The clinical problem GliaMimic addresses is well known but poorly modeled. Patients diagnosed with glioblastoma typically undergo surgical resection followed by radiotherapy and the oral alkylating agent temozolomide, or TMZ. Yet even with this aggressive regimen, median survival remains measured in months, and nearly all tumors recur. One central reason is that the laboratory models used to test new drugs rarely reproduce the temporal reality of treatment. Standard short-term assays expose tumor cells to a drug for a few days and measure how many die, a snapshot that may say little about what happens when cells survive initial therapy, recover, and repopulate the tumor weeks later. The Swiss team, drawn from Empa, ETH Zurich, Roche, and the Cantonal Hospital St. Gallen, set out to build a framework that follows the tumor’s trajectory longitudinally rather than at isolated endpoints.

At the heart of GliaMimic are three-dimensional tumor models: patient-derived organoids, or PDOs, grown directly from surgically resected glioblastoma tissue, alongside patient-derived spheroids and spheroids generated from well-established glioblastoma cell lines such as U87MG and U251MG. These three-dimensional architectures are crucial because they recreate aspects of the tumor microenvironment that flat, two-dimensional cell cultures cannot, including gradients of oxygen, nutrients, and drug penetration that influence whether cells at the core of a tumor mass are actually exposed to therapeutic agents. The platform incorporates the two pillars of current clinical treatment, ionizing irradiation and multi-dose TMZ, delivered in a schedule designed to mirror the clinical setting.

A defining feature of the platform is its monitoring strategy. Rather than destroying the cultures at each time point to harvest data, the researchers tracked tumor progression and treatment response non-invasively over a full four-week period. This was achieved through a combination of complementary readouts: measurements of metabolic activity using assays such as XTT, assessments of cell viability through fluorescent indicators including propidium iodide, and confocal laser scanning microscopy to visualize the three-dimensional structure and internal health of the organoids and spheroids. The multimodal approach allowed the same living cultures to be followed day after day, generating a continuous record of how each model responded to therapy and what happened afterward.

The results carry a sobering message for the field. When the models were exposed to clinically relevant concentrations of temozolomide, defined in the study as doses at or below 10 micromolar, the researchers found that substantial declines in metabolic activity and viability only emerged after prolonged exposure over the course of weeks. In contrast, the short-term assays that dominate the preclinical literature detected effects only at supraphysiological doses, concentrations far higher than patients would ever experience. In other words, many drug-screening pipelines may be systematically overestimating drug sensitivity by testing compounds under conditions that never resemble the clinical reality of glioblastoma chemotherapy, where the drug must act slowly over extended treatment cycles.

Equally striking was the diversity of behavior among the different model types. Patient-derived organoids, patient-derived spheroids, and their cell line-derived counterparts each exhibited distinct patterns of treatment response and post-treatment progression. Long-established cell lines, which have adapted to laboratory growth over decades, did not faithfully reproduce the dynamics of the patient-derived materials. The finding underscores a methodological point that the authors argue should reshape preclinical study design: the choice of model matters enormously, and conclusions drawn from a single cell line may not generalize to the heterogeneous tumors that clinicians actually face. For a disease as molecularly diverse as glioblastoma, where features such as MGMT promoter methylation status, IDH mutation state, and alterations in genes like EGFR, PTEN, TP53, and TERT shape both prognosis and treatment response, patient-derived models are likely to be essential.

Perhaps the most clinically resonant aspect of the work is what happened after treatment ceased. Following the completion of the irradiation and TMZ schedule, the platform captured distinct, patient-specific patterns of post-treatment tumor behavior. Across all models, persistent populations of viable and metabolically active cells remained, the laboratory equivalent of the residual disease that seeds recurrence in patients. In the patient-derived organoids, these post-treatment changes were more pronounced, suggesting that PDOs are particularly informative for studying the biology of recurrence, the phase of the disease that ultimately proves fatal. This capability to observe tumor evolution after therapy, rather than simply measuring initial cell killing, opens a window onto the mechanisms of resistance and regrowth that no static endpoint assay can provide.

