Previous studies have demonstrated that gamma-linolenic acid (GLA) is effective against glioma cells under both in vitro and in vivo conditions. In the present study we determined how GLA alone or in combination with irradiation alters the fatty acid (FA) and lipid profiles, the lipid droplet (LD) content, the lipid biosynthetic gene expression and the apoptosis of glioma cells. In GLA-treated cells direct correlations were found between the levels of various FAs and the expression of the corresponding FA biosynthetic genes. The total levels of saturated and monosaturated FAs decreased in concert with the down-regulation of FASN and SCD1 gene expression. Similarly, decreased FADS1 gene expression was paralleled by lowered arachidonic acid (20:4 n-6) and eicosapentaenoic acid (20:5 n-3) contents, while the down-regulation of FADS2 expression was accompanied by a diminished docosahexaenoic acid (22:6 n-3) content. Detailed mass spectrometric analyses revealed that individual treatments gave rise to distinct lipidomic fingerprints. Following uptake, GLA was subjected to elongation, resulting in dihomo-gamma-linolenic acid (20:3 n-6, DGLA), which was used for the synthesis of the LD constituent triacylglycerols and cholesteryl esters. Accordingly, an increased number of LDs were observed in response to GLA administration after irradiation. GLA increased the radioresponsiveness of U87 MG cells, as demonstrated by an increase in the number of apoptotic cells determined by FACS analysis. In conclusion, treatment with GLA increased the apoptosis of irradiated glioma cells, and GLA might therefore increase the therapeutic efficacy of irradiation in the treatment of gliomas.
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http://dx.doi.org/10.1016/j.bbalip.2015.06.003 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
Department of Immunology and Regenerative Biology, Weizmann Institute of Science, Rehovot 7610001, Israel.
Malignant gliomas are heterogeneous tumors, mostly incurable, arising in the central nervous system (CNS) driven by genetic, epigenetic, and metabolic aberrations. Mutations in isocitrate dehydrogenase (IDH1/2) enzymes are predominantly found in low-grade gliomas and secondary high-grade gliomas, with IDH1 mutations being more prevalent. Mutant-IDH1/2 confers a gain-of-function activity that favors the conversion of a-ketoglutarate (α-KG) to the oncometabolite 2-hydroxyglutarate (2-HG), resulting in an aberrant hypermethylation phenotype.
View Article and Find Full Text PDFMedicine (Baltimore)
January 2025
Department of Anesthesiology, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, P.R. China.
The presence of specific genetic mutations in patients with glioblastoma multiforme (GBM) is associated with improved survival outcomes. Disruption of the DNA damage response (DDR) pathway in tumor cells enhances the effectiveness of radiotherapy drugs, while increased mutational burden following tumor cell damage also facilitates the efficacy of immunotherapy. The ATRX gene, located on chromosome X, plays a crucial role in DDR.
View Article and Find Full Text PDFCell Rep
January 2025
Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai 200040, China; National Center for Neurological Disorders, Shanghai 200040, China; Shanghai Key Laboratory of Brain Function and Restoration and Neural Regeneration, Shanghai 200040, China; Neurosurgical Institute of Fudan University, Shanghai 200040, China; Shanghai Clinical Medical Center of Neurosurgery, Shanghai 200040, China. Electronic address:
Glioblastoma (GBM) is a highly lethal malignant brain tumor with poor survival rates, and chemoresistance poses a significant challenge to the treatment of patients with GBM. Here, we show that transketolase (TKT), a metabolic enzyme in the pentose phosphate pathway (PPP), attenuates the chemotherapy sensitivity of glioma cells in a manner independent of catalytic activity. Mechanistically, chemotherapeutic drugs can facilitate the translocation of TKT protein from the cytosol into the nucleus, where TKT physically interacts with XRN2 to regulate the resolution and removal of R-loops.
View Article and Find Full Text PDFClin Neuropharmacol
January 2025
Department of Neurosurgery, Yubei District Hospital of TCM, Chongqing, China.
Objective: Gliomas are a general designation for neuroepithelial tumors derived from the glial cells of the central nervous system. According to the histopathological and immunohistochemical features, the World Health Organization classifies gliomas into four grades. Bevacizumab is a monoclonal antibody targeting vascular endothelial growth factor that has been approved for the treatment of glioblastoma multiforme (GBM) as a second-line therapy.
View Article and Find Full Text PDFCells
January 2025
Department of Molecular Medicine and Pathology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, Auckland 1023, New Zealand.
The overall goal of this work was to assess the ability of Natural Killer cells to kill cultures of patient-derived glioblastoma cells. Herein we report impressive levels of NK-92 mediated killing of various patient-derived glioblastoma cultures observed at ET (effector: target) ratios of 5:1 and 1:1. This enabled direct comparison of the degree of glioblastoma cell loss across a broader range of glioblastoma cultures.
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