Pancreatic cancer has acquired another layer of biological complexity, according to a new study identifying a molecular pathway that may help tumors withstand gemcitabine, one of the most widely used chemotherapy drugs for the disease. Researchers led by H. Zhu, B. Xu, and R. Zhu report that vaccinia-related kinase 2, or VRK2, enables pancreatic cancer cells to survive gemcitabine treatment by redirecting their metabolism toward an intensified form of aerobic glycolysis. The study, published in Cell Death Discovery, places the glycolytic enzyme triosephosphate isomerase 1, known as TPI1, at the center of this resistance mechanism. The findings suggest that a protein kinase and a metabolic enzyme cooperate to create a cellular state in which chemotherapy becomes substantially less effective.
Pancreatic cancer is among the most lethal malignancies because it is frequently diagnosed after the disease has invaded surrounding tissues or spread to distant organs. Even when surgery is possible, recurrence is common, and systemic therapy remains essential for many patients. Gemcitabine, a nucleoside analogue, has long been a central component of pancreatic cancer treatment. Once transported into cancer cells, the drug is phosphorylated into active metabolites that resemble naturally occurring nucleotides. These metabolites can become incorporated into newly synthesized DNA, interrupt DNA replication, and inhibit the production of additional deoxynucleotides required for cell division. In principle, rapidly proliferating tumor cells should be particularly vulnerable to this form of attack. In practice, pancreatic tumors often adapt through changes in drug transport, DNA repair, cell death signaling, and metabolism.
The new work focuses on VRK2, a serine/threonine protein kinase whose activity has been associated with cellular signaling, stress responses, and tumor biology. Protein kinases regulate other proteins by transferring phosphate groups to them, a modification that can alter protein stability, location, interactions, or enzymatic activity. In pancreatic cancer, the researchers found that increased VRK2 was associated with resistance to gemcitabine. Cells containing elevated VRK2 were better able to maintain their viability during treatment, whereas reducing VRK2 weakened the resistant phenotype. This relationship indicates that VRK2 is not merely a passive marker of aggressive disease but may actively contribute to the cellular changes that allow malignant cells to tolerate chemotherapy.
The pathway identified by the researchers leads from VRK2 to TPI1, an enzyme positioned at a crucial junction in glycolysis. Glycolysis breaks down glucose through a series of reactions, ultimately generating pyruvate while producing a limited amount of ATP and metabolic intermediates. TPI1 catalyzes the reversible conversion of dihydroxyacetone phosphate into glyceraldehyde-3-phosphate, ensuring that carbon entering one branch of glycolysis can continue through the energy-producing portion of the pathway. Although this reaction may appear chemically simple, it is essential for maintaining the flow of glucose-derived carbon through the pathway. Altering TPI1 abundance or activity can therefore reshape the metabolic capacity of a cancer cell.
The study connects VRK2-dependent resistance with a stronger reliance on aerobic glycolysis, a metabolic pattern commonly associated with the Warburg effect. In this state, cells consume glucose rapidly and convert much of it into lactate even when oxygen is available for mitochondrial oxidative phosphorylation. Aerobic glycolysis yields less ATP per molecule of glucose than complete mitochondrial oxidation, but it can provide cancer cells with speed and flexibility. High glycolytic flux supplies intermediates for nucleotide, amino acid, and lipid synthesis, while also supporting the redox balance required for continued growth under stress. For a cell exposed to gemcitabine, this metabolic reprogramming may help preserve the resources needed to repair damage and avoid programmed cell death.
TPI1 appears to be a key mediator of this adaptation. According to the researchers, VRK2 promotes a TPI1-driven glycolytic program, allowing pancreatic cancer cells to increase glucose utilization and sustain energy production during chemotherapy exposure. This may be especially important because gemcitabine creates a replication crisis: DNA synthesis is disrupted, nucleotide pools are disturbed, and unresolved damage can activate apoptosis. By enhancing glycolytic metabolism, resistant cells may generate ATP more rapidly, maintain biosynthetic precursors, and support stress-management systems that prevent the damaged cells from crossing the threshold into cell death. The findings therefore frame drug resistance not only as a problem of drug entry or DNA repair, but also as a consequence of how tumor cells fuel themselves.
