To understand why the discovery matters, it helps to start with the biology of protein turnover. Inside every cell, proteins that are damaged, misfolded or simply no longer needed are tagged with small molecules called ubiquitin, a molecular label that condemns them to destruction by the proteasome, the cell’s waste-disposal complex. Deubiquitinating enzymes, or DUBs, do the opposite: they snip ubiquitin tags off proteins, rescuing them from degradation and extending their functional lifespan. When this balancing act goes wrong, proteins that should be cleared can accumulate to abnormal levels, and in cancer that often means proteins that drive uncontrolled growth are granted an unnatural stay of execution. USP12 belongs to the ubiquitin-specific protease family, and previous work has linked it to several cancers, but its role in ovarian cancer had remained poorly defined.

The identity of its partner in this study was equally obscure. TBC1D22A is a member of the TBC1 domain family, proteins that act as GTPase-activating proteins for Rab GTPases, the molecular switches that regulate vesicle trafficking, membrane trafficking and intracellular transport. While Rab proteins have increasingly been implicated in tumor progression, TBC1D22A’s specific oncogenic mechanisms in ovarian cancer, and crucially the upstream pathways that regulate it, had never been reported. The new study set out to fill that gap by asking a deceptively simple question: what keeps TBC1D22A stable inside ovarian cancer cells, and what happens when that stability is disrupted?

The answer emerged from an unbiased hunt for TBC1D22A’s molecular companions. Using liquid chromatography coupled with tandem mass spectrometry, or LC-MS/MS, the researchers screened for proteins that physically associate with TBC1D22A, and USP12 surfaced as a candidate interacting deubiquitinase. The team then confirmed the partnership through complementary techniques: co-immunoprecipitation experiments showed that the two proteins can be pulled down together from cell lysates, while immunofluorescence co-localization assays revealed that they occupy overlapping territories within the cell. Together, these approaches established that the association is not a fleeting accident of cellular crowding but a genuine physical interaction, the kind that can support a regulatory relationship.

With the interaction confirmed, the researchers moved on to the central mechanistic question: does USP12 actually control how much TBC1D22A exists inside a cell, and if so, how? The evidence points firmly to post-translational regulation. Cycloheximide chase experiments, which block new protein synthesis and allow researchers to watch existing proteins decay over time, showed that TBC1D22A degraded more slowly when USP12 was present. Proteasome inhibition assays demonstrated that TBC1D22A’s destruction proceeds through the ubiquitin-proteasome pathway. Most tellingly, in vivo ubiquitination assays revealed that USP12 directly reduces the ubiquitin load carried by TBC1D22A, effectively stripping off the degradation tags before the proteasome can act. Importantly, USP12 did not alter TBC1D22A transcription, meaning the enzyme works purely at the protein level, preserving existing TBC1D22A molecules rather than coaxing the gene to make more.

That stabilization has consequences. Through a series of gain-of-function and loss-of-function experiments, the team showed that USP12 promotes ovarian cancer cell proliferation, migration and invasion, and that these effects depend on TBC1D22A. When the researchers removed USP12, TBC1D22A levels fell and the cancer cells became less motile and less invasive; when they re-introduced TBC1D22A in rescue experiments, the aggressive behavior returned. This dependency is the crucial detail: it means USP12 is not simply a general growth promoter acting through many parallel routes, but a specific upstream regulator whose oncogenic influence flows through TBC1D22A. Depleting the downstream partner effectively neutralizes the upstream enzyme, which is exactly the kind of linear dependency that makes a signaling axis attractive as a drug target.

The signaling pathway connecting the pair to malignancy is one of the most famous in all of cancer biology. The PI3K-AKT-mTOR cascade integrates signals from growth factor receptors and relays them to the cell’s growth and survival machinery, promoting metabolism, protein synthesis, proliferation and resistance to cell death. It is hyperactivated in a large fraction of human tumors, including ovarian cancers, and has been the subject of intense pharmaceutical interest for decades. In this study, the USP12-TBC1D22A axis was associated with activation of this pathway, providing a plausible mechanistic bridge between a vesicle-trafficking regulator and the malignant phenotype. The researchers also validated their findings in vivo using subcutaneous xenograft models, in which manipulated ovarian cancer cells were grown as tumors in animals, confirming that the axis influences tumor growth outside the controlled environment of a culture dish.

The clinical data add a layer of real-world relevance. Transcriptomic analysis, tissue microarrays and data from The Cancer Genome Atlas cohorts showed that USP12 is upregulated in ovarian cancer tissues compared with normal tissue, and that its expression positively correlates with TBC1D22A levels, consistent with the stabilizing relationship uncovered in the lab. More ominously, high USP12 expression predicted poorer overall survival and poorer progression-free survival in patients. In other words, the same molecular relationship that drives aggressiveness in laboratory models also tracks with worse outcomes in the clinic, strengthening the case that the axis is not an artifact of experimental conditions but a genuine feature of the disease.

For patients, the implications are cautiously encouraging. Ovarian cancer is often treated with surgery and platinum-based chemotherapy, and while PARP inhibitors have improved outlooks for some patients with homologous recombination deficiency, many tumors eventually become resistant. A deubiquitinase such as USP12 represents a different class of target, and DUB inhibitors have become an active frontier in drug development precisely because these enzymes can be drugged in ways that stabilize-or destabilize-key disease proteins. If the USP12-TBC1D22A axis proves essential in a broader set of ovarian tumors, blocking USP12 could deprive cancer cells of their stabilized TBC1D22A supply and dampen PI3K-AKT-mTOR signaling, potentially complementing existing therapies. The correlation between USP12 and survival also suggests it could serve as a prognostic marker, helping clinicians identify patients whose disease is likely to progress more rapidly.