The researchers emphasize that GliaMimic is intended to move the field beyond static molecular diagnostics. Today, a glioblastoma patient’s tumor is profiled at diagnosis, and treatment decisions are informed by that single snapshot of genomic and histological information. But tumors are dynamic entities that change under the selective pressure of therapy. By providing a longitudinal record of how an individual patient’s tumor cells behave when exposed to the actual clinical treatment regimen, the platform offers a form of functional testing that complements genomic profiling. In a future precision medicine scenario, a drug regimen could be trialed in a patient’s own organoids before or alongside clinical administration, giving oncologists an empirical preview of whether the tumor is likely to respond, and whether resistant populations are poised to re-emerge.

The work also carries a methodological implication for the broader pharmaceutical and biotechnology community. Preclinical evaluation of brain tumor therapeutics frequently relies on 2D monolayer cultures treated for 48 to 72 hours, with results reported as a single inhibitory concentration value. GliaMimic demonstrates that such short-term, flat-culture paradigms can miss entirely the delayed effects of clinically relevant drug exposure, potentially advancing ineffective candidates and discarding promising ones. A four-week, multimodal, three-dimensional evaluation is more demanding in time and resources, but the platform’s authors contend that the added realism is essential for a disease where every therapeutic advance has been so painfully incremental.

The study represents a collaborative effort spanning materials science, pathology, neurosurgery, radiation oncology, and medical oncology, and it was built on surplus tumor tissue provided with ethical approval and patient consent from the Cantonal Hospital St. Gallen. The platform was developed in the Nanomaterials in Health Laboratory at Empa in St. Gallen, with key contributions from teams at Roche’s Pharma Research and Early Development unit in Basel. The work is dedicated to the memory of co-author Thomas Hundsberger, the clinical oncologist whose insight anchored the project’s connection to patient care.

For patients and families affected by glioblastoma, the immediate promise of GliaMimic is not a new drug but a better lens, a way of seeing, in the laboratory, the same slow drama of treatment response, survival, and recurrence that unfolds in the clinic. By making that drama visible over weeks in patient-derived models, the Swiss team has created a tool that could help identify therapies capable not merely of shrinking tumors on a lab plate, but of preventing the resilient remnants that are the true drivers of this disease’s devastating course. As the field continues its search for meaningful gains against glioblastoma, platforms like GliaMimic may prove to be the testing ground where the next generation of treatments is first proven worthy of clinical trials.

The compound, designated cp8, is a first-in-class hybrid molecule built on the scaffold of abiraterone, the CYP17A1 inhibitor approved for prostate cancer, onto which the team installed a hydroxamic acid group acting as a zinc-binding head for histone deacetylase inhibition. In the traditional three-part architecture of HDAC inhibitors—a surface recognition part, a linker, and a zinc-binding group—abiraterone serves as the surface recognition unit, tethered through an N-benzyl acrylamide linker in a critical beta configuration at the 3-position of the sterol core. That stereochemical detail proved decisive: among ten derivatives screened, only cp8, with the correct beta orientation, drove cell viability in temozolomide-resistant Pt#3-R glioblastoma cells down to 12.8 percent at 20 micromolar, while analogs bearing inverted configurations or alternative sulfonyl, benzoyl, and benzamide linkers fell short.

The potency numbers are striking. Against a panel of human and murine glioblastoma lines, including temozolomide-resistant and MGMT-positive cells such as T98G and P1S, cp8 achieved half-maximal inhibitory concentrations of 3 micromolar or less. The clinically validated pan-HDAC inhibitor vorinostat, known as SAHA, required concentrations of 30 micromolar or higher to reach comparable effects—a roughly tenfold gap. Mechanistically, cp8’s dependence on HDAC6 was confirmed using CRISPR-Cas9 knockout cells: when HDAC6 was deleted, cp8 treatment at 4 micromolar left nearly 75 percent of U87MG cells alive, whereas wild-type cells were reduced to about 10 percent viability. Treatment with cp8 also produced a striking accumulation of acetylated histone H3 and H4, including acetylation at residues H3K18, H3K23, H3K27, H4K5, H4K12, and H4K20, confirming functional blockade of multiple HDAC isoforms. In colony formation assays, cp8 reduced colony counts from 660 in the control group to just 6 at 0.8 micromolar, outperforming SAHA at identical doses.

