1
|
Wang X, Chen C, Yan J, Xu Y, Pan D, Wang L, Yang M. Druggability of Targets for Diagnostic Radiopharmaceuticals. ACS Pharmacol Transl Sci 2023; 6:1107-1119. [PMID: 37588760 PMCID: PMC10425999 DOI: 10.1021/acsptsci.3c00081] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Indexed: 08/18/2023]
Abstract
Targets play an indispensable and pivotal role in the development of radiopharmaceuticals. However, the initial stages of drug discovery projects are often plagued by frequent failures due to inadequate information on druggability and suboptimal target selection. In this context, we aim to present a comprehensive review of the factors that influence target druggability for diagnostic radiopharmaceuticals. Specifically, we explore the crucial determinants of target specificity, abundance, localization, and positivity rate and their respective implications. Through a detailed analysis of existing protein targets, we elucidate the significance of each factor. By carefully considering and balancing these factors during the selection of targets, more efficacious and targeted radiopharmaceuticals are expected to be designed for the diagnosis of a wide range of diseases in the future.
Collapse
Affiliation(s)
- Xinyu Wang
- NHC
Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular
Nuclear Medicine, Jiangsu Institute of Nuclear
Medicine, Wuxi 214063, PR China
- School
of Pharmacy, Nanjing Medical University, Nanjing 211166, PR China
| | - Chongyang Chen
- NHC
Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular
Nuclear Medicine, Jiangsu Institute of Nuclear
Medicine, Wuxi 214063, PR China
| | - Junjie Yan
- NHC
Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular
Nuclear Medicine, Jiangsu Institute of Nuclear
Medicine, Wuxi 214063, PR China
- School
of Pharmacy, Nanjing Medical University, Nanjing 211166, PR China
| | - Yuping Xu
- NHC
Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular
Nuclear Medicine, Jiangsu Institute of Nuclear
Medicine, Wuxi 214063, PR China
- School
of Pharmacy, Nanjing Medical University, Nanjing 211166, PR China
| | - Donghui Pan
- NHC
Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular
Nuclear Medicine, Jiangsu Institute of Nuclear
Medicine, Wuxi 214063, PR China
| | - Lizhen Wang
- NHC
Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular
Nuclear Medicine, Jiangsu Institute of Nuclear
Medicine, Wuxi 214063, PR China
| | - Min Yang
- NHC
Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular
Nuclear Medicine, Jiangsu Institute of Nuclear
Medicine, Wuxi 214063, PR China
- School
of Pharmacy, Nanjing Medical University, Nanjing 211166, PR China
| |
Collapse
|
2
|
Lian Y, Zeng S, Wen S, Zhao X, Fang C, Zeng N. Review and Application of Integrin Alpha v Beta 6 in the Diagnosis and Treatment of Cholangiocarcinoma and Pancreatic Ductal Adenocarcinoma. Technol Cancer Res Treat 2023; 22:15330338231189399. [PMID: 37525872 PMCID: PMC10395192 DOI: 10.1177/15330338231189399] [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: 02/14/2023] [Revised: 06/13/2023] [Accepted: 06/28/2023] [Indexed: 08/02/2023] Open
Abstract
Integrin Alpha v Beta 6 is expressed primarily in solid epithelial tumors, such as cholangiocarcinoma, pancreatic cancer, and colorectal cancer. It has been considered a potential and promising molecular marker for the early diagnosis and treatment of cancer. Cholangiocarcinoma and pancreatic ductal adenocarcinoma share genetic, histological, and pathophysiological similarities due to the shared embryonic origin of the bile duct and pancreas. These cancers share numerous clinicopathological characteristics, including growth pattern, poor response to conventional radiotherapy and chemotherapy, and poor prognosis. This review focuses on the role of integrin Alpha v Beta 6 in cancer progression. It addition, it reviews how the marker can be used in molecular imaging and therapeutic targets. We propose further research explorations and questions that need to be addressed. We conclude that integrin Alpha v Beta 6 may serve as a potential biomarker for cancer disease progression and prognosis.
Collapse
Affiliation(s)
- Yunyu Lian
- Zhujiang Hospital, The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
- First Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Silue Zeng
- First Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, China
- Guangdong Provincial Clinical and Engineering Technology Center of Digital Medicine, Guangzhou, China
| | - Sai Wen
- First Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, China
- Guangdong Provincial Clinical and Engineering Technology Center of Digital Medicine, Guangzhou, China
| | - Xingyang Zhao
- First Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, China
- Guangdong Provincial Clinical and Engineering Technology Center of Digital Medicine, Guangzhou, China
| | - Chihua Fang
- Zhujiang Hospital, The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
- First Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, China
- Guangdong Provincial Clinical and Engineering Technology Center of Digital Medicine, Guangzhou, China
| | - Ning Zeng
- Zhujiang Hospital, The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
- First Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, China
- Guangdong Provincial Clinical and Engineering Technology Center of Digital Medicine, Guangzhou, China
| |
Collapse
|
3
|
Ren J, Zhu S, Zhang G, Tan X, Qiu L, Lin J, Jiang L. 68Ga-Labeled Cystine Knot Peptide Targeting Integrin α vβ 6 for Lung Cancer PET Imaging. Mol Pharm 2022; 19:2620-2628. [PMID: 35674464 DOI: 10.1021/acs.molpharmaceut.2c00313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Integrin αvβ6 has been considered as a promising biomarker for lung cancer, and its expression is often related to poor prognosis. An αvβ6-binding cystine knot peptide R01-MG was previously engineered and validated. Here, we developed a positron emission tomography (PET) probe of R01-MG for imaging αvβ6-positive lung cancer. Cystine knot peptide R01-MG was synthesized through solid-phase peptide synthesis chemistry and radiolabeled with 68Ga after being conjugated with 1,4,7,10-tetraazacyclododecane-N,N',N″,N‴-tetraacetic acid (DOTA). The stability of 68Ga-DOTA-R01-MG was analyzed in phosphate-buffered saline (PBS) (pH 7.4) and fetal bovine serum (FBS). The cell uptake assay of the probe was evaluated using αvβ6-positive (A549 and H1975) and αvβ6-negative (H1299) lung cancer cell lines. In addition, small animal PET imaging and biodistribution studies of 68Ga-DOTA-R01-MG were performed in αvβ6-positive and αvβ6-negative lung cancer models. Our study showed that 68Ga-DOTA-R01-MG exhibited excellent stability in PBS and FBS. Small animal PET imaging and biodistribution data revealed that 68Ga-DOTA-R01-MG displayed rapid and good tumor uptake in animal models with αvβ6-positive lung cancer, and the probe was rapidly cleared from the normal tissues, resulting in good tumor-to-normal tissue contrasts. Meanwhile, no obvious tumor uptake of 68Ga-DOTA-R01-MG was observed in animal models with αvβ6-negative lung cancer, demonstrating specific binding of the probe to integrin αvβ6. In conclusion, 68Ga-DOTA-R01-MG has great potential to be a promising PET tracer for imaging αvβ6-positive lung cancer.
Collapse
Affiliation(s)
- Jingyun Ren
- PET Center, Department of Nuclear Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China
| | - Shiyu Zhu
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China.,Department of Radiopharmaceuticals, School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Guojin Zhang
- PET Center, Department of Nuclear Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China
| | - Xiaoyue Tan
- PET Center, Department of Nuclear Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China
| | - Ling Qiu
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China.,Department of Radiopharmaceuticals, School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Jianguo Lin
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, China.,Department of Radiopharmaceuticals, School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Lei Jiang
- PET Center, Department of Nuclear Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China.,Guangdong Provincial Key Laboratory of Artificial Intelligence in Medical Image Analysis and Application, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China
| |
Collapse
|
4
|
|
5
|
Kossatz S, Beer AJ, Notni J. It's Time to Shift the Paradigm: Translation and Clinical Application of Non-αvβ3 Integrin Targeting Radiopharmaceuticals. Cancers (Basel) 2021; 13:cancers13235958. [PMID: 34885066 PMCID: PMC8657165 DOI: 10.3390/cancers13235958] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/16/2021] [Accepted: 11/17/2021] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Cancer cells often present a different set of proteins on their surface than normal cells. This also applies to integrins, a class of 24 cell surface receptors which mainly are responsible for physically anchoring cells in tissues, but also fulfil a plethora of other functions. If a certain integrin is found on tumor cells but not on normal ones, radioactive molecules (named tracers) that specifically bind to this integrin will accumulate in the cancer lesion if injected into the blood stream. The emitted radiation can be detected from outside the body and allows for localization and thus, diagnosis, of cancer. Only one of the 24 integrins, the subtype αvβ3, has hitherto been thoroughly investigated in this context. We herein summarize the most recent, pertinent research on other integrins, and argue that some of these approaches might ultimately improve the clinical management of the most lethal cancers, such as pancreatic carcinoma. Abstract For almost the entire period of the last two decades, translational research in the area of integrin-targeting radiopharmaceuticals was strongly focused on the subtype αvβ3, owing to its expression on endothelial cells and its well-established role as a biomarker for, and promoter of, angiogenesis. Despite a large number of translated tracers and clinical studies, a clinical value of αvβ3-integrin imaging could not be defined yet. The focus of research has, thus, been moving slowly but steadily towards other integrin subtypes which are involved in a large variety of tumorigenic pathways. Peptidic and non-peptidic radioligands for the integrins α5β1, αvβ6, αvβ8, α6β1, α6β4, α3β1, α4β1, and αMβ2 were first synthesized and characterized preclinically. Some of these compounds, targeting the subtypes αvβ6, αvβ8, and α6β1/β4, were subsequently translated into humans during the last few years. αvβ6-Integrin has arguably attracted most attention because it is expressed by some of the cancers with the worst prognosis (above all, pancreatic ductal adenocarcinoma), which substantiates a clinical need for the respective theranostic agents. The receptor furthermore represents a biomarker for malignancy and invasiveness of carcinomas, as well as for fibrotic diseases, such as idiopathic pulmonary fibrosis (IPF), and probably even for Sars-CoV-2 (COVID-19) related syndromes. Accordingly, the largest number of recent first-in-human applications has been reported for radiolabeled compounds targeting αvβ6-integrin. The results indicate a substantial clinical value, which might lead to a paradigm change and trigger the replacement of αvβ3 by αvβ6 as the most popular integrin in theranostics.
Collapse
Affiliation(s)
- Susanne Kossatz
- Department of Nuclear Medicine, School of Medicine, Technical University of Munich, 81675 Munich, Germany;
- Central Institute for Translational Cancer Research (TranslaTUM), School of Medicine, Technical University of Munich, 81675 Munich, Germany
| | | | - Johannes Notni
- Department of Pathology, School of Medicine, Technical University of Munich, 81675 Munich, Germany
- TRIMT GmbH, 01454 Radeberg, Germany
- Correspondence: ; Tel.: +49-89-4140-6075; Fax: +49-89-4140-6949
| |
Collapse
|
6
|
Zhao H, Gao H, Luo C, Yang G, Zhao X, Gao S, Ma Q, Jia B, Shi J, Wang F. An Integrin-α vβ 6/α 5β 1-Bitargeted Probe for the SPECT Imaging of Pancreatic Adenocarcinoma in Preclinical and Primary Clinical Studies. Bioconjug Chem 2021; 32:1298-1305. [PMID: 34137602 DOI: 10.1021/acs.bioconjchem.1c00296] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pancreatic adenocarcinoma (PA) is one of the deadliest human malignancies. However, early detection, prediction of surgical resectability, and prognosis of PA are challenging with current conventional imaging technologies in the clinic. Molecular imaging technologies combined with novel imaging probes could be useful for early detection and accurate staging of PA. Integrin αvβ6 and α5β1 are found to be overexpressed in PA. In this study, integrin αvβ6/α5β1-bitargeted probes 99mTc-HYNIC-isoDGR (99mTc-isoDGR) and 99mTc-HYNIC-PEG4-PisoDGR2 (99mTc-3PisoDGR2) were prepared and evaluated in the BxPC-3 human pancreatic tumor model. Both subcutaneous and in situ BxPC-3 tumors could be clearly visualized by 99mTc-isoDGR nanoScan SPECT/CT imaging with a high ratio of tumor to background. The blocking study with excess nonradioactive peptide showed a significantly reduced tumor uptake, which confirmed the specificity of 99mTc-isoDGR. Biodistribution results confirmed the imaging results. The dimer tracer 99mTc-3PisoDGR2 significantly enhanced tumor uptake compared with 99mTc-isoDGR, and the spontaneous PA lesion in the mouse model could be clearly visualized by 99mTc-3PisoDGR2. The primary clinical study also verified the ability of 99mTc-3PisoDGR2 for detection of PA. Therefore, SPECT/CT imaging using the integrin αvβ6/α5β1-bitargeted 99mTc-3PisoDGR2 provided a potential approach for the noninvasive detection of PA.
