1
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Mittal S, Mallia MB. Molecular imaging of tumor hypoxia: Evolution of nitroimidazole radiopharmaceuticals and insights for future development. Bioorg Chem 2023; 139:106687. [PMID: 37406518 DOI: 10.1016/j.bioorg.2023.106687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 06/15/2023] [Indexed: 07/07/2023]
Abstract
Though growing evidence has been collected in support of the concept of dose escalation based on the molecular level images indicating hypoxic tumor sub-volumes that could be radio-resistant, validation of the concept is still a work in progress. Molecular imaging of tumor hypoxia using radiopharmaceuticals is expected to provide the required input to plan dose escalation through Image Guided Radiation Therapy (IGRT) to kill/control the radio-resistant hypoxic tumor cells. The success of the IGRT, therefore, is heavily dependent on the quality of images obtained using the radiopharmaceutical and the extent to which the image represents the true hypoxic status of the tumor in spite of the heterogeneous nature of tumor hypoxia. Available literature on radiopharmaceuticals for imaging hypoxia is highly skewed in favor of nitroimidazole as the pharmacophore given their ability to undergo oxygen dependent reduction in hypoxic cells. In this context, present review on nitroimidazole radiopharmaceuticals would be immensely helpful to the researchers to obtain a birds-eye view on what has been achieved so far and what can be tried differently to obtain a better hypoxia imaging agent. The review also covers various methods of radiolabeling that could be utilized for developing radiotracers for hypoxia targeting applications.
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Affiliation(s)
- Sweety Mittal
- Radiopharmaceuticals Division, Bhabha Atomic Research Center, Mumbai 400085, India.
| | - Madhava B Mallia
- Radiopharmaceuticals Division, Bhabha Atomic Research Center, Mumbai 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India.
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2
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Chia K, Paul RL, Weeks AJ, Naeem M, Mullen GE, Landau D, Blower PJ. Correlation of hypoxia PET tracer uptake with hypoxic radioresistance in cancer cells: PET biomarkers of resistance to stereotactic radiation therapy? Nucl Med Biol 2022; 110-111:10-17. [DOI: 10.1016/j.nucmedbio.2022.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/24/2022] [Accepted: 04/06/2022] [Indexed: 11/16/2022]
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3
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Huang Y, Fan J, Li Y, Fu S, Chen Y, Wu J. Imaging of Tumor Hypoxia With Radionuclide-Labeled Tracers for PET. Front Oncol 2021; 11:731503. [PMID: 34557414 PMCID: PMC8454408 DOI: 10.3389/fonc.2021.731503] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Accepted: 08/19/2021] [Indexed: 01/27/2023] Open
Abstract
The hypoxic state in a solid tumor refers to the internal hypoxic environment that appears as the tumor volume increases (the maximum radius exceeds 180-200 microns). This state can promote angiogenesis, destroy the balance of the cell’s internal environment, and lead to resistance to radiotherapy and chemotherapy, as well as poor prognostic factors such as metastasis and recurrence. Therefore, accurate quantification, mapping, and monitoring of hypoxia, targeted therapy, and improvement of tumor hypoxia are of great significance for tumor treatment and improving patient survival. Despite many years of development, PET-based hypoxia imaging is still the most widely used evaluation method. This article provides a comprehensive overview of tumor hypoxia imaging using radionuclide-labeled PET tracers. We introduced the mechanism of tumor hypoxia and the reasons leading to the poor prognosis, and more comprehensively included the past, recent and ongoing studies of PET radiotracers for tumor hypoxia imaging. At the same time, the advantages and disadvantages of mainstream methods for detecting tumor hypoxia are summarized.