There are, of course, important caveats. The study relied on cell lines, xenograft models and retrospective analysis of patient cohorts; prospective clinical validation, and demonstration that pharmacologically inhibiting USP12 benefits patients, remain future work. DUBs often have multiple substrates, so any therapeutic strategy would need to account for effects beyond TBC1D22A. Still, the work fills a genuine gap by identifying the first reported upstream regulatory pathway for TBC1D22A in ovarian cancer, and it does so with a methodologically thorough chain of evidence, from unbiased mass spectrometry through mechanistic biochemistry to animal models and human tissue data. As the authors conclude, the USP12-TBC1D22A axis may serve as a promising therapeutic target for ovarian cancer, and for a disease where new molecular handles are scarce, that promise is worth taking seriously.

Subject of Research: USP12-mediated deubiquitination and stabilization of TBC1D22A in ovarian cancer progression

Article Title: USP12 stabilizes TBC1D22A via deubiquitination to activate PI3K-AKT-mTOR signaling and promote ovarian cancer progression

Article References: Lv, X., Gong, R., Cai, X., & Guo, R. (2026). USP12 stabilizes TBC1D22A via deubiquitination to activate PI3K-AKT-mTOR signaling and promote ovarian cancer progression. Journal of Translational Medicine. https://doi.org/10.1186/s12967-026-09027-8

Image Credits: AI Generated

DOI: 10.1186/s12967-026-09027-8

Keywords: USP12, TBC1D22A, ovarian cancer, deubiquitinase, ubiquitin-proteasome pathway, PI3K-AKT-mTOR signaling, protein stability, Rab GTPase-activating protein, prognostic biomarker, xenograft model, Journal of Translational Medicine, cancer signaling

USP16 belongs to a large family of deubiquitinating enzymes, proteases that snip ubiquitin tags off target proteins. Ubiquitination is one of the cell’s principal mechanisms for marking proteins for destruction: when chains of ubiquitin molecules, particularly those linked through their lysine 48 residues, are attached to a protein, the proteasome recognizes the tag and degrades the cargo. Deubiquitinases reverse this process, rescuing proteins from degradation and thereby fine-tuning their abundance. In the new study, the researchers found that USP16 is markedly upregulated in gemcitabine-resistant pancreatic cancer specimens, and that elevated levels of the enzyme correlate with metastatic disease and poor patient prognosis, positioning USP16 as a potential biomarker of aggressive disease.

The functional experiments carried out by the team went beyond correlation. When the researchers silenced USP16 genetically or inhibited it pharmacologically, pancreatic cancer cells lost key malignant behaviors: proliferation slowed, invasive capacity diminished, and, critically, sensitivity to gemcitabine was restored. The same effects were reproduced in animal models, where USP16 suppression curbed tumor progression and re-sensitized tumors to chemotherapy. These results, the authors report, held both in vitro and in vivo, suggesting that USP16 is not merely a passenger mutation or a passive marker of aggressive disease but an active participant in maintaining the resistant phenotype.

The mechanistic heart of the paper lies in metabolism. Cancer cells famously favor glycolysis, the fermentation of glucose into lactate, even in the presence of abundant oxygen, a phenomenon known as the Warburg effect. This metabolic reprogramming supplies rapidly dividing tumors with biosynthetic building blocks and helps them survive environmental stress. The researchers demonstrated that USP16 promotes this glycolytic switch by stabilizing a transcription factor called Far Upstream Element Binding Protein 1, or FUBP1. Biochemical analysis showed that USP16 preferentially removes K48-linked polyubiquitin chains from FUBP1, shielding the protein from proteasomal destruction. With FUBP1 stabilized, pancreatic cancer cells accumulate higher levels of this transcription factor in the nucleus.

FUBP1, in turn, drives transcription of lactate dehydrogenase A, or LDHA, the enzyme that catalyzes the conversion of pyruvate to lactate, the final and defining step of anaerobic glycolysis. By enhancing FUBP1-dependent LDHA expression, USP16 effectively turns up the dial on lactate production, fueling the metabolic state that supports rapid proliferation and chemoresistance. The connection is biologically plausible: high glycolytic flux has been repeatedly linked to drug resistance in solid tumors, partly because glycolytic tumors maintain acidic, hypoxic microenvironments that blunt the efficacy of chemotherapeutic agents and promote survival signaling. The USP16-FUBP1-LDHA axis therefore offers a coherent explanation for how a single deubiquitinase can simultaneously promote metastatic behavior and undermine gemcitabine therapy.

Perhaps the most intricate portion of the study concerns how USP16 itself becomes overexpressed in pancreatic cancer in the first place. The researchers traced the excess USP16 to two upstream layers of regulation. The first involves N6-methyladenosine, or m6A, the most abundant internal chemical modification in messenger RNA. The methyltransferase-like 3 enzyme, METTL3, installs m6A marks on the USP16 transcript, and these modifications enhance the message’s translation or processing. The second layer involves Insulin-like Growth Factor 2 mRNA-Binding Protein 1, or IGF2BP1, a reader protein that recognizes m6A-modified transcripts and stabilizes them, preventing degradation. Together, METTL3-mediated methylation and IGF2BP1-dependent stabilization elevate USP16 protein levels in pancreatic cancer cells, setting the entire pathological cascade in motion.

