A mirror form of serine slowed brain tumor stem cells in lab tests
Original title: D-serine suppresses one-carbon metabolism by competing with mitochondrial L-serine transport
How far along is this research?
This is a preprint. Other scientists have not checked it yet, so treat it as an early signal rather than an answer.
This was only done in cells and in tissue outside the body.
The short version
In lab tests, a natural brain chemical slowed the growth of glioblastoma: A glioma that is given grade 4, the highest grade. It grows fast. Treatment usually starts soon after it is found. It often means surgery, then radiation and chemotherapy. See the glossary stem cells.
What was studied. Researchers looked at two mirror forms of a building block called serine, named L-serine and D-serine. They tested them in cells and in brain tissue outside the body.
What they found. D-serine blocked L-serine from getting into a working part of the cell. That part starts a chemical pathway that fast-growing cells rely on. Cells then had less glycine and formate, two things made by that pathway. When L-serine was low, D-serine slowed the growth of glioblastoma: A glioma that is given grade 4, the highest grade. It grows fast. Treatment usually starts soon after it is found. It often means surgery, then radiation and chemotherapy. See the glossary stem cells.
What this means, and what it doesn't
What it could mean: It points to a possible new way to starve tumor stem cells. It helps explain how these cells feed themselves. Doctors cannot use this in care today.
What it doesn't mean: This is early lab work. It was done in cells and in tissue, not in people. No one has shown it helps a patient live longer or feel better. It is not a treatment, and it is not a cure. It also does not mean serine supplements help.
Source: bioRxiv (preprint), September 26, 2026 · Read the original
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