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Affiliation(s)
- Yuan Huang
- Department of Oncology, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Junying Fan
- Department of Oncology, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Yi Li
- Department of Oncology, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Shaozhi Fu
- Department of Oncology, The Affiliated Hospital of Southwest Medical University, Luzhou, China.,Department of Oncology, Academician (Expert) Workstation of Sichuan Province, Luzhou, China
| | - Yue Chen
- Department of Oncology, Academician (Expert) Workstation of Sichuan Province, Luzhou, China.,Nuclear Medicine and Molecular Imaging key Laboratory of Sichuan Province, Department of Nuclear Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Jingbo Wu
- Department of Oncology, The Affiliated Hospital of Southwest Medical University, Luzhou, China.,Department of Oncology, Academician (Expert) Workstation of Sichuan Province, Luzhou, China
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4
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Decarli MC, do Amaral RLF, Dos Santos DP, Tofani LB, Katayama E, Rezende RA, Silva JVLD, Swiech K, Suazo CAT, Mota C, Moroni L, Moraes ÂM. Cell spheroids as a versatile research platform: formation mechanisms, high throughput production, characterization and applications. Biofabrication 2021; 13. [PMID: 33592595 DOI: 10.1088/1758-5090/abe6f2] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 02/16/2021] [Indexed: 11/12/2022]
Abstract
Three-dimensional cell culture has tremendous advantages to closely mimic the in vivo architecture and microenvironment of healthy tissue and organs, as well as of solid tumors. Spheroids are currently the most attractive 3D model to produce uniform reproducible cell structures as well as a potential basis for engineering large tissues and complex organs. In this review we discuss, from an engineering perspective, processes to obtain uniform 3D cell spheroids, comparing dynamic and static cultures and considering aspects such as mass transfer and shear stress. In addition, computational and mathematical modelling of complex cell spheroid systems are discussed. The non-cell-adhesive hydrogel-based method and dynamic cell culture in bioreactors are focused in detail and the myriad of developed spheroid characterization techniques is presented. The main bottlenecks and weaknesses are discussed, especially regarding the analysis of morphological parameters, cell quantification and viability, gene expression profiles, metabolic behavior and high-content analysis. Finally, a vast set of applications of spheroids as tools for in vitro study model systems is examined, including drug screening, tissue formation, pathologies development, tissue engineering and biofabrication, 3D bioprinting and microfluidics, together with their use in high-throughput platforms.
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Affiliation(s)
- Monize Caiado Decarli
- School of Chemical Engineering/Department of Engineering of Materials and of Bioprocesses, University of Campinas, Av. Albert Einstein, 500 - Bloco A - Cidade Universitária Zeferino Vaz, Cidade Universitária Zeferino Vaz, Campinas, SP, 13083-852, BRAZIL
| | - Robson Luis Ferraz do Amaral
- School of Pharmaceutical Sciences of Ribeirão Preto/Department of Pharmaceutical Sciences, University of São Paulo, Avenida do Café, no number, Ribeirão Preto, SP, 14040-903, BRAZIL
| | - Diogo Peres Dos Santos
- Departament of Chemical Engineering, Federal University of São Carlos, Rod. Washington Luiz (SP-310), km 235, São Carlos, SP, 13565-905, BRAZIL
| | - Larissa Bueno Tofani
- School of Pharmaceutical Sciences of Ribeirão Preto/Department of Pharmaceutical Sciences, University of São Paulo, Avenida do Café, no number, Ribeirão Preto, SP, 14040-903, BRAZIL
| | - Eric Katayama
