Synthesis and radiolabelling of DOTA-linked glutamine analogues with 67,68Ga as markers for increased glutamine metabolism in tumour cells
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Date
2013-06-19
Journal Title
Journal ISSN
Volume Title
Publisher
MDPI (Multidisciplinary Digital Publishing Institute)
Abstract
DOTA-linked glutamine analogues with a C6- alkyl and polyethyleneglycol (PEG) chain between the chelating group and the l-glutamine moiety were synthesised and labelled with 67,68Ga using established methods. High yields were achieved for the radiolabelling of the molecules with both radionuclides (>90%), although conversion of the commercially available 67Ga-citrate to the chloride species was a requirement for consistent high radiochemical yields. The generator produced 68Ga was in the [68Ga(OH)4]− form. The 67Ga complexes and the 67Ga complexes were demonstrated to be stable in PBS buffer for a week. Uptake studies were performed with longer lived 67Ga analogues against four tumour cell lines, as well as uptake inhibition studies against l-glutamine, and two known amino acid transporter inhibitors. Marginal uptake was exhibited in the PEG variant radio-complex, and inhibition studies indicate this uptake is via a non-targeted amino acid pathway. © 2013 by the authors
Description
Keywords
Tumor cells, Gallium 67, Gallium 68, Glutamine, Radiochemistry, Positron computed tomography, Polyethylene glycols, Amino acids
Citation
Pellegrini, P. A., Howell, N. R., Shepherd, R. K., Lengkeek, N. A., Oehlke, E., Katsifis, A. G., & Greguric, I. (2013). Synthesis and radiolabelling of DOTA-linked glutamine analogues with 67, 68Ga as markers for increased glutamine metabolism in tumour cells. Molecules, 18(6), 7160-7178. doi:10.3390/molecules18067160