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Generation and evaluation of antibody agents for molecular imaging of CD44v6-expressing cancers
AIM: The aim of this study was to generate and characterize scFv antibodies directed to human CD44v6, as well as to radiolabel and evaluate top candidates in vitro and in vivo for their potential use in CD44v6-targeted molecular imaging in cancer patients. MATERIALS AND METHODS: Phage display select...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Impact Journals LLC
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5630320/ https://www.ncbi.nlm.nih.gov/pubmed/29029420 http://dx.doi.org/10.18632/oncotarget.17996 |
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author | Haylock, Anna-Karin Nilvebrant, Johan Mortensen, Anja Velikyan, Irina Nestor, Marika Falk, Ronny |
author_facet | Haylock, Anna-Karin Nilvebrant, Johan Mortensen, Anja Velikyan, Irina Nestor, Marika Falk, Ronny |
author_sort | Haylock, Anna-Karin |
collection | PubMed |
description | AIM: The aim of this study was to generate and characterize scFv antibodies directed to human CD44v6, as well as to radiolabel and evaluate top candidates in vitro and in vivo for their potential use in CD44v6-targeted molecular imaging in cancer patients. MATERIALS AND METHODS: Phage display selections were used to isolate CD44v6-specific scFvs. A chain shuffling strategy was employed for affinity maturation based on a set of CD44v6-specific first-generation clones. Two second-generation scFv clones were then chosen for labeling with (111)In or (125)I and assessed for CD44v6-specific binding on cultured tumor cells. In vivo uptake and distribution was evaluated in tumor-bearing mice using a dual tumor model. Finally, a proof-of-concept small animal PET-CT study was performed on one of the candidates labeled with (124)I. RESULTS: Two affinity-matured clones, CD44v6-scFv-A11 and CD44v6-scFv-H12, displayed promising binding kinetics. Seven out of eight radiolabeled conjugates demonstrated CD44v6-specific binding. In vivo studies on selected candidates demonstrated very advantageous tumor-to-organ ratios, in particular for iodinated conjugates, where (125)I-labeled scFvs exhibited favorable kinetics and tumor-to-blood ratios above five already at 24 hours p.i.. The small animal PET-CT study using (124)I-labeled CD44v6-scFv-H12 was in line with the biodistribution data, clearly visualizing the high CD44v6-expressing tumor. CONCLUSION: The single chain fragments, CD44v6-scFv-A11 and CD44v6-scFv-H12 specifically bind to CD44v6, and the radiolabeled counterparts provide high tumor-to-blood ratios and fast clearance from organs and blood. We conclude that radioiodinated CD44v6-scFv-A11 and CD44v6-scFv-H12 possess features highly suitable for stringent molecular imaging. |
format | Online Article Text |
id | pubmed-5630320 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | Impact Journals LLC |
record_format | MEDLINE/PubMed |
spelling | pubmed-56303202017-10-12 Generation and evaluation of antibody agents for molecular imaging of CD44v6-expressing cancers Haylock, Anna-Karin Nilvebrant, Johan Mortensen, Anja Velikyan, Irina Nestor, Marika Falk, Ronny Oncotarget Research Paper AIM: The aim of this study was to generate and characterize scFv antibodies directed to human CD44v6, as well as to radiolabel and evaluate top candidates in vitro and in vivo for their potential use in CD44v6-targeted molecular imaging in cancer patients. MATERIALS AND METHODS: Phage display selections were used to isolate CD44v6-specific scFvs. A chain shuffling strategy was employed for affinity maturation based on a set of CD44v6-specific first-generation clones. Two second-generation scFv clones were then chosen for labeling with (111)In or (125)I and assessed for CD44v6-specific binding on cultured tumor cells. In vivo uptake and distribution was evaluated in tumor-bearing mice using a dual tumor model. Finally, a proof-of-concept small animal PET-CT study was performed on one of the candidates labeled with (124)I. RESULTS: Two affinity-matured clones, CD44v6-scFv-A11 and CD44v6-scFv-H12, displayed promising binding kinetics. Seven out of eight radiolabeled conjugates demonstrated CD44v6-specific binding. In vivo studies on selected candidates demonstrated very advantageous tumor-to-organ ratios, in particular for iodinated conjugates, where (125)I-labeled scFvs exhibited favorable kinetics and tumor-to-blood ratios above five already at 24 hours p.i.. The small animal PET-CT study using (124)I-labeled CD44v6-scFv-H12 was in line with the biodistribution data, clearly visualizing the high CD44v6-expressing tumor. CONCLUSION: The single chain fragments, CD44v6-scFv-A11 and CD44v6-scFv-H12 specifically bind to CD44v6, and the radiolabeled counterparts provide high tumor-to-blood ratios and fast clearance from organs and blood. We conclude that radioiodinated CD44v6-scFv-A11 and CD44v6-scFv-H12 possess features highly suitable for stringent molecular imaging. Impact Journals LLC 2017-05-18 /pmc/articles/PMC5630320/ /pubmed/29029420 http://dx.doi.org/10.18632/oncotarget.17996 Text en Copyright: © 2017 Haylock et al. http://creativecommons.org/licenses/by/3.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/) 3.0 (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
spellingShingle | Research Paper Haylock, Anna-Karin Nilvebrant, Johan Mortensen, Anja Velikyan, Irina Nestor, Marika Falk, Ronny Generation and evaluation of antibody agents for molecular imaging of CD44v6-expressing cancers |
title | Generation and evaluation of antibody agents for molecular imaging of CD44v6-expressing cancers |
title_full | Generation and evaluation of antibody agents for molecular imaging of CD44v6-expressing cancers |
title_fullStr | Generation and evaluation of antibody agents for molecular imaging of CD44v6-expressing cancers |
title_full_unstemmed | Generation and evaluation of antibody agents for molecular imaging of CD44v6-expressing cancers |
title_short | Generation and evaluation of antibody agents for molecular imaging of CD44v6-expressing cancers |
title_sort | generation and evaluation of antibody agents for molecular imaging of cd44v6-expressing cancers |
topic | Research Paper |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5630320/ https://www.ncbi.nlm.nih.gov/pubmed/29029420 http://dx.doi.org/10.18632/oncotarget.17996 |
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