This architecture, which the authors describe as a METTL3/IGF2BP1-USP16-FUBP1-LDHA regulatory axis, is notable because it links three major themes in contemporary cancer biology: epitranscriptomic regulation through RNA modifications, post-translational control through ubiquitination, and metabolic reprogramming through glycolysis. Each layer of the axis represents a potential point of therapeutic intervention, and the study’s demonstration that both genetic and pharmacological USP16 inhibition suppress tumor progression suggests that deubiquitinase inhibitors could form the basis of new combination strategies designed to be administered alongside gemcitabine.

The clinical implications are considerable. Gemcitabine resistance is one of the chief reasons pancreatic cancer has a five-year survival rate that remains among the lowest of any major cancer. If USP16 levels can be measured reliably in tumor biopsies, the enzyme could serve as a biomarker identifying patients likely to derive limited benefit from gemcitabine-based regimens, guiding clinicians toward alternative or intensified approaches. More ambitiously, if USP16 inhibitors can be developed with acceptable safety profiles, they might resensitize resistant tumors to existing chemotherapy, extending the usefulness of a drug that has been a workhorse in pancreatic oncology for decades. The study’s finding that pharmacological USP16 inhibition restored gemcitabine sensitivity in vivo provides an early proof of concept for that strategy.

Caveats remain, as they do with any preclinical study. The work was conducted in cell lines and animal models, and the translation of deubiquitinase inhibition into human therapy will require medicinal chemistry advances, since deubiquitinases share catalytic mechanisms that can make selective inhibition challenging. The authors also note that the published version is an early-release, peer-reviewed accepted manuscript subject to further editorial refinement. Nonetheless, the identification of a complete signaling axis, from RNA modification through protein stabilization to metabolic enzyme expression, gives researchers a detailed map of a resistance pathway that had remained poorly understood, and it adds USP16 to the growing list of deubiquitinating enzymes implicated in cancer metabolism.

For a disease that has seen painfully slow therapeutic progress, studies that illuminate the machinery of chemoresistance carry real weight. By showing how an m6A-modified, IGF2BP1-stabilized transcript elevates a deubiquitinase that in turn protects a transcription factor governing lactate metabolism, the research team has connected molecular layers that are usually studied in isolation. Whether targeting USP16 will ultimately improve outcomes for patients with pancreatic ductal adenocarcinoma will depend on the development of clinically viable inhibitors and appropriately designed trials, but the study establishes a clear, testable framework for attacking gemcitabine resistance at its metabolic roots, and it underscores how deeply the survival of this formidable cancer depends on the reprogramming of its energy economy.

Subject of Research: USP16-mediated glycolytic reprogramming and gemcitabine resistance in pancreatic ductal adenocarcinoma

Article Title: USP16 promotes pancreatic ductal adenocarcinoma progression and gemcitabine resistance through FUBP1/LDHA axis-mediated glycolysis

Article References: Dong, Y., Lin, C., Fang, H., Tan, Z., Lu, J., Liu, Z., Lai, S., & Wang, Y. (2026). USP16 promotes pancreatic ductal adenocarcinoma progression and gemcitabine resistance through FUBP1/LDHA axis-mediated glycolysis. Cellular and Molecular Life Sciences. https://doi.org/10.1007/s00018-026-06466-w

Image Credits: AI Generated

DOI: 10.1007/s00018-026-06466-w

Keywords: pancreatic ductal adenocarcinoma, USP16, deubiquitinase, FUBP1, LDHA, glycolysis, gemcitabine resistance, m6A modification, METTL3, IGF2BP1, cancer metabolism, chemoresistance

The research team, led by corresponding authors Hongzhang Li and Jiaoe Chen, focused on two proteins that had not previously been connected in this context: ONECUT2, a transcription factor belonging to the one-cut domain family, and YOD1, a deubiquitinase enzyme that removes ubiquitin tags from target proteins. Their central finding is that ONECUT2 directly switches on the gene encoding YOD1, and that the resulting surge in YOD1 activity stabilizes STAT3, a well-known cancer-promoting signaling protein, which in turn ramps up production of PD-L1, the molecular shield that many tumors use to evade destruction by the immune system.

To establish this pathway, the investigators assembled clinical samples from gastric cancer patients, carefully stratified according to whether their tumors and adjacent para-carcinoma tissues came from H. pylori-positive or H. pylori-negative individuals. When they quantified gene expression using quantitative real-time polymerase chain reaction and protein levels using Western blotting, a consistent pattern emerged: ONECUT2, YOD1, and PD-L1 were all significantly upregulated in the H. pylori-infected gastric tissues compared with their counterparts from uninfected patients. The same elevation appeared in laboratory cultures of AGS and HGC-27 gastric cancer cells after deliberate infection with the bacterium, providing a controllable model system for mechanistic dissection.

With the correlation established, the team moved to causality. Using short hairpin RNA vectors to silence ONECUT2 in the infected cells, they observed a marked attenuation of the malignant phenotype. Cell proliferation, measured by CCK-8 colorimetric assays, EdU incorporation assays that label cells actively synthesizing DNA, and colony formation tests, all declined when ONECUT2 was depleted. Transwell migration and invasion assays, which track the ability of cells to squeeze through membrane barriers, showed the same directional change, indicating that ONECUT2 supports not only growth but also the invasive behavior that makes gastric cancer so dangerous clinically.

The mechanistic heart of the paper lies in demonstrating that YOD1 is a direct transcriptional target of ONECUT2. Two complementary techniques converged on this conclusion. In a dual luciferase reporter assay, the researchers showed that the presence of ONECUT2 increased the activity of a reporter gene placed under the control of the YOD1 promoter, a classic signature of transcriptional activation. Chromatin immunoprecipitation, or ChIP, then confirmed the physical basis of that activation by demonstrating that ONECUT2 binds directly to the YOD1 promoter region in living cells. Together, these experiments elevate the ONECUT2-YOD1 relationship from a statistical association to a defined regulatory interaction.

