The research team, led by Gan Zhang, XuePeng Rao, Zhen Song, Yu Cheng, Tao Chen, Song Xiao, Guiyuan Mao, and corresponding author Tao Zeng of the Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, set out to resolve a lingering puzzle. Previous clinical work had shown that hypermethylation of the ZNF154 gene in urine is associated with an increased risk of bladder cancer recurrence, making ZNF154 an interesting biomarker candidate. Yet almost nothing was known about what the protein actually does inside bladder cancer cells. Methylation of a gene’s promoter typically silences it, so the researchers hypothesized that ZNF154 might be a brake on tumor growth—one that is frequently released when the gene is epigenetically shut down.

To test that idea, the team combined bioinformatics analysis of large-scale datasets with direct measurement of ZNF154 levels in bladder cancer tissues and cell lines. The results were consistent: ZNF154 was significantly downregulated in bladder cancer compared with normal tissue. That pattern alone did not prove causation, so the investigators performed a full battery of gain- and loss-of-function experiments. When they forced bladder cancer cells to overexpress ZNF154, the cells lost much of their capacity to proliferate. Conversely, when they reduced ZNF154 expression, the malignant phenotypes intensified. The tumor-suppressive character of the protein was now firmly established, but the mechanism remained to be determined.

The key clue emerged when the researchers examined how ZNF154-overexpressing cells were dying. The cells did not display the classical hallmarks of apoptosis, the most familiar form of programmed cell death. Instead, they showed the signature features of ferroptosis: visibly damaged mitochondria with shrunken cristae, elevated levels of lipid reactive oxygen species, and increased concentrations of malondialdehyde, a well-known byproduct of lipid peroxidation. At the same time, intracellular glutathione, the cell’s principal antioxidant shield against lipid damage, was depleted. Together, these changes paint a coherent biochemical picture: ZNF154 forces bladder cancer cells into a state in which their lipid membranes are progressively oxidized faster than they can be repaired, culminating in catastrophic membrane rupture and cell death.

At the molecular level, ferroptosis is governed largely by two sentinel proteins, SLC7A11 and GPX4. SLC7A11 is a cystine importer that supplies the raw material cells need to synthesize glutathione, while GPX4 is the only known mammalian enzyme capable of directly reducing lipid hydroperoxides to harmless lipids. When the team measured these proteins, they found that ZNF154 overexpression reduced the levels of both SLC7A11 and GPX4. In effect, ZNF154 dismantled the cell’s anti-ferroptotic defenses from two directions at once, cutting off the antioxidant supply line and disabling the final enzymatic firewall. This dual suppression explains why the lipid peroxidation markers rose so dramatically in the experimental cells.

But ZNF154 is a transcription factor, and transcription factors work by binding DNA and controlling other genes. How does it reach SLC7A11 and GPX4, which sit far downstream in the cell-death machinery? The answer, uncovered through a series of elegant mechanistic experiments, lies in a famous signaling axis: PTEN/PI3K/AKT. PTEN is one of the most studied tumor suppressors in all of cancer biology, a phosphatase that opposes the PI3K lipid kinase and thereby keeps AKT, the central survival kinase of the pathway, in check. Using gene set enrichment analysis and RNA sequencing, the researchers found that ZNF154 expression was associated with suppression of PI3K/AKT signaling. Chromatin immunoprecipitation followed by quantitative PCR showed that ZNF154 binds directly to the PTEN promoter, and dual-luciferase reporter assays confirmed that this binding activates PTEN transcription. In short, ZNF154 is a positive regulator of PTEN expression.

The causal chain was then tested with rescue experiments, the gold standard for establishing pathway relevance. When the researchers activated PI3K/AKT signaling experimentally, thereby bypassing the upstream effect of ZNF154 on PTEN, the ferroptotic phenotype induced by ZNF154 overexpression was reversed. Cells regained antioxidant capacity, lipid peroxidation markers fell, and survival signaling was restored. These results demonstrate that the PTEN/PI3K/AKT axis is not merely correlated with ZNF154’s effects but is functionally required for them. By boosting PTEN transcription, ZNF154 throttles back PI3K/AKT signaling, and since that pathway is known to support SLC7A11 and GPX4 expression and general cellular resilience, its suppression leaves bladder cancer cells exposed to lethal lipid oxidation.

To confirm that the mechanism operates in living organisms and not only in culture dishes, the team turned to xenograft models in which human T24 bladder cancer cells are implanted and grown in experimental animals. Tumors engineered to overexpress ZNF154 grew more slowly than controls, and analysis of the excised tumors revealed changes in ferroptosis-related markers consistent with the in vitro findings. This in vivo validation is critical, because the tumor microenvironment—with its variable oxygen, nutrient, and immune conditions—can dramatically alter cell-death programs. The concordance between the culture and animal data strengthens the argument that ZNF154 genuinely functions as a ferroptosis-promoting tumor suppressor in bladder cancer.

The clinical implications are twofold. First, ZNF154 may serve as a prognostic biomarker. Since urinary ZNF154 hypermethylation is already linked to recurrence risk, the new mechanistic data provide a plausible biological explanation for that association: when the gene is silenced, bladder cancer cells gain protection against ferroptosis and acquire a survival advantage that favors recurrence and progression. A biomarker with a defined mechanism is inherently more compelling than a statistical correlation alone. Second, ZNF154 or the pathway it controls could become a therapeutic target. Drugs that restore ZNF154 expression, mimic its PTEN-activating effect, or directly inhibit PI3K/AKT signaling could sensitize bladder tumors to ferroptosis-inducing agents, a strategy currently being explored across multiple cancer types. Conversely, patients whose tumors retain high ZNF154 expression might be candidates for therapies designed to push ferroptosis further.

As with any early-stage mechanistic study, important questions remain before translation to the clinic. The researchers note that the article is being shared early as a citable, peer-reviewed accepted version subject to further editorial refinement. Larger patient cohorts will be needed to establish whether ZNF154 expression levels reliably predict outcomes, and pharmacologic approaches to modulating the ZNF154–PTEN axis have yet to be developed. Nonetheless, the study adds a meaningful piece to the rapidly growing puzzle of ferroptosis regulation in cancer. By connecting an epigenetically silenced zinc finger protein to PTEN transcription, PI3K/AKT signaling, and the SLC7A11/GPX4 antioxidant system, the work traces a complete molecular circuit from gene silencing to cell-death escape—and in doing so, identifies a circuit that future therapies may deliberately rewire. For a disease as recurrent and treatment-resistant as bladder cancer, every new vulnerability matters, and ZNF154 may prove to be one worth pursuing.

Subject of Research: ZNF154-mediated regulation of ferroptosis in bladder cancer through the PTEN/PI3K/AKT signaling axis

Article Title: Mechanism of ZNF154-mediated regulation of ferroptosis in bladder cancer through the PTEN/PI3K/AKT axis

Article References: Mechanism of ZNF154-mediated regulation of ferroptosis in bladder cancer through the PTEN/PI3K/AKT axis. (n.d.). https://doi.org/10.1007/s00432-026-06614-6

Image Credits: AI Generated

DOI: 10.1007/s00432-026-06614-6

Keywords: ZNF154, ferroptosis, bladder cancer, PTEN, PI3K/AKT, SLC7A11, GPX4, lipid peroxidation, tumor suppressor, transcription factor, biomarker, xenograft