- Departament of Chemical Engineering, Federal University of São Carlos, Rod. Washington Luiz (SP-310), km 235, São Carlos, SP, 13565-905, BRAZIL
| | - Rodrigo Alvarenga Rezende
- Centro de Tecnologia da Informacao Renato Archer, Rod. Dom Pedro I (SP-65), km 143,6 - Amarais, Campinas, SP, 13069-901, BRAZIL
| | - Jorge Vicente Lopes da Silva
- Centro de Tecnologia da Informacao Renato Archer, Rod. Dom Pedro I (SP-65), km 143,6 - Amarais, Campinas, SP, 13069-901, BRAZIL
| | - Kamilla Swiech
- University of Sao Paulo, School of Pharmaceutical Sciences of Ribeirão Preto/Department of Pharmaceutical Sciences, Ribeirao Preto, SP, 14040-903, BRAZIL
| | - Cláudio Alberto Torres Suazo
- Department of Chemical Engineering, Federal University of São Carlos, Rod. Washington Luiz (SP-310), km 235, São Carlos, SP, 13565-905, BRAZIL
| | - Carlos Mota
- Department of Complex Tissue Regeneration (CTR), University of Maastricht , Universiteitssingel, 40, office 3.541A, Maastricht, 6229 ER, NETHERLANDS
| | - Lorenzo Moroni
- Complex Tissue Regeneration, Maastricht University, Universiteitsingel, 40, Maastricht, 6229ER, NETHERLANDS
| | - Ângela Maria Moraes
- School of Chemical Engineering/Department of Engineering of Materials and of Bioprocesses, University of Campinas, Av. Albert Einstein, 500 - Bloco A - Cidade Universitária Zeferino Vaz, Campinas, SP, 13083-852, BRAZIL
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5
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Zhang L, Yao X, Cao J, Hong H, Zhang A, Zhao R, Zhang Y, Zha Z, Liu Y, Qiao J, Zhu L, Kung HF. In Vivo Ester Hydrolysis as a New Approach in Development of Positron Emission Tomography Tracers for Imaging Hypoxia. Mol Pharm 2019; 16:1156-1166. [PMID: 30676751 DOI: 10.1021/acs.molpharmaceut.8b01131] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Hypoxia is an important biochemical and physiological condition associated with uncontrolled growth of tumor. Measurement of hypoxia in tumor tissue may be useful in characterization of tumor progression and monitoring drug treatment. [18F]FMISO is the most widely employed radiotracer for imaging of hypoxic tissue with positron emission tomography (PET). However, it showed relatively low uptake in hypoxic tissues, which led to low target-to-background contrast in PET images. To overcome these shortcomings, two novel 2-fluoroproprioic acid esters, nitroimidazole derivatives 2-fluoropropionic acid 2-(2-nitro-imidazol-1-yl)-ethyl ester (FNPFT, [19F]5) and 2-fluoropropionic acid 2-(2-methyl-5-nitro-imidazol-1-yl)-ethyl ester (FMNPFT, [19F]8), were prepared and tested. Radiolabeling of [18F]5 and [18F]8 was accomplished in 45 min (radiochemical purity >95%, the decay-corrected radiochemical yield of [18F]5 was 11 ± 2%, and that of [18F]8 was 13 ± 2%, n = 5). In vitro cell uptake studies using EMT-6 tumor cells showed that both radiotracers [18F]5 and [18F]8 displayed significantly higher uptake in hypoxic cells than those under normoxic condition, while 2-[18F]fluoropropionic acid (2-[18F]FPA) displayed no difference. Biodistribution studies in mice bearing EMT-6 tumor showed that [18F]5, [18F]8, and 2-[18F]FPA displayed similar tumor and major organ uptakes. Tumor uptake values for all three agents were higher than those of [18F]FMISO, respectively ( P < 0.05). This is likely due to a rapid in vivo hydrolysis of [18F]5 and [18F]8 to their metabolite, 2-[18F]FPA. Micro PET imaging studies in the same EMT-6 implanted mice tumor model also demonstrated that both [18F]5 and [18F]8 displayed similar tumor uptake comparable to that of 2-[18F]FPA. In conclusion, two new fluorine-18 labeled nitroimidazole derivatives, [18F]5 and [18F]8, showed good tumor uptakes in mice bearing EMT-6 tumor. However, in vivo biodistribution results suggested that they were more likely reflect the predominance of in vivo produced metabolite, 2-[18F]FPA, which may not be related to tumor hypoxic condition.
