod</sup> of [<sup>18</sup>F]-FDOPA, using an extended graphical Patlak analysis with the cerebellum as a reference region. This enables a direct comparison between preclinical and clinical output values. However, chronic intravenous catheters are technically difficult to maintain for longitudinal studies. Hence, in this study, intraperitoneal administration of [<sup>18</sup>F]-FDOPA was evaluated as a less-invasive alternative that facilitates longitudinal imaging. Our experiments comprised the following assessments: (i) comparison of [<sup>18</sup>F]-FDOPA uptake between intravenous and intraperitoneal radiotracer administration and optimisation of the time window used for extended Patlak analysis, (ii) comparison of <i>Ki</i> <sup>Mod</sup> in a within-subject design of both administration routes, (iii) test-retest evaluation of <i>Ki</i> <sup>Mod</sup> in a within-subject design of intraperitoneal radiotracer administration, and (iv) validation of <i>Ki</i> <sup>Mod</sup> estimates by comparing the two administration routes in a mouse model of hyperdopaminergia induced by subchronic ketamine. Our results demonstrate that intraperitoneal [<sup>18</sup>F]-FDOPA administration resulted in good brain uptake, with no significant effect of administration route on <i>Ki</i> <sup>Mod</sup> estimates (intraperitoneal: 0.024 ± 0.0047 min<sup>-1</sup>, intravenous: 0.022 ± 0.0041 min<sup>-1</sup>, <i>p</i> = 0.42) and similar coefficient of variation (intraperitoneal: 19.6%; intravenous: 18.4%). The technique had a moderate test-retest validity (intraclass correlation coefficient (ICC) = 0.52, <i>N</i> = 6) and thus supports longitudinal studies. Following subchronic ketamine administration, elevated <i>K</i> <sub><i>i</i></sub> <sup>Mod</sup> as compared to control condition was measured with a large effect size for both methods (intraperitoneal: Cohen's <i>d</i> = 1.3; intravenous: Cohen's <i>d</i> = 0.9), providing further evidence that ketamine has lasting effects on the dopamine system, which could contribute to its therapeutic actions and/or abuse liability.</p>","PeriodicalId":18855,"journal":{"name":"Molecular Imaging","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9881672/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9165489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-09eCollection Date: 2021-01-01DOI: 10.1155/2021/9305277
Julian L Goggi, Boominathan Ramasamy, Yun Xuan Tan, Siddesh V Hartimath, Jun Rong Tang, Peter Cheng, Rasha Msallam, Ann-Marie Chacko, You Yi Hwang, Edward G Robins
Hepatocellular carcinoma (HCC) is a notoriously difficult cancer to treat. The recent development of immune checkpoint inhibitors has revolutionised HCC therapy; however, successful response is only observed in a small percentage of patients. Biomarkers typically used to predict treatment response in other tumour types are ineffective in HCC, which arises in an immune-suppressive environment. However, imaging markers that measure changes in tumour infiltrating immune cells may supply information that can be used to determine which patients are responding to therapy posttreatment. We have evaluated [18F]AlF-mNOTA-GZP, a radiolabeled peptide targeting granzyme B, to stratify response to ICIs in a HEPA 1-tumours, a syngeneic model of HCC. Posttherapy, in vivo tumour retention of [18F]AlF-mNOTA-GZP was correlated to changes in tumour volume and tumour-infiltrating immune cells. [18F]AlF-mNOTA-GZP successfully stratified response to immune checkpoint inhibition in the syngeneic HEPA 1-6 model. FACS indicated significant changes in the immune environment including a decrease in immune suppressive CD4+ T regulatory cells and increases in tumour-associated GZB+ NK+ cells, which correlated well with tumour radiopharmaceutical uptake. While the immune response to ICI therapies differs in HCC compared to many other cancers, [18F]AlF-mNOTA-GZP retention is able to stratify response to ICI therapy associated with tumour infiltrating GZB+ NK+ cells in this complex tumour microenvironment.
{"title":"Granzyme B PET Imaging Stratifies Immune Checkpoint Inhibitor Response in Hepatocellular Carcinoma.","authors":"Julian L Goggi, Boominathan Ramasamy, Yun Xuan Tan, Siddesh V Hartimath, Jun Rong Tang, Peter Cheng, Rasha Msallam, Ann-Marie Chacko, You Yi Hwang, Edward G Robins","doi":"10.1155/2021/9305277","DOIUrl":"https://doi.org/10.1155/2021/9305277","url":null,"abstract":"<p><p>Hepatocellular carcinoma (HCC) is a notoriously difficult cancer to treat. The recent development of immune checkpoint inhibitors has revolutionised HCC therapy; however, successful response is only observed in a small percentage of patients. Biomarkers typically used to predict treatment response in other tumour types are ineffective in HCC, which arises in an immune-suppressive environment. However, imaging markers that measure changes in tumour infiltrating immune cells may supply information that can be used to determine which patients are responding to therapy posttreatment. We have evaluated [<sup>18</sup>F]AlF-mNOTA-GZP, a radiolabeled peptide targeting granzyme B, to stratify response to ICIs in a HEPA 1-tumours, a syngeneic model of HCC. Posttherapy, <i>in vivo</i> tumour retention of [<sup>18</sup>F]AlF-mNOTA-GZP was correlated to changes in tumour volume and tumour-infiltrating immune cells. [<sup>18</sup>F]AlF-mNOTA-GZP successfully stratified response to immune checkpoint inhibition in the syngeneic HEPA 1-6 model. FACS indicated significant changes in the immune environment including a decrease in immune suppressive CD4+ T regulatory cells and increases in tumour-associated GZB+ NK+ cells, which correlated well with tumour radiopharmaceutical uptake. While the immune response to ICI therapies differs in HCC compared to many other cancers, [<sup>18</sup>F]AlF-mNOTA-GZP retention is able to stratify response to ICI therapy associated with tumour infiltrating GZB+ NK+ cells in this complex tumour microenvironment.</p>","PeriodicalId":18855,"journal":{"name":"Molecular Imaging","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2021-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9328186/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40699909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-06eCollection Date: 2021-01-01DOI: 10.1155/2021/4629459
Christoph Eissler, Rudolf A Werner, Paula Arias-Loza, Naoko Nose, Xinyu Chen, Martin G Pomper, Steven P Rowe, Constantin Lapa, Andreas K Buck, Takahiro Higuchi
Objectives: This study is aimed at investigating the impact of frame numbers in preclinical electrocardiogram- (ECG-) gated 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) on systolic and diastolic left ventricular (LV) parameters in rats.
