bims-cagime 2025-08-24 papers

bims-cagime

Biomed News

on Cancer, aging and metabolism

Issue of 2025–08–24
twenty papers selected by
Kıvanç Görgülü, Technical University of Munich

Prospects for ferroptosis therapies in cancer.
Mechanism for oil-phase separation by the lipid droplet assembly complex.
KRAS: the Achilles' heel of pancreas cancer biology.
Form Follows Function: A New Paradigm of Pancreatic Cancer Progression.
The chemotherapy-induced senescence-associated secretome promotes cell detachment and metastatic dissemination through metabolic reprogramming.
Hypoxia Modulates Membrane Mechanics in Pancreatic Cancer.
The small GTPase Ran defines nuclear pore complex asymmetry.
Mitochondrial genome copy number variation across tissues in mice and humans.
P62/Sequestosome1 deficiency disrupts antioxidant and stress homeostasis during acute pancreatitis without exacerbating inflammation.
Targeting FSP1 triggers ferroptosis in lung cancer.
Mutant p53 affects the mitochondrial proteome, promoting mitochondrial fragmentation and OXPHOS in pancreatic ductal adenocarcinoma cells.
Experimental models of pancreas cancer: what has been the impact for precision medicine?
Role of listeriolysin O and phospholipases C in L. monocytogenes intercellular protrusion dynamics, resolution, and autophagy avoidance.
Vesicle tension in porous membranes: aspiration, spreading, and tube extraction.
Macrophages and macrophage extracellular vesicles confer cancer ferroptosis resistance via PRDX6-mediated mitophagy inhibition.
Dehydration promotes intracellular lipid synthesis and accumulation.
Generations in Flux: Tracking the Birth of Cellular Heterogeneity in Cancer.
Systemic Kras ablation disrupts myeloid cell homeostasis in adult mice.
Tracing the evolution of single-cell 3D genomes in Kras-driven cancers.
Quantifying collective interactions in biomolecular phase separation.

Nat Cancer. 2025 Aug 18.

Prospects for ferroptosis therapies in cancer.

Jessalyn M Ubellacker, Scott J Dixon.

Ferroptosis is a nonapoptotic form of cell death characterized by lethal membrane lipid peroxidation. This mechanism was first characterized in cancer cells well over a decade ago, and there is much enthusiasm for the concept that certain cancers may be treated by inducing ferroptosis. However, therapies that engage ferroptosis have yet to enter clinical testing. In this Review, we highlight the gap between our rapidly expanding knowledge of the ferroptosis mechanism and its translation into cancer therapies. We discuss the known challenges that may be slowing ferroptosis therapies from reaching the clinic.

DOI: https://doi.org/10.1038/s43018-025-01037-7
bioRxiv. 2025 Aug 13. pii: 2025.08.12.669882. [Epub ahead of print]

Mechanism for oil-phase separation by the lipid droplet assembly complex.

Pedro C Malia, Siyoung Kim, Yohannes Ambaw, Gregory A Voth, Tobias C Walther, Robert V Farese.

Cells store metabolic energy as triglyceride (TG) oils in lipid droplets (LDs). LDs form de novo from the endoplasmic reticulum. How the lipid droplet assembly complex (LDAC), composed of seipin and LDAF1 1,2 , catalyzes the organized formation of an oil phase in a membrane bilayer before spontaneous phase separation is triggered is unknown. Here, we reconstitute LD formation in vitro using purified LDAC and membranes containing physiologic levels of TG, demonstrating that the LDAC is both necessary and sufficient to catalyze oil-phase formation below the threshold of spontaneous phase separation. Structural studies of the LDAC reveal that LDAF1 forms a central ring within a seipin cage, creating a toroidal, membrane-spanning structure. Molecular dynamics simulations and biochemical assays show that this structure forms a selective chamber within the ER bilayer that limits phospholipids but allows TG to access a reaction compartment between the inner and outer rings of the LDAC. Within this compartment, TG interacts with LDAF1 and each other to form an oil phase to initiate LD formation. Thus, the LDAC acts as a protein catalyst for oil-phase separation in cells, revealing a fundamental mechanism for how cells resolve the biophysical challenge of storing oils within a hydrophilic environment in an organized manner.