What YOD1 does once it is produced is equally instructive. Deubiquitinases of the ubiquitin-specific protease and related families act as molecular editors, stripping ubiquitin chains from proteins and thereby protecting them from degradation by the proteasome, the cell’s waste-disposal machinery. The study’s supplementary experiments, including co-immunoprecipitation to detect the endogenous interaction between YOD1 and STAT3, cycloheximide chase assays to measure protein half-life, and ubiquitination assays, showed that YOD1 physically associates with STAT3 and slows its degradation. When YOD1 was knocked down, STAT3 ubiquitination increased and the protein’s half-life shortened, meaning the transcription factor was being destroyed more rapidly. Conversely, abundant YOD1 allows STAT3 to accumulate and remain active longer, amplifying the downstream signal.

STAT3 is a signal transducer and activator of transcription with a well-documented role in inflammation-driven cancers, and its phosphorylated form, p-STAT3, was elevated in the infected cells in this study. The final link in the chain is PD-L1, programmed death-ligand 1, a cell-surface protein whose expression STAT3 can promote. PD-L1 binds the PD-1 receptor on T cells and effectively instructs the immune system to stand down, a trick that tumors exploit to escape immunosurveillance. The finding that the ONECUT2-YOD1-STAT3 cascade culminates in PD-L1 upregulation therefore suggests a mechanism by which chronic H. pylori infection might not only drive tumor growth but also actively blunt the anti-tumor immune response within the gastric microenvironment.

Perhaps the most convincing evidence for the pathway’s coherence came from rescue experiments. When the researchers overexpressed YOD1 in cells lacking ONECUT2, the suppressed proliferation and migration were partially restored, and the recovery was mediated through the STAT3/PD-L1 signaling pathway. This epistasis-style experiment, in which a downstream component compensates for the loss of an upstream one, is a standard test of whether a proposed linear pathway is real. The partial nature of the rescue also hints that ONECUT2 may influence additional targets beyond YOD1, a question that will likely guide future work in this area.

The clinical implications are twofold. First, the ONECUT2/YOD1/STAT3/PD-L1 axis offers a set of potential biomarkers: patients whose H. pylori-associated tumors show high expression of these proteins might be identified as having more aggressive disease or a more immunosuppressive microenvironment, potentially informing treatment selection. Second, each node in the axis represents a conceivable therapeutic target. Deubiquitinase inhibitors are an increasingly active area of drug development, and PD-L1 is already the target of approved immune checkpoint blockade therapies in multiple cancers, although the authors frame the PD-L1 connection here as suggesting a potential role in immune-related regulation rather than as a demonstrated treatment strategy. The study, which was approved by the Ethics Committee of Sanmen People’s Hospital and supported by the Zhejiang Medical and Health Science and Technology Plan, was published open access on 1 October 2026 under DOI 10.1186/s12885-026-17088-7. As with any cell-line and tissue-based investigation, the findings will need validation in larger patient cohorts and in vivo models before they translate into clinical practice, but they provide a mechanistically grounded explanation for how a common bacterial infection can push gastric cells toward both malignancy and immune evasion at the same time.

Subject of Research: The role of the ONECUT2/YOD1/STAT3/PD-L1 signaling axis in malignant progression of Helicobacter pylori-associated gastric cancer.

Article Title: ONECUT2-mediated transcriptional activation of YOD1 promotes malignant progression in H. pylori-associated gastric cancer through the STAT3/PD-L1 signaling

Article References: Chen, N., Fang, X., Chen, Q., Lin, J., Li, H., Li, H., & Chen, J. (2026). ONECUT2-mediated transcriptional activation of YOD1 promotes malignant progression in H. pylori-associated gastric cancer through the STAT3/PD-L1 signaling. BMC Cancer. https://doi.org/10.1186/s12885-026-17088-7

Image Credits: AI Generated

DOI: 10.1186/s12885-026-17088-7

Keywords: gastric cancer, Helicobacter pylori, ONECUT2, YOD1, STAT3, PD-L1, deubiquitinase, transcription factor, immune evasion, cancer immunology, gene regulation, tumor progression

The study, led by researchers at the First Medical Centre of the Chinese PLA General Hospital, focused on a secreted protein called SFRP2, a member of the secreted frizzled-related protein family best known for modulating Wnt signalling. Although SFRP2 has traditionally been described as a Wnt antagonist, accumulating evidence has painted a more complicated picture, linking it to tumour progression in glioblastoma, osteosarcoma and lung cancer. What remained unclear was exactly how SFRP2 might contribute to colon cancer metastasis, and whether the protein could be exploited as a biomarker or therapeutic target.

To answer those questions, the team began by mining publicly available genomic datasets. Comparing primary tumours with metastatic colon cancer tissues in the GEO dataset GSE40367, they found SFRP2 among the genes most significantly elevated in metastatic samples. Data from The Cancer Genome Atlas confirmed that SFRP2 expression was higher in colon tumours than in normal tissue, while Kaplan–Meier survival analysis revealed a sobering pattern: patients with high SFRP2 levels had worse overall survival, worse recurrence-free survival and worse post-progression survival. Immunohistochemistry and western blotting of patient specimens showed the strongest SFRP2 signal in metastatic tumour tissue, above even primary tumours and healthy tissue.