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Affiliation(s)
- Lifang Zhang
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry , Beijing Normal University , Beijing 100875 , P. R. China
| | - Xinyue Yao
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry , Beijing Normal University , Beijing 100875 , P. R. China
| | - Jianhua Cao
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry , Beijing Normal University , Beijing 100875 , P. R. China
| | - Haiyan Hong
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry , Beijing Normal University , Beijing 100875 , P. R. China
| | - Aili Zhang
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry , Beijing Normal University , Beijing 100875 , P. R. China
| | - Ruiyue Zhao
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry , Beijing Normal University , Beijing 100875 , P. R. China
| | - Yan Zhang
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry , Beijing Normal University , Beijing 100875 , P. R. China
| | - Zhihao Zha
- Beijing Institute for Brain Disorders , Capital Medical University , Beijing 100069 , P. R. China.,Department of Radiology , University of Pennsylvania , Philadelphia , Pennsylvania 19014 , United States
| | - Yajing Liu
- Beijing Institute for Brain Disorders , Capital Medical University , Beijing 100069 , P. R. China
| | - Jinping Qiao
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry , Beijing Normal University , Beijing 100875 , P. R. China
| | - Lin Zhu
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry , Beijing Normal University , Beijing 100875 , P. R. China.,Beijing Institute for Brain Disorders , Capital Medical University , Beijing 100069 , P. R. China
| | - Hank F Kung
- Beijing Institute for Brain Disorders , Capital Medical University , Beijing 100069 , P. R. China.,Department of Radiology , University of Pennsylvania , Philadelphia , Pennsylvania 19014 , United States
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6
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Clinical and Pre-clinical Methods for Quantifying Tumor Hypoxia. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1136:19-41. [PMID: 31201714 DOI: 10.1007/978-3-030-12734-3_2] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Hypoxia, a prevalent characteristic of most solid malignant tumors, contributes to diminished therapeutic responses and more aggressive phenotypes. The term hypoxia has two definitions. One definition would be a physiologic state where the oxygen partial pressure is below the normal physiologic range. For most normal tissues, the normal physiologic range is between 10 and 20 mmHg. Hypoxic regions develop when there is an imbalance between oxygen supply and demand. The impact of hypoxia on cancer therapeutics is significant: hypoxic tissue is 3× less radiosensitive than normoxic tissue, the impaired blood flow found in hypoxic tumor regions influences chemotherapy delivery, and the immune system is dependent on oxygen for functionality. Despite the clinical implications of hypoxia, there is not a universal, ideal method for quantifying hypoxia, particularly cycling hypoxia because of its complexity and heterogeneity across tumor types and individuals. Most standard imaging techniques can be modified and applied to measuring hypoxia and quantifying its effects; however, the benefits and challenges of each imaging modality makes imaging hypoxia case-dependent. In this chapter, a comprehensive overview of the preclinical and clinical methods for quantifying hypoxia is presented along with the advantages and disadvantages of each.
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7
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Sigal IR, Sebro R. Preclinical PET tracers for the evaluation of sarcomas: understanding tumor biology. AMERICAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 2018; 8:428-440. [PMID: 30697463 PMCID: PMC6334210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 12/05/2018] [Indexed: 06/09/2023]
Abstract
Sarcomas are rare tumors of mesenchymal origin. Sarcomas display significant histological heterogeneity, resulting in significant imaging heterogeneity. 18F-FDG PET has is increasingly used for the evaluation, staging and surveillance of patients with sarcomas. 18F-FDG PET maximum SUV has been shown to be correlated with sarcoma grade and overall survival. This has led to interest in alternative PET tracers to assess the biological characteristics of tumors and guide treatment decisions. Here we investigate novel PET/CT tracers used for the evaluation of sarcomas over the past 20 years and summarize what we have learned about sarcoma tumor biology from these studies.
