Characterization of uptake of 3-[131I]iodo-α-methyl-L-tyrosine in human monocyte-macrophages

Prante, Olaf; Deichen, Jan Thiess; Hocke, Carsten; Kuwert, Torsten

doi:10.1016/j.nucmedbio.2003.10.006

Cited by 9 publications

(4 citation statements)

References 24 publications

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“…The α-hydrogen substituted amino acid, ( S )-[ 18 F] 15 , was a very good substrate for system L, with an in vitro transport profile very similar to that of [ 18 F]FET as previously reported using the same assay conditions and cell line . ( S )-[ 18 F] 14 is not a good substrate for system L, which is somewhat surprising given that aromatic substituted amino acids such as [ 18 F]FAMT and [ 123 I]IMT have been reported by other groups to be effective system L substrates. ,, In contrast, our in vitro cell uptake studies demonstrate that the presence or absence of an α-methyl group on the amino acid can dramatically change the mechanism of transport of this class of α-alkyl amino acids.…”

Section: Resultssupporting

confidence: 70%

Section: Resultsmentioning

confidence: 74%

“…24 (S)-[ 18 F]14 is not a good substrate for system L, which is somewhat surprising given that aromatic substituted amino acids such as [ 18 F]FAMT and [ 123 I]IMT have been reported by other groups to be effective system L substrates. 20,34,35 In contrast, our in vitro cell uptake studies demonstrate that the presence or absence of an α-methyl group on the amino acid can dramatically change the mechanism of transport of this class of α-alkyl amino acids. Although it is not clear if these results can be extended to aromatic amino acids, our previous finding that α-[ 18 F]fluoromethyl phenylalanine (FMePhe) was a poor system L substrate in the same DBT model suggests that these results may be applicable to amino acids with aromatic side chains.…”

Section: ■ Introductionmentioning

confidence: 78%

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Effect of α-Methyl versus α-Hydrogen Substitution on Brain Availability and Tumor Imaging Properties of Heptanoic [F-18]Fluoroalkyl Amino Acids for Positron Emission Tomography (PET)

Bouhlel

Alyami

et al. 2016

J. Med. Chem.

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Two [18F]fluoroalkyl substituted amino acids differing only by the presence or absence of a methyl group on the α-carbon, (S)-2-amino-7-[18F]fluoro-2-methylheptanoic acid ((S)-[18F]FAMHep, (S)-[18F]14) and (S)-2-amino-7-[18F]-fluoroheptanoic acid ((S)-[18F]FAHep, (S)-[18F]15), were developed for brain tumor imaging and compared to the well-established system L amino acid tracer, O-(2-[18F]fluoroethyl)-L-tyrosine ([18F]FET), in the delayed brain tumor (DBT) mouse model of high-grade glioma. Cell uptake, biodistribution, and PET/CT imaging studies showed differences in amino acid transport of these tracer by DBT cells. Recognition of (S)-[18F]15 but not (S)-[18F]14 by system L amino acid transporters led to approximately 8–10-fold higher uptake of the α-hydrogen substituted analogue (S)-[18F]15 in normal brain. (S)-[18F]15 had imaging properties similar to those of (S)-[18F]FET in the DBT tumor model while (S)-[18F]14 afforded higher tumor to brain ratios due to much lower uptake by normal brain. These results have important implications for the future development of α-alkyl and α,α-dialkyl substituted amino acids for brain tumor imaging.

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Section: Resultssupporting

confidence: 70%

Section: Resultsmentioning

confidence: 74%

Section: ■ Introductionmentioning

confidence: 78%

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Effect of α-Methyl versus α-Hydrogen Substitution on Brain Availability and Tumor Imaging Properties of Heptanoic [F-18]Fluoroalkyl Amino Acids for Positron Emission Tomography (PET)