The researchers then turned to laboratory models. When they exposed colon cancer cells to TGF-β, a molecule that drives epithelial-mesenchymal transition, SFRP2 levels rose in step with the loss of the epithelial marker E-cadherin and the gain of mesenchymal markers N-cadherin and Vimentin. Using a clever in vitro invasion system, they separated LoVo colon cancer cells into highly metastatic populations that penetrated a coated membrane and poorly metastatic populations that did not; the aggressive cells carried far more SFRP2. Functional tests drove the point home: overexpressing SFRP2 in HCT116 cells boosted migration and invasion, while silencing the gene in LoVo cells suppressed both. Strikingly, SFRP2 manipulation had no effect on cell proliferation, suggesting the protein’s role is specifically in the physical business of spreading rather than growing.

The mechanistic core of the study lies in SFRP2’s interaction with Snai1, a transcription factor that orchestrates epithelial-mesenchymal transition by repressing epithelial genes and activating mesenchymal ones. Gene set enrichment analysis pointed toward focal adhesion and cell adhesion pathways, and Pearson correlation analysis showed SFRP2 and Snai1 levels rising together in patient data. Co-immunoprecipitation experiments confirmed that the two proteins physically bind to each other, both at endogenous levels and when tagged versions were introduced into cells. Most importantly, when the team blocked new protein synthesis with cycloheximide, Snai1 lingered far longer in SFRP2-overexpressing cells, demonstrating that SFRP2 protects Snai1 from degradation. Treating SFRP2-deficient cells with the proteasome inhibitor MG132 restored Snai1 levels, pinpointing the ubiquitin-proteasome system as the route of destruction.

That discovery led the investigators to USP11, a deubiquitinating enzyme predicted by the BioGRID database to interact with Snai1. Ubiquitin tags normally mark proteins for destruction by the 26S proteasome, and deubiquitinases like USP11 remove those tags, extending a protein’s lifespan. The team showed that USP11 binds Snai1 and that SFRP2 strengthens this partnership: in the presence of SFRP2, the USP11–Snai1 interaction intensified, whereas silencing SFRP2 weakened it. When the researchers inhibited USP11’s enzymatic activity with mitoxantrone, Snai1 stability collapsed, even in SFRP2-overexpressing cells. Conversely, forcing USP11 expression in SFRP2-knockdown cells rescued Snai1 protein levels. The picture that emerges is of SFRP2 as a facilitator that recruits USP11 to Snai1, allowing the deubiquitinase to strip away the ubiquitin marks that would otherwise doom Snai1 to the cellular recycling bin.

Perhaps the most striking finding is that the relationship runs in both directions. Scanning the SFRP2 promoter with the JASPAR tool revealed a binding motif for Snai1, and follow-up experiments showed that Snai1 directly binds the SFRP2 promoter to drive its transcription. Overexpressing Snai1 raised SFRP2 levels; knocking it down lowered them. Mutating the binding site abolished the effect in luciferase reporter assays, and chromatin immunoprecipitation confirmed the interaction on native DNA. In other words, SFRP2 stabilizes Snai1, and Snai1 in turn manufactures more SFRP2—a self-reinforcing positive feedback loop that could lock cancer cells into an invasive, metastatic state once it is triggered.

The team then traced what this loop does downstream. Gene set enrichment analysis flagged the PI3K/AKT/mTOR pathway, a central growth and survival cascade frequently hijacked by tumours. In cells, SFRP2 overexpression increased phosphorylation of PI3K, AKT and mTOR, and manipulating Snai1 reversed those changes. Treatment with the PI3K inhibitor LY294002 dampened the pathway without altering Snai1 or SFRP2 levels, indicating the cascade lies downstream of the SFRP2–Snai1 axis rather than upstream. Functional assays confirmed the consequences: silencing Snai1 partially blocked the migratory and invasive boost conferred by SFRP2, while restoring Snai1 in SFRP2-deficient cells rescued their aggressive behaviour, along with mesenchymal markers such as N-cadherin, Slug and Vimentin.

Crucially, the story held up in living animals. In mouse models of metastasis, SFRP2-overexpressing colon cancer cells produced dramatically more liver metastases than controls, an effect abolished when Snai1 was simultaneously knocked down. Tumours from these animals showed elevated Snai1 and phosphorylated PI3K, AKT and mTOR, while SFRP2-silenced cells yielded fewer metastases unless Snai1 was re-expressed. The authors acknowledge limitations, including the reliance on cell lines and xenografts that cannot fully reproduce the complexity of the human tumour microenvironment, and they caution that other pathways may contribute. Even so, the identification of a SFRP2–Snai1–USP11 feedback loop wired into PI3K/AKT/mTOR signalling gives researchers a concrete set of intervention points. Given that elevated SFRP2 already correlates with poor survival, the loop could serve both as a prognostic marker for aggressive disease and as a target for drugs designed to break the circuit before colon cancer cells ever leave home.

Subject of Research: The role of SFRP2, Snai1 and USP11 in a feedback loop promoting colon cancer metastasis via PI3K/AKT/mTOR signalling

Article Title: SFRP2 Potentiates Metastasis of Colon Cancer by Enhancing Snai1 Protein Stability via USP11

Article References: Kuang, Y., Liu, X., Ke, M., Chang, Z., Jia, B., Li, B., & Qian, H. (2026). SFRP2 Potentiates Metastasis of Colon Cancer by Enhancing Snai1 Protein Stability via USP11. Journal of Cellular and Molecular Medicine, 30(17), Article e71318. https://doi.org/10.1111/jcmm.71318

Image Credits: AI Generated

DOI: 10.1111/jcmm.71318

Keywords: colon cancer, metastasis, SFRP2, Snai1, USP11, deubiquitinase, EMT, PI3K/AKT/mTOR, protein stability, biomarker, TGF-beta, liver metastasis