Collapse
Affiliation(s)
- Haitao Zhao
- Medical Isotopes Research Center and Department of Radiation Medicine, School of Basic Medical Sciences, Peking University, Beijing 100191, China.,Department of Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Hannan Gao
- Medical Isotopes Research Center and Department of Radiation Medicine, School of Basic Medical Sciences, Peking University, Beijing 100191, China
| | - Chuangwei Luo
- Medical Isotopes Research Center and Department of Radiation Medicine, School of Basic Medical Sciences, Peking University, Beijing 100191, China
| | - Guangjie Yang
- Medical Isotopes Research Center and Department of Radiation Medicine, School of Basic Medical Sciences, Peking University, Beijing 100191, China
| | - Xiaoyu Zhao
- Medical Isotopes Research Center and Department of Radiation Medicine, School of Basic Medical Sciences, Peking University, Beijing 100191, China
| | - Shi Gao
- Department of Nuclear Medicine, China-Japan Union Hospital, Jilin University, Changchun, Jilin 130033, China.,NHC Key Laboratory of Radiobiology, School of Public Health of Jilin University, Changchun, Jilin 130021, China
| | - Qingjie Ma
- Department of Nuclear Medicine, China-Japan Union Hospital, Jilin University, Changchun, Jilin 130033, China.,NHC Key Laboratory of Radiobiology, School of Public Health of Jilin University, Changchun, Jilin 130021, China
| | - Bing Jia
- Medical Isotopes Research Center and Department of Radiation Medicine, School of Basic Medical Sciences, Peking University, Beijing 100191, China
| | - Jiyun Shi
- Key Laboratory of Protein and Peptide Pharmaceuticals, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Fan Wang
- Medical Isotopes Research Center and Department of Radiation Medicine, School of Basic Medical Sciences, Peking University, Beijing 100191, China.,Key Laboratory of Protein and Peptide Pharmaceuticals, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| |
Collapse
|
7
|
Sachindra S, Hellberg T, Exner S, Prasad S, Beindorff N, Rogalla S, Kimura R, Gambhir SS, Wiedenmann B, Grötzinger C. SPECT/CT Imaging, Biodistribution and Radiation Dosimetry of a 177Lu-DOTA-Integrin αvβ6 Cystine Knot Peptide in a Pancreatic Cancer Xenograft Model. Front Oncol 2021; 11:684713. [PMID: 34136410 PMCID: PMC8200818 DOI: 10.3389/fonc.2021.684713] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 05/10/2021] [Indexed: 01/02/2023] Open
Abstract
INTRODUCTION Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignant neoplasms, as many cases go undetected until they reach an advanced stage. Integrin αvβ6 is a cell surface receptor overexpressed in PDAC. Consequently, it may serve as a target for the development of probes for imaging diagnosis and radioligand therapy. Engineered cystine knottin peptides specific for integrin αvβ6 have recently been developed showing high affinity and stability. This study aimed to evaluate an integrin αvβ6-specific knottin molecular probe containing the therapeutic radionuclide 177Lu for targeting of PDAC. METHODS The expression of integrin αvβ6 in PDAC cell lines BxPC-3 and Capan-2 was analyzed using RT-qPCR and immunofluorescence. In vitro competition and saturation radioligand binding assays were performed to calculate the binding affinity of the DOTA-coupled tracer loaded with and without lutetium to BxPC-3 and Capan-2 cell lines as well as the maximum number of binding sites in these cell lines. To evaluate tracer accumulation in the tumor and organs, SPECT/CT, biodistribution and dosimetry projections were carried out using a Capan-2 xenograft tumor mouse model. RESULTS RT-qPCR and immunofluorescence results showed high expression of integrin αvβ6 in BxPC-3 and Capan-2 cells. A competition binding assay revealed high affinity of the tracer with IC50 values of 1.69 nM and 9.46 nM for BxPC-3 and Capan-2, respectively. SPECT/CT and biodistribution analysis of the conjugate 177Lu-DOTA-integrin αvβ6 knottin demonstrated accumulation in Capan-2 xenograft tumors (3.13 ± 0.63%IA/g at day 1 post injection) with kidney uptake at 19.2 ± 2.5 %IA/g, declining much more rapidly than in tumors. CONCLUSION 177Lu-DOTA-integrin αvβ6 knottin was found to be a high-affinity tracer for PDAC tumors with considerable tumor accumulation and moderate, rapidly declining kidney uptake. These promising results warrant a preclinical treatment study to establish therapeutic efficacy.
Collapse
Affiliation(s)
- Sachindra Sachindra
- Department of Hepatology and Gastroenterology, Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Teresa Hellberg
- Department of Hepatology and Gastroenterology, Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Samantha Exner
- Department of Hepatology and Gastroenterology, Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Sonal Prasad
- Berlin Experimental Radionuclide Imaging Center (BERIC), Charité – Universitätsmedizin Berlin, Berlin, Germany
- Department of Nuclear Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Nicola Beindorff
- Berlin Experimental Radionuclide Imaging Center (BERIC), Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Stephan Rogalla
- Department of Radiology, Molecular Imaging Program at Stanford, Canary Center for Cancer Early Detection, Stanford University, Stanford, CA, United States
| | - Richard Kimura
- Department of Radiology, Molecular Imaging Program at Stanford, Canary Center for Cancer Early Detection, Stanford University, Stanford, CA, United States
| | - Sanjiv Sam Gambhir
- Department of Radiology, Molecular Imaging Program at Stanford, Canary Center for Cancer Early Detection, Stanford University, Stanford, CA, United States
| | - Bertram Wiedenmann
- Department of Hepatology and Gastroenterology, Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Carsten Grötzinger
- Department of Hepatology and Gastroenterology, Charité – Universitätsmedizin Berlin, Berlin, Germany
- Molecular Cancer Research Center (MKFZ), Charité – Universitätsmedizin Berlin, Berlin, Germany
- German Cancer Consortium (DKTK), Berlin, Germany
- German Cancer Research Center (DKFZ), Heidelberg, Germany
| |
Collapse
|
8
|
Ligand engineering for theranostic applications. Curr Opin Chem Biol 2021; 63:145-151. [PMID: 34004409 DOI: 10.1016/j.cbpa.2021.04.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 03/19/2021] [Accepted: 04/12/2021] [Indexed: 11/21/2022]
Abstract
Targeted therapy of cancer is considered as promising alternative approach to conventional chemotherapy and radiotherapy. Recent advancements in biotechnology have significantly improved the identification of novel radiopharmaceuticals allowing for more accurate imaging and therapeutic targeting of epithelial tumors. The successful development of radiotracers critically depends on the selection and validation of the tumor-specific target structure, the technical approach employed for the identification of a target-specific ligand, and the evaluation and improvement of the binding properties and the pharmacokinetic profile of the ligand by biotechnological procedures or chemical modification, respectively. Employing rational design of a quinoline-based fibroblast activation protein inhibitor (FAPI) and 'high-through put' display technology using a sunflower trypsin inhibitor1-based peptide library, several FAPI derivatives and a novel αvβ6 integrin-binding peptide (SFITGv6) were identified. FAPI and SFITGv6 represent powerful radiopharmaceuticals for diagnostic imaging and/or endoradiotherapy of FAP- and αvβ6 integrin-expressing epithelial tumors, respectively.
Collapse
|
9
|
Ludwig BS, Kessler H, Kossatz S, Reuning U. RGD-Binding Integrins Revisited: How Recently Discovered Functions and Novel Synthetic Ligands (Re-)Shape an Ever-Evolving Field. Cancers (Basel) 2021; 13:1711. [PMID: 33916607 PMCID: PMC8038522 DOI: 10.3390/cancers13071711] [Citation(s) in RCA: 92] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/22/2021] [Accepted: 03/29/2021] [Indexed: 12/19/2022] Open
Abstract
Integrins have been extensively investigated as therapeutic targets over the last decades, which has been inspired by their multiple functions in cancer progression, metastasis, and angiogenesis as well as a continuously expanding number of other diseases, e.g., sepsis, fibrosis, and viral infections, possibly also Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2). Although integrin-targeted (cancer) therapy trials did not meet the high expectations yet, integrins are still valid and promising targets due to their elevated expression and surface accessibility on diseased cells. Thus, for the future successful clinical translation of integrin-targeted compounds, revisited and innovative treatment strategies have to be explored based on accumulated knowledge of integrin biology. For this, refined approaches are demanded aiming at alternative and improved preclinical models, optimized selectivity and pharmacological properties of integrin ligands, as well as more sophisticated treatment protocols considering dose fine-tuning of compounds. Moreover, integrin ligands exert high accuracy in disease monitoring as diagnostic molecular imaging tools, enabling patient selection for individualized integrin-targeted therapy. The present review comprehensively analyzes the state-of-the-art knowledge on the roles of RGD-binding integrin subtypes in cancer and non-cancerous diseases and outlines the latest achievements in the design and development of synthetic ligands and their application in biomedical, translational, and molecular imaging approaches. Indeed, substantial progress has already been made, including advanced ligand designs, numerous elaborated pre-clinical and first-in-human studies, while the discovery of novel applications for integrin ligands remains to be explored.
Collapse
Affiliation(s)
- Beatrice S. Ludwig
- Department of Nuclear Medicine, University Hospital Klinikum Rechts der Isar and Central Institute for Translational Cancer Research (TranslaTUM), Technical University Munich, 81675 Munich, Germany;
| | - Horst Kessler
- Department of Chemistry, Institute for Advanced Study, Technical University Munich, 85748 Garching, Germany;
| | - Susanne Kossatz
- Department of Nuclear Medicine, University Hospital Klinikum Rechts der Isar and Central Institute for Translational Cancer Research (TranslaTUM), Technical University Munich, 81675 Munich, Germany;
- Department of Chemistry, Institute for Advanced Study, Technical University Munich, 85748 Garching, Germany;
| | - Ute Reuning
- Clinical Research Unit, Department of Obstetrics and Gynecology, University Hospital Klinikum Rechts der Isar, Technical University Munich, 81675 Munich, Germany
| |
Collapse
|
10
|
Urquiza M, Guevara V, Diaz-Sana E, Mora F. The Role of αvβ6 Integrin Binding Molecules in the Diagnosis and Treatment of Cancer. CURR ORG CHEM 2020. [DOI: 10.2174/1385272824999200528124936] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Peptidic and non-peptidic αvβ6 integrin-binding molecules have been used in
the clinic for detection and treatment of tumors expressing αvβ6 integrin, because this protein
is expressed in malignant epithelial cells of the oral cavity, pancreas, breast, ovary,
colon and stomach carcinomas but it is not expressed in healthy adult tissue except during
wound healing and inflammation. This review focuses on the landscape of αvβ6 integrinbinding
molecules and their use in cancer treatment and detection, and discusses recent
designs for tumor detection, treatment, and immunotherapy. In the last ten years, several
reviews abamp;#945;vβ6 integrin-binding molecules and their role in cancer detection and treatment.
Firstly, this review describes the role of the αvβ6 integrin in normal tissues, how the expression
of this protein is correlated with cancer severity and its role in cancer development. Taking into account
the potential of αvβ6 integrin-binding molecules in detection and treatment of specific tumors, special
attention is given to several high-affinity αvβ6 integrin-binding peptides used for tumor imaging; particularly,
the αvβ6-binding peptide NAVPNLRGDLQVLAQKVART [A20FMDV2], derived from the foot and mouth
disease virus. This peptide labeled with either 18F, 111In or with 68Ga has been used for PET imaging of αvβ6
integrin-positive tumors. Moreover, αvβ6 integrin-binding peptides have been used for photoacoustic and fluorescence
imaging and could potentially be used in clinical application in cancer diagnosis and intraoperative
imaging of αvβ6-integrin positive tumors. Additionally, non-peptidic αvβ6-binding molecules have been designed
and used in the clinic for the detection and treatment of αvβ6-expressing tumors. Anti-αvβ6 integrin antibodies
are another useful tool for selective identification and treatment of αvβ6 (+) tumors. The utility of
these αvβ6 integrin-binding molecules as a tool for tumor detection and treatment is discussed, considering
specificity, sensitivity and serum stability. Another use of the αvβ6 integrin-binding peptides is to modify the
Ad5 cell tropism for inducing oncolytic activity of αvβ6-integrin positive tumor cells by expressing
A20FMDV2 peptide within the fiber knob protein (Ad5NULL-A20). The newly designed oncolytic
Ad5NULL-A20 virotherapy is promising for local and systemic targeting of αvβ6-overexpressing cancers. Finally,
new evidence has emerged, indicating that chimeric antigen receptor (CAR) containing the αvβ6 integrin-
binding peptide on top of CD28+CD3 endodomain displays a potent therapeutic activity in a diverse
repertoire of solid tumor models.