Methods: 18F-FDG PET imaging using a dedicated small animal PET system with list mode data acquisition and continuous ECG recording was performed in diabetic and control rats. The list-mode data was sorted and reconstructed with different numbers of frames (4, 8, 12, and 16) per cardiac cycle into tomographic images. Using an automatic ventricular edge detection software, left ventricular (LV) functional parameters, including ejection fraction (EF), end-diastolic (EDV), and end-systolic volume (ESV), were calculated. Diastolic variables (time to peak filling (TPF), first third mean filling rate (1/3 FR), and peak filling rate (PFR)) were also assessed.
Results: Significant differences in multiple parameters were observed among the reconstructions with different frames per cardiac cycle. EDV significantly increased by numbers of frames (353.8 ± 57.7 μl∗, 380.8 ± 57.2 μl∗, 398.0 ± 63.1 μl∗, and 444.8 ± 75.3 μl at 4, 8, 12, and 16 frames, respectively; ∗P < 0.0001 vs. 16 frames), while systolic (EF) and diastolic (TPF, 1/3 FR and PFR) parameters were not significantly different between 12 and 16 frames. In addition, significant differences between diabetic and control animals in 1/3 FR and PFR in 16 frames per cardiac cycle were observed (P < 0.005), but not for 4, 8, and 12 frames.
Conclusions: Using ECG-gated PET in rats, measurements of cardiac function are significantly affected by the frames per cardiac cycle. Therefore, if you are going to compare those functional parameters, a consistent number of frames should be used.
{"title":"The Number of Frames on ECG-Gated <sup>18</sup>F-FDG Small Animal PET Has a Significant Impact on LV Systolic and Diastolic Functional Parameters.","authors":"Christoph Eissler, Rudolf A Werner, Paula Arias-Loza, Naoko Nose, Xinyu Chen, Martin G Pomper, Steven P Rowe, Constantin Lapa, Andreas K Buck, Takahiro Higuchi","doi":"10.1155/2021/4629459","DOIUrl":"https://doi.org/10.1155/2021/4629459","url":null,"abstract":"<p><strong>Objectives: </strong>This study is aimed at investigating the impact of frame numbers in preclinical electrocardiogram- (ECG-) gated <sup>18</sup>F-fluorodeoxyglucose (<sup>18</sup>F-FDG) positron emission tomography (PET) on systolic and diastolic left ventricular (LV) parameters in rats.</p><p><strong>Methods: </strong><sup>18</sup>F-FDG PET imaging using a dedicated small animal PET system with list mode data acquisition and continuous ECG recording was performed in diabetic and control rats. The list-mode data was sorted and reconstructed with different numbers of frames (4, 8, 12, and 16) per cardiac cycle into tomographic images. Using an automatic ventricular edge detection software, left ventricular (LV) functional parameters, including ejection fraction (EF), end-diastolic (EDV), and end-systolic volume (ESV), were calculated. Diastolic variables (time to peak filling (TPF), first third mean filling rate (1/3 FR), and peak filling rate (PFR)) were also assessed.</p><p><strong>Results: </strong>Significant differences in multiple parameters were observed among the reconstructions with different frames per cardiac cycle. EDV significantly increased by numbers of frames (353.8 ± 57.7 <i>μ</i>l<sup>∗</sup>, 380.8 ± 57.2 <i>μ</i>l<sup>∗</sup>, 398.0 ± 63.1 <i>μ</i>l<sup>∗</sup>, and 444.8 ± 75.3 <i>μ</i>l at 4, 8, 12, and 16 frames, respectively; <sup>∗</sup> <i>P</i> < 0.0001 vs. 16 frames), while systolic (EF) and diastolic (TPF, 1/3 FR and PFR) parameters were not significantly different between 12 and 16 frames. In addition, significant differences between diabetic and control animals in 1/3 FR and PFR in 16 frames per cardiac cycle were observed (<i>P</i> < 0.005), but not for 4, 8, and 12 frames.</p><p><strong>Conclusions: </strong>Using ECG-gated PET in rats, measurements of cardiac function are significantly affected by the frames per cardiac cycle. Therefore, if you are going to compare those functional parameters, a consistent number of frames should be used.</p>","PeriodicalId":18855,"journal":{"name":"Molecular Imaging","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8694669/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39788143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Developing sensitive diagnostic methods for a longitudinal evaluation of the status of liver fibrosis is a priority. This study is aimed at assessing the significance of longitudinal positron emission tomography (PET) imaging with 18F-labeling tracers for assessing liver fibrosis in a rat model with bile duct ligation (BDL). Twenty-one 6-week-old Sprague-Dawley male rats were used in this study. Longitudinal PET images using [18F]N-2-(2-fluoroethoxy)benzyl)-N-(4-phenoxypyridin-3-yl)acetamide ([18F]FEPPA) (n = 3), [18F]fluoroacetate ([18F]FAc) (n = 3), and 18F-fluoro-2-deoxy-D-glucose ([18F]FDG) (n = 3) were obtained at 0, 1, and 2 weeks after BDL. Biochemical assays, histological assays, immunohistochemical staining assays, and next generation sequencing analyses were also performed at 0 (n = 3), 1 (n = 3), 2 (n = 3), and 3 (n = 3) weeks after BDL, which demonstrated the severe damage in rat livers after BDL. Regarding [18F]FEPPA and [18F]FDG, there was a significantly higher uptake in the liver after BDL (both P < 0.05), which lasted until week 2. However, the uptake of [18F]FAc in the liver was not significantly different before and after BDL (P = 0.28). Collectively, both [18F]FEPPA and [18F]FDG can serve as sensitive probes for detecting the liver fibrosis. However, [18F]FAc is not recommended to diagnose liver fibrosis.
