Panel Disdussion

3rd International Congress 3rd International of Nuclear Congress Medicine of Nuclear & 15th Medicine Iranian Annual & 15th Iranian Congress Annual of
Nuclear Congress Medicine of Nuclear Medicine
Shahid Beheshti Shahid Beheshti University University of Medical Sciences of Medical 19-21 Sciences May 201119-21 May 2011
Radiolabeled Affibody molecules as novel class of tumor
targeted peptides for imaging and therapy
Seyed Jalal Hosseinimehr 1 , Anna Orlova 2 , Vladimir Tolmachev 2 ,
1 Department of Radiopharmacy
2 Division of Biomedical Radiation Sciences, Uppsala, Sweden
Affibody molecules are small, very stable, 58-amino acid residue
proteins derived from one of the IgG-binding domains of
staphylococcal protein A with the three-helix bundle structure.
Affibody molecules with small size (7 kDa) have rapid tumor
localization with fast clearance from nonspecific tissues. Affibody
molecules can bind to HER2, IGF-1R and EGFR with high affinity. With
these advantages, Affibody molecules are interesting as tumor
targeted peptide for nuclear medicine. Another advantage of Affibody
molecules is that they can be labeled with different radionuclides
such as gamma- and beta- emitters for imaging and therapy.
Recently, our research team prepared radiolabeled Affibody molecule
for tumor imaging with 99mTc and 111In. These radiolabeled
peptides showed excellent specific binding in vitro. Tumor bearing
mice imaging showed a high contrast imaging with tumor localization.
Affibody molecules can be labeled with beta emitters, such as 177Lu
or 186Re, and used a therapeutic agents. Recently, we have evaluate
a series of peptide-based chelators for 99mTc (and potentially for
186/188 Re), which can be incorporated a C-orN-terminus of Affibody
molecules. We have shown that modification of amino acids in such
chelators enables modification of biodistribution of Affibody
molecules.
Keywords: Affibody, molecules imaging, 99mTc
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