Collapse
Affiliation(s)
- Mauricio Urquiza
- Grupo de Investigacion en Hormonas (GIH), Department of Chemistry, National University of Columbia, Cra 30 # 45-03, Bogota, zip code 111321, Colombia
| | - Valentina Guevara
- Grupo de Investigacion en Hormonas (GIH), Department of Chemistry, National University of Columbia, Cra 30 # 45-03, Bogota, zip code 111321, Colombia
| | - Erika Diaz-Sana
- Grupo de Investigacion en Hormonas (GIH), Department of Chemistry, National University of Columbia, Cra 30 # 45-03, Bogota, zip code 111321, Colombia
| | - Felipe Mora
- Grupo de Investigacion en Hormonas (GIH), Department of Chemistry, National University of Columbia, Cra 30 # 45-03, Bogota, zip code 111321, Colombia
| |
Collapse
|
11
|
Timmer FEF, Geboers B, Ruarus AH, Schouten EAC, Nieuwenhuizen S, Puijk RS, de Vries JJJ, Meijerink MR, Scheffer HJ. Irreversible Electroporation for Locally Advanced Pancreatic Cancer. Tech Vasc Interv Radiol 2020; 23:100675. [PMID: 32591191 DOI: 10.1016/j.tvir.2020.100675] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Several minimally invasive image guided tumor ablation techniques have been added to the treatment spectrum for locally advanced pancreatic cancer (LAPC). Irreversible electroporation (IRE) might have a significant additive value in the management of this difficult-to-treat disease. As opposed to thermal ablative techniques, IRE induces cell death by the delivery of high-voltage electrical pulses. The electrical energy disrupts the cellular membrane integrity, causes loss of cellular homeostasis and ultimately results in cell death. The extracellular matrix of connective tissue in surrounding delicate structures such as bile ducts, bowel wall, and larger blood vessels is spared. The preservation of these structures makes IRE attractive for the treatment of pancreatic cancers that are unresectable due to their anatomical location (ie, LAPC and local recurrence after surgical resection). In addition to its cytoreductive abilities, evidence is emerging on IRE's capability to induce systemic immunomodulation through active in vivo vaccination against pancreatic cancer cells. These effects in combination with immunotherapy may offer a new treatment paradigm for tumors with low immunogenic potential like pancreatic ductal adenocarcinoma (PDAC). This review discusses several practical and technical issues of IRE for LAPC: clinical evaluation, indications, patient preparations, procedural steps, imaging characteristics, clinical results, and "tricks of the trade" used to improve the safety and efficacy of the treatment. Future directions such as the combination of IRE with immunotherapy will be shortly addressed.
Collapse
Affiliation(s)
- Florentine E F Timmer
- Department of Radiology and Nuclear Medicine at the Amsterdam University Medical Center, Vrije Universiteit-Cancer Center Amsterdam in Amsterdam, The Netherlands
| | - Bart Geboers
- Department of Radiology and Nuclear Medicine at the Amsterdam University Medical Center, Vrije Universiteit-Cancer Center Amsterdam in Amsterdam, The Netherlands.
| | - Alette H Ruarus
- Department of Radiology and Nuclear Medicine at the Amsterdam University Medical Center, Vrije Universiteit-Cancer Center Amsterdam in Amsterdam, The Netherlands
| | - Evelien A C Schouten
- Department of Radiology and Nuclear Medicine at the Amsterdam University Medical Center, Vrije Universiteit-Cancer Center Amsterdam in Amsterdam, The Netherlands
| | - Sanne Nieuwenhuizen
- Department of Radiology and Nuclear Medicine at the Amsterdam University Medical Center, Vrije Universiteit-Cancer Center Amsterdam in Amsterdam, The Netherlands
| | - Robbert S Puijk
- Department of Radiology and Nuclear Medicine at the Amsterdam University Medical Center, Vrije Universiteit-Cancer Center Amsterdam in Amsterdam, The Netherlands
| | - Jan J J de Vries
- Department of Radiology and Nuclear Medicine at the Amsterdam University Medical Center, Vrije Universiteit-Cancer Center Amsterdam in Amsterdam, The Netherlands
| | - Martijn R Meijerink
- Department of Radiology and Nuclear Medicine at the Amsterdam University Medical Center, Vrije Universiteit-Cancer Center Amsterdam in Amsterdam, The Netherlands
| | - Hester J Scheffer
- Department of Radiology and Nuclear Medicine at the Amsterdam University Medical Center, Vrije Universiteit-Cancer Center Amsterdam in Amsterdam, The Netherlands
| |
Collapse
|
12
|
Lukey PT, Coello C, Gunn R, Parker C, Wilson FJ, Saleem A, Garman N, Costa M, Kendrick S, Onega M, Kang'ombe AR, Listanco A, Davies J, Ramada-Magalhaes J, Moz S, Fahy WA, Maher TM, Jenkins G, Passchier J, Marshall RP. Clinical quantification of the integrin αvβ6 by [ 18F]FB-A20FMDV2 positron emission tomography in healthy and fibrotic human lung (PETAL Study). Eur J Nucl Med Mol Imaging 2020; 47:967-979. [PMID: 31814068 PMCID: PMC7075837 DOI: 10.1007/s00259-019-04586-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 10/16/2019] [Indexed: 12/18/2022]
Abstract
PURPOSE The RGD-integrin, αvβ6, plays a role in the pathogenesis of pulmonary fibrosis through activation of transforming growth factor beta (TGFβ). This study sought to quantify expression of αvβ6 in the lungs of healthy humans and subjects with pulmonary fibrosis using the αvβ6-selective [18F]FB-A20FMDV2 PET ligand. METHODS [18F]FB-A20FMDV2 PET/CT scans were performed in healthy subjects and those with fibrotic lung disease. Standard uptake values (SUV) and volume of distribution (VT) were used to quantify αvβ6 expression. In subjects with fibrotic lung disease, qualitative assessment of the relationship between αvβ6 expression and the distribution of fibrosis on high resolution computed tomography was conducted. RESULTS A total of 15 participants (6 healthy, 7 with idiopathic pulmonary fibrosis (IPF) and 2 with connective tissue disease (CTD) associated PF) were enrolled. VT and SUV of [18F]FB-A20FMDV2 were increased in the lungs of subjects with pulmonary fibrosis (PF) compared with healthy subjects. Geometric mean VT (95% CI) was 0.88 (0.60, 1.29) mL/cm3 for healthy subjects, and 1.40 (1.22, 1.61) mL/cm3 for subjects with IPF; and SUV was 0.54 (0.36, 0.81) g/mL for healthy subjects and 1.03 (0.86, 1.22) g/mL for subjects with IPF. The IPF/healthy VT ratio (geometric mean, (95% CI of ratio)) was 1.59 (1.09, 2.32) (probability ratio > 1 = 0.988)) and the SUV ratio was 1.91 (1.27, 2.87) (probability ratio > 1 = 0.996). Increased uptake of [18F]FB-A20FMDV2 in PF was predominantly confined to fibrotic areas. [18F]FB-A20FMDV2 measurements were reproducible at an interval of 2 weeks. [18F]FB-A20FMDV2 was safe and well tolerated. CONCLUSIONS Lung uptake of [18F]FB-A20FMDV2, a measure of expression of the integrin αvβ6, was markedly increased in subjects with PF compared with healthy subjects.
Collapse
Affiliation(s)
- Pauline T Lukey
- GlaxoSmithKline Research and Development, Brentford, UK.
- Target to Treatment Consulting Ltd, Stevenage BioScience Catalyst, Stevenage, SG1 2FX, UK.
| | | | | | | | | | | | - Nadia Garman
- GlaxoSmithKline Research and Development, Brentford, UK
| | - Maria Costa
- GlaxoSmithKline Research and Development, Brentford, UK
| | | | | | | | | | | | | | | | | | - Toby M Maher
- NIHR Respiratory Clinical Research Facility, Royal Brompton Hospital, London, UK
- Fibrosis Research Group, National Heart and Lung Institute, Imperial College, London, UK
| | - Gisli Jenkins
- National Institute for Health Research, Nottingham Biomedical Research Centre, Nottingham University Hospitals, Nottingham, UK
| | | | | |
Collapse
|
13
|
Feng X, Wang Y, Lu D, Xu X, Zhou X, Zhang H, Zhang T, Zhu H, Yang Z, Wang F, Li N, Liu Z. Clinical Translation of a 68Ga-Labeled Integrin α vβ 6-Targeting Cyclic Radiotracer for PET Imaging of Pancreatic Cancer. J Nucl Med 2020; 61:1461-1467. [PMID: 32086242 DOI: 10.2967/jnumed.119.237347] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 02/10/2020] [Indexed: 12/16/2022] Open
Abstract
The overexpression of integrin αvβ6 in pancreatic cancer makes it a promising target for noninvasive PET imaging. However, currently, most integrin αvβ6-targeting radiotracers are based on linear peptides, which are quickly degraded in the serum by proteinases. Herein, we aimed to develop and assess a 68Ga-labeled integrin αvβ6-targeting cyclic peptide (68Ga-cycratide) for PET imaging of pancreatic cancer. Methods: 68Ga-cycratide was prepared, and its PET imaging profile was compared with that of the linear peptide (68Ga-linear-pep) in an integrin αvβ6-positive BxPC-3 human pancreatic cancer mouse model. Five healthy volunteers (2 women and 3 men) underwent whole-body PET/CT imaging after injection of 68Ga-cycratide, and biodistribution and dosimetry were calculated. PET/CT imaging of 2 patients was performed to investigate the potential role of 68Ga-cycratide in pancreatic cancer diagnosis and treatment monitoring. Results: 68Ga-cycratide exhibited significantly higher tumor uptake than did 68Ga-linear-pep in BxPC-3 tumor-bearing mice, owing-at least in part-to markedly improved in vivo stability. 68Ga-cycratide could sensitively detect the pancreatic cancer lesions in an orthotopic mouse model and was well tolerated in all healthy volunteers. Preliminary PET/CT imaging in patients with pancreatic cancer demonstrated that 68Ga-cycratide was comparable to 18F-FDG for diagnostic imaging and postsurgery tumor relapse monitoring. Conclusion: 68Ga-cycratide is an integrin αvβ6-specific PET radiotracer with favorable pharmacokinetics and a favorable dosimetry profile. 68Ga-cycratide is expected to provide an effective noninvasive PET strategy for pancreatic cancer lesion detection and therapy response monitoring.
Collapse
Affiliation(s)
- Xun Feng
- Medical Isotopes Research Center and Department of Radiation Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China; and
| | - Yanpu Wang
- Medical Isotopes Research Center and Department of Radiation Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China; and
| | - Dehua Lu
- Medical Isotopes Research Center and Department of Radiation Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China; and
| | - Xiaoxia Xu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Nuclear Medicine, Peking University Cancer Hospital and Institute, Beijing, China
| | - Xin Zhou
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Nuclear Medicine, Peking University Cancer Hospital and Institute, Beijing, China
| | - Huiyuan Zhang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Nuclear Medicine, Peking University Cancer Hospital and Institute, Beijing, China
| | - Ting Zhang
- Medical Isotopes Research Center and Department of Radiation Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China; and
| | - Hua Zhu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Nuclear Medicine, Peking University Cancer Hospital and Institute, Beijing, China
| | - Zhi Yang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Nuclear Medicine, Peking University Cancer Hospital and Institute, Beijing, China
| | - Fan Wang
- Medical Isotopes Research Center and Department of Radiation Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China; and
| | - Nan Li
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Nuclear Medicine, Peking University Cancer Hospital and Institute, Beijing, China
| | - Zhaofei Liu
- Medical Isotopes Research Center and Department of Radiation Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China; and
| |
Collapse
|
14
|
Onega M, Parker CA, Coello C, Rizzo G, Keat N, Ramada-Magalhaes J, Moz S, Tang SP, Plisson C, Wells L, Ashworth S, Slack RJ, Vitulli G, Wilson FJ, Gunn R, Lukey PT, Passchier J. Preclinical evaluation of [ 18F]FB-A20FMDV2 as a selective marker for measuring α Vβ 6 integrin occupancy using positron emission tomography in rodent lung. Eur J Nucl Med Mol Imaging 2020; 47:958-966. [PMID: 31897589 PMCID: PMC7075836 DOI: 10.1007/s00259-019-04653-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 12/09/2019] [Indexed: 11/18/2022]
Abstract
Purpose Integrin αvβ6 belongs to the RGD subset of the integrin family, and its expression levels are a prognostic and theranostic factor in some types of cancer and pulmonary fibrosis. This paper describes the GMP radiolabelling of the synthetic 20 amino acid peptide A20FMDV2 (NAVPNLRGDLQVLAQKVART), derived from the foot-and-mouth disease virus, and characterises the use of [18F]FB-A20FMDV2 as a high affinity, specific and selective PET radioligand for the quantitation and visualisation of αvβ6 in rodent lung to support human translational studies. Methods The synthesis of [18F]FB-A20FMDV2 was performed using a fully automated and GMP-compliant process. Sprague-Dawley rats were used to perform homologous (unlabelled FB-A20FMDV2) and heterologous (anti-αvβ6 antibody 8G6) blocking studies. In order to generate a dosimetry estimate, tissue residence times were generated, and associated tissue exposure and effective dose were calculated using the Organ Level Internal Dose Assessment/Exponential Modelling (OLINDA/EXM) software. Results [18F]FB-A20FMDV2 synthesis was accomplished in 180 min providing ~800 MBq of [18F]FB-A20FMDV2 with a molar activity of up to 150 GBq/μmol and high radiochemical purity (> 97%). Following i.v. administration to rats, [18F]FB-A20FMDV2 was rapidly metabolised with intact radiotracer representing 5% of the total radioactivity present in rat plasma at 30 min. For the homologous and heterologous block in rats, lung-to-heart SUV ratios at 30–60 min post-administration of [18F]FB-A20FMDV2 were reduced by 38.9 ± 6.9% and 56 ± 19.2% for homologous and heterologous block, respectively. Rodent biodistribution and dosimetry calculations using OLINDA/EXM provided a whole body effective dose in humans 33.5 μSv/MBq. Conclusion [18F]FB-A20FMDV2 represents a specific and selective PET ligand to measure drug-associated αvβ6 integrin occupancy in lung. The effective dose, extrapolated from rodent data, is in line with typical values for compounds labelled with fluorine-18 and combined with the novel fully automated and GMP-compliant synthesis and allows for clinical use in translational studies. Electronic supplementary material The online version of this article (10.1007/s00259-019-04653-5) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Mayca Onega
- Imanova Ltd trading as Invicro, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Christine A Parker
- GlaxoSmithKline, Medicines Research Centre, Gunnels Wood Road, Hertfordshire, SG1 2NY, UK
| | - Christopher Coello
- Imanova Ltd trading as Invicro, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Gaia Rizzo
- Imanova Ltd trading as Invicro, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Nicholas Keat
- Imanova Ltd trading as Invicro, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Joaquim Ramada-Magalhaes
- Imanova Ltd trading as Invicro, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Sara Moz
- Imanova Ltd trading as Invicro, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Sac-Pham Tang
- Imanova Ltd trading as Invicro, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Christophe Plisson
- Imanova Ltd trading as Invicro, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Lisa Wells
- Imanova Ltd trading as Invicro, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Sharon Ashworth
- Imanova Ltd trading as Invicro, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Robert J Slack
- GlaxoSmithKline, Medicines Research Centre, Gunnels Wood Road, Hertfordshire, SG1 2NY, UK
| | - Giovanni Vitulli
- GlaxoSmithKline, Medicines Research Centre, Gunnels Wood Road, Hertfordshire, SG1 2NY, UK
| | - Frederick J Wilson
- GlaxoSmithKline, Medicines Research Centre, Gunnels Wood Road, Hertfordshire, SG1 2NY, UK
| | - Roger Gunn
- Imanova Ltd trading as Invicro, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Pauline T Lukey
- GlaxoSmithKline, Medicines Research Centre, Gunnels Wood Road, Hertfordshire, SG1 2NY, UK
| | - Jan Passchier
- Imanova Ltd trading as Invicro, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK.