{"title":"Comparison of <sup>18</sup>F-FDG, <sup>18</sup>F-Fluoroacetate, and <sup>18</sup>F-FEPPA for Imaging Liver Fibrosis in a Bile Duct-Ligated Rat Model.","authors":"Chun-Yi Wu, Hsin-Hua Hsieh, Pei-An Chu, Wen-Hsiang Hong, Ting-Yu Chang, Chia-Fang Hsu, Siao-Ting Lin, Po-Hsun Su, Shin-Lei Peng","doi":"10.1155/2021/7545284","DOIUrl":"https://doi.org/10.1155/2021/7545284","url":null,"abstract":"<p><p>Developing sensitive diagnostic methods for a longitudinal evaluation of the status of liver fibrosis is a priority. This study is aimed at assessing the significance of longitudinal positron emission tomography (PET) imaging with <sup>18</sup>F-labeling tracers for assessing liver fibrosis in a rat model with bile duct ligation (BDL). Twenty-one 6-week-old Sprague-Dawley male rats were used in this study. Longitudinal PET images using [<sup>18</sup>F]N-2-(2-fluoroethoxy)benzyl)-N-(4-phenoxypyridin-3-yl)acetamide ([<sup>18</sup>F]FEPPA) (<i>n</i> = 3), [<sup>18</sup>F]fluoroacetate ([<sup>18</sup>F]FAc) (<i>n</i> = 3), and 18F-fluoro-2-deoxy-D-glucose ([<sup>18</sup>F]FDG) (<i>n</i> = 3) were obtained at 0, 1, and 2 weeks after BDL. Biochemical assays, histological assays, immunohistochemical staining assays, and next generation sequencing analyses were also performed at 0 (<i>n</i> = 3), 1 (<i>n</i> = 3), 2 (<i>n</i> = 3), and 3 (<i>n</i> = 3) weeks after BDL, which demonstrated the severe damage in rat livers after BDL. Regarding [<sup>18</sup>F]FEPPA and [<sup>18</sup>F]FDG, there was a significantly higher uptake in the liver after BDL (both <i>P</i> < 0.05), which lasted until week 2. However, the uptake of [<sup>18</sup>F]FAc in the liver was not significantly different before and after BDL (<i>P</i> = 0.28). Collectively, both [<sup>18</sup>F]FEPPA and [<sup>18</sup>F]FDG can serve as sensitive probes for detecting the liver fibrosis. However, [<sup>18</sup>F]FAc is not recommended to diagnose liver fibrosis.</p>","PeriodicalId":18855,"journal":{"name":"Molecular Imaging","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2021-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8654319/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39834411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-04eCollection Date: 2021-01-01DOI: 10.1155/2021/9982020
Hao Jiang, Jiwei Gu, Haiyang Zhao, Sumit Joshi, Joel S Perlmutter, Robert J Gropler, Robyn S Klein, Tammie L S Benzinger, Zhude Tu
Sphingosine-1-phosphate receptor 1 (S1PR1) plays a crucial role in infectious diseases. Targeting S1PR1 provides protection against pathogens, such as influenza viruses. This study is aimed at investigating S1PR1 in response to bacterial infection by assessing S1PR1 expression in S. aureus-infected mice. A rodent local muscle bacterial infection model was developed by injecting S. aureus to the lower hind limb of Balb/c mice. The changes of S1PR1 expression in response to bacterial infection and blocking treatment were assessed using ex vivo biodistribution and in vivo positron emission tomography (PET) after intravenous injection of an S1PR1-specific radiotracer [18F]TZ4877. The specificity of [18F]TZ4877 was assessed using S1PR1-specific antagonist, NIBR-0213, and S1PR1-specific DsiRNA pretreated the animals. Immunohistochemical studies were performed to confirm the increase of S1PR1 expression in response to infection. Ex vivo biodistribution data showed that the uptake of [18F]TZ4877 was increased 30.6%, 54.3%, 74.3%, and 115.3% in the liver, kidney, pancreas, and thymus of the infected mice, respectively, compared to that in normal control mice, indicating that S1PR1 is involved in the early immune response to bacterial infection. NIBR-0213 or S1PR1-specific DsiRNA pretreatment reduced the tissue uptake of [18F]TZ4877, suggesting that uptake of [18F]TZ4877 is specific. Our PET/CT study data also confirmed that infected mice have increased [18F]TZ4877 uptake in several organs comparing to that in normal control mice. Particularly, compared to control mice, a 39% increase of [18F]TZ4877 uptake was observed in the infected muscle of S. aureus mice, indicating that S1PR1 expression was directly involved in the inflammatory response to infection. Overall, our study suggested that S1PR1 plays an important role in the early immune response to bacterial infection. The uptake of [18F]TZ4877 is tightly correlated with the S1R1 expression in response to S. aureus infection. PET with S1PR1-specific radiotracer [18F]TZ4877 could provide a noninvasive tool for detecting the early S1PR1 immune response to infectious diseases.