DOI: https://doi.org/10.1101/2025.08.12.669882
J Clin Invest. 2025 Aug 15. pii: e191939. [Epub ahead of print]135(16):

KRAS: the Achilles' heel of pancreas cancer biology.

Kristina Drizyte-Miller, Taiwo Talabi, Ashwin Somasundaram, Adrienne D Cox, Channing J Der.

The genetic landscape of pancreatic ductal adenocarcinoma (PDAC) is well-established and dominated by four key genetic driver mutations. Mutational activation of the KRAS oncogene is the initiating genetic event, followed by genetic loss of function of the CDKN2A, TP53, and SMAD4 tumor suppressor genes. Disappointingly, this information has not been leveraged to develop clinically effective targeted therapies for PDAC treatment, where current standards of care remain cocktails of conventional cytotoxic drugs. Nearly all (~95%) PDAC harbors KRAS mutations, and experimental studies have validated the essential role of KRAS mutation in PDAC tumorigenic and metastatic growth. Identified in 1982 as the first gene shown to be aberrantly activated in human cancer, KRAS has been the focus of intensive drug discovery efforts. Widely considered "undruggable," KRAS has been the elephant in the room for PDAC treatment. This perception was shattered recently with the approval of two KRAS inhibitors for the treatment of KRASG12C-mutant lung and colorectal cancer, fueling hope that KRAS inhibitors will lead to a breakthrough in PDAC therapy. In this Review, we summarize the key role of aberrant KRAS signaling in the biology of pancreatic cancer; provide an overview of past, current, and emerging anti-KRAS treatment strategies; and discuss current challenges that limit the clinical efficacy of directly targeting KRAS for pancreatic cancer treatment.

DOI: https://doi.org/10.1172/JCI191939
bioRxiv. 2025 Aug 13. pii: 2025.08.12.667175. [Epub ahead of print]

Form Follows Function: A New Paradigm of Pancreatic Cancer Progression.

William Gasper, Giada Pontecorvi, Zhikai Chi, Sebastian Enrico, Lily Goodman, Haneen Amarneh, Evelyn Mazzarelli, Joshua Thomas, Lucia Zhang, Rachel Handloser, Seth LeCates, Ana Lucia Tomescu, Francesca Rossi, Myla Sykes, Anjali Bhatt, Nicholas Fazio, Alessandro Bifolco, Nafeesah Fatimah, Austin Seamann, Cheryl Lewis, Shelby Melton, Herbert J Zeh, Megan B Wachsmann, Dario Ghersi, Matteo Ligorio.

Pancreatic ductal adenocarcinoma (PDAC) exhibits a distinctive propensity to invade nearby organs and infiltrate large blood vessels, even in the absence of distant metastasis. While the genetic and transcriptomic drivers of PDAC progression have been well studied, the mechanisms by which these molecular changes translate into functional, invasive behavior remain largely unknown. Here, we uncover a striking level of tissue organization, characterized by previously unrecognized spatial and geometric properties within and among tumor structures. Leveraging the first large-scale, AI-assisted, human-curated PDAC atlas from hematoxylin and eosin (H&E) images, we annotated, classified, and characterized 144,474 malignant and normal structures from treatment-naive (n=118) and neoadjuvant-treated PDAC patients (n=50). Additionally, we developed a new computational tool, SHAPE, to investigate PDAC aggressiveness through a comprehensive geometrization of cancer progression. Using traditional H&E-stained slides and three-dimensional (3D) tissue reconstruction experiments, we observed that invading tumor structures display an eccentric morphology with pronounced local angular coherence. These geometric and spatial properties revealed coherent architectural patterns, with invasive structures closely tracking vessels and nerves as they infiltrate surrounding tissue. Mechanistically, integration of morphological features from 39,045annotated tumor structures with whole-genome and RNA sequencing data revealed that PDACs with numerous eccentric structures exhibit increased copy number alterations (CNAs), loss of heterozygosity (LoH) on the p-arm of chromosome 17, and a quasi-mesenchymal/basal-like molecular subtype. Spatial transcriptomic analysis of 1,650 tumor structures from six additional PDAC patients further confirmed upregulation of invasive cellular programs within highly eccentric structures, such as epithelial-to-mesenchymal transition (EMT), angiogenesis, coagulation, and complement pathways, underscoring their infiltrative nature. Finally, cross-validation of our AI-based method enabled a fully automated, highly interpretable computational approach to assist pathologists and clinicians in evaluating neoadjuvant chemotherapy response, predicting patient survival, and guiding chemotherapy in adjuvant settings. Collectively, these findings deepen our understanding of PDAC progression, identify a new hallmark of tumor architecture, and pave the way for full integration of AI-driven morphology-based approaches into clinical workflows to improve the management of PDAC patients.

