Skip to main content

Main menu

  • Home
  • Content
    • Current
    • Ahead of print
    • Past Issues
    • JNM Supplement
    • SNMMI Annual Meeting Abstracts
    • Continuing Education
    • JNM Podcasts
  • Subscriptions
    • Subscribers
    • Institutional and Non-member
    • Rates
    • Journal Claims
    • Corporate & Special Sales
  • Authors
    • Submit to JNM
    • Information for Authors
    • Assignment of Copyright
    • AQARA requirements
  • Info
    • Reviewers
    • Permissions
    • Advertisers
  • About
    • About Us
    • Editorial Board
    • Contact Information
  • More
    • Alerts
    • Feedback
    • Help
    • SNMMI Journals
  • SNMMI
    • JNM
    • JNMT
    • SNMMI Journals
    • SNMMI

User menu

  • Subscribe
  • My alerts
  • Log in
  • My Cart

Search

  • Advanced search
Journal of Nuclear Medicine
  • SNMMI
    • JNM
    • JNMT
    • SNMMI Journals
    • SNMMI
  • Subscribe
  • My alerts
  • Log in
  • My Cart
Journal of Nuclear Medicine

Advanced Search

  • Home
  • Content
    • Current
    • Ahead of print
    • Past Issues
    • JNM Supplement
    • SNMMI Annual Meeting Abstracts
    • Continuing Education
    • JNM Podcasts
  • Subscriptions
    • Subscribers
    • Institutional and Non-member
    • Rates
    • Journal Claims
    • Corporate & Special Sales
  • Authors
    • Submit to JNM
    • Information for Authors
    • Assignment of Copyright
    • AQARA requirements
  • Info
    • Reviewers
    • Permissions
    • Advertisers
  • About
    • About Us
    • Editorial Board
    • Contact Information
  • More
    • Alerts
    • Feedback
    • Help
    • SNMMI Journals
  • View or Listen to JNM Podcast
  • Visit JNM on Facebook
  • Join JNM on LinkedIn
  • Follow JNM on Twitter
  • Subscribe to our RSS feeds
OtherBasic Science (Animal or Phantoms)

Targeting Fibroblast Activation Protein: Radiosynthesis and Preclinical Evaluation of an 18F-labeled FAP Inhibitor

Johannes Toms, Jürgen Kogler, Simone Maschauer, Christoph Daniel, Christian Schmidkonz, Torsten Kuwert and Olaf Prante
Journal of Nuclear Medicine April 2020, jnumed.120.242958; DOI: https://doi.org/10.2967/jnumed.120.242958
Johannes Toms
1 Friedrich-Alexander University Erlangen-Nürnberg (FAU), Department of Nuclear Medicine, Germany;
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Jürgen Kogler
1 Friedrich-Alexander University Erlangen-Nürnberg (FAU), Department of Nuclear Medicine, Germany;
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Simone Maschauer
1 Friedrich-Alexander University Erlangen-Nürnberg (FAU), Department of Nuclear Medicine, Germany;
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Christoph Daniel
2 Friedrich-Alexander University Erlangen-Nürnberg (FAU), Department of Nephropathology, Germany
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Christian Schmidkonz
1 Friedrich-Alexander University Erlangen-Nürnberg (FAU), Department of Nuclear Medicine, Germany;
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Torsten Kuwert
1 Friedrich-Alexander University Erlangen-Nürnberg (FAU), Department of Nuclear Medicine, Germany;
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Olaf Prante
1 Friedrich-Alexander University Erlangen-Nürnberg (FAU), Department of Nuclear Medicine, Germany;
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • Article
  • Figures & Data
  • Supplemental
  • Info & Metrics
  • PDF
Loading