{"title":"PET Study of Sphingosine-1-phosphate Receptor 1 Expression in Response to <i>S. aureus</i> Infection.","authors":"Hao Jiang, Jiwei Gu, Haiyang Zhao, Sumit Joshi, Joel S Perlmutter, Robert J Gropler, Robyn S Klein, Tammie L S Benzinger, Zhude Tu","doi":"10.1155/2021/9982020","DOIUrl":"10.1155/2021/9982020","url":null,"abstract":"<p><p>Sphingosine-1-phosphate receptor 1 (S1PR1) plays a crucial role in infectious diseases. Targeting S1PR1 provides protection against pathogens, such as influenza viruses. This study is aimed at investigating S1PR1 in response to bacterial infection by assessing S1PR1 expression in <i>S. aureus</i>-infected mice. A rodent local muscle bacterial infection model was developed by injecting <i>S. aureus</i> to the lower hind limb of Balb/c mice. The changes of S1PR1 expression in response to bacterial infection and blocking treatment were assessed using ex vivo biodistribution and <i>in vivo</i> positron emission tomography (PET) after intravenous injection of an S1PR1-specific radiotracer [<sup>18</sup>F]TZ4877. The specificity of [<sup>18</sup>F]TZ4877 was assessed using S1PR1-specific antagonist, NIBR-0213, and S1PR1-specific DsiRNA pretreated the animals. Immunohistochemical studies were performed to confirm the increase of S1PR1 expression in response to infection. <i>Ex vivo</i> biodistribution data showed that the uptake of [<sup>18</sup>F]TZ4877 was increased 30.6%, 54.3%, 74.3%, and 115.3% in the liver, kidney, pancreas, and thymus of the infected mice, respectively, compared to that in normal control mice, indicating that S1PR1 is involved in the early immune response to bacterial infection. NIBR-0213 or S1PR1-specific DsiRNA pretreatment reduced the tissue uptake of [<sup>18</sup>F]TZ4877, suggesting that uptake of [<sup>18</sup>F]TZ4877 is specific. Our PET/CT study data also confirmed that infected mice have increased [<sup>18</sup>F]TZ4877 uptake in several organs comparing to that in normal control mice. Particularly, compared to control mice, a 39% increase of [<sup>18</sup>F]TZ4877 uptake was observed in the infected muscle of <i>S. aureus</i> mice, indicating that S1PR1 expression was directly involved in the inflammatory response to infection. Overall, our study suggested that S1PR1 plays an important role in the early immune response to bacterial infection. The uptake of [<sup>18</sup>F]TZ4877 is tightly correlated with the S1R1 expression in response to <i>S. aureus</i> infection. PET with S1PR1-specific radiotracer [<sup>18</sup>F]TZ4877 could provide a noninvasive tool for detecting the early S1PR1 immune response to infectious diseases.</p>","PeriodicalId":18855,"journal":{"name":"Molecular Imaging","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2021-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8654346/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9235557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background: Some studies have reported the effectiveness of [18F]PI-2620 as an effective tau-binding radiotracer; however, few reports have applied semiquantitative analysis to the tracer. Therefore, this study's aim was to perform a semiquantitative analysis of [18F]PI-2620 in individuals with normal cognition and patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD).
Methods: Twenty-six cognitively normal (CN) subjects, 7 patients with AD, and 36 patients with MCI were enrolled. A dynamic positron emission tomography (PET) scan was performed 30-75 min postinjection. PET and T1-weighted magnetic resonance imaging scans were coregistered. The standardized uptake value ratio (SUVr) was used for semiquantitative analysis. The P-Mod software was applied to create volumes of interest. The ANOVA and post hoc Tukey HSD were used for statistical analysis.
Results: In the AD group, the occipital lobe had a significantly higher mean SUVr (1.46 ± 0.57) than in the CN and MCI groups. Compared with the CN group, the AD group showed significantly higher mean SUVr in the fusiform gyrus (1.06 ± 0.09 vs. 1.49 ± 0.86), inferior temporal (1.07 ± 0.07 vs. 1.46 ± 0.08), parietal lobe, lingual gyrus, and precuneus regions. Similarly, the AD group demonstrated a higher mean SUVr than the MCI group in the precuneus, lingual, inferior temporal, fusiform, supramarginal, orbitofrontal, and superior temporal regions. The remaining observed regions, including the striatum, basal ganglia, thalamus, and white matter, showed a low SUVr across all groups with no statistically significant differences.
Conclusion: A significantly higher mean SUVr of [18F]PI-2620 was observed in the AD group; a significant area of the brain in the AD group demonstrated tau protein deposit in concordance with Braak Stages III-V, providing useful information to differentiate AD from CN and MCI. Moreover, the low SUVr in the deep striatum and thalamus could be useful for excluding primary tauopathies.
{"title":"The Evaluation of Tau Deposition with [<sup>18</sup>F]PI-2620 by Using a Semiquantitative Method in Cognitively Normal Subjects and Patients with Mild Cognitive Impairment and Alzheimer's Disease.","authors":"Attapon Jantarato, Sira Vachatimanont, Natphimol Boonkawin, Sukanya Yaset, Anchisa Kunawudhi, Chetsadaporn Promteangtrong, Jintana Assanasen, Nithi Mahanonda, Chanisa Chotipanich","doi":"10.1155/2021/6640054","DOIUrl":"https://doi.org/10.1155/2021/6640054","url":null,"abstract":"<p><strong>Background: </strong>Some studies have reported the effectiveness of [<sup>18</sup>F]PI-2620 as an effective tau-binding radiotracer; however, few reports have applied semiquantitative analysis to the tracer. Therefore, this study's aim was to perform a semiquantitative analysis of [<sup>18</sup>F]PI-2620 in individuals with normal cognition and patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD).</p><p><strong>Methods: </strong>Twenty-six cognitively normal (CN) subjects, 7 patients with AD, and 36 patients with MCI were enrolled. A dynamic positron emission tomography (PET) scan was performed 30-75 min postinjection. PET and T1-weighted magnetic resonance imaging scans were coregistered. The standardized uptake value ratio (SUVr) was used for semiquantitative analysis. The P-Mod software was applied to create volumes of interest. The ANOVA and post hoc Tukey HSD were used for statistical analysis.</p><p><strong>Results: </strong>In the AD group, the occipital lobe had a significantly higher mean SUVr (1.46 ± 0.57) than in the CN and MCI groups. Compared with the CN group, the AD group showed significantly higher mean SUVr in the fusiform gyrus (1.06 ± 0.09 vs. 1.49 ± 0.86), inferior temporal (1.07 ± 0.07 vs. 1.46 ± 0.08), parietal lobe, lingual gyrus, and precuneus regions. Similarly, the AD group demonstrated a higher mean SUVr than the MCI group in the precuneus, lingual, inferior temporal, fusiform, supramarginal, orbitofrontal, and superior temporal regions. The remaining observed regions, including the striatum, basal ganglia, thalamus, and white matter, showed a low SUVr across all groups with no statistically significant differences.</p><p><strong>Conclusion: </strong>A significantly higher mean SUVr of [<sup>18</sup>F]PI-2620 was observed in the AD group; a significant area of the brain in the AD group demonstrated tau protein deposit in concordance with Braak Stages III-V, providing useful information to differentiate AD from CN and MCI. Moreover, the low SUVr in the deep striatum and thalamus could be useful for excluding primary tauopathies.</p>","PeriodicalId":18855,"journal":{"name":"Molecular Imaging","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2021-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8328488/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39302112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background: Inducible nitric oxide synthase (iNOS) plays a crucial role in neuroinflammation, especially microglial activity, and may potentially represent a useful biomarker of neuroinflammation. In this study, we carefully defined a strategic plan to develop iNOS-targeted molecular PET imaging using (4'-amino-5',8'-difluoro-1'H-spiro[piperidine-4,2'-quinazolin]-1-yl)(4-fluorophenyl)methanone ([18F]FBAT) as a tracer in a mouse model of lipopolysaccharide- (LPS-) induced brain inflammation.