| |
Collapse
|
15
|
Davis RA, Drake C, Ippisch RC, Moore M, Sutcliffe JL. Fully automated peptide radiolabeling from [ 18F]fluoride. RSC Adv 2019; 9:8638-8649. [PMID: 35518701 PMCID: PMC9061836 DOI: 10.1039/c8ra10541c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Accepted: 02/26/2019] [Indexed: 11/21/2022] Open
Abstract
The biological properties of receptor-targeted peptides have made them popular diagnostic imaging and therapeutic agents. Typically, the synthesis of fluorine-18 radiolabeled receptor-targeted peptides for positron emission tomography (PET) imaging is a time consuming, complex, multi-step synthetic process that is highly variable based on the peptide. The complexity associated with the radiolabeling route and lack of robust automated protocols can hinder translation into the clinic. A fully automated batch production to radiolabel three peptides (YGGFL, cRGDyK, and Pyr-QKLGNQWAVGHLM) from fluorine-18 using the ELIXYS FLEX/CHEM® radiosynthesizer in a two-step process is described. First, the prosthetic group, 6-[18F]fluoronicotinyl-2,3,5,6-tetrafluorophenyl ester ([18F]FPy-TFP) was synthesized and subsequently attached to the peptide. The [18F]FPy-peptides were synthesized in 13-26% decay corrected yields from fluorine-18 with high molar activity 1-5 Ci μmol-1 and radiochemical purity of >99% in an overall synthesis time of 97 ± 3 minutes.
Collapse
Affiliation(s)
- Ryan A Davis
- Department of Internal Medicine, Division of Hematology and Oncology, University of California Davis CA USA +1-916-734-7572 +1-916-734-5536
- Department of Biomedical Engineering, University of California Davis CA USA
| | | | - Robin C Ippisch
- Department of Biomedical Engineering, University of California Davis CA USA
| | | | - Julie L Sutcliffe
- Department of Internal Medicine, Division of Hematology and Oncology, University of California Davis CA USA +1-916-734-7572 +1-916-734-5536
- Department of Biomedical Engineering, University of California Davis CA USA
- Center for Molecular and Genomic Imaging, University of California Davis CA USA
| |
Collapse
|
16
|
Hausner SH, Bold RJ, Cheuy LY, Chew HK, Daly ME, Davis RA, Foster CC, Kim EJ, Sutcliffe JL. Preclinical Development and First-in-Human Imaging of the Integrin α vβ 6 with [ 18F]α vβ 6-Binding Peptide in Metastatic Carcinoma. Clin Cancer Res 2019; 25:1206-1215. [PMID: 30401687 PMCID: PMC6377828 DOI: 10.1158/1078-0432.ccr-18-2665] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 09/28/2018] [Accepted: 11/02/2018] [Indexed: 01/08/2023]
Abstract
PURPOSE The study was undertaken to develop and evaluate the potential of an integrin αvβ6-binding peptide (αvβ6-BP) for noninvasive imaging of a diverse range of malignancies with PET. EXPERIMENTAL DESIGN The peptide αvβ6-BP was prepared on solid phase and radiolabeled with 4-[18F]fluorobenzoic acid. In vitro testing included ELISA, serum stability, and cell binding studies using paired αvβ6-expressing and αvβ6-null cell lines. In vivo evaluation (PET/CT, biodistribution, and autoradiography) was performed in a mouse model bearing the same paired αvβ6-expressing and αvβ6-null cell xenografts. A first-in-human PET/CT imaging study was performed in patients with metastatic lung, colon, breast, or pancreatic cancer. RESULTS [18F]αvβ6-BP displayed excellent affinity and selectivity for the integrin αvβ6 in vitro [IC50(αvβ6) = 1.2 nmol/L vs IC50(αvβ3) >10 μmol/L] in addition to rapid target-specific cell binding and internalization (72.5% ± 0.9% binding and 52.5% ± 1.8%, respectively). Favorable tumor affinity and selectivity were retained in the mouse model and excretion of unbound [18F]αvβ6-BP was rapid, primarily via the kidneys. In patients, [18F]αvβ6-BP was well tolerated without noticeable adverse side effects. PET images showed significant uptake of [18F]αvβ6-BP in both the primary lesion and metastases, including metastasis to brain, bone, liver, and lung. CONCLUSIONS The clinical impact of [18F]αvβ6-BP PET imaging demonstrated in this first-in-human study is immediate for a broad spectrum of malignancies.
Collapse
Affiliation(s)
- Sven H Hausner
- Division of Hematology/Oncology, Department of Internal Medicine, University of California Davis, Davis and Sacramento, California
| | - Richard J Bold
- Division of Surgical Oncology, Department of Surgery, University of California Davis, Davis and Sacramento, California
| | - Lina Y Cheuy
- Department of Biomedical Engineering, University of California Davis, Davis and Sacramento, California
| | - Helen K Chew
- Division of Hematology/Oncology, Department of Internal Medicine, University of California Davis, Davis and Sacramento, California
| | - Megan E Daly
- Department of Radiation Oncology, University of California Davis, Davis and Sacramento, California
| | - Ryan A Davis
- Division of Hematology/Oncology, Department of Internal Medicine, University of California Davis, Davis and Sacramento, California
| | - Cameron C Foster
- Division of Nuclear Medicine, Department of Radiology, University of California Davis, Davis and Sacramento, California
| | - Edward J Kim
- Division of Hematology/Oncology, Department of Internal Medicine, University of California Davis, Davis and Sacramento, California
| | - Julie L Sutcliffe
- Division of Hematology/Oncology, Department of Internal Medicine, University of California Davis, Davis and Sacramento, California.
- Department of Biomedical Engineering, University of California Davis, Davis and Sacramento, California
- Center for Molecular and Genomic Imaging, University of California Davis, Davis and Sacramento, California
| |
Collapse
|
17
|
|
18
|
Liu H, Gao L, Yu X, Zhong L, Shi J, Jia B, Li N, Liu Z, Wang F. Small-animal SPECT/CT imaging of cancer xenografts and pulmonary fibrosis using a 99mTc-labeled integrin αvβ6-targeting cyclic peptide with improved in vivo stability. BIOPHYSICS REPORTS 2018; 4:254-264. [PMID: 30533490 PMCID: PMC6245143 DOI: 10.1007/s41048-018-0071-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 07/17/2018] [Indexed: 12/20/2022] Open
Abstract
Abstract Integrin αvβ6 is expressed at an undetectable level in normal tissues, but is remarkably upregulated during many pathological processes, especially in cancer and fibrosis. Noninvasive imaging of integrin αvβ6 expression using a radiotracer with favorable in vivo pharmacokinetics would facilitate disease diagnosis and therapy monitoring. Through disulfide-cyclized method, we synthesized in this study, a new integrin αvβ6-targeted cyclic peptide (denoted as cHK), and radiolabeled it with 99mTc. The ability of the resulting radiotracer 99mTc–HYNIC–cHK to detect integrin αvβ6 expression in pancreatic cancer xenografts and idiopathic pulmonary fibrosis was evaluated using small-animal single-photon emission computed tomography (SPECT)/computed tomography (CT). 99mTc–HYNIC–cHK showed significantly improved in vivo metabolic stability compared to the linear peptide-based radiotracer 99mTc–HYNIC–HK. 99mTc–HYNIC–cHK exhibited similar biodistribution properties to 99mTc–HYNIC–HK, but the tumor-to-muscle ratio was significantly increased (2.99 ± 0.87 vs. 1.82 ± 0.27, P < 0.05). High-contrast images of integrin αvβ6-positive tumors and bleomycin-induced fibrotic lungs were obtained by SPECT/CT imaging using 99mTc–HYNIC–cHK. Overall, our studies demonstrate that 99mTc–HYNIC–cHK is a promising SPECT radiotracer for the noninvasive imaging of integrin αvβ6 in living subjects. Graphical Abstract ![]()
Collapse
Affiliation(s)
- Hao Liu
- Medical Isotopes Research Center and Department of Radiation Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191 China
| | - Liquan Gao
- Medical Isotopes Research Center and Department of Radiation Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191 China
| | - Xinhe Yu
- Medical Isotopes Research Center and Department of Radiation Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191 China
| | - Lijun Zhong
- Medical and Healthy Analytical Center, Peking University, Beijing, 100191 China
| | - Jiyun Shi
- Key Laboratory of Protein and Peptide Pharmaceuticals, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101 China
| | - Bing Jia
- Medical Isotopes Research Center and Department of Radiation Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191 China
- Medical and Healthy Analytical Center, Peking University, Beijing, 100191 China
| | - Nan Li
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing, 100142 China
| | - Zhaofei Liu
- Medical Isotopes Research Center and Department of Radiation Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191 China
| | - Fan Wang
- Medical Isotopes Research Center and Department of Radiation Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191 China
- Key Laboratory of Protein and Peptide Pharmaceuticals, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101 China
| |
Collapse
|
19
|
Tummers WS, Willmann JK, Bonsing BA, Vahrmeijer AL, Gambhir SS, Swijnenburg RJ. Advances in Diagnostic and Intraoperative Molecular Imaging of Pancreatic Cancer. Pancreas 2018; 47:675-689. [PMID: 29894417 PMCID: PMC6003672 DOI: 10.1097/mpa.0000000000001075] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis. To improve outcomes, there is a critical need for improved tools for detection, accurate staging, and resectability assessment. This could improve patient stratification for the most optimal primary treatment modality. Molecular imaging, used in combination with tumor-specific imaging agents, can improve established imaging methods for PDAC. These novel, tumor-specific imaging agents developed to target specific biomarkers have the potential to specifically differentiate between malignant and benign diseases, such as pancreatitis. When these agents are coupled to various types of labels, this type of molecular imaging can provide integrated diagnostic, noninvasive imaging of PDAC as well as image-guided pancreatic surgery. This review provides a detailed overview of the current clinical imaging applications, upcoming molecular imaging strategies for PDAC, and potential targets for imaging, with an emphasis on intraoperative imaging applications.
