title: Design, synthesis, and validation of Axl-targeted monoclonal antibody probe for microPET imaging in human lung cancer xenograft.
abstract: Accumulating experimental evidence indicates that overexpression of the oncogenic receptor tyrosine kinase, Axl, plays a key role in the tumorigenesis and metastasis of various types of cancer. The objective of this study is to design a novel imaging probe based on the monoclonal antibody, h173, for microPET imaging of Axl expression in human lung cancer. A bifunctional chelator, DOTA, was conjugated to h173, followed by radiolabeling with (64)Cu. The binding of DOTA-h173 to the Axl receptor was first evaluated by a cell uptake assay and flow cytometry analysis using human lung cancer cell lines. The probe (64)Cu-DOTA-h173 was further evaluated by microPET imaging, and ex vivo histology studies in the Axl-positive A549 tumors. In vitro cellular study showed that Axl probe, (64)Cu-DOTA-h173, was highly immuno-reactive with A549 cells. Western blot analysis confirmed that Axl is highly expressed in the A549 cell line. For microPET imaging, the A549 xenografts demonstrated a significantly higher (64)Cu-DOTA-h173 uptake compared to the NCI-H249 xenograft (a negative control model). Furthermore, (64)Cu-DOTA-h173 uptake in A549 is significantly higher than that of (64)Cu-DOTA-hIgG. Immuno-fluorescence staining was consistent with the in vivo micro-PET imaging results. In conclusion, (64)Cu-DOTA-h173 could be potentially used as a probe for noninvasive imaging of Axl expression, which could collect important information regarding tumor response to Axl-targeted therapeutic interventions.
authors: Molecular Imaging Center, Department of Radiology, University of Southern California , Los Angeles, California 90089, United States.
authors: Shuanglong
authors: S
authors: Liu
authors: Dan
authors: D
authors: Li
authors: Jiacong
authors: J
authors: Guo
authors: Nicolette
authors: N
authors: Canale
authors: Xiuqing
authors: X
authors: Li
authors: Ren
authors: R
authors: Liu
authors: Valery
authors: V
authors: Krasnoperov
authors: Parkash S
authors: PS
authors: Gill
authors: Peter S
authors: PS
authors: Conti
authors: Hong
authors: H
authors: Shan
authors: Zibo
authors: Z
authors: Li
mesh_terms: D000818:Animals; D061067:Antibodies, Monoclonal, Humanized / Q000737:chemistry / Q000493:pharmacokinetics; D015153:Blotting, Western; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000201:enzymology / Q000276:immunology / Q000473:pathology; D003301:Copper Radioisotopes / Q000493:pharmacokinetics; D015195:Drug Design; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000201:enzymology / Q000276:immunology / Q000473:pathology; D051379:Mice; D008819:Mice, Nude; D049268:Positron-Emission Tomography / Q000379:methods*; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors / Q000276:immunology*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D020794:Receptor Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000276:immunology*; D014018:Tissue Distribution; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays; D000094963:Axl Receptor Tyrosine Kinase
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D003301:Copper Radioisotopes; D011518:Proto-Oncogene Proteins; D019275:Radiopharmaceuticals; D020794:Receptor Protein-Tyrosine Kinases; D000094963:Axl Receptor Tyrosine Kinase
keywords: Axl receptor; lung cancer; monoclonal antibody; positron emission tomography (PET)