Abstract #0320

Specific Targeting of EGF Receptor Expression with Monoclonal Antibody Conjugates in Human Gliomas using MRI

Mohammed Salman Shazeeb^1,2, Christopher Howard Sotak^1,3, Alexei Bogdanov, Jr.^3,4

¹Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA, USA; ²Graduate School of Biomedical Sciences, University of Massachusetts Medical School, Worcester, MA, USA; ³Radiology, University of Massachusetts Medical School, Worcester, MA, USA; ⁴Cell Biology, University of Massachusetts Medical School, Worcester, MA, USA

Specific targeted EGF receptor imaging in Gli36 tumor xenografts implanted in the rat brain was achieved using anti-EGFR monoclonal antibody conjugates (mACs) that facilitate local binding of a paramagnetic molecular substrate diTyr-DTPA(Gd) at the EGFR/EGFRvIII-overexpressing sites. Following anti-EGFR mAC administration, diTyr-DTPA(Gd) was retained for a significantly longer period of time as compared to the administration of the contrast agent without mAC or with anti-EpCAM mAC pre-treatment. Retention of diTyr-DTPA(Gd) following anti-EGFR mAC administration is consistent with enzyme-mediated coupling of the paramagnetic agent to EGFR/EGFRvIII-overexpressing cells in the tumor allowing effective MRI visualization of conjugate co-localization at the targeted site.