Purpose: O-(2-F-fluoroethyl)-L-tyrosine (F-FET) is an established tracer for the diagnosis of brain tumors with PET. This study investigates the influence of blood-brain barrier (BBB) permeability on F-FET uptake in two rat glioma models and one human xenograft model.
Methods: F98 glioma, 9L gliosarcoma or human U87 glioblastoma cells were implanted into the striatum of 56 Fischer or RNU rats. Thereafter, animals were divided into a control group and a group receiving injections of the glucocorticoid dexamethasone (Dex). After 12-13 days of tumor growth animals received injection of Evans blue dye (EBD) to visualize BBB disturbance and underwent F-FET PET followed by autoradiography. Time activity curves, standardized uptake values (SUV) and Tumor-to-brain ratios (TBR) of F-FET uptake [18-61 min post injection (p.i.)] were evaluated using a volume-of-Interest (VOI) analysis. BBB disturbance was quantitatively evaluated by EBD fluorescence. The membrane gaps of blood vessel endothelial tight junctions were measured using electron microscopy to visualize ultrastructural BBB alterations in one untreated and one Dex treated F98 glioma. Data were analyzed by two-way ANOVAs.
Results: In Dex treated animals EBD extravasation was significantly reduced in 9L (P < 0.001) and U87 (P = 0.008) models and showed a trend in F98 models (P = 0.053). In contrast, no significant differences of F-FET uptake were observed between Dex treated animals and control group except a decrease of the TBR in the 9L tumor model in PET (P < 0.01). Ultrastructural evaluation of tumor blood vessel endothelia revealed significant reduction of the cleft diameter between endothelial cells after Dex treatment in F98 model (P = 0.010).
Conclusion: Despite a considerable reduction of BBB permeability in rat gliomas after Dex treatment, no relevant changes of F-FET uptake were noted in this experimental study. Thus, F-FET uptake in gliomas appears to be widely independent of the permeability of the BBB.
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http://dx.doi.org/10.1007/s00259-016-3508-0 | DOI Listing |
Biochem Pharmacol
January 2025
School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur, India. Electronic address:
Temozolomide is universally used to treat glioblastoma due to its unique ability to cross the blood-brain barrier and inhibit tumor growth through DNA alkylation. However, over time, the inevitable emergence of resistance to temozolomide impedes successful treatment of this cancer. As a result, there is an urgent need to identify new therapeutic targets to improve treatment outcomes for this malignancy.
View Article and Find Full Text PDFBiomed Pharmacother
January 2025
Departament de Farmacologia, Toxicologia i Química Terapèutica, Facultat de Farmàcia i Ciències de l'Alimentació, Universitat de Barcelona (UB), Av. de Joan XXIII, 27-31, Barcelona 08028, Spain; Institut de Neurociències, Universitat de Barcelona (UB), Passeig de la Vall d'Hebron, 171, Barcelona 08035, Spain; Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED), Instituto de Carlos III, Av. Monforte de Lemos, 3-5, Madrid 28029, Spain; Institut d'Investigació Sanitària Pere Virgili (IISPV), Hospital Universitari Sant Joan de Reus, Av. Josep Laporte, 2, Reus 43204, Spain. Electronic address:
The rise of antimicrobial resistance has made necessary the increase of the antibacterial arsenal against multidrug-resistant bacteria. In this context, colistin has re-emerged as a first-line antibiotic in critical situations despite its nephro- and neuro- toxicity at peripheral level. However, the mechanism underlying its toxicity remains unknown, particularly in relation to the central nervous system (CNS).
View Article and Find Full Text PDFCureus
December 2024
Internal Medicine, University of South Florida, Tampa, USA.
CNS lymphoma is a rare form of non-Hodgkin lymphoma that primarily affects the brain, spinal cord, leptomeninges, or eyes, leading to severe neurological or ophthalmological complications. This case report details a 44-year-old male with human immunodeficiency virus and diffuse large B-cell lymphoma who experienced permanent vision loss due to optic perineuritis, a rare presenting symptom indicative of underlying CNS involvement. Despite previous remission, imaging revealed focal enhancements suggesting CNS lymphoma, highlighting diagnostic and management challenges in relapsed lymphoma, especially in immunocompromised patients.
View Article and Find Full Text PDFNeuromolecular Med
January 2025
Pharmacy College, Al-Farahidi University, Baghdad, Iraq.
The primary source of short-chain fatty acids (SCFAs), now recognized as critical mediators of host health, particularly in the context of neurobiology and cancer development, is the gut microbiota's fermentation of dietary fibers. Recent research highlights the complex influence of SCFAs, such as acetate, propionate, and butyrate, on brain cancer progression. These SCFAs impact immune modulation and the tumor microenvironment, particularly in brain tumors like glioma.
View Article and Find Full Text PDFBrain cancer continues to be one of the most formidable malignancies to manage, mainly attributable to the presence of the blood-brain barrier (BBB) limiting the permeability of drugs and the diverse characteristics of brain tumors complicating treatment. The management of brain tumors has been hampered by many different factors, including the impermeability of the BBB, which restricts the delivery of chemotherapeutic agents to the tumor site, as well as intertumoral heterogeneity and the influence of brain tumor stem cells. In addition, small molecular weight drugs cannot specifically accumulate in malignant cells and have a limited circulation half-life.
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