Targeting Free Prostate-Specific Antigen for In Vivo Imaging of Prostate Cancer Using a Monoclonal Antibody Specific for Unique Epitopes Accessible on Free Prostate-Specific Antigen Alone.
Author
Summary, in English
This study investigated the feasibility of targeting the free, unbound forms of prostate-specific antigen (fPSA) for in vivo imaging of prostate adenocarcinomas (PCa), as PSA is produced and secreted at abundance during every clinical stage and grade of PCa, including castration-resistant disease. We injected (125)I-labeled monoclonal antibody PSA30 (specific for an epitope uniquely accessible on fPSA alone) intravenously in male nude mice carrying subcutaneous xenografts of LNCaP tumors (n=36). Mice were sacrificed over a time course from 4 hours to 13 days after injecting (125)I-labeled PSA30. Tissue uptake of (125)I-PSA30 at 48 and 168 hours after intravenous injection was compared with two clinically used positron emission tomography radiopharmaceuticals, (18)F-fluoro-deoxy-glucose ((18)F-FDG) or (18)F-choline, in cryosections using Digital AutoRadiography (DAR) and also compared with immunohistochemical staining of PSA and histopathology. On DAR, the areas with high (125)I-PSA30 uptake corresponded mainly to morphologically intact and PSA-producing LNCaP cells, but did not associate with the areas of high uptake of either (18)F-FDG or (18)F-choline. Biodistribution of (125)I-PSA30 measured in dissected organs ex vivo during 4 to 312 hours after intravenous injection demonstrated maximum selective tumor uptake 24-48 hours after antibody injection. Our data showed selective uptake in vivo of a monoclonal antibody highly specific for fPSA in LNCaP cells. Hence, in vivo imaging of fPSA may be feasible with putative usefulness in disseminated PCa.
Department/s
- BioCARE: Biomarkers in Cancer Medicine improving Health Care, Education and Innovation
- Urological cancer, Malmö
- Clinical Chemistry, Malmö
- Systemic Radiation Therapy Group
- Medical Radiation Physics, Malmö
- Head and Neck Cancer Research Group
- Systemic radiation therapy
- Medical Radiation Physics, Lund
- eSSENCE: The e-Science Collaboration
- EpiHealth: Epidemiology for Health
Publishing year
2012
Language
English
Pages
243-251
Publication/Series
Cancer Biotherapy & Radiopharmaceuticals
Volume
27
Issue
4
Document type
Journal article
Publisher
Mary Ann Liebert, Inc.
Topic
- Cancer and Oncology
Status
Published
Research group
- Urological cancer, Malmö
- Clinical Chemistry, Malmö
- Systemic Radiation Therapy Group
- Medical Radiation Physics, Malmö
- Head and Neck Cancer Research Group
ISBN/ISSN/Other
- ISSN: 1557-8852