Methods: An in vitro model, murine microglial BV2 cell line, was used to assess the uptake of [18F]FBAT in response to iNOS induction at the cellular level. In vivo whole-body dynamic PET/MR imaging was acquired in LPS-treated (5 mg/kg) and control mice. Standard uptake value (SUV), total volume of distribution (Vt), and area under the curve (AUC) based on the [18F]FBAT PET signals were determined. The expression of iNOS was confirmed by immunohistochemistry (IHC) of brain tissues.
Results: At the end of synthesis, the yield of [18F]FBAT was 2.2-3.1% (EOS), radiochemical purity was >99%, and molar radioactivity was 125-137 GBq/μmol. In vitro, [18F]FBAT rapidly and progressively accumulated in murine microglial BV2 cells exposed to LPS; however, [18F]FBAT accumulation was inhibited by aminoguanidine, a selective iNOS inhibitor. In vivo biodistribution studies of [18F]FBAT showed a significant increase in the liver and kidney on LPS-treated mice. At 3 h postinjection of LPS, in vivo, the [18F]FBAT accumulation ratios at 30 min post intravenous (i.v.) radiotracer injection for the whole brain, cortex, cerebellum, and brainstem were 2.16 ± 0.18, 1.53 ± 0.25, 1.41 ± 0.21, and 1.90 ± 0.12, respectively, compared to those of mice not injected with LPS. The mean area under the curve (AUC0-30min), total volume of distribution (Vt, mL/cm3), and Ki (influx rate) of [18F]FBAT were 1.9 ± 0.21- and 1.4 ± 0.22-fold higher in the 3 h LPS group, respectively, than in the control group. In the pharmacokinetic two-compartment model, the whole brain Ki of [18F]FBAT was significantly higher in mice injected with LPS compared to the control group. Aminoguanidine, selective iNOS inhibitor, pretreatment significantly reduced the AUC0-30min and Vt values in LPS-induced mice. Quantitative analysis of immunohistochemically stained brain sections confirmed iNOS was preferentially upregulated in the cerebellum and cortex of mice injected with LPS.
Conclusion: An automated robotic method was established for radiosynthesis of [18F]FBAT, and the preliminary in vitro and in vivo results demonstrated the fe
背景:诱导型一氧化氮合酶(iNOS)在神经炎症,尤其是小胶质细胞活性中起着至关重要的作用,可能是神经炎症的一个有用的生物标志物。在本研究中,我们精心制定了一项战略计划,利用(4'-氨基-5',8'-二氟-1' h -螺[哌啶-4,2'-喹唑啉]-1-基)(4-氟苯基)甲烷([18F]FBAT)作为示踪剂,在脂多糖(LPS-)诱导的脑炎症小鼠模型中开发inos靶向分子PET成像。方法:采用小鼠小胶质BV2细胞系体外模型,在细胞水平评估iNOS诱导下[18F]FBAT的摄取。在lps处理(5 mg/kg)和对照小鼠体内获得全身动态PET/MR成像。根据[18F]FBAT PET信号确定标准摄取值(SUV)、分布总量(V t)和曲线下面积(AUC)。脑组织免疫组化(IHC)证实iNOS的表达。结果:合成结束时,[18F]FBAT的产率为2.2 ~ 3.1% (EOS),放射化学纯度>99%,摩尔放射性为125 ~ 137 GBq/μmol。在体外,[18F]FBAT在暴露于LPS的小鼠小胶质BV2细胞中迅速渐进地积累;然而,[18F]选择性iNOS抑制剂氨基胍可抑制FBAT的积累。体内生物分布研究表明[18F]FBAT在lps处理小鼠的肝脏和肾脏中显著增加。注射LPS后3 h,与未注射LPS小鼠相比,静脉注射放射性示踪剂后30 min全脑、皮质、小脑和脑干的[18F]FBAT积累比分别为2.16±0.18、1.53±0.25、1.41±0.21和1.90±0.12。3 h LPS组[18F]FBAT的平均曲线下面积(AUC0-30min)、总分布容积(V t, mL/cm3)和ki(内流率)分别比对照组高1.9±0.21倍和1.4±0.22倍。在药代动力学双室模型中,注射LPS小鼠[18F]FBAT的全脑ki明显高于对照组。选择性iNOS抑制剂氨基胍预处理可显著降低lps诱导小鼠的AUC0-30min和vt值。免疫组织化学染色的脑切片定量分析证实,注射LPS小鼠的小脑和皮层iNOS优先上调。结论:建立了一种自动化机器人放射合成[18F]FBAT的方法,初步的体外和体内实验结果表明,通过[18F]FBAT PET/MRI无创成像检测lps治疗的神经炎症中iNOS活性/表达的可行性。
{"title":"Automated Synthesis and Initial Evaluation of (4'-Amino-5',8'-difluoro-1'H-spiro[piperidine-4,2'-quinazolin]-1-yl)(4-[<sup>18</sup>F]fluorophenyl)methanone for PET/MR Imaging of Inducible Nitric Oxide Synthase.","authors":"Skye Hsin-Hsien Yeh, Wen-Sheng Huang, Chuang-Hsin Chiu, Chuan-Lin Chen, Hui-Ting Chen, Dae Yoon Chi, Zhengxing Ge, Tsung-Hsun Yu, Pao-Yeh Wang, Yu-Yeh Kuo, Chun-Tse Hung, Geng-Ying Li, Chi-Wei Chang","doi":"10.1155/2021/9996125","DOIUrl":"https://doi.org/10.1155/2021/9996125","url":null,"abstract":"<p><strong>Background: </strong>Inducible nitric oxide synthase (iNOS) plays a crucial role in neuroinflammation, especially microglial activity, and may potentially represent a useful biomarker of neuroinflammation. In this study, we carefully defined a strategic plan to develop iNOS-targeted molecular PET imaging using (4'-amino-5',8'-difluoro-1'H-spiro[piperidine-4,2'-quinazolin]-1-yl)(4-fluorophenyl)methanone ([<sup>18</sup>F]FBAT) as a tracer in a mouse model of lipopolysaccharide- (LPS-) induced brain inflammation.