Proliferation-dependent changes in amino acid transport and glucose metabolism in glioma cell lines.

Amino acid imaging is increasingly being used for assessment of brain tumor malignancy, extent of disease, and prognosis. This study explores the relationship between proliferative activity, amino acid transport, and glucose metabolism in three glioma cell lines (U87, Hs683, C6) at different phases of growth in culture. Growth phase was characterized by direct cell counting, proliferation index determined by flow cytometry, and [(3)H]thymidine (TdR) accumulation, and was compared with the uptake of two non-metabolized amino acids ([(14)C]aminocyclopentane carboxylic acid (ACPC) and [(14)C]aminoisobutyric acid (AIB)), and [(18)F]fluorodeoxyglucose (FDG).

Assessment of treatment response by autoradiography with (14)C-aminocyclopentane carboxylic acid, (67)Ga-DTPA, and (18)F-FDG in a herpes simplex virus thymidine kinase/ganciclovir brain tumor model.

Unlabelled: Assessments of herpes simplex virus 1 thymidine kinase (HSV-tk)/ganciclovir (GCV) treatment response, early in the course of therapy, are important in the evaluation and clinical management of patients. This study addresses whether imaging amino acid transport, glucose utilization, and passive vascular permeability provides an early indication of treatment response and can predict long-term outcome.

Methods: Fischer 344 rats with intracerebral HSV-tk transduced RG2TK+ xenografts were studied.