5458-82-2Relevant articles and documents
Synthesis and preclinical characterization of 1-(6′-deoxy-6′-[18F]fluoro-β-D-allofuranosyl)-2-nitroimidazole (β-6′-[18F]FAZAL) as a positron emission tomography radiotracer to assess tumor hypoxia
Wanek, Thomas,Kreis, Katharina,Kri?ková, Petra,Schweifer, Anna,Denk, Christoph,Stanek, Johann,Mairinger, Severin,Filip, Thomas,Sauberer, Michael,Edelhofer, Patricia,Traxl, Alexander,Muchitsch, Viktoria E.,Mereiter, Kurt,Hammerschmidt, Friedrich,Cass, Carol E.,Damaraju, Vijaya L.,Langer, Oliver,Kuntner, Claudia
, p. 5326 - 5339 (2016/10/22)
Positron emission tomography (PET) using fluorine-18 (18F)-labeled 2-nitroimidazole radiotracers has proven useful for assessment of tumor oxygenation. However, the passive diffusion-driven cellular uptake of currently available radiotracers results in slow kinetics and low tumor-to-background ratios. With the aim to develop a compound that is actively transported into cells, 1-(6′-deoxy-6′-[18F]fluoro-β-D-allofuranosyl)-2-nitroimidazole (β-[18F]1), a putative nucleoside transporter substrate, was synthetized by nucleophilic [18F]fluoride substitution of an acetyl protected labeling precursor with a tosylate leaving group (β-6) in a final radiochemical yield of 12?±?8% (n?=?10, based on [18F]fluoride starting activity) in a total synthesis time of 60?min with a specific activity at end of synthesis of 218?±?58?GBq/μmol (n?=?10). Both radiolabeling precursor β-6 and unlabeled reference compound β-1 were prepared in multistep syntheses starting from 1,2:5,6-di-O-isopropylidene-α-D-allofuranose. In vitro experiments demonstrated an interaction of β-1 with SLC29A1 and SLC28A1/2/3 nucleoside transporter as well as hypoxia specific retention of β-[18F]1 in tumor cell lines. In biodistribution studies in healthy mice β-[18F]1 showed homogenous tissue distribution and excellent metabolic stability, which was unaffected by tissue oxygenation. PET studies in tumor bearing mice showed tumor-to-muscle ratios of 2.13?±?0.22 (n?=?4) at 2?h after administration of β-[18F]1. In ex vivo autoradiography experiments β-[18F]1 distribution closely matched staining with the hypoxia marker pimonidazole. In conclusion, β-[18F]1 shows potential as PET hypoxia radiotracer which merits further investigation.