</p><p><strong>Methods: </strong>An <i>in vitro</i> model, murine microglial BV2 cell line, was used to assess the uptake of [<sup>18</sup>F]FBAT in response to iNOS induction at the cellular level. <i>In vivo</i> whole-body dynamic PET/MR imaging was acquired in LPS-treated (5 mg/kg) and control mice. Standard uptake value (SUV), total volume of distribution (<i>V</i> <sub>t</sub>), and area under the curve (AUC) based on the [<sup>18</sup>F]FBAT PET signals were determined. The expression of iNOS was confirmed by immunohistochemistry (IHC) of brain tissues.</p><p><strong>Results: </strong>At the end of synthesis, the yield of [<sup>18</sup>F]FBAT was 2.2-3.1% (EOS), radiochemical purity was >99%, and molar radioactivity was 125-137 GBq/<i>μ</i>mol. <i>In vitro</i>, [<sup>18</sup>F]FBAT rapidly and progressively accumulated in murine microglial BV2 cells exposed to LPS; however, [<sup>18</sup>F]FBAT accumulation was inhibited by aminoguanidine, a selective iNOS inhibitor. <i>In vivo</i> biodistribution studies of [<sup>18</sup>F]FBAT showed a significant increase in the liver and kidney on LPS-treated mice. At 3 h postinjection of LPS, <i>in vivo</i>, the [<sup>18</sup>F]FBAT accumulation ratios at 30 min post intravenous (i.v.) radiotracer injection for the whole brain, cortex, cerebellum, and brainstem were 2.16 ± 0.18, 1.53 ± 0.25, 1.41 ± 0.21, and 1.90 ± 0.12, respectively, compared to those of mice not injected with LPS. The mean area under the curve (AUC<sub>0-30min</sub>), total volume of distribution (<i>V</i> <sub>t</sub>, mL/cm<sup>3</sup>), and <i>K</i> <sub>i</sub> (influx rate) of [<sup>18</sup>F]FBAT were 1.9 ± 0.21- and 1.4 ± 0.22-fold higher in the 3 h LPS group, respectively, than in the control group. In the pharmacokinetic two-compartment model, the whole brain <i>K</i> <sub>i</sub> of [<sup>18</sup>F]FBAT was significantly higher in mice injected with LPS compared to the control group. Aminoguanidine, selective iNOS inhibitor, pretreatment significantly reduced the AUC<sub>0-30min</sub> and <i>V</i> <sub>t</sub> values in LPS-induced mice. Quantitative analysis of immunohistochemically stained brain sections confirmed iNOS was preferentially upregulated in the cerebellum and cortex of mice injected with LPS.</p><p><strong>Conclusion: </strong>An automated robotic method was established for radiosynthesis of [<sup>18</sup>F]FBAT, and the preliminary <i>in vitro</i> and <i>in vivo</i> results demonstrated the fe","PeriodicalId":18855,"journal":{"name":"Molecular Imaging","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2021-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8328489/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39302114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The recently emerging technique of sparse reconstruction has received much attention in the field of photoacoustic imaging (PAI). Compressed sensing (CS) has large potential in efficiently reconstructing high-quality PAI images with sparse sampling signal. In this article, we propose a CS-based error-tolerant regularized smooth L0 (ReSL0) algorithm for PAI image reconstruction, which has the same computational advantages as the SL0 algorithm while having a higher degree of immunity to inaccuracy caused by noise. In order to evaluate the performance of the ReSL0 algorithm, we reconstruct the simulated dataset obtained from three phantoms. In addition, a real experimental dataset from agar phantom is also used to verify the effectiveness of the ReSL0 algorithm. Compared to three L0 norm, L1 norm, and TV norm-based CS algorithms for signal recovery and image reconstruction, experiments demonstrated that the ReSL0 algorithm provides a good balance between the quality and efficiency of reconstructions. Furthermore, the PSNR of the reconstructed image calculated by the introduced method was better than the other three methods. In particular, it can notably improve reconstruction quality in the case of noisy measurement.