DOI: https://doi.org/10.1101/2025.08.12.667175
bioRxiv. 2025 Aug 12. pii: 2023.12.02.569652. [Epub ahead of print]

The chemotherapy-induced senescence-associated secretome promotes cell detachment and metastatic dissemination through metabolic reprogramming.

Aidan R Cole, Raquel Buj, Apoorva Uboveja, Evan Levasseur, Hui Wang, Katarzyna M Kedziora, Adam Chatoff, Andrea Andress Huacachino, Mariola M Marcinkiewicz, Amandine Amalric, Baixue Yang, Naveen Kumar Tangudu, Jeff Danielson, Amal Elwah, Sierra White, Danyang Li, Callen T Wallace, Felicia Lazure, Esther Elishaev, Lauren Borho, Dorota E Jazwinska, Matthew S Laird, Huda Atiya, Benjamin G Bitler, Denarda Dangaj, Lan G Coffman, George Tseng, Steffi Oesterreich, Ana P Gomes, Aditi U Gurkar, Francisco J Schopfer, Francesmary Modugno, Simon C Watkins, Ioannis K Zervantonakis, Wayne Stallaert, Nadine Hempel, Nathaniel W Snyder, Katherine M Aird.

Cellular senescence, characterized by a stable cell cycle arrest, is a well-documented consequence of several widely used chemotherapeutics that has context-dependent roles in cancer. Although senescent cells are non-proliferative, they remain biologically active and secrete a complex and diverse array of factors collectively known as the se-nescence-associated secretome (SAS), which exerts pro-tumorigenic effects. Here, we aimed to mechanistically investigate how the SAS contributes to metastatic dissemination of high grade serous ovarian cancer (HGSOC) using standard-of-care cisplatin as a se-nescence inducer. Our findings demonstrate that the cisplatin-induced SAS enhances the dissemination of HGSOC in vivo without affecting cell proliferation or viability. We found that the SAS facilitates cell detachment, an effect that is mediated by a metabolic com-ponent. Using a metabolically focused CRISPR knockout screen, we identified complex I as the key driver of SAS-mediated cell detachment in bystander cells and validated that inhibition of complex I activity decreases HGSOC dissemination in vivo . Mechanistically, this effect was driven by SAS-mediated inhibition of an NAD + -SIRT-SREBP axis, leading to decreased plasma membrane cholesterol that increased cell detachment. Excitingly, we found that fructose is the key SAS component upstream of the NAD + -SIRT-SREBP-cholesterol axis mediating increased detachment of bystander cells, and a high fructose diet increases HGSOC dissemination in vivo . These findings reveal that the cisplatin-induced SAS reprograms the metabolic microenvironment in HGSOC, driving cancer cell detachment and promoting metastatic dissemination in a paracrine fashion. They also point to a previously unrecognized pro-tumorigenic effect of the SAS that may contribute to the high recurrence rate of HGSOC patients.

DOI: https://doi.org/10.1101/2023.12.02.569652
J Membr Biol. 2025 Aug 18.

Hypoxia Modulates Membrane Mechanics in Pancreatic Cancer.

Prema Kumari Agarwala, Shobhna Kapoor.

