Researchers at the University of Lausanne found a hidden weakness in cancer cells that appears when the cells cannot get vitamin B7.
All cells need to change how they work when nutrients run low. Some cells, especially cancer cells, become very dependent on an amino acid called glutamine. Glutamine helps build proteins and DNA, so without it cells cannot grow.
Many tumors are "glutamine addicted," meaning they rely heavily on this nutrient. While this seems like a clear target, cancer often finds other ways to survive.
In a recent study, a team led by assistant professor Alexis Jourdain explained how cancer cells bypass the need for glutamine.
How Pyruvate and Vitamin B7 Support Cell Growth
The scientists focused on a carbon‑rich molecule called pyruvate. They discovered that pyruvate can keep cells dividing even when glutamine is scarce, but only if a mitochondrial enzyme called pyruvate carboxylase is working.
Pyruvate carboxylase needs vitamin B7 (also known as biotin) to function. Without vitamin B7 the enzyme stops, and the cell can no longer grow. In this way, biotin acts like a "metabolic key" that lets pyruvate replace missing glutamine.
The Role of the FBXW7 Gene
The researchers also looked at a gene called FBXW7, which often mutates in cancers. Certain mutations make tumor cells even more dependent on glutamine. This discovery came from work with metabolomics and proteomics labs at the university and a partner team in the United States.
Why Some Treatments Fail
These findings help explain why drugs that block glutamine sometimes do not work. Cancer cells can switch to alternative pathways, like using pyruvate with biotin, to stay alive.