STAMBPL1 belongs to the JAMM family of deubiquitinases, a group of metalloproteases named after the JAB1/MPN domain metalloenzyme motif that sits at the heart of their catalytic machinery. What makes STAMBPL1 remarkable is its exquisite specificity: unlike enzymes that indiscriminately cut many types of ubiquitin chains, STAMBPL1 selectively dismantles chains linked through lysine 63, one of the seven lysine residues on ubiquitin that can serve as attachment points. This linkage selectivity is not an accident of chemistry but the product of an elegant bipartite structural recognition mode, in which the enzyme engages the ubiquitin chain at two distinct surfaces simultaneously. Structural studies, including the landmark crystallographic work that revealed how AMSH-family enzymes cleave Lys63-linked chains, showed that the catalytic domain cradles the distal ubiquitin while auxiliary elements contact the proximal one, ensuring that only the correct chain geometry is processed.

This molecular precision translates into an astonishing breadth of physiological influence. Because Lys63-linked ubiquitin chains rarely signal for protein destruction in the proteasome, they instead act as scaffolding codes that assemble signaling complexes and direct membrane traffic. STAMBPL1 therefore sits at critical junctions of cellular logistics. On early endosomes, it is anchored by clathrin and trims ubiquitin tags from internalized receptors, controlling whether they are recycled back to the cell surface or degraded. It modulates apoptotic pathways by regulating the stability of proteins such as the X-linked inhibitor of apoptosis protein, participates in metabolic homeostasis through the mechanistic target of rapamycin complex 1, shapes immune signaling through the transcription factor NF-κB, and governs epithelial-mesenchymal plasticity, the developmental program that cells hijack during metastasis. In male germ cells, a related family member is even expressed specifically during haploid stages of spermatogenesis, underscoring how deeply this enzyme lineage is woven into reproduction and development.

The review, authored by Hu Lei, Hanzhang Xu, Li Yang, and Yingli Wu of Shanghai Jiao Tong University School of Medicine, systematically integrates two decades of structural, cell biological, and translational research into a coherent portrait of STAMBPL1 as both a guardian of homeostasis and, when its expression goes awry, a driver of malignancy. The authors emphasize that the enzyme’s influence extends far beyond the cancer cell itself, touching viral pathogenesis, inflammatory responses, and the metabolic rewiring that tumors impose on their surroundings. It is this dual identity, essential in normal physiology yet exploitable by tumors, that has propelled STAMBPL1 to the front ranks of candidate drug targets within the ubiquitin system.

The cancer connection is strikingly consistent across tumor types. Aberrant upregulation of STAMBPL1 has now been documented in an expanding roster of human malignancies, including gastric cancer, colorectal cancer, hepatocellular carcinoma, cholangiocarcinoma, lung adenocarcinoma, non-small cell lung cancer, triple-negative breast cancer, prostate cancer, and kidney renal clear cell carcinoma. In study after study, elevated levels of the enzyme correlate with advanced clinicopathological features, such as larger tumors, deeper invasion, later-stage disease, and lymph node involvement, as well as with unfavorable patient survival. The pattern is so reproducible that STAMBPL1 is increasingly viewed not merely as a biomarker but as an active participant in tumor progression, a molecular accomplice whose presence tips the scales toward growth, spread, and treatment resistance.

Mechanistically, STAMBPL1 promotes the malignant phenotype through both catalytic and noncatalytic means, and the review dissects these pathways with unusual granularity. In gastric cancer, STAMBPL1 removes Lys63-linked ubiquitin chains from IQGAP1, a scaffolding protein, thereby stabilizing it and hyperactivating the JAK2/STAT3 signaling axis that drives proliferation and migration. In hepatocellular carcinoma, the enzyme deubiquitinates TRAF2 to ignite WNT, PI3K, and NF-κB signaling, while a separate feedback loop involving the oncogene MYC, STAMBPL1, and the protein TOE1 stabilizes the epidermal growth factor receptor, further amplifying growth signals. The enzyme’s own expression is transcriptionally controlled by SREBP1, the master regulator of lipid synthesis, linking STAMBPL1 activity directly to the metabolic reprogramming that fast-growing tumors require. In colorectal cancer, STAMBPL1 promotes growth and migration through the NF-κB pathway, and in lung adenocarcinoma it advances progression by suppressing the expression of DHRS2, a metabolic enzyme with tumor-suppressive properties.

The enzyme’s reach extends to some of the most clinically vexing problems in oncology: drug resistance and immune evasion. In breast cancer, STAMBPL1 stabilizes MKP-1, a phosphatase that blunts stress-activated kinase signaling, thereby helping cells survive cisplatin chemotherapy. In triple-negative breast cancer, the most aggressive and least treatable breast cancer subtype, STAMBPL1 interacts with the transcription factor FOXO1 to activate a GRHL3/HIF1A/VEGFA axis that promotes angiogenesis, the formation of new blood vessels that feed the tumor. In kidney renal clear cell carcinoma, a balance between STAMBPL1 and the E3 ligase TRIM21 controls the stability of AXL, a receptor tyrosine kinase that shapes both the mesenchymal, invasive phenotype of tumor cells and the immune response mounted against them. Meanwhile, the mTOR pathway, a central metabolic checkpoint, is jointly modulated by STAMBPL1 and the E3 ligase RNF167, which together regulate the stability of mTOR-associated components and the stress protein Sestrin2, a mechanism implicated in gastric cancer progression through the action of SMAD3.