Collapse
Affiliation(s)
- Willemieke S. Tummers
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, Stanford, CA. Department of Surgery, Leiden University Medical Center, Leiden, The Netherlands
| | - Juergen K. Willmann
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, Stanford, CA. Juergen K. Willmann died January 8, 2018
| | - Bert A. Bonsing
- Department of Surgery, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Sanjiv S. Gambhir
- Address correspondence to: R.J. Swijnenburg, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands (). Tel: +31 71 526 4005, Fax: +31 71 526 6750
| | - Rutger-Jan Swijnenburg
- Department of Surgery, Leiden University Medical Center, Albinusdreef 2, 2300 RC, Leiden, The Netherlands
| |
Collapse
|
20
|
Fiedler L, Kellner M, Oos R, Böning G, Ziegler S, Bartenstein P, Zeidler R, Gildehaus FJ, Lindner S. Fully Automated Production and Characterization of 64 Cu and Proof-of-Principle Small-Animal PET Imaging Using 64 Cu-Labelled CA XII Targeting 6A10 Fab. ChemMedChem 2018; 13:1230-1237. [PMID: 29667369 DOI: 10.1002/cmdc.201800130] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 04/09/2018] [Indexed: 01/26/2023]
Abstract
64 Cu is a cyclotron-produced radionuclide which offers, thanks to its characteristic decay scheme, the possibility of combining positron emission tomography (PET) investigations with radiotherapy. We evaluated the Alceo system from Comecer SpA to automatically produce 64 Cu for radiolabelling purposes. We established a 64 Cu production routine with high yields and radionuclide purity in combination with excellent operator radiation protection. The carbonic anhydrase XII targeting 6A10 antibody Fab fragment was successfully radiolabelled with the produced 64 Cu, and proof-of-principle small-animal PET experiments on mice bearing glioma xenografts were performed. We obtained a high tumor-to-contralateral muscle ratio, which encourages further in vivo investigations of the radioconjugate regarding a possible application in diagnostic tumor imaging.
Collapse
Affiliation(s)
- Luise Fiedler
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377, Munich, Germany
| | - Markus Kellner
- Helmholtz-Zentrum München, German Research Center for Environmental Health, Research Group Gene Vectors, Marchioninistrasse 25, 81377, Munich, Germany
| | - Rosel Oos
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377, Munich, Germany
| | - Guido Böning
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377, Munich, Germany
| | - Sibylle Ziegler
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377, Munich, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377, Munich, Germany
| | - Reinhard Zeidler
- Helmholtz-Zentrum München, German Research Center for Environmental Health, Research Group Gene Vectors, Marchioninistrasse 25, 81377, Munich, Germany.,Department of Otorhinolaryngology, University Hospital, LMU Munich, Marchioninistrasse 15, 81377, Munich, Germany
| | - Franz Josef Gildehaus
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377, Munich, Germany
| | - Simon Lindner
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistrasse 15, 81377, Munich, Germany
| |
Collapse
|
21
|
Roesch S, Lindner T, Sauter M, Loktev A, Flechsig P, Müller M, Mier W, Warta R, Dyckhoff G, Herold-Mende C, Haberkorn U, Altmann A. Comparison of the RGD Motif–Containing αvβ6 Integrin–Binding Peptides SFLAP3 and SFITGv6 for Diagnostic Application in HNSCC. J Nucl Med 2018; 59:1679-1685. [DOI: 10.2967/jnumed.118.210013] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 03/28/2018] [Indexed: 12/18/2022] Open
|
22
|
Ibrahim IS, Bonsing BA, Swijnenburg RJ, Welling L, Veenendaal RA, Wasser MNJM, Morreau H, Inderson A, Vasen HFA. Dilemmas in the management of screen-detected lesions in patients at high risk for pancreatic cancer. Fam Cancer 2017; 16:111-115. [PMID: 27406244 PMCID: PMC5243878 DOI: 10.1007/s10689-016-9915-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In 3–5 % of all cases of pancreatic ductal adenocarcinoma (PDAC), hereditary factors influence etiology. While surveillance of high-risk individuals may improve the prognosis, this study describes two very different outcomes in patients with screen-detected lesions. In 2000, a surveillance program of carriers of a CDKN2A/p16-Leiden-mutation consisting of annual MRI was initiated. Patients with a suspected pancreatic lesion undergo CT-scan and Endoscopic Ultrasound, and surgery is offered when a lesion is confirmed. In 2015, two patients with a screen-detected solid lesion were identified. In both patients, lesions were visible on MRI and CT scan, while the EUS was unremarkable. Surgical resection of the head of the pancreas resulted in nearly fatal complications in the first patient. This patient was shown to have a benign lesion. In contrast, timely identification of an early cancer in the second patient was accompanied by an uneventful postoperative course. These cases underline the risks inherent to a PDAC prevention program. All patients should be fully informed about the possible outcomes before joining a surveillance program.
Collapse
Affiliation(s)
- Isaura S Ibrahim
- Department of Gastroenterology and Hepatology, Leiden University Medical Centre, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Bert A Bonsing
- Department of Surgery, Leiden University Medical Centre, Leiden, The Netherlands
| | | | - Lieke Welling
- Department of Surgery, Leiden University Medical Centre, Leiden, The Netherlands
| | - Roeland A Veenendaal
- Department of Gastroenterology and Hepatology, Leiden University Medical Centre, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Martin N J M Wasser
- Department of Radiology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Hans Morreau
- Department of Pathology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Akin Inderson
- Department of Gastroenterology and Hepatology, Leiden University Medical Centre, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Hans F A Vasen
- Department of Gastroenterology and Hepatology, Leiden University Medical Centre, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands.
| |
Collapse
|
23
|
Tummers WS, Farina-Sarasqueta A, Boonstra MC, Prevoo HA, Sier CF, Mieog JS, Morreau J, van Eijck CH, Kuppen PJ, van de Velde CJ, Bonsing BA, Vahrmeijer AL, Swijnenburg RJ. Selection of optimal molecular targets for tumor-specific imaging in pancreatic ductal adenocarcinoma. Oncotarget 2017; 8:56816-56828. [PMID: 28915633 PMCID: PMC5593604 DOI: 10.18632/oncotarget.18232] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Accepted: 05/01/2017] [Indexed: 12/21/2022] Open
Abstract
Discrimination of pancreatic ductal adenocarcinoma (PDAC) from chronic pancreatitis (CP) or peritumoral inflammation is challenging, both at preoperative imaging and during surgery, but it is crucial for proper therapy selection. Tumor-specific molecular imaging aims to enhance this discrimination and to help select and stratify patients for resection. We evaluated various biomarkers for the specific identification of PDAC and associated lymph node metastases. Using immunohistochemistry (IHC), expression levels and patterns were investigated of integrin αvβ6, carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5), Cathepsin E (Cath E), epidermal growth factor receptor (EGFR), hepatocyte growth factor receptor (c-MET), thymocyte differentiation antigen 1 (Thy1), and urokinase-type plasminogen activator receptor (uPAR). In a first cohort, multiple types of pancreatic tissue were evaluated (n=62); normal pancreatic tissue (n=8), CP (n=7), PDAC (n=9), tumor associated lymph nodes (n=32), and PDAC after neoadjuvant radiochemotherapy (n=6). In a second cohort, tissues were investigated (n=55) with IHC and immunofluorescence (IF) for concordance of biomarker expression in all tissue types, obtained from an individual patient. Integrin αvβ6 and CEACAM5 showed significantly higher expression levels in PDAC versus normal pancreatic tissue (P=0.001 and P<0.001, respectively) and CP (P=0.003 and P<0.001, respectively). Avβ6 and CEACAM5 expression identified tumor-positive lymph nodes correctly in 84% and 68%, respectively, and in 100% of tumor-negative nodes for both biomarkers. In conclusion, αvβ6 and CEACAM5 are excellent biomarkers to differentiate PDAC from surrounding tissue and to identify lymph node metastases. Individually or combined, these biomarkers are promising targets for tumor-specific molecular imaging of PDAC.
Collapse
Affiliation(s)
- Willemieke S Tummers
- Department of Surgery, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Martin C Boonstra
- Department of Surgery, Leiden University Medical Center, Leiden, The Netherlands
| | - Hendrica A Prevoo
- Department of Surgery, Leiden University Medical Center, Leiden, The Netherlands
| | - Cornelis F Sier
- Department of Surgery, Leiden University Medical Center, Leiden, The Netherlands
| | - Jan S Mieog
- Department of Surgery, Leiden University Medical Center, Leiden, The Netherlands
| | - Johannes Morreau
- Department of Pathology, Leiden University Medical Center, Leiden, The Netherlands
| | - Casper H van Eijck
- Department of Surgery, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Peter J Kuppen
- Department of Surgery, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Bert A Bonsing
- Department of Surgery, Leiden University Medical Center, Leiden, The Netherlands
| | | | | |
Collapse
|
24
|
Altmann A, Sauter M, Roesch S, Mier W, Warta R, Debus J, Dyckhoff G, Herold-Mende C, Haberkorn U. Identification of a Novel ITGα vβ 6-Binding Peptide Using Protein Separation and Phage Display. Clin Cancer Res 2017; 23:4170-4180. [PMID: 28468949 DOI: 10.1158/1078-0432.ccr-16-3217] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 01/19/2017] [Accepted: 02/15/2017] [Indexed: 11/16/2022]
Abstract
Purpose: Targeted therapies are regarded as promising approaches to increase 5-year survival rate of head and neck squamous cell carcinoma (HNSCC) patients.Experimental design: For the selection of carcinoma-specific peptides membrane proteome of HNO97 tumor cells fractionated by the ProteomeLab PF2D system and corresponding HNO97 cells were deployed for an alternating biopanning using a sunflower trypsin inhibitor1-based phage display (SFTI8Ph) library. Stability, binding properties and affinity of novel candidates were assessed in vitro using radio-HPLC, binding experiments and surface plasmon resonance assay (SPR), respectively. Subsequently, the affinity of the peptide was verified in situ by using peptide histochemistry, in vitro using flow cytometry, and in vivo by positron emissions tomography (PET/CT).Results: We identified a novel ITGαvβ6 binding peptide (SFITGv6) containing the amino acid sequence FRGDLMQL. SFITGv6 provides stability over a period of 24 hours and demonstrates high affinity (KD = 14.8 nmol/L) for ITGαvβ6 In HNO97 cells, a maximal uptake and internalization of up to 37.3% and 37.5%, respectively, was measured. Small-animal PET imaging and biodistribution studies of HNO97 xenografted Balb/c nu/nu mice showed tumor-specific accumulation of 68Ga- and 177Lu-labeled DOTA-SFITGv6, respectively, 30 to 60 minutes after injection. Moreover, peptide histochemistry revealed a strong and homogenous binding of biotin-labeled SFITGv6 to HNSCC tumors and breast- and lung cancer-derived brain metastases. Finally, first PET/CT scans of HNSCC and NSCLC patients displayed SFITGv6 accumulation specifically in tumors, but not in inflammatory lesions.Conclusions: Thus, SFITGv6 represents a novel powerful tracer for imaging and possibly for endoradiotherapy of ITGαvβ6-positive carcinoma. Clin Cancer Res; 23(15); 4170-80. ©2017 AACR.
Collapse
Affiliation(s)
- Annette Altmann
- Clinical Cooperation Unit Nuclear Medicine, German Cancer Research Center (DKFZ) Heidelberg, Germany.,Department of Nuclear Medicine, University Hospital Heidelberg, Germany
| | - Max Sauter
- Department of Nuclear Medicine, University Hospital Heidelberg, Germany
| | - Saskia Roesch
- Division of Experimental Neurosurgery, Department of Neurosurgery, University Hospital Heidelberg, Germany.,Department of Head and Neck Surgery, University of Heidelberg, Germany
| | - Walter Mier
- Department of Nuclear Medicine, University Hospital Heidelberg, Germany
| | - Rolf Warta
- Division of Experimental Neurosurgery, Department of Neurosurgery, University Hospital Heidelberg, Germany.,Department of Head and Neck Surgery, University of Heidelberg, Germany
| | - Jürgen Debus
- Department of Radiooncology, University Hospital Heidelberg, Germany
| | - Gerhard Dyckhoff
- Department of Head and Neck Surgery, University of Heidelberg, Germany
| | - Christel Herold-Mende
- Division of Experimental Neurosurgery, Department of Neurosurgery, University Hospital Heidelberg, Germany
| | - Uwe Haberkorn
- Clinical Cooperation Unit Nuclear Medicine, German Cancer Research Center (DKFZ) Heidelberg, Germany. .,Department of Nuclear Medicine, University Hospital Heidelberg, Germany.,Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Heidelberg, Germany
| |
Collapse
|
25
|
Abadjian MCZ, Edwards WB, Anderson CJ. Imaging the Tumor Microenvironment. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1036:229-257. [PMID: 29275475 DOI: 10.1007/978-3-319-67577-0_15] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The tumor microenvironment consists of tumor, stromal, and immune cells, as well as extracellular milieu. Changes in numbers of these cell types and their environments have an impact on cancer growth and metastasis. Non-invasive imaging of aspects of the tumor microenvironment can provide important information on the aggressiveness of the cancer, whether or not it is metastatic, and can also help to determine early response to treatment. This chapter provides an overview on non-invasive in vivo imaging in humans and mouse models of various cell types and physiological parameters that are unique to the tumor microenvironment. Current clinical imaging and research investigation are in the areas of nuclear imaging (positron emission tomography (PET) and single photon emission computed tomography (SPECT)), magnetic resonance imaging (MRI) and optical (near infrared (NIR) fluorescence) imaging. Aspects of the tumor microenvironment that have been imaged by PET, MRI and/or optical imaging are tumor associated inflammation (primarily macrophages and T cells), hypoxia, pH changes, as well as enzymes and integrins that are highly prevalent in tumors, stroma and immune cells. Many imaging agents and strategies are currently available for cancer patients; however, the investigation of novel avenues for targeting aspects of the tumor microenvironment in pre-clinical models of cancer provides the cancer researcher with a means to monitor changes and evaluate novel treatments that can be translated into the clinic.
