In vitro characterization of an iodine-125 labeled anti-epidermal growth factor receptor murine monoclonal antibody (MAB-425) in human high grade glioma cells: Binding, uptake, transport and localization

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1993

OSTI ID:7007725

Emrich, J G

The aim of this study was to determine intracellular accumulation and possible nuclear translocation of [sup 125]I-labeled murine monoclonal antibody (MAb) 425 in human high grade glioma cells following internalization of this antibody, a prerequisite for the induction of radiotoxic effects. Four human high grade glioma cell lines known to express epidermal growth factor receptor (EGF-R) and a colorectal carcinoma cell line with negligible EGF-R expression were incubated for various time periods with a saturating concentration of [sup 125]I-MAb 425. No measurable intranuclear uptake of radioactivity was detected within an incubation period of less than 6 hr. After an incubation of 24-28 hr, only 0.5-2% of the internalized radioactivity was detected in the nuclear fraction. It may be possible to inhibit [sup 125]I-MAb 425 degradation with the addition of chloroquine. Overall, the data indicate that the major portion of the [sup 125]I-MAb 425 is degraded following internalization. Inhibition of lysosomal activity results in a significant increase in intracellular, but more importantly, intranuclear accumulation of [sup 125]I-MAb 425. Since radioactivity is released from the glioma cells following [sup 125]I-MAb 425 internalization, discontinuous gel electrophoresis was performed to determine the nature of the released cell products. The cell supernatants were examined at 0, 24 and 48 hr post incubation to determine the nature of any cell-associated radioactivity released from the cell surface or interior. A protein band corresponding to a molecular weight of 167 kDa was detected in all cell supernatants. Parallel electrophoretic gels were processed for autoradiographic studies in order to indicate corresponding radioactive components. In addition, immunostaining by Western blot with peroxidase-labeled goat anti-mouse antibody was performed to confirm the antibody nature of the protein bands.

• Research Organization: Hahnemann Univ., Philadelphia, PA (United States). School of Medicine
• OSTI ID: 7007725
• Country of Publication: United States
• Language: English

Related Subjects

560160* -- Radionuclide Effects
Kinetics
& Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANTIBODIES
BETA DECAY RADIOISOTOPES
DAYS LIVING RADIOISOTOPES
DISTRIBUTION
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IODINE 125
IODINE ISOTOPES
ISOTOPES
LABELLED COMPOUNDS
LABELLING
MONOCLONAL ANTIBODIES
NUCLEI
ODD-EVEN NUCLEI
RADIOISOTOPES
RADIONUCLIDE KINETICS
RADIOPHARMACEUTICALS
TISSUE DISTRIBUTION
TRANSLOCATION
UPTAKE