Abstract

Fibroblast activation protein (FAP) has emerged as an interesting molecular target used in the imaging and therapy of various types of cancers. Gallium-68–labeled chelator-linked FAP inhibitors (FAPIs) have been successfully applied to positron emission tomography (PET) imaging of various tumor types. To broaden the spectrum of applicable PET tracers for extended imaging studies of FAP-dependent diseases, we herein report the radiosynthesis and preclinical evaluation of an 18F–labeled glycosylated FAP inhibitor ([18F]FGlc-FAPI). Methods: An alkyne-bearing precursor was synthesized and subjected to click chemistry–based radiosynthesis of [18F]FGlc-FAPI by two-step 18F-fluoroglycosylation. FAP-expressing HT1080hFAP cells were used to study competitive binding to FAP, cellular uptake, internalization, and efflux of [18F]FGlc-FAPI in vitro. Biodistribution studies and in vivo small animal PET studies of [18F]FGlc-FAPI compared to [68Ga]Ga-FAPI-04 were conducted in nude mice bearing HT1080hFAP tumors or U87MG xenografts. Results: [18F]FGlc-FAPI was synthesized with a 15% radioactivity yield and a high radiochemical purity of >99%. In HT1080hFAP cells, [18F]FGlc-FAPI showed specific uptake, a high internalized fraction, and low cellular efflux. Compared to FAPI-04 (IC50 = 32 nM), the glycoconjugate, FGlc-FAPI (IC50 = 167 nM), showed slightly lower affinity for FAP in vitro, while plasma protein binding was higher for [18F]FGlc-FAPI. Biodistribution studies revealed significant hepatobiliary excretion of [18F]FGlc-FAPI; however, small animal PET studies in HT1080hFAP xenografts showed higher specific tumor uptake of [18F]FGlc-FAPI (4.5 % injected dose per gram of tissue [ID/g]) compared to [68Ga]Ga-FAPI-04 (2 %ID/g). In U87MG tumor–bearing mice, both tracers showed similar tumor uptake, but [18F]FGlc-FAPI showed a higher tumor retention. Interestingly, [18F]FGlc-FAPI demonstrated high specific uptake in bone structures and joints. Conclusion: [18F]FGlc-FAPI is an interesting candidate for translation to the clinic, taking advantage of the longer half-life and physical imaging properties of F-18. The availability of [18F]FGlc-FAPI may allow extended PET studies of FAP-related diseases, such as cancer, but also arthritis, heart diseases, or pulmonary fibrosis.

  • Molecular Imaging
  • Oncology: General
  • Radiopharmaceuticals
  • cancer-associated fibroblasts
  • fibroblast activation protein
  • fluorine-18
  • fluoroglycosylation
  • positron emission tomography
  • Copyright © 2020 by the Society of Nuclear Medicine and Molecular Imaging, Inc.
PreviousNext
Back to top

In this issue

Journal of Nuclear Medicine: 66 (5)
Journal of Nuclear Medicine
Vol. 66, Issue 5
May 1, 2025
  • Table of Contents
  • Table of Contents (PDF)
  • About the Cover
  • Index by author
  • Complete Issue (PDF)
Download PDF
Article Alerts
Sign In to Email Alerts with your Email Address
Email Article

Thank you for your interest in spreading the word on Journal of Nuclear Medicine.

NOTE: We only request your email address so that the person you are recommending the page to knows that you wanted them to see it, and that it is not junk mail. We do not capture any email address.

Enter multiple addresses on separate lines or separate them with commas.
Targeting Fibroblast Activation Protein: Radiosynthesis and Preclinical Evaluation of an 18F-labeled FAP Inhibitor
(Your Name) has sent you a message from Journal of Nuclear Medicine
(Your Name) thought you would like to see the Journal of Nuclear Medicine web site.
Citation Tools
Targeting Fibroblast Activation Protein: Radiosynthesis and Preclinical Evaluation of an 18F-labeled FAP Inhibitor
Johannes Toms, Jürgen Kogler, Simone Maschauer, Christoph Daniel, Christian Schmidkonz, Torsten Kuwert, Olaf Prante
Journal of Nuclear Medicine Apr 2020, jnumed.120.242958; DOI: 10.2967/jnumed.120.242958

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero
Share
Targeting Fibroblast Activation Protein: Radiosynthesis and Preclinical Evaluation of an 18F-labeled FAP Inhibitor
Johannes Toms, Jürgen Kogler, Simone Maschauer, Christoph Daniel, Christian Schmidkonz, Torsten Kuwert, Olaf Prante
Journal of Nuclear Medicine Apr 2020, jnumed.120.242958; DOI: 10.2967/jnumed.120.242958
Twitter logo Facebook logo LinkedIn logo Mendeley logo
  • Tweet Widget
  • Facebook Like
  • Google Plus One
Bookmark this article

Jump to section

  • Article
  • Figures & Data
  • Supplemental
  • Info & Metrics
  • PDF

Related Articles

  • This Month in JNM
  • PubMed
  • Google Scholar

Cited By...

  • Molecular Imaging with Fibroblast Activation Protein Tracers depicts Inflammatory Joint Damage and its Transition to Resolution of Inflammation
  • Synthesis, Preclinical Evaluation, and a Pilot Clinical PET Imaging Study of 68Ga-Labeled FAPI Dimer
  • FAPI PET/CT: Will It End the Hegemony of 18F-FDG in Oncology?
  • Google Scholar

Similar Articles

Keywords

  • Molecular imaging
  • Oncology: General
  • radiopharmaceuticals
  • cancer-associated fibroblasts
  • fibroblast activation protein
  • fluorine-18
  • fluoroglycosylation
  • Positron Emission Tomography
SNMMI

© 2025 SNMMI

Powered by HighWire