{"title":"A Photoacoustic Imaging Algorithm Based on Regularized Smoothed L<sub>0</sub> Norm Minimization.","authors":"Xueyan Liu, Limei Zhang, Yining Zhang, Lishan Qiao","doi":"10.1155/2021/6689194","DOIUrl":"10.1155/2021/6689194","url":null,"abstract":"<p><p>The recently emerging technique of sparse reconstruction has received much attention in the field of photoacoustic imaging (PAI). Compressed sensing (CS) has large potential in efficiently reconstructing high-quality PAI images with sparse sampling signal. In this article, we propose a CS-based error-tolerant regularized smooth L0 (ReSL0) algorithm for PAI image reconstruction, which has the same computational advantages as the SL0 algorithm while having a higher degree of immunity to inaccuracy caused by noise. In order to evaluate the performance of the ReSL0 algorithm, we reconstruct the simulated dataset obtained from three phantoms. In addition, a real experimental dataset from agar phantom is also used to verify the effectiveness of the ReSL0 algorithm. Compared to three L<sub>0</sub> norm, L<sub>1</sub> norm, and TV norm-based CS algorithms for signal recovery and image reconstruction, experiments demonstrated that the ReSL0 algorithm provides a good balance between the quality and efficiency of reconstructions. Furthermore, the PSNR of the reconstructed image calculated by the introduced method was better than the other three methods. In particular, it can notably improve reconstruction quality in the case of noisy measurement.</p>","PeriodicalId":18855,"journal":{"name":"Molecular Imaging","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8187066/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39014568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-25eCollection Date: 2021-01-01DOI: 10.1155/2021/5594514
Yanina Dockx, Christel Vangestel, Tim Van den Wyngaert, Manon Huizing, Sven De Bruycker, Patrick Pauwels, Steven Staelens, Sigrid Stroobants
We investigated the potential use of [18F]FDG PET as a response biomarker for PI3K pathway targeting therapies in two HER-2-overexpressing cancer models. Methods. CD-1 nude mice were inoculated with HER-2-overexpressing JIMT1 (trastuzumab-resistant) or SKOV3 (trastuzumab-sensitive) human cancer cells. Animals were treated with trastuzumab, everolimus (mTOR inhibitor), PIK90 (PI3K inhibitor), saline, or combination therapy. [18F]FDG scans were performed at baseline, two, and seven days after the start of the therapy. Tumors were delineated on CT images and relative tumor volumes (RTV) and maximum standardized uptake value (SUVmax) were calculated. Levels of pS6 and pAkt on protein tumor lysates were determined with ELISA. Results. In the SKOV3 xenografts, all treatment schedules resulted in a gradual decrease in RTV and delta SUVmax (ΔSUVmax). For all treatments combined, ΔSUVmax after 2 days was predictive for RTV after 7 days (r = 0.69, p = 0.030). In JIMT1 tumors, monotherapy with everolimus or PIK90 resulted in a decrease in RTV (-30% ± 10% and -20% ± 20%, respectively) and ΔSUVmax (-39% ± 36% and -42% ± 8%, respectively) after 7 days of treatment, but not earlier, while trastuzumab resulted in nonsignificant increases compared to control. Combination therapies resulted in RTV and ΔSUVmax decrease already at day 2, except for trastuzumab+everolimus, where an early flare was observed. For all treatments combined, ΔSUVmax after 2 days was predictive for RTV after 7 days (r = 0.48, p = 0.028), but the correlation could be improved when combination with everolimus (r = 0.59, p = 0.023) or trastuzumab (r = 0.69, p = 0.015) was excluded. Conclusion. Reduction in [18F]FDG after 2 days correlated with tumor volume changes after 7 days of treatment and confirms the use of [18F]FDG PET as an early response biomarker. Treatment response can however be underestimated in schedules containing trastuzumab or everolimus due to temporary increased [18F]FDG uptake secondary to negative feedback loop and crosstalk between different pathways.
我们研究了[18F]FDG PET作为两种her -2过表达癌症模型中PI3K通路靶向治疗的反应性生物标志物的潜在用途。方法。用her -2过表达的JIMT1(曲妥珠单抗耐药)或SKOV3(曲妥珠单抗敏感)人癌细胞接种CD-1裸鼠。动物接受曲妥珠单抗、依维莫司(mTOR抑制剂)、PIK90 (PI3K抑制剂)、生理盐水或联合治疗。[18F]在治疗开始后的基线、第2天和第7天进行FDG扫描。在CT图像上圈定肿瘤,计算相对肿瘤体积(RTV)和最大标准化摄取值(SUVmax)。ELISA法检测肿瘤蛋白裂解物中pS6和pAkt的表达水平。结果。在SKOV3异种移植物中,所有治疗方案都导致RTV和delta SUVmax逐渐降低(ΔSUVmax)。对于所有联合治疗,2天后ΔSUVmax可预测7天后的RTV (r = 0.69, p = 0.030)。在JIMT1肿瘤中,依维莫司或PIK90单药治疗导致治疗7天后RTV(分别为-30%±10%和-20%±20%)和ΔSUVmax(分别为-39%±36%和-42%±8%)下降,但不早,而曲妥珠单抗导致与对照组相比无显著增加。联合治疗导致RTV和ΔSUVmax在第2天已经下降,除了曲妥珠单抗+依维莫司,观察到早期发作。对于所有联合治疗,2天后ΔSUVmax可预测7天后的RTV (r = 0.48, p = 0.028),但当排除依维莫司(r = 0.59, p = 0.023)或曲妥珠单抗(r = 0.69, p = 0.015)时,相关性可以得到改善。结论。2天后[18F]FDG的减少与治疗7天后肿瘤体积的变化相关,证实了[18F]FDG PET作为早期反应生物标志物的使用。然而,在含有曲妥珠单抗或依维莫司的方案中,由于负反馈回路和不同通路之间的串扰导致FDG摄取暂时增加[18F],治疗反应可能被低估。
{"title":"Early Changes in [<sup>18</sup>F]FDG Uptake as a Readout for PI3K/Akt/mTOR Targeted Drugs in HER-2-Positive Cancer Xenografts.","authors":"Yanina Dockx, Christel Vangestel, Tim Van den Wyngaert, Manon Huizing, Sven De Bruycker, Patrick Pauwels, Steven Staelens, Sigrid Stroobants","doi":"10.1155/2021/5594514","DOIUrl":"https://doi.org/10.1155/2021/5594514","url":null,"abstract":"<p><p>We investigated the potential use of [<sup>18</sup>F]FDG PET as a response biomarker for PI3K pathway targeting therapies in two HER-2-overexpressing cancer models. <i>Methods</i>. CD-1 nude mice were inoculated with HER-2-overexpressing JIMT1 (trastuzumab-resistant) or SKOV3 (trastuzumab-sensitive) human cancer cells. Animals were treated with trastuzumab, everolimus (mTOR inhibitor), PIK90 (PI3K inhibitor), saline, or combination therapy. [<sup>18</sup>F]FDG scans were performed at baseline, two, and seven days after the start of the therapy. Tumors were delineated on CT images and relative tumor volumes (RTV) and maximum standardized uptake value (SUV<sub>max</sub>) were calculated. Levels of pS6 and pAkt on protein tumor lysates were determined with ELISA. <i>Results</i>. In the SKOV3 xenografts, all treatment schedules resulted in a gradual decrease