Authors: AnnCharlott Steffen Anna Orlova Maria Wikman Fredrik Y Nilsson Stefan Ståhl Gregory P Adams Vladimir Tolmachev Jörgen Carlsson
Publish Date: 2006/03/15
Volume: 33, Issue: 6, Pages: 631-638
Abstract
Targeted delivery of radionuclides for diagnostic and therapeutic applications has until recently largely been limited to receptor ligands antibodies and antibodyderived molecules Here we present a new type of molecule a 15kDa bivalent affibody called ZHER242 with potential for such applications The ZHER242 affibody showed high apparent affinity K D=3 nM towards the oncogene product HER2 also called p185/neu or cerbB2 which is often overexpressed in breast and ovarian cancers The purpose of this study was to investigate the in vivo properties of the new targeting agentThe radioiodinated ZHER242 affibody was primarily excreted through the kidneys and significant amounts of radioactivity were specifically targeted to the tumours The bloodborne radioactivity was at all times mainly in the macromolecular fraction A tumourtoblood ratio of about 101 was obtained 8 h post injection and the tumours could be easily visualised with a gamma camera at this time pointThe authors thank Charles Widström at the department of Nuclear Medicine at Uppsala University Hospital for help with the gamma camera Thanks also to Kenneth Wester and Veronika Asplund Eriksson for help with the immunohistochemistry autoradiography and photographic procedures The work was financially supported by grant no 0980B0417XCC 040171 from the Swedish Cancer Society
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