In the high-stakes world of tumor survival, cancer cells are often notorious for their "glutamine addiction." But while some tumors find a clever way to cheat death by switching fuels, new research reveals that a common vitamin—and a critical genetic "switch"—might finally be what stops them in their tracks.

Axar.az reports that most aggressive cancers are metabolic gluttons. They crave glutamine, an amino acid that acts as the raw material for building new DNA and proteins. For years, scientists hoped that simply "starving" tumors of glutamine would be a silver bullet. The problem? Cancer cells are masters of adaptation. When glutamine runs dry, they often pivot to an alternative fuel source: pyruvate.

Researchers at the University of Lausanne (UNIL) have finally mapped out how they pull off this disappearing act. It turns out that for a cancer cell to successfully switch fuels, it needs a "metabolic license" in the form of Vitamin B7 (biotin).

Biotin: The Key to the Backdoor

The study, led by Assistant Professor Alexis Jourdain and Dr. Miriam Lisci, discovered that an enzyme called pyruvate carboxylase is the engine behind this fuel-switching maneuver. However, this engine won't start without a spark plug—and that spark plug is biotin.

When the researchers cut off the supply of Vitamin B7, the enzyme stalled. Without its biotin "license," the cancer cell couldn't use pyruvate to compensate for the lack of glutamine. Deprived of both its primary fuel and its backup plan, the cell’s growth hit a dead end.

The FBXW7 "Trap"

The discovery gets even more provocative when looking at the genetics of the tumor itself. The team focused on a gene called FBXW7, a well-known tumor suppressor that is frequently broken or mutated in human cancers, particularly in the colon, liver, and blood.

Under normal conditions, FBXW7 acts like a biological quality-control manager. It ensures the cell keeps enough "backup engines" (the pyruvate carboxylase enzyme) ready to go. But when FBXW7 is mutated, a chaotic buildup of a protein called c-MYC occurs. This protein physically blocks the cell from producing its backup engine.

"When FBXW7 is mutated, the backup plan fails," explains Dr. Lisci. "The cells lose their flexibility and become hopelessly trapped in their addiction to glutamine."

Why This Changes the Game

This research solves a long-standing mystery: why do glutamine-blocking drugs work for some patients but fail for others?

If a patient’s cancer has a healthy FBXW7 gene and plenty of Vitamin B7, the tumor simply "escapes" the treatment by switching to pyruvate. However, if the tumor has an FBXW7 mutation, it is effectively cornered. By targeting these specific genetic signatures, doctors may soon be able to:

- Starve the "Addicts": Use glutamine-blocking therapies specifically on patients whose genetic profile (FBXW7 mutations) prevents them from switching fuels.

- Double-Hit Therapy: Combine treatments that block glutamine with those that interfere with biotin or the pyruvate engine, leaving the cancer with no room to breathe.

By understanding the "metabolic flexibility" of these cells, scientists aren't just looking for a way to stop cancer—they're looking for the keys to lock every possible exit.

This report is based on findings published in Molecular Cell (2026) by the University of Lausanne and Northeastern University.