The most surprising discovery emerged from RNA sequencing of drug-resistant Pt#3-R cells. Cp8’s transcriptional fingerprint included a distinctive upregulation of the filaggrin gene, FLG—a structural protein famous for aggregating keratin filaments in the epidermis and maintaining the skin’s hydration and barrier function, but essentially unstudied in brain tumors. Mining of The Cancer Genome Atlas and the Chinese Glioma Genome Atlas revealed that higher FLG expression correlated significantly with better survival in glioblastoma patients (p = 0.001), while FLG mutations, present in 8 to 14 percent of tumors in different datasets, were associated with worse outcomes. Immunohistochemistry on patient tissue microarrays and experimental mouse tumors showed FLG expression markedly depleted in glioblastoma compared with adjacent normal tissue.

Functional experiments established FLG as a genuine suppressor rather than a bystander. When researchers knocked down FLG with small interfering RNA in T98G cells, cell survival rose, active caspase-3 fell, and the stem cell markers Oct4 and SOX2 climbed 2.1-fold and 1.8-fold respectively, accompanied by enhanced temozolomide resistance. Pathway analysis of FLG-silenced cells revealed activation of pro-inflammatory and growth-factor signaling networks centered on IL1B, TNF, IL6, FGF2, JUN, PTGER2, and CREB1—transcriptional programs that sustain glioma stem-like states, phenotypic plasticity, and therapy resistance. Conversely, overexpressing FLG through CRISPR-Cas9–mediated promoter insertion reduced glioblastoma cell viability, raised caspase-3 activity, and, critically, sensitized MGMT-positive T98G cells to temozolomide at 600 micromolar. Because the filaggrin precursor protein spans roughly 4,061 amino acids, conventional cloning proved impractical, making the gene-editing approach essential. Notably, the FLG-boosting effect was unique to cp8; SAHA failed to induce FLG expression, and individual silencing of HDAC1, HDAC2, or HDAC6 each raised FLG while lowering SOX2, linking the epigenetic target to the filaggrin effect.

The compound simultaneously dismantled the other pillars of resistance. In MGMT-positive T98G cells, cp8 at 3 micromolar cut MGMT protein expression by 68 percent, directly undermining the primary enzymatic defense against temozolomide-induced DNA alkylation. In glioma sphere assays modeling glioma stem cells, cp8 shrank neurosphere size by 54 percent and suppressed Oct4 and SOX2 in both monolayer and spheroid cultures, an effect mirrored by accumulation of acetylated tubulin, the classic readout of HDAC6 inhibition. Immunofluorescence confirmed visibly weakened Oct4 and SOX2 staining after cp8 exposure. When MGMT was experimentally overexpressed in Pt#3 cells, the antiproliferative effect of cp8 was partially blunted, but its induction of reactive oxygen species was untouched, indicating the compound’s oxidative assault proceeds independently of MGMT status.

That oxidative assault is central to cp8’s mechanism. Using MitoSOX and CellROX probes, the team documented dose-dependent surges in mitochondrial superoxide and total cellular ROS after 48 hours of treatment, with the ROS signal colocalizing precisely with active caspase-3–positive apoptotic cells. Staining for 4-hydroxynonenal, a marker of toxic lipid peroxidation, intensified in cp8-treated glioma spheres, and TUNEL staining of mouse tumor tissue showed a clear increase in apoptotic cells. The picture is one of a compound that floods resistant cells with mitochondrial ROS they can no longer clear—overwhelming the redox adaptation that ordinarily lets glioma stem cells evade apoptosis and sustain temozolomide resistance.

The in vivo results were decisive. In a CT-2A allograft model, intraperitoneal cp8 at 10 milligrams per kilogram twice weekly extended median survival to 59 days, compared with 34 days in vehicle controls (p < 0.001) and 49 days for SAHA-treated animals, while reducing tumor volume by 72 percent. Tumors from cp8-treated mice showed reduced Oct4 and SOX2 and elevated FLG by immunohistochemistry, confirming the mechanism operated inside living brain tissue. In an orthotopic xenograft of temozolomide-resistant Pt#3-R cells, cp8 alone extended median survival to 55.5 days versus 24 days for controls, and interestingly, adding temozolomide conferred no statistically significant additional benefit—likely because cp8’s single-agent efficacy on resistant cells left little room for improvement. Against SAHA head-to-head in a luciferase-tagged U87MG xenograft, cp8 more powerfully suppressed tumor growth as measured by IVIS imaging and nearly doubled survival advantage (59 days versus 49 days in one model; 49 versus 30 in another). Tolerability testing in healthy C57BL/6 mice at doses up to 80 milligrams per kilogram revealed stable body weights and unremarkable liver and kidney biochemistry, with no histological signs of toxicity in hepatic or renal tissue.

