Aptameer-gebaseerde radiofarmaca: karakterisatie van het HB5 aptameer tegen HER2+ borstkanker: Aptamer-based radiopharamceuticals: characterization of the HB5 aptamer targeting HER2 in breast cancer

This thesis is embedded in the CATAMARAN research project, which is aimed at developing aptamer-based radiopharmaceuticals for targeted radiotherapy and molecular diagnosis of cancers. In this thesis, we attempted to characterize in vitro the binding properties of the DNA aptamer HB5. This aptamer is already described in literature and targets the protein HER2, which is overexpressed in several cancer cells including breast cancer. The first step is the production of HB5 in sufficient quantities. Herefore, we performed asymmetric PCR or PCR with a subsequent separation of the double-stranded PCR product. We can conclude that both techniques are not ideal in the production of HB5, especially regarding the production of pure aptamers. Next, flow cytometry is used to study the binding properties to HER2. We can conclude that a subtile binding can be detected, although it was difficult to confirm. Finally, the chemical toxicity of gallium3+, suitable for molecular imaging, and its decay product of zinc were investigated on endothelial cells using flow cytometry. We can conclude that in vitro no toxic effects were observed with the diagnostic doses.