Bouhlel

Alyami

et al. 2016

J. Med. Chem.

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“…Some natural amino acid based tracers such as [ 11 C]methionine (MET) and [ 11 C]tyrosine (TYR), their uptake reflects transport, protein synthesis and non-protein metabolic pathways such as transamination and transmethylation, which makes imaging kinetic analysis difficult [6–8]. While uptake of non-natural amino acids such as O -(2-[ 18 F]fluoroethyl)-L-tyrosine (FET, [ 18 F] 1 ) [9], 3-[ 18 F]fluoro-αmethyl-L-tyrosine (FMT) [10], anti-1-amino-3-[ 18 F]fluoro-cyclobutyl-1-carboxylic acid (FACBC) [11], 3-[ 123 I]-α-methyl-L-tyrosine (IMT) [12] represents mainly transport activity but not protein synthesis. It appears that their differences in protein metabolism do not translate into difference in clinical applicability[3].…”

Section: Introductionmentioning

confidence: 99%

Synthesis, uptake mechanism characterization and biological evaluation of 18F labeled fluoroalkyl phenylalanine analogs as potential PET imaging agents

Wang

Qü

Lieberman

et al. 2011

Nuclear Medicine and Biology

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Introduction Amino acids based tracers represent a promising class of tumor metabolic imaging agents with successful clinical applications. Two new phenylalanine derivatives, p-(2-[18F]fluoroethyl)-L-phenylalanine (FEP, [18F]2) and p-(3-[18F]fluoropropyl)-L-phenylalanine (FPP, [18F]3) were synthesized and evaluated in comparison to clinically utilized O-(2-[18F]fluoroethyl)-L-tyrosine (FET, [18F]1). Methods FEP ([18F]2) and FPP ([18F]3) were successfully synthesized by a rapid and efficient two-step nucleophilic fluorination of tosylate precursors and deprotection reaction. In vitro cell uptake studies were carried out in 9L glioma cells. In vivo studies, 9L tumor xenografts were implanted in Fisher 344 rats. Results FEP ([18F]2) and FPP ([18F]3) could be efficiently labeled within 90 min with good enantiomeric purity (>95%), good yield (11–37%) and high specific activity (21–69 GBq/μmol). Cell uptake studies showed FEP had higher uptake than FPP as well as reference ligand FET ([18F]1). Uptake mechanism studies suggested that FEP is a selective substrate for system L and prefers its subtype LAT1. In vivo biodistribution studies demonstrated FEP had specific accumulation in tumor cells and tumor to background ratio reached 1.45 at 60 min. Small animal PET imaging studies showed FEP was comparable to FET for imaging rats bearing 9L tumor model. FEP had high uptake in 9L tumor compared to surrounding tissue and was quickly excreted through urinary tract. Conclusion Biological evaluations indicate that FEP ([18F]2) is a potential useful tracer for tumor imaging with PET.

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Radiometal-theranostics: the first 20 years*

Roesch

Martin

2022

J Radioanal Nucl Chem

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This review describes the basic principles of radiometal-theranostics and its dawn based on the development of the positron-emitting 86Y and 86Y-labeled radiopharmaceuticals to quantify biodistribution and dosimetry of 90Y-labeled analogue therapeutics. The nuclear and inorganic development of 86Y (including nuclear and cross section data, irradiation, radiochemical separation and recovery) led to preclinical and clinical evaluation of 86Y-labeled citrate and EDTMP complexes and yielded organ radiation doses in terms of mGy/MBq 90Y. The approach was extended to [86/90Y]Y-DOTA-TOC, yielding again yielded organ radiation doses in terms of mGy/MBq 90Y. The review further discusses the consequences of this early development in terms of further radiometals that were used (68Ga, 177Lu etc.), more chelators that were developed, new biological targets that were addressed (SSTR, PSMA, FAP, etc.) and subsequent generations of radiometal-theranostics that resulted out of that.

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Characterization of uptake of 3-[131I]iodo-α-methyl-L-tyrosine in human monocyte-macrophages

Cited by 9 publications

References 24 publications

Effect of α-Methyl versus α-Hydrogen Substitution on Brain Availability and Tumor Imaging Properties of Heptanoic [F-18]Fluoroalkyl Amino Acids for Positron Emission Tomography (PET)

Effect of α-Methyl versus α-Hydrogen Substitution on Brain Availability and Tumor Imaging Properties of Heptanoic [F-18]Fluoroalkyl Amino Acids for Positron Emission Tomography (PET)

Synthesis, uptake mechanism characterization and biological evaluation of 18F labeled fluoroalkyl phenylalanine analogs as potential PET imaging agents

Radiometal-theranostics: the first 20 years*

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