Perhaps most provocatively, STAMBPL1 emerges as a gatekeeper of apoptosis, the programmed cell death that chemotherapy and targeted therapies ultimately try to trigger. A series of studies has shown that natural-product compounds can sensitize tumor cells to TRAIL, an apoptosis-inducing immune molecule, by promoting STAMBPL1-dependent degradation of survival proteins. Honokiol, from the magnolia tree, cepharanthine, an alkaloid used in Japanese medicine, and tubeimoside-1, a saponin from a traditional Chinese medicinal plant, all act through STAMBPL1 to lower the levels of survivin and c-FLIP, two proteins that shield cancer cells from death signals. Conversely, in gastric cancer, the long non-coding RNA NEAT1 promotes proliferation and invasion by modulating a microRNA axis that regulates STAMBPL1 expression, while in prostate cancer, inhibiting the enzyme triggers apoptosis by forcing the degradation of XIAP. Even infectious disease intersects this story: the human T-cell leukemia virus type 1 exploits STAMBPL1 for Tax protein nuclear export and NF-κB activation, and Helicobacter pylori-induced reactive oxygen species direct the turnover of STAMBPL1 within the COP9 signalosome complex, augmenting apoptotic cell death in infected gastric tissue.

Encouragingly, the review highlights that STAMBPL1 is no longer an untouchable target. Preclinical studies have validated multiple therapeutic strategies, ranging from natural-product modulators such as gamabufotalin, which exerts anti-hepatocellular carcinoma effects through amino acid metabolism by targeting STAMBPL1, and liquidambaric acid, which disrupts a positive feedback loop between STAMBPL1 and the antioxidant regulator NRF2 in cholangiocarcinoma, to rationally designed peptide inhibitors and engineered ubiquitin variants. The ubiquitin variant approach is particularly elegant: researchers have characterized engineered ubiquitin-based proteins that bind the catalytic domain of JAMM-family enzymes with high affinity and block their activity, providing both research tools and potential therapeutic leads. Biophysical techniques such as surface plasmon resonance, the cellular thermal shift assay, and drug affinity responsive target stability assays have been deployed to confirm compound engagement with the enzyme inside living cells, lending pharmacological rigor to these efforts.

What emerges from this synthesis is a picture of STAMBPL1 as a molecular switch with outsized consequences: flip it one way and cells traffic receptors, tune immune signals, and balance metabolism; flip it the other way and tumors proliferate, invade, resist chemotherapy, and hide from the immune system. The Shanghai Jiao Tong University team argues that the enzyme’s structural uniqueness, particularly its bipartite recognition of Lys63-linked chains, offers a blueprint for designing inhibitors that spare other deubiquitinases and minimize toxicity. As the ubiquitin system matures into one of the richest target spaces in modern drug discovery, STAMBPL1 stands out as a target whose biology is now mapped from crystal structure to clinical correlation, and whose inhibition, the evidence suggests, could strike at the very heart of how cancers grow, spread, and survive.

Subject of Research: The roles of the JAMM-family deubiquitinase STAMBPL1 in cellular homeostasis and human cancer

Article Title: Roles of JAMM-family deubiquitinase STAMBPL1 in cellular homeostasis and human cancer

Article References: Roles of JAMM-family deubiquitinase STAMBPL1 in cellular homeostasis and human cancer. (n.d.). https://doi.org/10.1007/s11033-026-12784-w

Image Credits: AI Generated

DOI: 10.1007/s11033-026-12784-w

Keywords: STAMBPL1, deubiquitinase, JAMM family, Lys63-linked polyubiquitin, cancer, NF-κB, mTORC1, JAK2/STAT3, apoptosis, chemotherapy resistance, ubiquitin variants, therapeutic target

The ubiquitin–proteasome system is the cell’s principal machinery for controlled protein destruction. Small ubiquitin tags are attached to target proteins through an enzymatic cascade involving activating enzymes, conjugating enzymes and ligases, and proteins carrying specific ubiquitin chains are recognized and degraded by the proteasome, a barrel-shaped proteolytic complex. Because the system governs the abundance of virtually every regulatory protein in the cell, including tumor suppressors, cell-cycle drivers and signaling components, it has long been considered a rich source of therapeutic targets. The clinical success of proteasome inhibitors in multiple myeloma, and more recently the explosive growth of targeted protein degrader technologies, have confirmed that manipulating protein turnover can be a powerful anti-cancer strategy.

Deubiquitinases, or DUBs, sit at the opposite end of this pathway. Rather than attaching ubiquitin, these proteases remove it, cleaving ubiquitin chains from substrates or editing the architecture of the chains themselves. In doing so, DUBs stabilize proteins that would otherwise be destroyed, fine-tune signaling complexes and recycle ubiquitin for reuse. The human genome encodes roughly one hundred DUBs, distributed across several mechanistically distinct families, including cysteine proteases of the USP, UCH, OTU and MJD classes and metalloproteases of the JAMM family. Their activities touch nearly every cellular process, and a growing body of evidence shows that many DUBs are dysregulated in cancer, where they act as oncogenes or tumor suppressors depending on the context.

The review’s central thesis is that DUBs are deeply intertwined with KRAS biology, and that this connection creates therapeutic openings that conventional approaches have overlooked. KRAS operates as a molecular switch, cycling between an active, GTP-bound state and an inactive, GDP-bound state, and transmitting signals downstream through the RAF–MEK–ERK and PI3K–AKT pathways. Each stage of this circuit is buffered by ubiquitin-dependent regulation. Ubiquitin ligases such as the CUL3 complex, which recognizes active KRAS through the adaptor protein calcoco-2, can ubiquitinate KRAS and promote its degradation, acting as a built-in brake on signaling. DUBs that remove ubiquitin from KRAS or from components of its downstream pathways effectively remove that brake, amplifying and prolonging the oncogenic signal. Conversely, inhibiting the right DUB could restore the degradation of mutant KRAS or sensitize tumor cells to existing inhibitors.