Collapse
Affiliation(s)
| | - W Barry Edwards
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Carolyn J Anderson
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA.
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA.
- Department of Pharmacology & Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA.
| |
Collapse
|
26
|
Foot-and-mouth disease virus-like particles as integrin-based drug delivery system achieve targeting anti-tumor efficacy. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2016; 13:1061-1070. [PMID: 27993721 DOI: 10.1016/j.nano.2016.12.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 10/31/2016] [Accepted: 12/06/2016] [Indexed: 12/13/2022]
Abstract
The surface of foot-and-mouth disease virus (FMDV)-like particles (VLPs) contains a conserved arginine-glycine-aspartic acid (RGD) motif. Natural FMDV specifically attaches to overexpressed integrin receptors in several cancer cells. The FMDV VLPs produced in Escherichia coli were used for the first time as a delivery system of anti-tumor drug doxorubicin (DOX). The DOX-loaded VLPs exhibited a distinct release profile in different physiological conditions. The effects of FMDV-VLPs-DOX on cellular internalization and viability were evaluated in vitro by cell imaging, MTT assay and apoptosis, respectively. The anti-tumor efficacy in vivo was also determined in a nude mouse xenograft model based on tumor volume/weight and histological changes. The FMDV-VLPs-DOX complex significantly inhibited the proliferation of tumor and improved the pathological damage of DOX to non-targeting tissues. All results supported the potential of FMDV VLPs as a platform for specific targeted delivery of drugs or chemical reagents.
Collapse
|
27
|
de Geus SWL, Boogerd LSF, Swijnenburg RJ, Mieog JSD, Tummers WSFJ, Prevoo HAJM, Sier CFM, Morreau H, Bonsing BA, van de Velde CJH, Vahrmeijer AL, Kuppen PJK. Selecting Tumor-Specific Molecular Targets in Pancreatic Adenocarcinoma: Paving the Way for Image-Guided Pancreatic Surgery. Mol Imaging Biol 2016; 18:807-819. [PMID: 27130234 PMCID: PMC5093212 DOI: 10.1007/s11307-016-0959-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
PURPOSE The purpose of this study was to identify suitable molecular targets for tumor-specific imaging of pancreatic adenocarcinoma. PROCEDURES The expression of eight potential imaging targets was assessed by the target selection criteria (TASC)-score and immunohistochemical analysis in normal pancreatic tissue (n = 9), pancreatic (n = 137), and periampullary (n = 28) adenocarcinoma. RESULTS Integrin αvβ6, carcinoembryonic antigen (CEA), epithelial growth factor receptor (EGFR), and urokinase plasminogen activator receptor (uPAR) showed a significantly higher (all p < 0.001) expression in pancreatic adenocarcinoma compared to normal pancreatic tissue and were confirmed by the TASC score as promising imaging targets. Furthermore, these biomarkers were expressed in respectively 88 %, 71 %, 69 %, and 67 % of the pancreatic adenocarcinoma patients. CONCLUSIONS The results of this study show that integrin αvβ6, CEA, EGFR, and uPAR are suitable targets for tumor-specific imaging of pancreatic adenocarcinoma.
Collapse
Affiliation(s)
- Susanna W L de Geus
- Department of Surgery, Leiden University Medical Center, Albinusdreef 2, 2300 RC, Leiden, The Netherlands
| | - Leonora S F Boogerd
- Department of Surgery, Leiden University Medical Center, Albinusdreef 2, 2300 RC, Leiden, The Netherlands
| | - Rutger-Jan Swijnenburg
- Department of Surgery, Leiden University Medical Center, Albinusdreef 2, 2300 RC, Leiden, The Netherlands
| | - J Sven D Mieog
- Department of Surgery, Leiden University Medical Center, Albinusdreef 2, 2300 RC, Leiden, The Netherlands
| | - Willemieke S F J Tummers
- Department of Surgery, Leiden University Medical Center, Albinusdreef 2, 2300 RC, Leiden, The Netherlands
| | - Hendrica A J M Prevoo
- Department of Surgery, Leiden University Medical Center, Albinusdreef 2, 2300 RC, Leiden, The Netherlands
| | - Cornelis F M Sier
- Department of Surgery, Leiden University Medical Center, Albinusdreef 2, 2300 RC, Leiden, The Netherlands
| | - Hans Morreau
- Department of Pathology, Leiden University Medical Center, Leiden, The Netherlands
| | - Bert A Bonsing
- Department of Surgery, Leiden University Medical Center, Albinusdreef 2, 2300 RC, Leiden, The Netherlands
| | - Cornelis J H van de Velde
- Department of Surgery, Leiden University Medical Center, Albinusdreef 2, 2300 RC, Leiden, The Netherlands
| | - Alexander L Vahrmeijer
- Department of Surgery, Leiden University Medical Center, Albinusdreef 2, 2300 RC, Leiden, The Netherlands
| | - Peter J K Kuppen
- Department of Surgery, Leiden University Medical Center, Albinusdreef 2, 2300 RC, Leiden, The Netherlands.
| |
Collapse
|
28
|
Zhang C, Kimura R, Abou-Elkacem L, Levi J, Xu L, Gambhir SS. A Cystine Knot Peptide Targeting Integrin αvβ6 for Photoacoustic and Fluorescence Imaging of Tumors in Living Subjects. J Nucl Med 2016; 57:1629-1634. [PMID: 27230926 DOI: 10.2967/jnumed.115.169383] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 04/14/2016] [Indexed: 11/16/2022] Open
Abstract
Photoacoustic imaging is a nonionizing biomedical imaging modality with higher resolution and imaging depth than fluorescence imaging, which has greater sensitivity. The combination of the 2 imaging modalities could improve the detection of cancer. Integrin αvβ6 is a cell surface marker overexpressed in many different cancers. Here, we report the development and evaluation of a dye-labeled cystine knot peptide, which selectively recognizes integrin αvβ6 with high affinity, for photoacoustic and fluorescence imaging. The new dual-modality probe may find clinical application in cancer diagnosis and intraoperative imaging of integrin αvβ6-positive tumors. METHODS An engineered cystine knot peptide, R01, that recognizes integrin αvβ6 was labeled with Atto 740 (A740) and evaluated for its specific cell uptake and its sensitivity threshold. A740-R01 was injected via the tail vein into nude mice xenografted with A431 (integrin αvβ6-positive) or 293T (integrin αvβ6-negative) tumors. Photoacoustic and fluorescence scans of tumors were acquired before and at 0.5, 1, 2, and 4 h after injection of A740-R01. Dynamic photoacoustic scans of various normal organs were also acquired. Ex vivo fluorescence imaging of tissues was performed 1 h after injection. RESULTS The A740-R01 demonstrated integrin αvβ6-dependent binding to A431 cells in culture. Sensitivity studies indicated that the probe may potentially detect lesions as small as 1 or 6 mm3 by fluorescence or photoacoustic imaging, respectively. The photoacoustic and fluorescence signals of A431 xenografts at 1 h after injection were 1.87 ± 0.25 arbitrary units (AU) and 8.27 ± 0.87 AU, respectively. Target specificity was confirmed by low tumor uptake in 293T tumors at 1 h after injection (1.07 ± 0.15 AU and 1.10 ± 0.14 AU for photoacoustic and fluorescence signals, respectively). A740-R01 exhibited hepatobiliary clearance marked by high uptake in the liver, spleen, and intestine but low uptake in the kidneys. CONCLUSION A740-R01 specifically targeted integrin αvβ6 with low nanomolar affinity. A740-R01 was able to detect integrin αvβ6 both in vitro and in vivo by photoacoustic and fluorescence imaging. A740-R01 is able to detect αvβ6-positive tumors in living subjects and may have clinical application in cancer diagnosis and real-time image-guided surgery.
Collapse
Affiliation(s)
- Chao Zhang
- Department of Radiology, Molecular Imaging Program at Stanford, Canary Center for Cancer Early Detection, Stanford University, Stanford, California; and Department of Medical Ultrasound, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Richard Kimura
- Department of Radiology, Molecular Imaging Program at Stanford, Canary Center for Cancer Early Detection, Stanford University, Stanford, California; and
| | - Lotfi Abou-Elkacem
- Department of Radiology, Molecular Imaging Program at Stanford, Canary Center for Cancer Early Detection, Stanford University, Stanford, California; and
| | - Jelena Levi
- Department of Radiology, Molecular Imaging Program at Stanford, Canary Center for Cancer Early Detection, Stanford University, Stanford, California; and
| | - Lingyun Xu
- Department of Radiology, Molecular Imaging Program at Stanford, Canary Center for Cancer Early Detection, Stanford University, Stanford, California; and
| | - Sanjiv Sam Gambhir
- Department of Radiology, Molecular Imaging Program at Stanford, Canary Center for Cancer Early Detection, Stanford University, Stanford, California; and
| |
Collapse
|
29
|
White JB, Boucher DL, Zettlitz KA, Wu AM, Sutcliffe JL. Development and characterization of an αvβ6-specific diabody and a disulfide-stabilized αvβ6-specific cys-diabody. Nucl Med Biol 2015; 42:945-57. [PMID: 26341848 DOI: 10.1016/j.nucmedbio.2015.07.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 07/25/2015] [Accepted: 07/31/2015] [Indexed: 11/15/2022]
Abstract
INTRODUCTION This work describes the development and characterization of two antibody fragments that specifically target the α(v)β(6) integrin, a non-covalent diabody and a disulfide-stabilized cys-diabody. The diabodies were analyzed for their ability to bind both immobilized and cell surface-bound α(v)β(6). Radiolabeling was done using non-site-specific and site-specific conjugation approaches with N-succinimidyl 4-[(18)F]fluorobenzoate ([(18)F]-SFB) and the bifunctional chelator 1,4,7-triazacyclononane-triacetic acid maleimide (NOTA-maleimide) and copper-64 ([(64)Cu]), respectively. The affects of each radiolabeling method on RCY, RCP, and immunoreactivity were analyzed for the [(18)F]-FB-α(v)β(6) diabody, [(18)F]-FB-α(v)β(6) cys-diabody, and the [(64)Cu]-NOTA-α(v)β(6) cys-diabody. METHODS Diabodies were constructed from the variable domains of the humanized 6.3G9 anti-α(v)β(6) intact antibody. The anti-α(v(β(6) cys-diabody was engineered with C-terminal cysteines to enable covalent dimerization and site-specific modification. Biochemical characterization included SDS-PAGE, Western blot, and electrospray ionization to confirm MW, and flow cytometry and ELISA experiments were used to determine binding affinity and specificity to α(v)β(6). The diabodies were radiolabeled with [(18)F]-SFB and in addition, the anti-α(v)β(6) cys-diabody was also radiolabeled site-specifically using NOTA-maleimide and [(64)Cu]. Immunoreactivities were confirmed using in vitro cell binding to DX3Puroβ(6) (α(v)β(6)+) and DX3Puro (α(v)β(6)-)cell lines. RESULTS The diabodies were purified from cell culture supernatants with purities >98%. Subnanomolar binding affinity towards αvβ6 was confirmed by ELISA (diabody IC(50)=0.8 nM, cys-diabody IC(50)=0.6 nM) and flow cytometry revealed high specificity only to the DX3Puroβ(6) cell line for both diabodies. RCYs were 22.6%±3.6% for the [(18)F]-FB-α(v)β(6) diabody, 8.3%±1.7% for the [(18)F]-FB-α(v)β(6) cys-diabody and 43.5%±5.5% for the [(64)Cu]-NOTA-α(v)β(6) cys-diabody. In vitro cell binding assays revealed excellent specificity and retention of immunoreactivity ([(18)F]-FB-α(v)β(6) diabody=58.7%±6.7%, [(18)F]-FB-α(v)β(6) cys-diabody=80.4%±4.4%, [(64)Cu]-NOTA-α(v)β(6) cys-diabody=59.4%±0.6%) regardless of the radiolabeling method used. CONCLUSIONS Two novel diabodies with excellent binding affinity and specificity for the α(v)β(6) integrin in vitro were developed. Radiolabeling of the diabodies with fluorine-18 ([(18)F]) and [(64)Cu] revealed advantages and disadvantages with regards to methodologies and RCYs, however immunoreactivities were well preserved regardless of radiolabeling approach.
