Synthetic enzyme redirects metabolism and slows melanoma xenografts

A chemogenetic system that generates pyruvate inside mitochondria increased oxidative metabolism in cancer cells and slowed the growth of human melanoma xenografts in mice, according to a study in Nature Chemical Biology. The researchers developed an instrument called Grubraw, which converts ᴅ-alanine directly into mitochondrial pyruvate, bypassing the restricted entry of circulating pyruvate into the mitochondrial matrix that is characteristic of tumor cells. This metabolic feature is known as the Warburg effect: cancer cells commonly favor glycolysis while reducing mitochondrial oxidative phosphorylation, even when oxygen is available.

The team built Grubraw as a tool for testing what happens when oxidative metabolism is activated inside cancer cells despite this preference for glycolysis. The enzyme acts at the point where the study’s authors say pyruvate influx is limited, producing pyruvate within the mitochondrial compartment rather than relying on pyruvate transported from outside the cell. In HeLa Kyoto cells, this activity activated oxidative phosphorylation. It also increased the export of extracellular pyruvate, indicating that surplus mitochondrial pyruvate was not simply retained for fuel but was being disposed of through the cell membrane. The study further showed that Grubraw altered major metabolic fluxes in cells supplied with labeled glucose, providing a way to trace how carbon moved through glycolytic, mitochondrial and extracellular pathways.

Grubraw’s effects were not confined to one experimental cell line. The researchers found that its activity modulated metabolism across a series of cancer cell lines, although the supplied article abstract does not specify the full set of lines tested or the magnitude of each response. The broader cellular result was that activating mitochondria increased oxidative metabolism in cancer cells displaying Warburg metabolism. At the same time, Grubraw caused cancer cells to export excess mitochondrial pyruvate, revealing an unexpected route by which the cells controlled carbon flux. Rather than using all of the additional pyruvate to expand mitochondrial energy production, they routed it out of the cell.

Molecular analysis also found that mitochondrial activation through Grubraw suppressed transcription of genes involved in cell-cycle progression, cell proliferation and DNA replication. These gene-expression changes accompanied slower growth in vivo: human melanoma xenografts grew more slowly when the cancer cells’ mitochondria were activated with the chemogenetic system. The experiment therefore connected three measured observations—altered mitochondrial metabolism, reduced expression of growth-related genes and slower xenograft growth—but the abstract does not establish which of these changes was solely responsible for the tumor effect. Nor does the reported work demonstrate that Grubraw is a usable cancer treatment. The evidence comes from engineered cancer cells and mouse xenografts, and the published summary does not describe testing in people, long-term safety, delivery methods or treatment outcomes in human patients.

Subject of Research: Chemogenetic activation of mitochondrial metabolism in cancer cells and melanoma xenografts

Article Title: Chemogenetic activation of mitochondria counteracts the Warburg effect in tumor cells

Article References: Bass, D. Y., Potekhina, E. S., Ivanenko, A. V., Moshchenko, A. A., Korzhenevskiy, D. A., Nesterenko, A. M., Shevchenko, E. K., Karnaeva, A. E., Zakirova, N. F., Ivanov, A. V., Shimolina, L. E., Shirmanova, M. V., Lyang, O. V., Patsap, O. I., Kudryashova, O. M., Gazizova, G. R., Shagimardanova, E. I., Mariasina, S. S., Ivlev, V. A., … Belousov, V. V. (2026). Chemogenetic activation of mitochondria counteracts the Warburg effect in tumor cells. Nature Chemical Biology. https://doi.org/10.1038/s41589-026-02350-7

Image Credits: AI Generated

DOI: 10.1038/s41589-026-02350-7

Keywords: chemogenetics, mitochondria, Warburg effect, cancer metabolism, pyruvate, oxidative phosphorylation, melanoma, xenografts, glycolysis, Grubraw, Chemogenetic, activation