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Affiliation(s)
- Ian R Sigal
- Department of Radiology, University of Pennsylvania3400 Spruce Street, Philadelphia, PA 19104, USA
| | - Ronnie Sebro
- Department of Radiology, University of Pennsylvania3400 Spruce Street, Philadelphia, PA 19104, USA
- Department of Orthopedic Surgery, University of Pennsylvania3400 Spruce Street, Philadelphia, PA 19104, USA
- Department of Genetics, University of Pennsylvania3400 Spruce Street, Philadelphia, PA 19104, USA
- Department of Epidemiology and Biostatistics, University of Pennsylvania3400 Spruce Street, Philadelphia, PA 19104, USA
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8
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Yu J, Liang F, Huang H, Pirttiniemi P, Yu D. Effects of loading on chondrocyte hypoxia, HIF-1α and VEGF in the mandibular condylar cartilage of young rats. Orthod Craniofac Res 2017; 21:41-47. [PMID: 29271061 DOI: 10.1111/ocr.12212] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/22/2017] [Indexed: 12/19/2022]
Abstract
OBJECTIVES To investigate hypoxia-inducible factor 1-alpha (HIF-1α) and vascular endothelial growth factor (VEGF) expression under altered loading, and to explore the relationship between loading and hypoxia in the mandibular condylar cartilage of young rats. SETTING AND SAMPLE POPULATION Eighty Sprague-Dawley rats. MATERIAL AND METHODS The reduced loading group was fed soft food, and their incisors were cut to avoid occlusal contact. The increased loading group was fed hard food and had forced jaw-opening. Ten rats from each group (n = 10) were sacrificed at 12, 24, 48, and 96 hours after initiation of the experiment. Pimonidazole hydrochloride (Hypoxyprobe-1, HP-1) was used as a hypoxia marker to confirm the hypoxic state. Hypoxic chondrocytes as indicated by HP-1, HIF-1α and VEGF protein expressions were recognized by immunohistochemical detection. HIF-1α and VEGF mRNA expressions were detected by semi-quantitative RT-PCR. RESULTS Hypoxyprobe-1 was confined in the upper layers of cartilage, and was most strongly expressed in the weight-bearing area of TMJ at 12 and 96 hours. Staining of HIF-1α and VEGF was most strongly expressed in the chondrocytes of the fibrous and proliferative layer at all time points. Furthermore, expressions were also displayed in the hypertrophic and calcified layers at 48 and 96 hours. The expressions of HIF-1α and VEGF mRNA were higher in the increased loading group than in the reduced loading group at 48 and 96 hours (P < . 05). CONCLUSION Mechanical loading seems to directly induce weight-bearing area hypoxia followed by new vessel formation, which indicates that these factors are related and important for the development of cartilage.
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Affiliation(s)
- J Yu
- Department of Oral Development and Orthodontics, Institute of Dentistry, University of Oulu, Oulu, Finland
| | - F Liang
- Department of Oral and Maxillofacial Surgery, College of Stomatology, Guangxi Medical University, Nanning, China
| | - H Huang
- Department of Oral and Maxillofacial Surgery, College of Stomatology, Guangxi Medical University, Nanning, China
| | - P Pirttiniemi
- Department of Oral Development and Orthodontics, Institute of Dentistry, University of Oulu, Oulu, Finland
| | - D Yu
- Department of Stomatology, First Affiliated Hospital of Guangxi Medical University, Nanning, China
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9
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Raccagni I, Valtorta S, Moresco RM, Belloli S. Tumour hypoxia: lessons learnt from preclinical imaging. Clin Transl Imaging 2017. [DOI: 10.1007/s40336-017-0248-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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10
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Challapalli A, Carroll L, Aboagye EO. Molecular mechanisms of hypoxia in cancer. Clin Transl Imaging 2017; 5:225-253. [PMID: 28596947 PMCID: PMC5437135 DOI: 10.1007/s40336-017-0231-1] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 04/21/2017] [Indexed: 02/07/2023]
Abstract
PURPOSE Hypoxia is a condition of insufficient oxygen to support metabolism which occurs when the vascular supply is interrupted, or when a tumour outgrows its vascular supply. It is a negative prognostic factor due to its association with an aggressive tumour phenotype and therapeutic resistance. This review provides an overview of hypoxia imaging with Positron emission tomography (PET), with an emphasis on the biological relevance, mechanism of action, highlighting advantages, and limitations of the currently available hypoxia radiotracers. METHODS A comprehensive PubMed literature search was performed, identifying articles relating to biological significance and measurement of hypoxia, MRI methods, and PET imaging of hypoxia in preclinical and clinical settings, up to December 2016. RESULTS A variety of approaches have been explored over the years for detecting and monitoring changes in tumour hypoxia, including regional measurements with oxygen electrodes placed under CT guidance, MRI methods that measure either oxygenation or lactate production consequent to hypoxia, different nuclear medicine approaches that utilise imaging agents the accumulation of which is inversely related to oxygen tension, and optical methods. The advantages and disadvantages of these approaches are reviewed, along with individual strategies for validating different imaging methods. PET is the preferred method for imaging tumour hypoxia due to its high specificity and sensitivity to probe physiological processes in vivo, as well as the ability to provide information about intracellular oxygenation levels. CONCLUSION Even though hypoxia could have significant prognostic and predictive value in the clinic, the best method for hypoxia assessment has in our opinion not been realised.
