Monoclonal antibody localization in subcutaneous and intracranial human glioma xenografts: paired-label and imaging analysis.

The murine antiglioma monoclonal antibody 81C6 has been shown to specifically localize in U-251 MG and D-54 MG human glioma subcutaneous and intracranial athymic mouse xenografts expressing the human gliomamesenchymal extracellular matrix glycoprotein GMEM. In paired-label studies 81C6 reached peak levels of localization in subcutaneous and intracranial xenografts in 24 to 48 hours and persisted there for an additional 5 to 7 days before declining. The percent localized 81C6 in U-251 MG subcutaneous xenografts was tumor size dependent ranging from 2% in 200-300 mg tumors to 15% in 1 gram tumors. Subcutaneous xenografts of U-251 MG were readily radioimaged from 1 up to 6 days following administration of 131-I-81C6. The specificity of 81C6 localization has also been demonstrated by tissue autoradiography, elution of radiolabeled 81C6 from tumor xenografts, and in vivo inhibition of radiolabeled 81C6 localization by unlabeled 81C6. D-54 MG intracranial xenografts were permeable to 81C6 and control immunoglobulin but specific localization occurred only with 81C6. Radiolabeled 81C6 monoclonal antibody and U-251 MG and D-54 MG human glioma xenografts provide a useful operationally tumor specific monoclonal antibody tumor localization model for the examination of monoclonal antibody pharmacokinetics, radioimaging, radioimmunotherapy and combined modality therapy in intracranial human glioma xenografts.

Duke Scholars

Author Darell Doty Bigner Neurosurgery