SLC7A11 (also known as xCT) xenobiotic transporter.
XCT (xenobiotic transporter) is a protein that plays a crucial role in the transport of xenobiotics, including chemotherapeutic agents, across cell membranes.
xCT overexpressed in: breast, lung, colon, prostate, GBM, Pancreatic (with poor prognosis)
Cancer cells often experience high levels of oxidative stress; upregulation of SLC7A11 helps to counteract this stress and supports cell survival.
Targeting SLC7A11 can sensitize tumor cells to oxidative damage and ferroptosis, offering a potential therapeutic avenue.
SLC7A11 encodes the light chain subunit of the cystine/glutamate antiporter system X_c⁻. This transporter imports cystine into the cell and exports glutamate out. The imported cystine is then used to synthesize glutathione (GSH), a major antioxidant that helps control intracellular ROS levels.
Many cancer cells experience elevated oxidative stress due to increased metabolic activity and stress conditions within the tumor microenvironment. Upregulation of SLC7A11 can provide a survival advantage by boosting GSH synthesis, thereby neutralizing ROS and preventing oxidative damage.
High SLC7A11 activity helps prevent ferroptosis by ensuring continuous glutathione production. Glutathione is a cofactor for glutathione peroxidase 4 (GPX4), a key enzyme that detoxifies lipid peroxides.
Mechanism: When SLC7A11 is inhibited, cystine uptake is reduced. This leads to glutathione depletion, compromised GPX4 activity, and eventually the accumulation of lipid peroxides that trigger ferroptosis.
Inducing ferroptosis has become a promising anticancer strategy. Inhibitors targeting SLC7A11 (or related pathways) can lower glutathione levels, increasing susceptibility to ferroptotic cell death. This is especially attractive in cancers with high SLC7A11 expression, where blocking its function may selectively induce ferroptosis and overcome drug resistance.
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