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Affiliation(s)
- Amarnath Challapalli
- Department of Clinical Oncology, Bristol Cancer Institute, Horfield Road, Bristol, United Kingdom
| | - Laurence Carroll
- Department of Surgery and Cancer, Imperial College, GN1, Commonwealth Building, Hammersmith Hospital, Du Cane Road, London, W120NN United Kingdom
| | - Eric O. Aboagye
- Department of Surgery and Cancer, Imperial College, GN1, Commonwealth Building, Hammersmith Hospital, Du Cane Road, London, W120NN United Kingdom
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Abstract
Clinical studies using Eppendorf needle sensors have invariably documented the resistance of hypoxic human tumors to therapy. These studies first documented the need for individual patient measurement of hypoxia, as hypoxia varied from tumor to tumor. Furthermore, hypoxia in sarcomas and cervical cancer leads to distant metastasis or local or regional spread, respectively. For various reasons, the field has moved away from direct needle sensor oxygen measurements to indirect assays (hypoxia-inducible factor-related changes and bioreductive metabolism) and the latter can be imaged noninvasively. Many of hypoxia's detrimental therapeutic effects are reversible in mice but little treatment improvement in hypoxic human tumors has been seen. The question is why? What factors cause human tumors to be refractory to antihypoxia strategies? We suggest the primary cause to be the complexity of hypoxia formation and its characteristics. Three basic types of hypoxia exist, encompassing various diffusional (distance from perfused vessel), temporal (on or off cycling), and perfusional (blood flow efficiency) limitations. Surprisingly, there is no current information on their relative prevalence in human tumors and even animal models. This is important because different hypoxia subtypes are predicted to require different diagnostic and therapeutic approaches, but the implications of this remain unknown. Even more challenging, no agreement exists for the best way to measure hypoxia. Some results even suggest that hypoxia is unlikely to be targetable therapeutically. In this review, the authors revisit various critical aspects of this field that are sometimes forgotten or misrepresented in the recent literature. As most current noninvasive imaging studies involve PET-isotope-labeled 2-nitroimidazoles, we emphasize key findings made in our studies using 2-(2-nitro-1H-imidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl)acetamide (EF5) and F-18-labeled EF5. These show the importance of differentiating hypoxia subtypes, optimizing drug pharmacology, ensuring drug and isotope stability, identifying key biochemical and physiological variables in tumors, and suggesting therapeutic strategies that are most likely to succeed.
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Affiliation(s)
- Cameron J Koch
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA.
| | - Sydney M Evans
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA
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12
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Ramogida CF, Pan J, Ferreira CL, Patrick BO, Rebullar K, Yapp DTT, Lin KS, Adam MJ, Orvig C. Nitroimidazole-Containing H2dedpa and H2CHXdedpa Derivatives as Potential PET Imaging Agents of Hypoxia with (68)Ga. Inorg Chem 2015; 54:4953-65. [PMID: 25928800 DOI: 10.1021/acs.inorgchem.5b00554] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
(68)Ga is an attractive radiometal for use in positron emission tomography (PET) imaging. The success of (68)Ga-based agents is dependent on a chelator that exhibits rapid radiometal incorporation, and strong kinetic inertness to prevent transchelation of (68)Ga in vivo. The linear chelating agents H2dedpa (1,2-[[6-carboxypyridin-2-yl]methylamino]ethane) and H2CHXdedpa (CHX = cyclohexyl/cyclohexane) (N4O2) have recently been developed that bind Ga(3+) quickly and under mild conditions, ideal properties to be incorporated into a (68)Ga PET imaging agent. Herein, nitroimidazole (NI) derivatives of H2dedpa and H2CHXdedpa to investigate specific targeting of hypoxic tumor cells are investigated, given that NI can be reduced and retained exclusively in hypoxic cells. Nine N,N'-bis-alkylated derivatives of H2dedpa and H2CHXdedpa have been synthesized; they have been screened for their ability to bind gallium, and cyclic voltammetry of nonradioactive complexes was performed to probe the redox cycling mechanism of NI. The compounds were radiolabeled with (67)Ga and (68)Ga and show promising radiolabeling efficiencies (>99%) when labeled at 10(-5) M for 10 min at room temperature. Moreover, stability studies (via apo-transferrin challenge, 37 °C) show that the (67)Ga complexes exhibit exceptional stability (86-99% intact) after 2 h. In vitro uptake studies under hypoxic (0.5% O2) and normoxic (21% O2) conditions in three cancerous cell lines [HT-29 (colon), LCC6(HER-2) (breast), and CHO (Chinese hamster ovarian)] were performed. Of the four H2dedpa or H2CHXdedpa NI derivatives tested, all showed preferential uptake in hypoxic cells compared to normoxic cells with hypoxic/normoxic ratios as high as 7.9 ± 2.7 after 120 min. The results suggest that these novel bis-alkylated NI-containing H2dedpa and H2CHXdedpa ligands would be ideal candidates for further testing in vivo for PET imaging of hypoxia with (68)Ga.