Pharmacokinetic analysis in Sprague–Dawley rats showed cp8 penetrates the blood–brain barrier with a brain-to-plasma exposure ratio of roughly 21.4 percent, achieving rapid equilibrium between circulation and brain parenchyma. The caveats are real: a short plasma half-life of about 0.48 hours and high systemic clearance of 12.6 liters per hour per kilogram mean the compound will need medicinal chemistry optimization or specialized delivery strategies to widen its therapeutic window. The authors also note that distinguishing mutated from functional filaggrin protein was not possible with available antibodies, leaving questions about which FLG species matters most in tumors.

Even with those caveats, the study delivers two significant contributions at once. It validates filaggrin—long known as a dermatology gene—as a previously unrecognized tumor-suppressive factor and therapeutic target in glioblastoma, and it demonstrates that a single rationally designed molecule can strike stemness, MGMT expression, and redox homeostasis simultaneously, precisely the triad of mechanisms that has made temozolomide resistance so difficult to defeat. For a disease where more than half of patients develop drug resistance and median survival remains measured in months, a multitargeted compound that reached 59-day survival in aggressive mouse models without systemic toxicity offers a genuinely new template for the next generation of anti-glioblastoma drug discovery.

The team reports that MYOF emerges as a novel therapeutic target in glioblastoma, linking the gene’s activity to key processes that help tumors survive and expand. Instead of treating glioblastoma as a single-pathway problem, the study frames MYOF as part of a mechanistic network—one that can be exploited when disrupted.

Using a combination of molecular profiling and functional experiments, the researchers mapped how MYOF influences tumor-relevant signaling. They observed that altering MYOF activity changes cellular behavior consistent with impaired malignancy, suggesting MYOF is not merely associated with disease state but actively contributes to tumor fitness.

Importantly, the work extends beyond biology into the realm of therapy development. The authors describe drug discovery efforts guided by the mechanistic insights from MYOF’s role, emphasizing how target definition can accelerate the search for compounds with meaningful effects in glioblastoma models.

While the study focuses on MYOF, it also highlights a broader theme: effective glioblastoma therapies may require intercepting specific nodes that coordinate multiple cancer traits. By targeting MYOF, the researchers aim to undermine the tumor’s ability to maintain its malignant programs.

The findings also propose how MYOF modulation could influence pathways tied to survival under stress, a hallmark of aggressive tumor behavior. In this sense, the target is positioned as a potential lever to weaken glioblastoma resilience rather than simply slowing growth.

The researchers conclude that MYOF warrants further investigation as a candidate for preclinical development, with additional work needed to validate performance across diverse tumor contexts. If subsequent studies confirm the results, MYOF could become a practical target for next-generation glioblastoma therapeutics.

The paper appears in Cell Death Discoveries (2026) under DOI: https://doi.org/10.1038/s41420-026-03254-0.

Subject of Research: glioblastoma; MYOF as a therapeutic target
Article Title: Uncovering MYOF as a novel therapeutic target in glioblastoma: mechanistic insights and drug discovery.
Article References: Zhao, P., Chen, Z., Zhu, J. et al. Cell Death Discov. (2026). https://doi.org/10.1038/s41420-026-03254-0
Image Credits: AI Generated
DOI: https://doi.org/10.1038/s41420-026-03254-0

Glioblastoma, notorious for its aggressive clinical course and resistance to treatment, often faces fluctuating nutrient availability within the tumor mass, particularly glucose scarcity. Tumor cells’ metabolic plasticity enables them to switch from glycolysis to alternative pathways to continue generating ATP, the cellular energy currency. This study illuminates how glioblastoma cells harness fructolysis, facilitated by a molecular switch involving ERK1 kinase activity on GLYCTK2, to thrive despite nutrient stress.

ERK1, a mitogen-activated protein kinase, has long been implicated in diverse cell signaling cascades governing proliferation and survival. However, its direct involvement in metabolic regulation within glioblastoma cells presents a novel dimension to its functionality. The phosphorylation of GLYCTK2 — a kinase responsible for key regulatory steps in fructose metabolism — by ERK1 effectively activates fructolysis, enabling glioblastoma cells to bypass glucose dependency.