Collapse
Affiliation(s)
- Jason B White
- Department of Biomedical Engineering, University of California, Davis, Davis, CA
| | - David L Boucher
- Department of Biomedical Engineering, University of California, Davis, Davis, CA
| | - Kirstin A Zettlitz
- Crump Institute for Molecular Imaging, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Anna M Wu
- Crump Institute for Molecular Imaging, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Julie L Sutcliffe
- Department of Biomedical Engineering, University of California, Davis, Davis, CA; Division of Hematology/Oncology, Department of Internal Medicine, University of California, Davis, Sacramento, CA; Center for Molecular and Genomic Imaging, University of California, Davis, Davis, CA; Radiochemistry Research and Training Facility, University of California, Davis, Sacramento, CA.
| |
Collapse
|
30
|
Vectors for the delivery of radiopharmaceuticals in cancer therapeutics. Ther Deliv 2015; 5:893-912. [PMID: 25337647 DOI: 10.4155/tde.14.57] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Internal radiation using radiopharmaceuticals promises efficient cancer therapeutics. The specificity and selectivity required for screening and pinpointing tumor cells for cell-kill has been made possible by targeted ligands based on 'magic bullet' and tracer principle- theories nearing a century. Overexpression of certain receptors has been exploited using biomolecules for targeting. The pragmatic analysis, however, is not as promising compared with the theoretical knowledge of available gamut of vectors and targets. The complex interplay of in vitro and in vivo parameters, and the effect of radionuclides involve a systematic assessment of radiopharmaceuticals as diagnostic and therapeutic agent. This review presents different vectors with their pros and cons, present status and recent design variations followed by a future perspective based on novel approaches.
Collapse
|
31
|
Hausner SH, Bauer N, Hu LY, Knight LM, Sutcliffe JL. The Effect of Bi-Terminal PEGylation of an Integrin αvβ₆-Targeted ¹⁸F Peptide on Pharmacokinetics and Tumor Uptake. J Nucl Med 2015; 56:784-90. [PMID: 25814519 DOI: 10.2967/jnumed.114.150680] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 02/13/2015] [Indexed: 02/05/2023] Open
Abstract
UNLABELLED Radiotracers based on the peptide A20FMDV2 selectively target the cell surface receptor integrin αvβ6. This integrin has been identified as a prognostic indicator correlating with the severity of disease for several challenging malignancies. In previous studies of A20FMDV2 peptides labeled with 4-(18)F-fluorobenzoic acid ((18)F-FBA), we have shown that the introduction of poly(ethylene glycol) (PEG) improves pharmacokinetics, including increased uptake in αvβ6-expressing tumors. The present study evaluated the effect of site-specific C-terminal or dual (N- and C-terminal) PEGylation, yielding (18)F-FBA-A20FMDV2-PEG28 (4) and (18)F-FBA-PEG28-A20FMDV2-PEG28 (5), on αvβ6-targeted tumor uptake and pharmacokinetics. The results are compared with (18)F-FBA -labeled A20FMDV2 radiotracers (1- 3) bearing either no PEG or different PEG units at the N terminus. METHODS The radiotracers were prepared and radiolabeled on solid phase. Using 3 cell lines, DX3puroβ6 (αvβ6+), DX3puro (αvβ6-), and BxPC-3 (αvβ6+), we evaluated the radiotracers in vitro (serum stability; cell binding and internalization) and in vivo in mouse models bearing paired DX3puroβ6-DX3puro and, for 5, BxPC-3 xenografts. RESULTS The size and location of the PEG units significantly affected αvβ6 targeting and pharmacokinetics. Although the C-terminally PEGylated 4 showed some improvements over the un-PEGylated (18)F-FBA-A20FMDV2 (1), it was the bi-terminally PEGylated 5 that displayed the more favorable combination of high αvβ6 affinity, selectivity, and pharmacokinetic profile. In vitro, 5 bound to αvβ6-expressing DX3puroβ6 and BxPC-3 cells with 60.5% ± 3.3% and 48.8% ± 8.3%, respectively, with a significant fraction of internalization (37.2% ± 4.0% and 37.6% ± 4.1% of total radioactivity, respectively). By comparison, in the DX3puro control 5: showed only 3.0% ± 0.5% binding and 0.9% ± 0.2% internalization. In vivo, 5: maintained high, αvβ6-directed binding in the paired DX3puroβ6-DX3puro model (1 h: DX3puroβ6, 2.3 ± 0.2 percentage injected dose per gram [%ID/g]; DX3puroβ6/DX3puro ratio, 6.5:1; 4 h: 10.7:1). In the pancreatic BxPC-3 model, uptake was 4.7 ± 0.9 %ID/g (1 h) despite small tumor sizes (20-80 mg). CONCLUSION The bi-PEGylated radiotracer 5 showed a greatly improved pharmacokinetic profile, beyond what was predicted from individual N- or C-terminal PEGylation. It appears that the 2 PEG units acted synergistically to result in an improved metabolic profile including high αvβ6+ tumor uptake and retention.
Collapse
Affiliation(s)
- Sven H Hausner
- Division of Hematology/Oncology, Department of Internal Medicine, University of California Davis, Sacramento, California Department of Biomedical Engineering, University of California Davis, Davis, California
| | - Nadine Bauer
- Department of Biomedical Engineering, University of California Davis, Davis, California
| | - Lina Y Hu
- Department of Biomedical Engineering, University of California Davis, Davis, California
| | - Leah M Knight
- Division of Hematology/Oncology, Department of Internal Medicine, University of California Davis, Sacramento, California
| | - Julie L Sutcliffe
- Division of Hematology/Oncology, Department of Internal Medicine, University of California Davis, Sacramento, California
| |
Collapse
|
32
|
Characterization and evaluation of (64)Cu-labeled A20FMDV2 conjugates for imaging the integrin αvβ 6. Mol Imaging Biol 2015; 16:567-77. [PMID: 24448825 DOI: 10.1007/s11307-013-0717-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
PURPOSE The integrin αvβ6 is overexpressed in a variety of aggressive cancers and serves as a prognosis marker. This study describes the conjugation, radiolabeling, and in vitro and in vivo evaluation of four chelators to determine the best candidate for (64)Cu radiolabeling of A20FMDV2, an αvβ6 targeting peptide. PROCEDURES Four chelators were conjugated onto PEG28-A20FMDV2 (1): 11-carboxymethyl-1,4,8,11-tetraazabicyclo[6.6.2]hexadecane-4-methanephosphonic acid (CB-TE1A1P), 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA), and 4,4'-((3,6,10,13,16,19-hexazazbicyclo[6.6.6]ico-sane-1,8-diylbis(aza-nediyl))bis(methylene)dibenzoic acid (BaBaSar). All peptides were radiolabeled with (64)Cu in ammonium acetate buffer at pH 6 and formulated to pH 7.2 in PBS for use. The radiotracers were evaluated using in vitro cell binding and internalization assays and serum stability assays. In vivo studies conducted include blocking, biodistribution, and small animal PET imaging. Autoradiography and histology were also conducted. RESULTS All radiotracers were radiolabeled in good radiochemical purity (>95 %) under mild conditions (37-50 °C for 15 min) with high specific activity (0.58-0.60 Ci/μmol). All radiotracers demonstrated αvβ6-directed cell binding (>46 %) with similar internalization levels (>23 %). The radiotracers (64)Cu-CB-TE1A1P-1 and (64)Cu-BaBaSar-1 showed improved specificity for the αvβ6 positive tumor in vivo over (64)Cu-DOTA-1 and (64)Cu-NOTA-1 (+/- tumor uptake ratios-3.82 +/- 0.44, 3.82 ± 0.41, 2.58 ± 0.58, and 1.29 ± 0.14, respectively). Of the four radiotracers, (64)Cu-NOTA-1 exhibited the highest liver uptake (10.83 ± 0.1 % ID/g at 4 h). CONCLUSIONS We have successfully conjugated, radiolabeled, and assessed the four chelates CB-TE1A1P, DOTA, NOTA, and BaBaSar both in vitro and in vivo. However, the data suggests no clear "best candidate" for the (64)Cu-radiolabeling of A20FMDV2, but instead a trade-off between the different properties (e.g., stability, selectivity, pharmacokinetics, etc.) with no obvious effects of the individual chelators.
Collapse
|
33
|
Way JD, Bergman C, Wuest F. Sonogashira cross-coupling reaction with 4-[18F]fluoroiodobenzene for rapid 18F-labelling of peptides. Chem Commun (Camb) 2015; 51:3838-41. [DOI: 10.1039/c5cc00182j] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The study describes the Sonogashira cross-coupling reaction with 4-[18F]fluoroiodobenzene ([18F]FIB) as novel and efficient method for rapid labelling of peptides with the short-lived positron emitter fluorine-18.
Collapse
Affiliation(s)
- Jenilee D. Way
- Department of Oncology
- University of Alberta
- Edmonton
- Canada
| | - Cody Bergman
- Department of Oncology
- University of Alberta
- Edmonton
- Canada
| | - Frank Wuest
- Department of Oncology
- University of Alberta
- Edmonton
- Canada
| |
Collapse
|
34
|
Ackerman SE, Currier NV, Bergen JM, Cochran JR. Cystine-knot peptides: emerging tools for cancer imaging and therapy. Expert Rev Proteomics 2014; 11:561-72. [DOI: 10.1586/14789450.2014.932251] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
35
|
PET radiopharmaceuticals for imaging integrin expression: tracers in clinical studies and recent developments. BIOMED RESEARCH INTERNATIONAL 2014; 2014:871609. [PMID: 25013808 PMCID: PMC4072020 DOI: 10.1155/2014/871609] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 04/29/2014] [Indexed: 11/17/2022]
Abstract
Noninvasive determination of integrin expression has become an interesting approach in nuclear medicine. Since the discovery of the first 18F-labeled cyclic RGD peptide as radiotracer for imaging integrin αvβ3 expression in vivo, there have been carried out enormous efforts to develop RGD peptides for PET imaging. Moreover, in recent years, additional integrins, including α5β1 and αvβ6 came into the focus of pharmaceutical radiochemistry. This review will discuss the tracers already evaluated in clinical trials and summarize the preliminary outcome. It will also give an overview on recent developments to further optimize the first-generation compounds such as [18F]Galacto-RGD. This includes recently developed 18F-labeling strategies and also new approaches in 68Ga-complex chemistry. Furthermore, the approaches to develop radiopharmaceuticals targeting integrin α5β1 and αvβ6 will be summarized and discussed.
Collapse
|
36
|
Liu H, Wu Y, Wang F, Liu Z. Molecular imaging of integrin αvβ6 expression in living subjects. AMERICAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 2014; 4:333-345. [PMID: 24982819 PMCID: PMC4074499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 05/15/2014] [Indexed: 06/03/2023]
Abstract
Integrins, a family of cell adhesion molecules composed of α and β heterodimeric subunits, are involved in a wide range of cell-extracellular matrix and cell-cell interactions. The study of integrin family members as targets for molecular imaging and therapy has been generally limited with the exception of integrin αvβ3. vβ6, a member of the integrin family, is expressed at low or undetectable levels in normal tissues, but is widely upregulated during many pathological and physiological processes, especially cancer and fibrosis, making it a promising target for molecular imaging. Noninvasive and quantitative imaging of integrin vβ6 expression would be very useful for disease diagnosis, treatment monitoring, and prognosis assessment. Although various molecular probes have been developed for positron emission tomography and single-photon emission computed tomography imaging of integrin vβ6 expression in preclinical animal models, further research efforts are required to optimize integrin vβ6-targeting probes for future potential clinical applications in the fields of oncology and beyond.
Collapse
Affiliation(s)
- Hao Liu
- Medical Isotopes Research Center, Peking UniversityBeijing 100191, China
- Department of Radiation Medicine, School of Basic Medical Sciences, Peking UniversityBeijing 100191, China
| | - Yue Wu
- Medical Isotopes Research Center, Peking UniversityBeijing 100191, China
- Department of Radiation Medicine, School of Basic Medical Sciences, Peking UniversityBeijing 100191, China
| | - Fan Wang
- Medical Isotopes Research Center, Peking UniversityBeijing 100191, China
- Department of Radiation Medicine, School of Basic Medical Sciences, Peking UniversityBeijing 100191, China
| | - Zhaofei Liu
- Medical Isotopes Research Center, Peking UniversityBeijing 100191, China
- Department of Radiation Medicine, School of Basic Medical Sciences, Peking UniversityBeijing 100191, China
| |
Collapse
|
37
|
Singh AN, McGuire MJ, Li S, Hao G, Kumar A, Sun X, Brown KC. Dimerization of a phage-display selected peptide for imaging of αvβ6- integrin: two approaches to the multivalent effect. Theranostics 2014; 4:745-60. [PMID: 24883124 PMCID: PMC4038756 DOI: 10.7150/thno.7811] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 10/10/2013] [Indexed: 12/28/2022] Open
Abstract
The integrin αvβ6 is an emerging biomarker for non-small cell lung cancer (NSCLC). An αvβ6-binding peptide was previously selected from a phage-displayed peptide library. Here, we utilize a multivalent design to develop a peptidic probe for positron emission tomography (PET) imaging of αvβ6+ NSCLC tumors. Multimeric presentation of this peptide, RGDLATLRQL, on a bifunctional copper chelator was achieved using two approaches: dimerization of the peptide followed by conjugation to the chelator (H2-D10) and direct presentation of two copies of the peptide on the chelator scaffold (H2-(M10)2). Binding affinities of the divalent peptide conjugates are four-fold higher than their monovalent counterpart (H2-M10), suggestive of multivalent binding. PET imaging using the bivalent 64Cu-labeled conjugates showed rapid and persistent accumulation in αvβ6+ tumors. By contrast, no significant accumulation was observed in αvβ6- tumors. Irrespective of the dimerization approach, all divalent probes showed three-fold higher tumor uptake than the monovalent probe, indicating the role of valency in signal enhancement. However, the divalent probes have elevated uptake in non-target organs, especially the kidneys. To abrogate nonspecific uptake, the peptide's N-terminus was acetylated. The resultant bivalent probe, 64Cu- AcD10, showed drastic decrease of kidney accumulation while maintaining tumor uptake. In conclusion, we developed an αvβ6-integrin specific probe with optimized biodistribution for noninvasive PET imaging of NSCLC. Further, we have demonstrated that use of multivalent scaffolds is a plausible method to improve library selected peptides, which would be suboptimal or useless otherwise, for imaging probe development.
