Radiosynthesis and in vivo evaluation of 1-[18F]fluoroelacridar as a positron emission tomography tracer for P-glycoprotein and breast cancer resistance protein
作者:Bernd Dörner、Claudia Kuntner、Jens P. Bankstahl、Thomas Wanek、Marion Bankstahl、Johann Stanek、Julia Müllauer、Florian Bauer、Severin Mairinger、Wolfgang Löscher、Donald W. Miller、Peter Chiba、Markus Müller、Thomas Erker、Oliver Langer
DOI:10.1016/j.bmc.2011.02.039
日期:2011.4
Aim of this study was to label the potent dual P-glycoprotein (Pgp) and breast cancer resistance protein (BCRP) inhibitor elacridar (1) with F-18 to provide a positron emission tomography (PET) radiotracer to visualize Pgp and BCRP. A series of new 1- and 2-halogen- and nitro-substituted derivatives of 1 (4a-e) was synthesized as precursor molecules and reference compounds for radiolabelling and shown to display comparable in vitro potency to 1 in increasing rhodamine 123 accumulation in a cell line overexpressing human Pgp (MDCKII-MDR1). 1-[F-18]fluoroelacridar ([F-18]4b) was synthesized in a decay-corrected radiochemical yield of 1.7 +/- 0.9% by a 1-step no-carrier added nucleophilic aromatic F-18-substitution of 1-nitro precursor 4c. Small-animal PET imaging of [F-18]4b was performed in naive rats, before and after administration of unlabelled 1 (5 mg/kg, n = 3), as well as in wild-type and Mdr1a/b((-/-)) Bcrp1((-/-)) mice (n = 3). In PET experiments in rats, administration of unlabelled 1 increased brain activity uptake by a factor of 9.5 (p = 0.0002, 2-tailed Student's t-test), whereas blood activity levels remained unchanged. In Mdr1a/b((-/-)) Bcrp1((-/-)) mice, the mean brain-to-blood ratio of activity at 60 min after tracer injection was 7.6 times higher as compared to wild-type animals (p = 0.0002). HPLC analysis of rat brain tissue extracts collected at 40 min after injection of [F-18]4b revealed that 93 +/- 7% of total radioactivity in brain was in the form of unchanged [F-18] 4b. In conclusion, the in vivo behavior of [F-18]4b was found to be similar to previously described [C-11]1 suggesting transport of [F-18]4b by Pgp and/or BCRP at the rodent BBB. However, low radiochemical yields and a significant degree of in vivo defluorination will limit the utility of [F-18]4b as a PET tracer. (C) 2011 Elsevier Ltd. All rights reserved.
Molecular design, synthesis and biological research of novel pyridyl acridones as potent DNA-binding and apoptosis-inducing agents
A series of novel pyridyl acridone derivatives comprised of a pseudo-five-cyclic system to extend the pi-conjugated acridone chromophore, were designed and synthesized as potent DNA binding antitumor compounds. Most synthesized compounds displayed good activity against human leukemia K562 cells in MU tests, with compound 6d exhibiting the highest activity with IC50 value at 0.46 mu M. Moreover, 6d showed potent activities against solid tumor cell lines (0.16-3.79 mu M). Several experimental studies demonstrated that the antitumor mode of action of compound 6d involves DNA intercalation, topoisomerase I inhibition, and apoptosis induction through the mitochondrial pathway. In summary, compound 6d represents a novel and promising lead structure for the development of new potent anticancer DNA-binding agents. (C) 2015 Elsevier Masson SAS. All rights reserved.
Discovery of novel polysubstituted
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-alkyl acridone analogues as histone deacetylase isoform-selective inhibitors for cancer therapy