Cancer cells are often described as metabolic opportunists, consuming extraordinary amounts of glucose to sustain rapid growth. A new experimental drug takes advantage of that appetite rather than trying to suppress it. In studies involving cancer cells and mice with melanoma, researchers at The University of Texas at Austin and collaborating institutions used a two-part compound to force tumor cells into higher gear metabolically while simultaneously blocking their ability to use fat as an alternative fuel. The result was a severe energy crisis that killed many cancer cells and slowed tumor growth.
The strategy, reported in Nature Chemical Biology, centers on an enzyme called PFKL, or the liver isoform of phosphofructokinase. PFKL regulates a critical step in glycolysis, the biochemical pathway that converts glucose into energy and metabolic building blocks. Tumors frequently rely heavily on glycolysis, even when oxygen is available, a phenomenon associated with the Warburg effect. Instead of inhibiting this pathway, the researchers designed a molecule called XJ-4-85 that activates PFKL and accelerates glucose breakdown inside cancer cells.
That metabolic acceleration is only half of the drug’s mechanism. Once XJ-4-85 binds to PFKL, the compound releases a chemical payload that interferes with CPT2, an enzyme required for mitochondrial fatty-acid oxidation. CPT2 helps transport fatty-acid-derived molecules through the mitochondrial system so they can be broken down to produce energy. By disrupting CPT2, the drug removes a major backup fuel source precisely when the cancer cell is consuming glucose at an unusually high rate.
Structural studies helped reveal how the compound operates. Cryo-electron microscopy showed XJ-4-85 associated with PFKL at two sites, identified as K677 and K315. These interactions stabilize an activated form of the enzyme, increasing glycolytic activity. The molecule is also designed to undergo a chemical transformation after binding, releasing an electrophilic payload that can act on its second target. This architecture allows the same small molecule to combine selective protein recognition with a separate, covalent mechanism of enzyme disruption.
The researchers describe the approach as a “two-headed dragon” because it attacks cancer metabolism from opposite directions. Increasing glycolysis raises the demand for glucose and places additional pressure on the cell’s metabolic machinery. Blocking fatty-acid oxidation prevents the cell from switching to lipids when glucose metabolism becomes insufficient. With both pathways compromised, cancer cells may be unable to maintain adequate energy production, redox balance and biosynthetic capacity, leaving them vulnerable to metabolic collapse.
In laboratory experiments, the compound showed activity against human melanoma, leukemia, breast cancer, lung cancer, liver cancer and neuroblastoma cells. In mouse models of an aggressive melanoma, treatment caused extensive cancer-cell death and suppressed tumor growth. The researchers reported that noncancerous cells were less affected under the conditions tested, suggesting that the compound may exploit differences between tumor and normal-cell metabolism. However, this selectivity remains an experimental observation rather than evidence of safety in people.
The work represents a chemical alternative to antibody-drug conjugates, which use antibodies to recognize markers on cancer cells and deliver toxic payloads. Antibodies can be highly selective, but their large size generally limits them to targets accessible on the cell surface. Small molecules such as XJ-4-85 can enter cells and reach intracellular proteins, including metabolic enzymes. They are also potentially simpler to manufacture and modify, although achieving reliable tumor selectivity and controlling off-target chemical reactions remain major challenges.
The researchers call this broader class of compounds electrophile-drug conjugates, or EDCs. Unlike conventional drug conjugates that may simply carry a toxin to a target cell, EDCs are designed to use a recognition element to engage a protein and then release a reactive component capable of forming a lasting chemical interaction with another target. The concept could eventually be adapted beyond cancer, but its usefulness will depend on whether scientists can precisely control where and when the electrophilic payload is released.
The findings are still at an early preclinical stage. The drug has been tested in cultured cells and animal models, not in human patients, and further studies will be needed to evaluate dosing, distribution, toxicity, immune effects and the possibility of resistance. Cancer cells can rewire their metabolism, and tumors are biologically diverse, so the treatment may not work equally well across all cancers. Even so, the study offers a striking change in direction: rather than starving tumors by cutting off glucose, researchers are attempting to make cancer cells consume more sugar while closing the metabolic escape route provided by fat.
Subject of Research: Animals
Article Title: A Covalent PFKL Activator Suppresses Tumor Growth
News Publication Date: 5-Aug-2026
Web References: https://www.nature.com/articles/s41589-026-02289-9; https://doi.org/10.1038/s41589-026-02289-9
References: Nature Chemical Biology, “A Covalent PFKL Activator Suppresses Tumor Growth,” DOI: 10.1038/s41589-026-02289-9
Image Credits: Eric Lynch, University of Washington, and Xiaoding Jiang, University of Texas at Austin
Keywords: cancer metabolism, cancer treatment, cancer medication, chemotherapy, melanoma, glycolysis, PFKL, CPT2, fatty-acid metabolism, electrophile-drug conjugates, drug discovery, experimental cancer therapy