Several individual DUBs have emerged as particularly compelling nodes in this network. The USP family member USP11, for example, has been reported to stabilize KRAS by removing its ubiquitin marks, thereby sustaining ERK signaling in KRAS-mutant cells. USP21 and USP22 have similarly been implicated in supporting KRAS-driven transcriptional programs, partly through their effects on chromatin regulators and signaling intermediates. On the downstream side, DUBs such as USP9X, USP5 and CYLD regulate the stability of RAF, MEK and ERK pathway components as well as NF-kappaB signaling, shaping both the intensity of the oncogenic output and the inflammatory milieu of the tumor microenvironment. Because these enzymes act at multiple points in the circuit, they offer a way to modulate KRAS signaling even when direct inhibition of the protein itself is technically or clinically difficult.

This matters enormously for the translational landscape. The G12C inhibitors sotorasib and adagrasib demonstrated that covalent drugs can reach mutant KRAS in the recessed pocket of its switch-II region, yet their impact is limited to the roughly one in eight KRAS-mutant tumors that carry the G12C alteration, and resistance through pathway reactivation, tissue plasticity and drug-tolerant persister cells develops within months. Approaches that work through protein turnover are intrinsically broader. A DUB inhibitor, or a degrader built on DUB biology, would not need a druggable pocket on KRAS itself; it would only need to shift the balance of the degradation machinery. The review highlights this as a route toward tumors carrying non-G12C mutations such as G12D, G12V and Q61, which together account for the majority of KRAS-driven cancers and remain without approved targeted therapies.

The therapeutic logic also extends to combination strategies. Preclinical studies indicate that degrading or destabilizing KRAS, whether through ligase recruitment or through DUB inhibition, can cooperate with upstream and downstream blockade, for instance pairing proteasome-directed approaches with SHP2 inhibitors, MEK inhibitors or ERK inhibitors to collapse the adaptive signaling networks that tumors deploy under treatment pressure. In resistant tumors where KRAS amplification or bypass signaling restores ERK output, lowering the total pool of KRAS protein could re-sensitize cells to doses of pathway inhibitors that are otherwise survivable. The review frames DUB targeting as a complementary pillar to the degrader boom: while molecular glue compounds and PROTACs recruit ubiquitin ligases to tag targets for destruction, DUB inhibitors would work by removing the enzymes that protect oncogenic proteins from destruction.

The challenges, however, are substantial, and the review is candid about them. DUBs are proteases, and designing selective inhibitors for cysteine protease active sites has proven difficult, with many early compounds suffering from broad reactivity and poor pharmacology. Redundancy is a second obstacle: multiple DUBs can often compensate for one another, meaning that single-agent inhibition may produce modest effects unless the dominant node in a given tumor is correctly identified. There is also the problem of context. The same DUB can act as an oncogene in one cancer and a tumor suppressor in another, so patient stratification and biomarker development will be essential. Finally, because the ubiquitin system regulates a vast range of non-cancerous processes, including immune signaling and DNA repair, systemic toxicity must be carefully evaluated.

To navigate these difficulties, the review outlines several priorities for the field. Better structural biology and cryo-electron microscopy of DUB-substrate complexes could reveal allosteric and protein-protein interaction surfaces that are more drug-friendly than catalytic sites. Proteomic approaches that map the ubiquitin landscape of KRAS-mutant tumors, increasingly accessible through ubiquitin-remnant mass spectrometry, could identify which DUBs are genuinely rate-limiting in which genetic backgrounds. And emerging chemical modalities, including covalent fragments targeting non-catalytic cysteines, targeted protein degraders and PROTAC-inspired molecules that eliminate DUBs themselves rather than merely inhibiting them, may open doors that classical enzyme inhibitors could not. The authors argue that systematic functional genomics, using CRISPR screens in panels of KRAS-mutant cell lines, will be key to converting the growing catalog of DUB-KRAS interactions into a validated target hierarchy.

The significance of this synthesis lies in its reframing of a familiar problem. Rather than treating KRAS as a target to be occupied, it treats the KRAS-mutant cell as a network whose protein economy can be rewired. The ubiquitin–proteasome system provides the levers, and deubiquitinases, once obscure players in basic cell biology, are now positioned as actionable points of intervention in some of medicine’s most intractable cancers. If the chemical and biological hurdles can be overcome, the coming years could see DUB-directed therapies enter clinical trials for pancreatic, lung and colorectal cancers, offering new hope to patients whose tumors have eluded the first generation of KRAS drugs.

Subject of Research: Therapeutic targeting of deubiquitinases in the ubiquitin–proteasome system to treat KRAS-driven cancers.

Article Title: Rewiring KRAS-driven cancers through the ubiquitin–proteasome system: therapeutic opportunities with a focus on deubiquitinase

Article References: Lee, Y., Hwang, S., Shin, H., Choi, K., Seo, S., Kim, H., Yang, J. S., Kim, Y. J., Kim, Y.-M., & Song, E. J. (2026). Rewiring KRAS-driven cancers through the ubiquitin–proteasome system: therapeutic opportunities with a focus on deubiquitinase. Experimental & Molecular Medicine. https://doi.org/10.1038/s12276-026-01837-6

Image Credits: AI Generated

DOI: 10.1038/s12276-026-01837-6

Keywords: KRAS, deubiquitinase, ubiquitin-proteasome system, targeted cancer therapy, protein degradation, RAS signaling, proteasome inhibitors, oncology, USP family, drug resistance, Rewiring, KRAS-driven