Mechanistically, this phosphorylation event enhances GLYCTK2 enzymatic activity, accelerating the breakdown of fructose into metabolites that feed into the glycolytic and pentose phosphate pathways. Such metabolic reprogramming allows the tumor cells to maintain biosynthetic and bioenergetic homeostasis under conditions where extracellular glucose is insufficient. The research uncovers that this adaptation is not a passive response but an actively regulated survival tactic orchestrated by oncogenic signaling pathways.

To probe this paradigm, the researchers employed a sophisticated combination of phosphoproteomics, in vitro kinase assays, and metabolic flux analysis. These methods collectively validated that GLYCTK2 phosphorylation sites were directly targeted by ERK1, resulting in augmented enzyme functionality. Notably, glioblastoma cell lines subjected to glucose deprivation exhibited elevated levels of phosphorylated GLYCTK2 and concomitant increases in fructose utilization, underscoring the physiological relevance of this regulatory mechanism.

Interestingly, when ERK1 signaling was pharmacologically inhibited or when GLYCTK2 phosphorylation sites were genetically mutated, glioblastoma cells demonstrated impaired fructolysis and reduced viability under low-glucose conditions. This finding not only reinforces the indispensable role of the ERK1-GLYCTK2 axis in metabolic adaptation but also highlights a potential vulnerability for therapeutic exploitation.

The study’s metabolic tracing data further reveal that fructolysis intermediates replenish pools of key metabolites such as glyceraldehyde-3-phosphate and dihydroxyacetone phosphate, feeding into energy-producing and biosynthetic pathways essential for maintaining tumor growth and oxidative balance. This metabolic flexibility grants glioblastoma cells a competitive edge in nutrient-poor microenvironments, facilitating sustained proliferation despite metabolic stress.

Moreover, the investigation delves into the broader implications of fructolysis activation in oncogenic metabolism, suggesting that this pathway may represent a universal adaptation beyond glioblastoma. Since high fructose consumption is increasingly scrutinized for its links to cancer and metabolic disorders, understanding cellular fructose metabolism mechanisms could reveal new intersections between diet, tumor biology, and therapeutic strategies.

The research also posits that ERK1-mediated GLYCTK2 phosphorylation might serve as a biomarker for metabolic phenotyping in glioblastoma, enabling the identification of tumors reliant on fructose metabolism. Such insights pave the way for designing precision medicine approaches that selectively target metabolic dependencies unique to tumor cells, sparing normal tissues that predominantly utilize glucose.

From a translational perspective, the study propounds that small molecule inhibitors disrupting ERK1 activity or GLYCTK2 function could synergize with existing therapies to thwart glioblastoma survival pathways under metabolic duress. Given the notoriously poor prognosis associated with glioblastoma, strategies that cripple the tumor’s metabolic resilience hold promise to improve patient outcomes.

Furthermore, the findings challenge the conventional perception that glucose is the sole major fuel for cancer cells, underscoring the metabolic versatility that underlies tumor progression and therapy resistance. This paradigm shift encourages the scientific community to re-evaluate metabolic targets within the broader context of tumor microenvironmental fluctuations.

In conclusion, this pioneering work elucidates a critical biochemical axis whereby ERK1 orchestrates metabolic adaptation through GLYCTK2 phosphorylation, enabling glioblastoma cells to exploit fructolysis for survival in glucose-deprived niches. The convergence of oncogenic signaling with metabolic reprogramming underscores a sophisticated survival network that cancer cells deploy, offering fresh avenues for therapeutic intervention in one of the most formidable brain tumors.

As the field advances, further exploration into the interplay between kinase signaling and metabolic enzyme regulation will be paramount. Understanding how glioblastoma and other malignancies coordinate such adaptive responses could catalyze the development of next-generation metabolic inhibitors, fine-tuned to disrupt tumor metabolism without harming normal cell function.

This research, published in Cell Death Discovery, not only enriches our fundamental understanding of glioblastoma biology but also propels the development of innovative, metabolism-centered treatment modalities. It stands as a testament to the critical importance of interrogating tumor metabolism within the multifaceted landscape of cancer cell survival strategies.

Subject of Research:
Article Title:
Article References: Li, Y., Zhang, F., Hu, F. et al. ERK1-mediated GLYCTK2 phosphorylation promotes fructolysis to sustain glioblastoma survival under glucose deprivation. Cell Death Discov. 11, 266 (2025). https://doi.org/10.1038/s41420-025-02544-3
Image Credits: AI Generated
DOI: https://doi.org/10.1038/s41420-025-02544-3
Keywords: