A novel pretargeting method for measuring antibody internalization in tumor cells
Authors
Liu, GuozhengDou, Shuping
Yin, Dongguang
Squires, Shayne
Liu, Xinrong
Wang, Yi
Rusckowski, Mary
Hnatowich, Donald J.
UMass Chan Affiliations
Department of Radiology, Division of Nuclear MedicineDocument Type
Journal ArticlePublication Date
2007-04-28Keywords
AcidsAnimals
Antibodies
Cell Line, Tumor
Cell Membrane
Drug Delivery Systems
Flow Cytometry
Humans
Mice
Mice, Inbred BALB C
Mice, Nude
Neoplasms
Xenograft Model Antitumor Assays
Life Sciences
Medicine and Health Sciences
Metadata
Show full item recordAbstract
A novel pretargeting method has been developed to quantitate antibody cellular internalization. In this study, the antibody was conjugated with a phosphorodiamidate morpholino oligomer (MORF) specific for the complementary MORF (cMORF) as an effector. Half the tumor cells were incubated with the MORF-antibody (pretargeting group) and the other half with the same MORF-antibody at the same concentration but radiolabeled (direct targeting group). After incubation, the same dosage of radiolabeled cMORF was added to the wells of the pretargeting group. The radioactivity of the direct targeting cells represented the sum of both internalized and cell-surface-bound antibodies, whereas the radioactivity of the pretargeting cells resulted only from the surface-bound antibodies, as the radiolabeled cMORF does not penetrate the cell surface. Therefore, the difference in radioactivity accumulation between pretargeting and direct targeting provides the internalized fraction. In this example, the internalization of a MORF conjugated anti-prostate-specific membrane antigen antibody, 3C6, in LNCaP cells was examined, and the average cell-surface residence time was determined as 2 hours. This method of measuring antibody internalization is directly applicable to pretargeting applications but can be a universal alternative to the conventional acid-wash method, with the advantage of leaving the cell membrane undamaged.Source
Cancer Biother Radiopharm. 2007 Feb;22(1):33-9. Link to article on publisher's site
DOI
10.1089/cbr.2006.339Permanent Link to this Item
http://hdl.handle.net/20.500.14038/38381PubMed ID
17461727Related Resources
ae974a485f413a2113503eed53cd6c53
10.1089/cbr.2006.339