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Affiliation(s)
- Caterina F Ramogida
- †Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada.,‡TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - Jinhe Pan
- §BC Cancer Agency, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Cara L Ferreira
- ∥Nordion, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - Brian O Patrick
- †Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Karla Rebullar
- †Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Donald T T Yapp
- §BC Cancer Agency, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Kuo-Shyan Lin
- §BC Cancer Agency, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Michael J Adam
- ‡TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - Chris Orvig
- †Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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13
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Koch CJ, Evans SM. Pharmacokinetic and pharmacodynamic modifiers of EF5 uptake and binding. J Nucl Med 2015; 56:653. [PMID: 25745093 DOI: 10.2967/jnumed.114.151662] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Cameron J Koch
- University of Pennsylvania Medical Center 195 John Morgan Building Philadelphia, PA 19104 E-mail:
| | - Sydney M Evans
- University of Pennsylvania Medical Center 195 John Morgan Building Philadelphia, PA 19104 E-mail:
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14
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Chitneni SK, Bida GT, Zalutsky MR, Dewhirst MW. Reply: Pharmacokinetic and Pharmacodynamic Modifiers of EF5 Uptake and Binding. J Nucl Med 2015; 56:653-4. [PMID: 25745087 DOI: 10.2967/jnumed.115.154054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
| | - Gerald T Bida
- Duke University Medical Center Box 3808Durham, NC 27710 E-mail:
| | | | - Mark W Dewhirst
- Duke University Medical Center Box 3808Durham, NC 27710 E-mail:
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Carlin S, Humm J. Hypoxia imaging. Guest editorial. Semin Nucl Med 2015; 45:98-100. [PMID: 25704382 DOI: 10.1053/j.semnuclmed.2014.10.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - John Humm
- Department of Radiology; Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY
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Abstract
In view of the trend towards personalized treatment strategies for (cancer) patients, there is an increasing need to noninvasively determine individual patient characteristics. Such information enables physicians to administer to patients accurate therapy with appropriate timing. For the noninvasive visualization of disease-related features, imaging biomarkers are expected to play a crucial role. Next to the chemical development of imaging probes, this requires preclinical studies in animal tumour models. These studies provide proof-of-concept of imaging biomarkers and help determine the pharmacokinetics and target specificity of relevant imaging probes, features that provide the fundamentals for translation to the clinic. In this review we describe biological processes derived from the “hallmarks of cancer” that may serve as imaging biomarkers for diagnostic, prognostic and treatment response monitoring that are currently being studied in the preclinical setting. A number of these biomarkers are also being used for the initial preclinical assessment of new intervention strategies. Uniquely, noninvasive imaging approaches allow longitudinal assessment of changes in biological processes, providing information on the safety, pharmacokinetic profiles and target specificity of new drugs, and on the antitumour effectiveness of therapeutic interventions. Preclinical biomarker imaging can help guide translation to optimize clinical biomarker imaging and personalize (combination) therapies.
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