Generation and Evaluation of Bispecific Affibody Molecules for Simultaneous Targeting of EGFR and HER2
2012 (English)In: Bioconjugate chemistry, ISSN 1043-1802, E-ISSN 1520-4812, Vol. 23, no 9, 1802-1811 p.Article in journal (Refereed) Published
Co-expression of several ErbB receptors has been found in many cancers and has been linked with increased aggressiveness of tumors and a worse patient prognosis. This makes the simultaneous targeting of two surface receptors by using bispecific constructs an increasingly appreciated strategy. Here we have generated six such bispecific targeting proteins, which each comprising two monomeric affibody molecules with specific binding to either of the two human epidermal growth factor receptors, EGFR and HER2, respectively. The bispecific constructs were designed with (i) alternative positioning (N- or C-terminal) of the different affibody molecules, (ii) two alternative peptide linkers (Gly4Ser)3 or (Ser4Gly)3, and (iii) affibody molecules with different affinity (nanomolar or picomolar) for HER2. Using both Biacore technology and cell binding assays it was demonstrated that all six constructs could bind simultaneously to both their target proteins. N-terminal positioning of the monomeric affibody molecules was favorable to promote the binding to respective target. Interestingly, bispecific constructs containing the novel (Ser4Gly)3 linker displayed a higher affinity in cell binding, as compared to constructs containing the more conventional linker, (Gly4Ser)3. It could further be concluded that bispecific constructs (but not the monomeric affibody molecules) induced dimerization and phosphorylation of EGFR in SKBR3 cells, which express fairly high levels of both receptors. It was also investigated whether the bispecific binding would influence cell growth or sensitize cells for ionizing radiation, but no such effects were observed.
Place, publisher, year, edition, pages
2012. Vol. 23, no 9, 1802-1811 p.
HER2, EGFR, bispecifik, dual targeting
Medical and Health Sciences
Research subject Biomedical Radiation Science
IdentifiersURN: urn:nbn:se:uu:diva-160172DOI: 10.1021/bc3000645ISI: 000308833600011OAI: oai:DiVA.org:uu-160172DiVA: diva2:449057