At the molecular level, the proposed mechanism illustrates how signaling and metabolism become intertwined in cancer. VRK2 functions as an upstream regulatory factor, while TPI1 operates within the core machinery of glucose breakdown. A kinase-driven increase in glycolytic capacity could influence several downstream processes simultaneously, including the production of lactate, the balance between oxidized and reduced cofactors, and the availability of carbon skeletons for macromolecule synthesis. These changes can alter the response to chemotherapy even if the drug reaches the tumor and forms its intended molecular targets. In this model, gemcitabine resistance is not simply a genetic shield against the drug; it is a physiological state maintained by a coordinated signaling-metabolic network.
The researchers used experimental approaches to examine the relationship among VRK2, TPI1, glycolysis, and gemcitabine response in pancreatic cancer models. Their analyses support the view that manipulating VRK2 changes the metabolic behavior of tumor cells and that TPI1 is necessary for the resistance program. When the pathway is disrupted, the cells become more vulnerable to gemcitabine, linking the biochemical observations to a potentially actionable therapeutic strategy. The work also strengthens the idea that metabolic enzymes traditionally viewed as housekeeping proteins can become critical dependencies in cancer. A tumor may survive by exploiting a normal metabolic reaction, but that dependence can create a weakness if it is identified and selectively targeted.
The findings raise the possibility of combining gemcitabine with therapies directed against VRK2, TPI1, or associated glycolytic processes. Such an approach could, in theory, force resistant cancer cells away from the metabolic state that protects them during treatment. However, translating this concept into a clinical therapy will require careful evaluation. Glycolysis is essential in many normal tissues, and systemic inhibition could produce toxicity. VRK2 may also participate in signaling pathways outside the tumor, while TPI1 is required for ordinary cellular metabolism throughout the body. The most effective strategy may therefore depend on identifying tumors with unusually high VRK2 activity or a demonstrable TPI1-centered glycolytic signature, allowing treatment to be directed toward patients most likely to benefit.
The study’s broader message is that pancreatic cancer resistance may be understood more effectively when genetic signaling, metabolism, and cell-death control are considered together. A tumor cell does not respond to gemcitabine in isolation; it responds as a living system that can alter its fuel consumption, stress pathways, and biosynthetic priorities. By linking VRK2 to TPI1-driven aerobic glycolysis, the researchers provide a mechanistic explanation for how pancreatic cancer cells can remain viable under chemotherapy pressure. Further studies will need to determine how consistently this pathway operates in patient tumors, whether it predicts treatment failure, and which combinations can block it without harming healthy tissue. If validated, the VRK2–TPI1 axis could become a new target in the continuing effort to make gemcitabine more effective against one of the most treatment-resistant cancers.
Subject of Research: The role of vaccinia-related kinase 2 and TPI1-driven aerobic glycolysis in pancreatic cancer resistance to gemcitabine.
Article Title: Vaccinia-related kinase 2 confers pancreatic cancer with gemcitabine resistance through TPI1-driven aerobic glycolysis.
Article References: Zhu, H., Xu, B., Zhu, R. et al. Vaccinia-related kinase 2 confers pancreatic cancer with gemcitabine resistance through TPI1-driven aerobic glycolysis. Cell Death Discov. (2026). https://doi.org/10.1038/s41420-026-03303-8
Image Credits: AI Generated
DOI: https://doi.org/10.1038/s41420-026-03303-8
Keywords: Pancreatic cancer, gemcitabine resistance, vaccinia-related kinase 2, VRK2, TPI1, aerobic glycolysis, cancer metabolism, Warburg effect, chemotherapy resistance.
Tags: aerobic glycolysis in tumorsgemcitabine resistance mechanismskinase-enzyme interactions in cancermetabolic reprogramming in pancreatic cancermolecular basis of pancreatic cancer recurrencemolecular pathways of chemotherapy resistancepancreatic cancer chemoresistancepancreatic cancer treatment challengestargeting glycolytic enzymes for therapyTPI1 role in glycolysistumor metabolism and drug resistanceVRK2 kinase in cancer
