Unlabelled: Fluorinated derivatives of etanidazole are being explored as probes for tumor hypoxia. Our research group has synthesized [18F]fluoroetanidazole (FETA) and now reports the oxygen dependency of binding to cells in vitro, the biodistribution of the tracer in tumor-bearing mice and the analysis of metabolites in their plasma and urine.
Methods: Four cultured rodent cell lines (V79, 36B10, EMT6 and RIF1) were incubated with [18F]FETA for various times under graded O2 concentrations. We also compared the biodistributions of [18F]FETA and [18F]fluoromisonidazole (FMISO) at 2 and 4 h postinjection in C3H mice bearing KHTn tumors (130-430 mg). Reverse-phase high-performance liquid chromatography was used to distinguish metabolites from parent drugs in urine and plasma of mice injected with [18F]FETA or [18F]FMISO.
Results: In cells labeled in vitro, O2 levels of 600-1300 ppm inhibited binding by 50% relative to uptake under anoxic conditions (<10 ppm). These inhibitory values are not statistically different from those reported for [18F]FMISO in the same cell lines (700-1500 ppm). In the biodistribution studies, uptake in heart, intestine, kidney and tumor was similar for both tracers 4 h after injection, whereas retention of [18F]FETA in liver and lung was significantly lower. Less uptake of [18F]FETA in liver suggests that this nitroimidazole is metabolized less than [18F]FMISO. The brain-to-blood ratios indicate that [18F]FETA readily crosses the blood-brain barrier. High-performance liquid chromatography of urine demonstrated that 10% of [18F]FETA-derived activity was in metabolites at 2 h postinjection, with 15% in metabolites by 4 h; comparable values for [18F]FMISO were 36% and 57%, respectively.
Conclusion: We conclude from these data that [18F]FETA holds promise as a new hypoxia tracer in patients, having oxygen dependency of binding similar to [18F]FMISO in vitro and displaying less retention in liver and fewer metabolites in vivo.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
Halofuginone prevents inflammation and proliferation of high-altitude pulmonary hypertension by inhibiting the TGF-β1/Smad signaling pathway.
Sci Rep
January 2025
General Hospital of Xinjiang Military Command, 359 North Friendship Road, Sayibak, Ürümqi, 830000, Xinjiang, China.
The inflammatory response of lung tissue and abnormal proliferation of pulmonary artery smooth muscle cells are involved in the pathogenesis of high-altitude pulmonary hypertension (HAPH). Halofuginone (HF), an active ingredient derivative of Chang Shan (Dichroa febrifuga Lour. [Hydrangeaceae]), has antiproliferative, antihypertrophic, antifibrotic, and other effects, but its protective effects on HAPH remains unclear.
View Article and Find Full Text PDFOptimizing interventional therapy: A homogeneous lipiodol formulation of Tirapazamine and Sorafenib responsive to post-embolization microenvironment.
J Control Release
January 2025
State Key Laboratory of Infectious Disease Vaccine Development, Xiang An Biomedicine Laboratory, National Innovation Platform for Industry-Education Integration in Vaccine Research, Fujian Engineering Research Center of Molecular Theranostic Technology, Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen 361102, China. Electronic address:
Transcatheter arterial chemoembolization (TACE) is the principal treatment option for patients with unresectable hepatocellular carcinoma (HCC). However, the hypoxic microenvironment following TACE can promote angiogenesis and suppress tumor ferroptosis, resulting in an unfavorable prognosis. Tirapazamine (TPZ), a hypoxia-activated prodrug with specific cytotoxicity for hypoxic cells, making it a potential candidate for TACE.
View Article and Find Full Text PDFEnhancing immunotherapy efficacy in oral cancer through AKB-9778-mediated vascular normalization.
Int Immunopharmacol
January 2025
State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan 430079, China; Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Wuhan University, Wuhan 430079, China. Electronic address:
Tumor vasculature exhibit numerous abnormal features distinct from those of healthy vessels, potentially advancing tumor development by establishing an aberrant microenvironment. Therefore, vascular normalization has proven to be an effective tactic for substantially enhancing treatment efficacy across multiple tumors. However, the methods to attain vascular normalization may vary among tumor types.
View Article and Find Full Text PDFBiological characterization of breast cancer spheroid formed by fast fabrication method.
In Vitro Model
February 2024
Faculty of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-Cho, Koganei, Tokyo 184-8588 Japan.
Unlabelled: Engineered three-dimensional (3D) tissue culture platforms are useful for reproducing and elucidating complex in vivo biological phenomena. Spheroids, 3D aggregates of living cells, are produced based on physicochemical or microfabrication technologies and are commonly used even in cancer pathology research. However, conventional methods have difficulties in constructing 3D structures depending on the cell types, and require specialized techniques/lab know-how to reproducibly control the spheroid size and shape.
View Article and Find Full Text PDFAn Oxidative Stress Nanoamplifier to Enhance the Efficacy of Cisplatin in Head and Neck Cancer.
Angew Chem Int Ed Engl
January 2025
NCNST: National Center for Nanoscience and Technology, CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, No 11, Zhongguancun Beiyitiao, Haidian, 100190, Beijing, CHINA.
Cisplatin (CP) is a first-line platinum-based drug used for the treatment of head and neck cancer. However, tumor cells can diminish the therapeutic effects of CP through the detoxification system mediated by glutathione (GSH) and the nucleotide excision repair (NER) pathway. Herein, we present a light-activable and pH-responsive oxidative stress nanoamplifier (FPLC@IR OSNA), comprising an amphiphilic compound (FPLC) with Fmoc-lysine acting as a connector between a nitroimidazole derivative and a pH-responsive cinnamaldehyde (CA) derivative, loaded with photosensitizer IR780.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!