Vitamin B7 deficiency can deprive cancer of metabolic flexibility

In a study published in the journal Molecular Cell, a team led by Alexis Jourdain conducted a large-scale genetic-nutritional screening. It turned out that when glutamine is scarce, cancer cells switch to another carbon source—pyruvate. For this, they need the enzyme pyruvate carboxylase, which only works in the presence of biotin. Without sufficient vitamin B7, this "backup engine" shuts down, and the cells lose the ability to grow during glutamine deficiency.

The role of the FBXW7 gene is particularly interesting. This gene is often mutated in various types of cancer. When FBXW7 functions normally, it helps maintain pyruvate carboxylase levels. With a gene mutation, the enzyme partially disappears, making cells even more dependent on glutamine. Thus, FBXW7 mutations make the tumor vulnerable: it becomes more "addicted" to glutamine and tolerates its shortage worse.

In experiments on cell lines and models, researchers confirmed: if cells are deprived of biotin or pyruvate carboxylase is blocked, tumors with FBXW7 mutations stop growing much faster. This opens up a potential strategy—combining glutamine blockade with biotin restriction or inhibitors of the required enzyme. This approach could make therapy more effective specifically for those tumors with FBXW7 mutations.

The authors emphasize that biotin acts as a kind of "metabolic license," allowing cancer to bypass one of its weaknesses. Without this license, the tumor's flexibility drops sharply.

It's important to understand: this is still fundamental research in vitro and on models. No one is suggesting that patients restrict biotin or take supplements on their own—this could be dangerous. However, the discovery provides a clear target for developing new combination therapies that account for cancer's metabolic flexibility.

The work helps better understand why some anti-glutamine drugs don't always work: tumors simply switch to pyruvate using biotin. Now scientists have an idea of how to deprive them of this backup plan.

The work was published in the journal Molecular Cell in 2026.

Source: Lisci M., Vericel F., Liu Y. et al. Functional nutrient-genetic profiling reveals biotin and FBXW7 are essential to bypass glutamine addiction. Molecular Cell 86(5), 901–916 (2026). https://doi.org/10.1016/j.molcel.2026.02.002