A scientific study reveals how tumors use extracellular glutathione to obtain cysteine, highlighting its role beyond an antioxidant and suggesting new therapeutic approaches.
Researchers have found that extracellular glutathione serves as a source of cysteine for tumors, according to a study detailed in a scientific publication. The study demonstrates that depleting intracellular glutathione does not hinder tumor growth, emphasizing the abundance of glutathione in the tumor microenvironment.
Glutathione, a tripeptide composed of cysteine, glutamate, and glycine, can be catabolized to release amino acids essential for cancer cells. Experiments showed that supplementing with glutathione rescues cancer cell survival and growth under cystine-deficient conditions, with this effect depending on the activity of gamma-glutamyltransferases.
Role of Gamma-Glutamyltransferases in Tumor Support
Gamma-glutamyltransferases play a key role in breaking down extracellular glutathione, releasing glutamate and the dipeptide cysteinylglycine, which further yields cysteine and glycine. The research indicates that targeting these enzymes pharmacologically reduces tumor cysteine levels and slows tumor growth.
The study highlights that while cysteine is crucial for cancer cells, traditional sources like cystine uptake may not be the only pathway. Findings suggest tumors can acquire cysteine from extracellular glutathione catabolism, challenging previous understandings of amino acid supply in cancers.
Further, the research notes that animals lacking certain cysteine uptake mechanisms remain viable, implying alternative sources like glutathione breakdown. Pharmacological inhibition of gamma-glutamyltransferases prevents glutathione breakdown, offering a potential strategy for cancer treatment.
The investigation involved multiple authors and examined glutathione's non-canonical role as an amino acid reservoir. It concludes that depriving tumors of extracellular glutathione or inhibiting its catabolism could be a therapeutically tractable approach for patients.
Similar studies referenced in the research explore related metabolic adaptations in cancers, reinforcing the importance of amino acid restriction as an anticancer strategy.
More Coverage
- U.S. Accuses Iran of Running Hacktivist Group Behind Stryker Cyberattack
- Luka Doncic Scores 60 Points as Los Angeles Lakers Defeat Miami Heat in NBA Game
- Slovenia's Parliamentary Election: Tight Race Between Center-Left and Right-Wing Parties
- Meta Removes End-to-End Encryption from Instagram DMs, Sparking Security Concerns
