TY - JOUR
T1 - EphA2 as a Diagnostic Imaging Target in Glioblastoma
T2 - A Positron Emission Tomography/Magnetic Resonance Imaging Study
AU - Puttick, Simon
AU - Stringer, Brett W.
AU - Day, Bryan W.
AU - Bruce, Zara C.
AU - Ensbey, Kathleen S.
AU - Mardon, Karine
AU - Cowin, Gary J.
AU - Thurecht, Kristofer J.
AU - Whittaker, Andrew K.
AU - Fay, Michael
AU - Boyd, Andrew W.
AU - Rose, Stephen
PY - 2015/7/1
Y1 - 2015/7/1
N2 - Noninvasive imaging is a critical technology for diagnosis, classification, and subsequent treatment planning for patients with glioblastoma. It has been shown that the EphA2 receptor tyrosine kinase (RTK) is overexpressed in a number of tumors, including glioblastoma. Expression levels of Eph RTKs have been linked to tumor progression, metastatic spread, and poor patient prognosis. As EphA2 is expressed at low levels in normal neural tissues, this protein represents an attractive imaging target for delineation of tumor infiltration, providing an improved platform for image-guided therapy. In this study, EphA2-4B3, a monoclonal antibody specific to human EphA2, was labeled with 64Cu through conjugation to the chelator 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA). The resulting complex was used as a positron emission tomography (PET) tracer for the acquisition of high-resolution longitudinal PET/ magnetic resonance images. EphA2-4B3-NOTA-64Cu images were qualitatively and quantitatively compared to the current clinical standards of [18F]FDOPA and gadolinium (Gd) contrast-enhanced MRI. We show that EphA2-4B3-NOTA-64Cu effectively delineates tumor boundaries in three different mouse models of glioblastoma. Tumor to brain contrast is significantly higher in EphA2-4B3- NOTA-64Cu images than in [18F]FDOPA images and Gd contrast-enhanced MRI. Furthermore, we show that nonspecific uptake in the liver and spleen can be effectively blocked by a dose of nonspecific (isotype control) IgG.
AB - Noninvasive imaging is a critical technology for diagnosis, classification, and subsequent treatment planning for patients with glioblastoma. It has been shown that the EphA2 receptor tyrosine kinase (RTK) is overexpressed in a number of tumors, including glioblastoma. Expression levels of Eph RTKs have been linked to tumor progression, metastatic spread, and poor patient prognosis. As EphA2 is expressed at low levels in normal neural tissues, this protein represents an attractive imaging target for delineation of tumor infiltration, providing an improved platform for image-guided therapy. In this study, EphA2-4B3, a monoclonal antibody specific to human EphA2, was labeled with 64Cu through conjugation to the chelator 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA). The resulting complex was used as a positron emission tomography (PET) tracer for the acquisition of high-resolution longitudinal PET/ magnetic resonance images. EphA2-4B3-NOTA-64Cu images were qualitatively and quantitatively compared to the current clinical standards of [18F]FDOPA and gadolinium (Gd) contrast-enhanced MRI. We show that EphA2-4B3-NOTA-64Cu effectively delineates tumor boundaries in three different mouse models of glioblastoma. Tumor to brain contrast is significantly higher in EphA2-4B3- NOTA-64Cu images than in [18F]FDOPA images and Gd contrast-enhanced MRI. Furthermore, we show that nonspecific uptake in the liver and spleen can be effectively blocked by a dose of nonspecific (isotype control) IgG.
KW - Neuroimaging
KW - EphA2 receptor tyrosine kinase (RTK)
UR - http://www.scopus.com/inward/record.url?scp=84942863596&partnerID=8YFLogxK
U2 - 10.2310/7290.2015.00008
DO - 10.2310/7290.2015.00008
M3 - Article
C2 - 26218510
AN - SCOPUS:84942863596
VL - 14
SP - 385
EP - 395
JO - Molecular Imaging
JF - Molecular Imaging
SN - 1536-0121
IS - 6
ER -