  Aggressive cancer cells such as pancreatic cells exhibit an enhanced metastatic phenotype that involves cell migration and invasion. Cellular membrane deformation is a key process implicit in cell movement. This implicates a link between altered lipid metabolism during cancer progression and modulated membrane properties and hence associated functions. One of the key factors underlying the aggressiveness of pancreatic cancer is the presence of the highest percentage of hypoxia, which further adds to the lipid metabolic reprogramming. The subsequent effect of hypoxia-induced lipidome changes on membrane properties governing cell movement was investigated in this work using a combination of cell biology, microscopy, and spectroscopy. Our findings revealed that hypoxia induces distinct lipidome signatures in a cell-line-dependent fashion, which in turn differentially modulates the cell membrane stiffness. The correlation of cell stiffness with other membrane properties and the actin cytoskeleton shows a random correlation indicating that hypoxic stress distinctly regulates specific membrane attributes governing cellular functioning and should be consulted for the development of effective treatments for pancreatic cancer.

Keywords:  Hypoxia; Lipidomics; Membrane Mechanics and Dynamics; Metastasis; Pancreatic Cancer

DOI:  https://doi.org/10.1007/s00232-025-00358-z
Cell. 2025 Aug 12. pii: S0092-8674(25)00814-1. [Epub ahead of print]

The small GTPase Ran defines nuclear pore complex asymmetry.

Jenny Sachweh, Mandy Börmel, Sven Klumpe, Anja Becker, Reiya Taniguchi, Marta Anna Kubańska, Verena Pintschovius, Eva Kaindl, Jürgen M Plitzko, Florian Wilfling, Martin Beck, Bernhard Hampoelz.

  Nuclear pore complexes (NPCs) bridge across the nuclear envelope and mediate nucleocytoplasmic exchange. They consist of hundreds of nucleoporin building blocks and exemplify the structural complexity of macromolecular assemblies. To ensure transport directionality, different nucleoporin complexes are attached to the cytoplasmic and nuclear face of the NPC. How those asymmetric structures are faithfully assembled onto the symmetric scaffold architecture that exposes the same interaction surfaces to either side remained enigmatic. Here, we combine cryo-electron tomography, subtomogram averaging, and template matching with live imaging to address this question in budding yeast and Drosophila. We genetically induce ectopic nuclear pores and show that pores outside the nuclear envelope are symmetric. We furthermore demonstrate that the peripheral NPC configuration is affected by the nucleotide state of the small GTPase Ran. Our findings indicate that the nuclear transport system is self-regulatory, namely that the same molecular mechanism controls both transport and transport channel composition.

Keywords:  Ran GTPase; asymmetry; biogenesis; cryo-ET; heterogeneity; in situ structural biology; nuclear envelope; nuclear pore complex; nucleoporins

DOI:  https://doi.org/10.1016/j.cell.2025.07.025
Proc Natl Acad Sci U S A. 2024 Aug 13. 121(33): e2402291121

Mitochondrial genome copy number variation across tissues in mice and humans.

Sneha P Rath, Rahul Gupta, Ellen Todres, Hong Wang, Alexis A Jourdain, Kristin G Ardlie, Sarah E Calvo, Vamsi K Mootha.

  The mammalian mitochondrial genome (mtDNA) is multicopy and its copy number (mtCN) varies widely across tissues, in development and in disease. Here, we systematically catalog this variation by assaying mtCN in 52 human tissues across 952 donors (10,499 samples from the Genotype-Tissue Expression project) and 20 murine tissues using qPCR, capturing 50- and 200-fold variation, respectively. We also estimate per cell mtCN across 173 human cell lines from the Cancer Cell Line Encyclopedia using whole-genome sequencing data and observe >50-fold variation. We then leverage the vast amount of genomics data available for these repositories to credential our resource and uncover mtDNA-related biology. Using already existing proteomics data, we show that variation in mtCN can be predicted by variation in TFAM, histone, and mitochondrial ribosome protein abundance. We also integrate mtCN estimates with the CRISPR gene dependency measurements to find that cell lines with high mtCN are resistant to loss of GPX4, a glutathione phospholipid hydroperoxidase. Our resource captures variation in mtCN across mammalian tissues and should be broadly useful to the research community.

Keywords:  GPX4; TFAM; histone; mitochondrial ribosome; mtDNA

DOI:  https://doi.org/10.1073/pnas.2402291121
Pancreatology. 2025 Aug 11. pii: S1424-3903(25)00573-3. [Epub ahead of print]

P62/Sequestosome1 deficiency disrupts antioxidant and stress homeostasis during acute pancreatitis without exacerbating inflammation.

