logo
    A Carbonic Anhydrase IX/SLC1A5 Axis Regulates Glutamine Metabolism Dependent Ferroptosis in Hypoxic Tumor Cells
    11
    Citation
    53
    Reference
    10
    Related Paper
    Citation Trend
    Abstract:
    Abstract The ability of tumor cells to alter their metabolism to support survival and growth presents a challenge to effectively treat cancers. Carbonic anhydrase IX (CAIX) is a hypoxia-induced, metabolic enzyme that plays a crucial role in pH regulation in tumor cells. Recently, through a synthetic lethal screen, we identified CAIX to play an important role in redox homeostasis. In this study, we show that CAIX interacts with the glutamine (Gln) transporter, solute carrier family 1 member 5 (SLC1A5), and coordinately functions to maintain redox homeostasis through the glutathione/glutathione peroxidase 4 (GSH/GPX4) axis. Inhibition of CAIX increases Gln uptake by SLC1A5 and concomitantly increases GSH levels. The combined inhibition of CAIX activity and Gln metabolism or the GSH/GPX4 axis results in an increase in lipid peroxidation and induces ferroptosis, both in vitro and in vivo. Thus, this study demonstrates cotargeting of CAIX and Gln metabolism as a potential strategy to induce ferroptosis in tumor cells.
    Keywords:
    GPX4
    Homeostasis
    Rats flown for 7 days on Cosmos-1667 were for the first time used to measure antioxidative enzymes (superoxide dismutase, glutathione peroxidase, glutathione reductase, catalase), lipid peroxidation products (diene conjugates, malonic dialdehyde, Schiff bases) and tocopherol. Enhanced lipid peroxidation in the heart was completely compensated by activation of antioxidative enzymes. The content of all lipid peroxidation products measured in the liver increased; this was accompanied by a decrease of glutathione peroxidase and an increase of superoxide dismutase activities. It is suggested that lipid peroxidation was activated in response to altered gravity.
    GPX4
    Glutathione reductase
    Citations (2)
    The calcium-independent phospholipase iPLA2β has been identified as a transcriptional target of the tumor suppressor TP53 (or p53). Unlike GPX4 (glutathione peroxidase 4), iPLA2β is not required for normal homeostasis but critical for ferroptosis during stress responses. Our results implicate iPLA2β as an essential regulator in a noncanonical ferroptosis pathway.
    GPX4
    Homeostasis
    Increased lipid peroxidation is shown to be an early event of Alzheimer's disease (AD). However, it is not clear whether and how increased lipid peroxidation might lead to amyloidogenesis, a hallmark of AD. Glutathione peroxidase 4 (Gpx4) is an essential antioxidant defense enzyme that protects an organism against lipid peroxidation. Gpx4+/- mice show increased lipid peroxidation in brain, as evidenced by their elevated levels of 4-hydroxy-2-nonenal. To understand the role of lipid peroxidation in amyloidogenesis, we studied secretase activities in Gpx4+/- mice as a function of age. Both young (6 months) and middle-aged (17-20 months) Gpx4+/- mice had higher levels of beta-secretase activity than their age-matched wildtype controls, and the increased beta-secretase activity in Gpx4+/- mice was a result of up-regulation of beta-site amyloid precursor protein cleavage enzyme 1 (BACE1) expression at the protein level. The high level of BACE1 protein led to increased endogenous beta-amyloid (Abeta)(1-40) in middle-aged Gpx4+/- mice. We further studied amyloidogenesis in APPGpx4+/- mice. Our data indicate that APPGpx4+/- mice had significantly increased amyloid plaque burdens and increased Abeta(1-40) and Abeta(1-42) levels compared with APPGpx4+/+ mice. Therefore, our results indicate that increased lipid peroxidation leads to increased amyloidogenesis through up-regulation of BACE1 expression in vivo, a mechanism that may be important in pathogenesis of AD at early stages.
    GPX4
    Pathogenesis
    The Effects of Hyperthyroidism on Lipid Peroxidation, Erythrocyte Glutathione and Glutathione Peroxidase The aim of this study was to determine if lipid peroxidation, glutathione, and glutathione peroxidase levels can be effected by hyperthyroidism. Twenty-three subjects with hyperthyroidism (18 females/5 males), and 19 euthyroid subjects (11 females/8 males) were examined in this study. Plasma and erythrocytes malondialdehyde (MDA), erythrocytes glutathione (GSH) and glutathione peroxidase (GSH-PX) were measured. Results show that an increase in lipid peroxidation was observed in the hyperthyroid patients (p < 0.001). This was accompanied by a decrease in glutathione and glutathione peroxidase in the same subjects (p < 0.001). The results suggest that hyperthyroidism has some effects on lipid peroxidation and free radical scavengers.
    GPX4
    Malondialdehyde
    Glutathione reductase
    GPX3
    Citations (8)