RT Journal Article SR Electronic T1 Small-Animal PET Imaging of Pancreatic Cancer Xenografts Using a 64Cu-Labeled Monoclonal Antibody, MAb159 JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 908 OP 913 DO 10.2967/jnumed.115.155812 VO 56 IS 6 A1 Hui Wang A1 Dan Li A1 Shuanglong Liu A1 Ren Liu A1 Hong Yuan A1 Valery Krasnoperov A1 Hong Shan A1 Peter S. Conti A1 Parkash S. Gill A1 Zibo Li YR 2015 UL http://jnm.snmjournals.org/content/56/6/908.abstract AB Overexpression of the GRP78 receptor on cell surfaces has been linked with tumor growth, metastasis, and resistance to therapy. We developed a 64Cu-labeled probe for PET imaging of tumor GRP78 expression based on a novel anti-GRP78 monoclonal antibody, MAb159. Methods: MAb159 was conjugated with the 64Cu-chelator DOTA through lysines on the antibody. DOTA–human IgG was also prepared as a control that did not bind to GRP78. The resulting PET probes were evaluated in BXPC3 pancreatic cancer xenografts in athymic nude mice. Results: The radiotracer was synthesized with a specific activity of 0.8 MBq/μg of antibody. In BXPC3 xenografts, 64Cu-DOTA-MAb159 demonstrated prominent tumor accumulation (4.3 ± 1.2, 15.4 ± 2.6, and 18.3 ± 1.0 percentage injected dose per gram at 1, 17, and 48 after injection, respectively). In contrast, 64Cu-DOTA–human IgG had low BXPC3 tumor accumulation (4.8 ± 0.5, 7.5 ± 0.7, and 4.6 ± 0.8 percentage injected dose per gram at 1, 17, and 48 h after injection, respectively). Conclusion: We demonstrated that GRP78 can serve as a valid target for pancreatic cancer imaging. The success of this approach will be valuable for evaluating disease course and therapeutic efficacy at the earliest stages of anti-GRP78 treatment. Moreover, these newly developed probes may have important applications in other types of cancer overexpressing GRP78.