Collapse
|
38
|
Neubauer S, Rechenmacher F, Brimioulle R, Di Leva FS, Bochen A, Sobahi TR, Schottelius M, Novellino E, Mas-Moruno C, Marinelli L, Kessler H. Pharmacophoric modifications lead to superpotent αvβ3 integrin ligands with suppressed α5β1 activity. J Med Chem 2014; 57:3410-7. [PMID: 24654918 DOI: 10.1021/jm500092w] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The selective targeting of the αvβ3 integrin subtype without affecting the structurally closely related receptor α5β1 is crucial for understanding the details of their biological and pathological functions and thus of great relevance for diagnostic and therapeutic approaches in cancer treatment. Here, we present the synthesis of highly active RGD peptidomimetics for the αvβ3 integrin with remarkable selectivity against α5β1. Incorporation of a methoxypyridine building block into a ligand scaffold and variation of different functional moieties led to αvβ3-antagonistic activities in the low nanomolar or even subnanomolar range. Furthermore, docking studies were performed to give insights into the binding modes of the novel compounds. The presented library comprises powerful ligands for specific addressing and blocking of the αvβ3 integrin subtype, thereby representing privileged tools for integrin-based personalized medicine.
Collapse
Affiliation(s)
- Stefanie Neubauer
- Department Chemie, Institute for Advanced Study (IAS) and Center of Integrated Protein Science (CIPSM), Technische Universität München , Lichtenbergstrasse 4, 85747 Garching, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Liu Z, Liu H, Ma T, Sun X, Shi J, Jia B, Sun Y, Zhan J, Zhang H, Zhu Z, Wang F. Integrin αvβ6–Targeted SPECT Imaging for Pancreatic Cancer Detection. J Nucl Med 2014; 55:989-94. [PMID: 24711651 DOI: 10.2967/jnumed.113.132969] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 02/14/2014] [Indexed: 01/15/2023] Open
|
40
|
Zhu X, Li J, Hong Y, Kimura RH, Ma X, Liu H, Qin C, Hu X, Hayes TR, Benny P, Gambhir SS, Cheng Z. 99mTc-labeled cystine knot peptide targeting integrin αvβ6 for tumor SPECT imaging. Mol Pharm 2014; 11:1208-17. [PMID: 24524409 PMCID: PMC3993876 DOI: 10.1021/mp400683q] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Integrin
αvβ6 is overexpressed
in a variety of cancers, and its expression is often associated with
poor prognosis. Therefore, there is a need to develop affinity reagents
for noninvasive imaging of integrin αvβ6 expression since it may provide early cancer diagnosis, more
accurate prognosis, and better treatment planning. We recently engineered
and validated highly stable cystine knot peptides that selectively
bind integrin αvβ6 with no cross-reactivity
to integrins αvβ5, α5β1, or αvβ3, also
known to be overexpressed in many cancers. Here, we developed a single
photon emission computed tomography (SPECT) probe for imaging integrin
αvβ6 positive tumors. Cystine knot
peptide, S02, was first conjugated with a single amino
acid chelate (SAAC) and labeled with [99mTc(H2O)3(CO)3]+. The resulting probe, 99mTc-SAAC-S02, was then evaluated by in
vitro cell uptake studies using two αvβ6 positive cell lines (human lung adenocarcinoma cell line
HCC4006 and pancreatic cancer cell line BxPC-3) and two αvβ6 negative cell lines (human lung adenocarcinoma
cell line H838 and human embryonic kidney cell line 293T). Next, SPECT/CT
and biodistribution studies were performed in nude mice bearing HCC4006
and H838 tumor xenografts to evaluate the in vivo performance of 99mTc-SAAC-S02. Significant
differences in the uptake of 99mTc-SAAC-S02
were observed in αvβ6 positive vs
negative cells (P < 0.05). Biodistribution and
small animal SPECT/CT studies revealed that 99mTc-SAAC-S02 accumulated to moderate levels in antigen positive tumors
(∼2% ID/g at 1 and 6 h postinjection, n =
3 or 4/group). Moreover, the probe demonstrated tumor-to-background
tissue ratios of 6.81 ± 2.32 (tumor-to-muscle) and 1.63 ±
0.18 (tumor-to-blood) at 6 h postinjection in αvβ6 positive tumor xenografts. Co-incubation of the probe with
excess amount of unlabeled S02 as a blocking agent demonstrated
significantly reduced tumor uptake, which is consistent with specific
binding to the target. Renal filtration was the main route of clearance.
In conclusion, knottin peptides are excellent scaffolds for which
to develop highly stable imaging probes for a variety of oncological
targets. 99mTc-SAAC-S02 demonstrates promise
for use as a SPECT agent to image integrin αvβ6 expression in living systems.
Collapse
Affiliation(s)
- Xiaohua Zhu
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, and Bio-X Program, Canary Center at Stanford for Cancer Early Detection, Stanford University , Stanford, California 94305-5344, United States
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Chen ZY, Wang YX, Lin Y, Zhang JS, Yang F, Zhou QL, Liao YY. Advance of molecular imaging technology and targeted imaging agent in imaging and therapy. BIOMED RESEARCH INTERNATIONAL 2014; 2014:819324. [PMID: 24689058 PMCID: PMC3943245 DOI: 10.1155/2014/819324] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2013] [Revised: 12/29/2013] [Accepted: 12/30/2013] [Indexed: 02/06/2023]
Abstract
Molecular imaging is an emerging field that integrates advanced imaging technology with cellular and molecular biology. It can realize noninvasive and real time visualization, measurement of physiological or pathological process in the living organism at the cellular and molecular level, providing an effective method of information acquiring for diagnosis, therapy, and drug development and evaluating treatment of efficacy. Molecular imaging requires high resolution and high sensitive instruments and specific imaging agents that link the imaging signal with molecular event. Recently, the application of new emerging chemical technology and nanotechnology has stimulated the development of imaging agents. Nanoparticles modified with small molecule, peptide, antibody, and aptamer have been extensively applied for preclinical studies. Therapeutic drug or gene is incorporated into nanoparticles to construct multifunctional imaging agents which allow for theranostic applications. In this review, we will discuss the characteristics of molecular imaging, the novel imaging agent including targeted imaging agent and multifunctional imaging agent, as well as cite some examples of their application in molecular imaging and therapy.
Collapse
Affiliation(s)
- Zhi-Yi Chen
- Department of Ultrasound Medicine, Laboratory of Ultrasound Molecular Imaging, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, China
| | - Yi-Xiang Wang
- Department of Imaging and Interventional Radiology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Yan Lin
- Department of Ultrasound Medicine, Laboratory of Ultrasound Molecular Imaging, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, China
| | - Jin-Shan Zhang
- Department of Nuclear Medicine, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, China
| | - Feng Yang
- Department of Ultrasound Medicine, Laboratory of Ultrasound Molecular Imaging, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, China
| | - Qiu-Lan Zhou
- Department of Ultrasound Medicine, Laboratory of Ultrasound Molecular Imaging, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, China
| | - Yang-Ying Liao
- Department of Ultrasound Medicine, Laboratory of Ultrasound Molecular Imaging, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, China
| |
Collapse
|
42
|
Stern LA, Case BA, Hackel BJ. Alternative Non-Antibody Protein Scaffolds for Molecular Imaging of Cancer. Curr Opin Chem Eng 2013; 2. [PMID: 24358455 DOI: 10.1016/j.coche.2013.08.009] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The development of improved methods for early detection and characterization of cancer presents a major clinical challenge. One approach that has shown excellent potential in preclinical and clinical evaluation is molecular imaging with small-scaffold, non-antibody based, engineered proteins. These novel diagnostic agents produce high contrast images due to their fast clearance from the bloodstream and healthy tissues, can be evolved to bind a multitude of cancer biomarkers, and are easily functionalized by site-specific bioconjugation methods. Several small protein scaffolds have been verified for in vivo molecular imaging including affibodies and their two-helix variants, knottins, fibronectins, DARPins, and several natural ligands. Further, the biodistribution of these engineered ligands can be optimized through rational mutation of the conserved regions, careful selection and placement of chelator, and modification of molecular size.
Collapse
Affiliation(s)
- Lawrence A Stern
- Department of Chemical Engineering and Materials Science, University of Minnesota - Twin Cities, Minneapolis, MN 55455
| | - Brett A Case
- Department of Chemical Engineering and Materials Science, University of Minnesota - Twin Cities, Minneapolis, MN 55455
| | - Benjamin J Hackel
- Department of Chemical Engineering and Materials Science, University of Minnesota - Twin Cities, Minneapolis, MN 55455
| |
Collapse
|
43
|
Qin S, Fite BZ, Gagnon MKJ, Seo JW, Curry FR, Thorsen F, Ferrara KW. A physiological perspective on the use of imaging to assess the in vivo delivery of therapeutics. Ann Biomed Eng 2013; 42:280-98. [PMID: 24018607 DOI: 10.1007/s10439-013-0895-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Accepted: 08/14/2013] [Indexed: 12/25/2022]
Abstract
Our goal is to provide a physiological perspective on the use of imaging to optimize and monitor the accumulation of nanotherapeutics within target tissues, with an emphasis on evaluating the pharmacokinetics of organic particles. Positron emission tomography (PET), magnetic resonance imaging (MRI) and ultrasound technologies, as well as methods to label nanotherapeutic constructs, have created tremendous opportunities for preclinical optimization of therapeutics and for personalized treatments in challenging disease states. Within the methodology summarized here, the accumulation of the construct is estimated directly from the image intensity. Particle extravasation is then estimated based on classical physiological measures. Specifically, the transport of nanotherapeutics is described using the concept of apparent permeability, which is defined as the net flux of solute across a blood vessel wall per unit surface area of the blood vessel and per unit solute concentration difference across the blood vessel wall. The apparent permeability to small molecule MRI constructs is accurately shown to be far larger than that estimated for proteins such as albumin or nanoconstructs such as liposomes. Further, the quantitative measurements of vascular permeability are shown to facilitate detection of the transition from a pre-malignant to a malignant cancer and to quantify the delivery enhancement resulting from interventions such as ultrasound. While PET-based estimates facilitate quantitative comparisons of many constructs, high field MRI proves useful in the visualization of model drugs within small lesions and in the evaluation of the release and intracellular trafficking of nanoparticles and cargo.
Collapse
Affiliation(s)
- Shengping Qin
- Department of Biomedical Engineering, University of California, Davis, Davis, CA, USA,
| | | | | | | | | | | | | |
Collapse
|
44
|
Marelli UK, Rechenmacher F, Sobahi TRA, Mas-Moruno C, Kessler H. Tumor Targeting via Integrin Ligands. Front Oncol 2013; 3:222. [PMID: 24010121 PMCID: PMC3757457 DOI: 10.3389/fonc.2013.00222] [Citation(s) in RCA: 165] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 08/13/2013] [Indexed: 01/02/2023] Open
Abstract
Selective and targeted delivery of drugs to tumors is a major challenge for an effective cancer therapy and also to overcome the side-effects associated with current treatments. Overexpression of various receptors on tumor cells is a characteristic structural and biochemical aspect of tumors and distinguishes them from physiologically normal cells. This abnormal feature is therefore suitable for selectively directing anticancer molecules to tumors by using ligands that can preferentially recognize such receptors. Several subtypes of integrin receptors that are crucial for cell adhesion, cell signaling, cell viability, and motility have been shown to have an upregulated expression on cancer cells. Thus, ligands that recognize specific integrin subtypes represent excellent candidates to be conjugated to drugs or drug carrier systems and be targeted to tumors. In this regard, integrins recognizing the RGD cell adhesive sequence have been extensively targeted for tumor-specific drug delivery. Here we review key recent examples on the presentation of RGD-based integrin ligands by means of distinct drug-delivery systems, and discuss the prospects of such therapies to specifically target tumor cells.
Collapse
Affiliation(s)
- Udaya Kiran Marelli
- Institute for Advanced Study (IAS) and Center for Integrated Protein Science (CIPSM), Department Chemie, Technische Universität München , Garching , Germany
| | | | | | | | | |
Collapse
|