Skip to main content
main-content

01.09.2009 | Original Article | Ausgabe 9/2009

European Journal of Nuclear Medicine and Molecular Imaging 9/2009

The influence of Bz-DOTA and CHX-A″-DTPA on the biodistribution of ABD-fused anti-HER2 Affibody molecules: implications for 114mIn-mediated targeting therapy

Zeitschrift:
European Journal of Nuclear Medicine and Molecular Imaging > Ausgabe 9/2009
Autoren:
Vladimir Tolmachev, Helena Wållberg, Karl Andersson, Anders Wennborg, Hans Lundqvist, Anna Orlova

Abstract

Purpose

Affibody molecules represent a novel class of high-affinity agents for radionuclide tumour targeting. Fusion of the Affibody molecules with an albumin-binding domain (ABD) enables modification of the blood kinetics of the Affibody molecules and reduction of the renal dose. 177Lu-CHX-A″-DTPA-ABD-(ZHER2:342)2, an anti-HER2 Affibody molecule-ABD fusion protein has earlier demonstrated promising results in treatment of HER2-expressing micro-xenografts in mice. The use of the in vivo generator 114mIn/114In as a label for ABD-fused Affibody molecules would create preconditions for efficient treatment of both micrometastases (due to conversion and Auger electrons of 114mIn) and bulky tumours (due to high-energy beta particles from the daughter nuclide 114In). The goal of this study was to investigate if different chelators influence the biodistribution of ABD-(ZHER2:342)2 and to find an optimal chelator for attachment of 114mIn to the Affibody molecule-ABD fusion protein.

Methods

Isothiocyanate derivatives of Bz-DOTA and CHX-A″-DTPA were coupled to ABD-(ZHER2:342)2. The cellular processing of both conjugates was studied in vitro. The influence of chelators on the biodistribution was investigated in mice using double isotope (114mIn and 111In) labelling.

Results

The apparent affinity of CHX-A″-DTPA-ABD-(ZHER2:342)2 and Bz-DOTA-ABD-(ZHER2:342)2 to the extracellular domain of HER2 was similar, 13.5 and 15.0 pM, respectively. It was found that both conjugates were internalized by SKOV-3 cells. The use of CHX-A″-DTPA provided better cellular retention of the radioactivity, better tumour accumulation of radioactivity and better tumour to organ dose ratios than Bz-DOTA-ABD-(ZHER2:342)2.

Conclusion

CHX-A″-DTPA is more suitable for 114mIn labelling of Affibody molecule-ABD fusion proteins for radionuclide therapy.

Bitte loggen Sie sich ein, um Zugang zu diesem Inhalt zu erhalten

★ PREMIUM-INHALT
e.Med Interdisziplinär

Mit e.Med Interdisziplinär erhalten Sie Zugang zu allen CME-Fortbildungen und Fachzeitschriften auf SpringerMedizin.de. Zusätzlich können Sie eine Zeitschrift Ihrer Wahl in gedruckter Form beziehen – ohne Aufpreis.

Weitere Produktempfehlungen anzeigen
Literatur
Über diesen Artikel

Weitere Artikel der Ausgabe 9/2009

European Journal of Nuclear Medicine and Molecular Imaging 9/2009 Zur Ausgabe
  1. Das kostenlose Testabonnement läuft nach 14 Tagen automatisch und formlos aus. Dieses Abonnement kann nur einmal getestet werden.

  2. Das kostenlose Testabonnement läuft nach 14 Tagen automatisch und formlos aus. Dieses Abonnement kann nur einmal getestet werden.