in RTV and delta SUV<sub>max</sub> (<i>Δ</i>SUV<sub>max</sub>). For all treatments combined, <i>Δ</i>SUV<sub>max</sub> after 2 days was predictive for RTV after 7 days (<i>r</i> = 0.69, <i>p</i> = 0.030). In JIMT1 tumors, monotherapy with everolimus or PIK90 resulted in a decrease in RTV (-30% ± 10% and -20% ± 20%, respectively) and <i>Δ</i>SUV<sub>max</sub> (-39% ± 36% and -42% ± 8%, respectively) after 7 days of treatment, but not earlier, while trastuzumab resulted in nonsignificant increases compared to control. Combination therapies resulted in RTV and <i>Δ</i>SUV<sub>max</sub> decrease already at day 2, except for trastuzumab+everolimus, where an early flare was observed. For all treatments combined, <i>Δ</i>SUV<sub>max</sub> after 2 days was predictive for RTV after 7 days (<i>r</i> = 0.48, <i>p</i> = 0.028), but the correlation could be improved when combination with everolimus (<i>r</i> = 0.59, <i>p</i> = 0.023) or trastuzumab (<i>r</i> = 0.69, <i>p</i> = 0.015) was excluded. <i>Conclusion</i>. Reduction in [<sup>18</sup>F]FDG after 2 days correlated with tumor volume changes after 7 days of treatment and confirms the use of [<sup>18</sup>F]FDG PET as an early response biomarker. Treatment response can however be underestimated in schedules containing trastuzumab or everolimus due to temporary increased [<sup>18</sup>F]FDG uptake secondary to negative feedback loop and crosstalk between different pathways.</p>","PeriodicalId":18855,"journal":{"name":"Molecular Imaging","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2021-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8169268/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39014567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-31eCollection Date: 2021-01-01DOI: 10.1155/2021/6660358
Skye Hsin-Hsien Yeh, Ming Hsien Lin, I I Leo Garcia Flores, Uday Mukhopadhyay, Danial Young, Kazuma Ogawa, Jeong-Hwan Jeong, William Tong, Juri G Gelovani, Nobuyoshi Fukumitsu
Combining standard drugs with low doses of histone deacetylase inhibitors (HDACIs) is a promising strategy to increase the efficacy of chemotherapy. The ability of well-tolerated doses of HDACIs that act as chemosensitizers for platinum-based chemotherapeutics has recently been proven in many types and stages of cancer in vitro and in vivo. Detection of changes in HDAC activity/expression may provide important prognostic and predictive information and influence treatment decision-making. Use of [18F] FAHA, a HDAC IIa-specific radionuclide, for molecular imaging may enable longitudinal, noninvasive assessment of HDAC activity/expression in metastatic cancer. We evaluated the synergistic anticancer effects of cisplatin and the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) in xenograft models of nonsmall cell lung cancer (NSCLC) using [18F] FAHA and [18F] FDG PET/CT imaging. Cisplatin alone significantly increased [18F] FAHA accumulation and reduced [18F] FDG accumulation in H441 and PC14 xenografts; coadministration of cisplatin and SAHA resulted in the opposite effects. Immunochemical staining for acetyl-histone H3 confirmed the PET/CT imaging findings. Moreover, SAHA had a more significant effect on the acetylome in PC14 (EGFR exon 19 deletion mutation) xenografts than H441 (wild-type EGFR and KRAS codon 12 mutant) xenografts. In conclusion, [18F] FAHA enables quantitative visualization of HDAC activity/expression in vivo, thus, may represent a clinically useful, noninvasive tool for the management of patients who may benefit from synergistic anticancer therapy.
{"title":"<i>In Vivo</i> Evaluation of the Combined Anticancer Effects of Cisplatin and SAHA in Nonsmall Cell Lung Carcinoma Using [<sup>18</sup>F]FAHA and [<sup>18</sup>F]FDG PET/CT Imaging.","authors":"Skye Hsin-Hsien Yeh, Ming Hsien Lin, I I Leo Garcia Flores, Uday Mukhopadhyay, Danial Young, Kazuma Ogawa, Jeong-Hwan Jeong, William Tong, Juri G Gelovani, Nobuyoshi Fukumitsu","doi":"10.1155/2021/6660358","DOIUrl":"https://doi.org/10.1155/2021/6660358","url":null,"abstract":"<p><p>Combining standard drugs with low doses of histone deacetylase inhibitors (HDACIs) is a promising strategy to increase the efficacy of chemotherapy. The ability of well-tolerated doses of HDACIs that act as chemosensitizers for platinum-based chemotherapeutics has recently been proven in many types and stages of cancer <i>in vitro</i> and <i>in vivo</i>. Detection of changes in HDAC activity/expression may provide important prognostic and predictive information and influence treatment decision-making. Use of [<sup>18</sup>F] FAHA, a HDAC IIa-specific radionuclide, for molecular imaging may enable longitudinal, noninvasive assessment of HDAC activity/expression in metastatic cancer. We evaluated the synergistic anticancer effects of cisplatin and the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) in xenograft models of nonsmall cell lung cancer (NSCLC) using [<sup>18</sup>F] FAHA and [<sup>18</sup>F] FDG PET/CT imaging. Cisplatin alone significantly increased [<sup>18</sup>F] FAHA accumulation and reduced [<sup>18</sup>F] FDG accumulation in H441 and PC14 xenografts; coadministration of cisplatin and SAHA resulted in the opposite effects. Immunochemical staining for acetyl-histone H3 confirmed the PET/CT imaging findings. Moreover, SAHA had a more significant effect on the acetylome in PC14 (<i>EGFR</i> exon 19 deletion mutation) xenografts than H441 (wild-type <i>EGFR</i> and <i>KRAS</i> codon 12 mutant) xenografts. In conclusion, [<sup>18</sup>F] FAHA enables quantitative visualization of HDAC activity/expression <i>in vivo</i>, thus, may represent a clinically useful, noninvasive tool for the management of patients who may benefit from synergistic anticancer therapy.</p>","PeriodicalId":18855,"journal":{"name":"Molecular Imaging","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2021-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8032518/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38817790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}