PT - JOURNAL ARTICLE AU - Hui Wang AU - Dan Li AU - Shuanglong Liu AU - Ren Liu AU - Hong Yuan AU - Valery Krasnoperov AU - Hong Shan AU - Peter S. Conti AU - Parkash S. Gill AU - Zibo Li TI - Small-Animal PET Imaging of Pancreatic Cancer Xenografts Using a <sup>64</sup>Cu-Labeled Monoclonal Antibody, MAb159 AID - 10.2967/jnumed.115.155812 DP - 2015 Jun 01 TA - Journal of Nuclear Medicine PG - 908--913 VI - 56 IP - 6 4099 - http://jnm.snmjournals.org/content/56/6/908.short 4100 - http://jnm.snmjournals.org/content/56/6/908.full SO - J Nucl Med2015 Jun 01; 56 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.