In vivo tumor localization of technetium-labeled metalothionein/monoclonal antibody conjugates

Conference · Sun Jan 01 04:00:00 EST 1984 · J. Nucl. Med.; (United States)

OSTI ID:6594233

Tolman, G L; Hadjian, R J; Morelock, M M; Jones, P L; Neacy, W; Liberatore, F A; Sands, H; Gallagher, B M

The use of radioiodinated monoclonal antibodies (MAb) directed against tumor associated antigens for imaging has reinforced the need for additional labeling methods to permit the use of other medically relevant radionuclides. The low molecular weight metal binding protein, metallothionein (MT) has a high avidity for several radionuclides including Tc-99m. The conjugation of a Zn-MT to MAb B6.2 directed against human breast carcinoma was studied using glutaraldehyde as the bifunctional cross-linker. The Zn-MT-B6.2 conjugate was labeled with Tc-99m to form a Tc-99m labeled MT-B6.2 conjugate. Radiolabeled conjugates were shown to retain high immunoreactivity compared to radio-iodinated B6.2 in a direct cell binding assay on target MCF7 breast carcinoma cells and a low non-specific binding to antigen negative melanoma cells. These conjugates were evaluated in athymic mice bearing subcutaneous Clouser breast or A375 nonspecific melanoma tumors. The specificity of uptake in the target tumor to nonspecific tumor was equivalent to that of the radioiodinated antibody over the first 24 hours in vivo. The blood clearance was more rapid for the Tc-99m MT conjugates and this enhanced clearance permitted superior images to be obtained within 24 hours. This labeling methodology produces stable Tc-99m labeled antibodies, retaining high immunoreactivity and demonstrating good localization and imaging in this model system.

• Research Organization: New England Nuclear Corp., Immunopharmaceutical R and D Dept., No. Billerica, MA 01862
• OSTI ID: 6594233
• Report Number(s): CONF-840619-
• Conference Information: Journal Name: J. Nucl. Med.; (United States) Journal Volume: 25:5
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400702 -- Radiochemistry & Nuclear Chemistry-- Properties of Radioactive Materials
550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ANTIBODIES
ANTIGENS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CARCINOMAS
CHEMICAL PREPARATION
COUNTING TECHNIQUES
DIAGNOSTIC TECHNIQUES
DISEASES
DISTRIBUTION
DRUGS
FUNCTIONS
GLANDS
HOURS LIVING RADIOISOTOPES
IMMUNOLOGY
IN VIVO
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LABELLED COMPOUNDS
LABELLING
MAMMARY GLANDS
MELANOMAS
METALLOPROTEINS
METALLOTHIONEIN
MONOCLONAL ANTIBODIES
NEOPLASMS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RADIOIMMUNOLOGY
RADIOISOTOPE SCANNING
RADIOISOTOPES
RADIONUCLIDE KINETICS
RADIOPHARMACEUTICALS
RETENTION FUNCTIONS
SCINTISCANNING
SYNTHESIS
TECHNETIUM 99
TECHNETIUM ISOTOPES
TISSUE DISTRIBUTION
YEARS LIVING RADIOISOTOPES