Wenting Chen, Jingren Wang, Eiji Warabi, Mai Imasaka, Yuki Takeda, Hiroshi Nishiura, Satoru Takahashi, Masaki Ohmuraya.

   BACKGROUNDS: Acute pancreatitis (AP) is a common inflammatory disease of the pancreas, characterized by complex pathogenesis and limited specific treatment options. The selective autophagy adapter protein p62/sequestosome1 emerged as a key player in cellular stress responses, with emerging evidence suggesting its role in modulating both infection-driven and sterile inflammation. However, the role of p62 in the pathogenesis of AP remains unclear.
METHODS: To investigate the role of p62 in AP, we generated pancreas-specific conditional knockout mice (p62ff; Ptf1acre/+) and induced AP by 12 repeated intraperitoneal cerulein injections. Mice were sacrificed either 1 h or 8 h after the final injection. Pancreatic damage was assessed along with serum amylase levels, intrapancreatic trypsin activity, proinflammatory cytokines, antioxidant genes, ER stress and cell death markers using immunohistochemistry, qRT-PCR, and western blotting.
RESULTS: p62ff; Ptf1acre/+ mice showed normal growth and pancreatic development. Upon cerulein challenge, both p62 knockout and control mice developed comparable pancreatic injury, without significant differences in histological scores, amylase, or trypsin activity. However, p62-deficient mice displayed significantly impaired antioxidant responses. Notably, Nqo1 expression was reduced and Keap1 accumulated, indicating disrupted Nrf2 signaling. Ferroptosis markers also showed genotype- and time-dependent changes: GPX4 was reduced at 1 h, while FTH1 without significant differences in p62-deficient mice. Periodic acid-Schiff staining further revealed increased glycogen depletion in knockout mice, suggesting elevated metabolic stress.
CONCLUSIONS: These findings suggest that while p62 deletion does not affect overall AP severity, it compromises redox homeostasis and metabolic recovery, highlighting a protective role for p62 during pancreatic injury.

Keywords:  Autophagy; Cell death; Cerulein; Inflammation; Pancreatic acinar cell

DOI:  https://doi.org/10.1016/j.pan.2025.07.416
bioRxiv. 2025 Aug 11. pii: 2025.08.07.668766. [Epub ahead of print]

Targeting FSP1 triggers ferroptosis in lung cancer.

Katherine Wu, Alec J Vaughan, Jozef P Bossowski, Yuan Hao, Aikaterini Ziogou, Seon Min Kim, Tae Ha Kim, Mari N Nakamura, Ray Pillai, Mariana Mancini, Sahith Rajalingam, Mingqi Han, Toshitaka Nakamura, Lidong Wang, Suckwoo Chung, Diane Simeone, David Shackelford, Yun Pyo Kang, Marcus Conrad, Thales Papagiannakopoulos.

Pre-clinical and clinical studies have demonstrated how dietary antioxidants or mutations activating antioxidant metabolism promote cancer, highlighting a central role oxidative stress in tumorigenesis. However, it is unclear if oxidative stress ultimately increases to a point of cell death. Emerging evidence indicates that cancer cells are susceptible to ferroptosis, a form of cell death that is triggered by uncontrolled lipid peroxidation. Despite broad enthusiasm about harnessing ferroptosis as a novel anti-cancer strategy, it remains unknown whether ferroptosis is a barrier to tumorigenesis and if it can be leveraged therapeutically. Using genetically-engineered mouse models (GEMMs) of lung adenocarcinoma (LUAD), we performed tumor specific loss-of-function studies of the two key ferroptosis suppressors, glutathione peroxidase 4 ( Gpx4 ) and ferroptosis suppressor protein 1 ( Fsp1 ), and observed increased lipid peroxidation, ferroptosis and robust suppression of tumorigenesis, suggesting that lung tumors are highly sensitive to ferroptosis. Furthermore, across multiple pre-clinical models, we found that FSP1 was selectively required for ferroptosis protection in vivo , but not in vitro , underscoring a heightened need to buffer lipid peroxidation under physiological conditions. Lipidomic analyses revealed that Fsp1-knockout (Fsp1 KO ) tumors had an accumulation of lipid peroxides, and inhibition of ferroptosis with genetic, dietary, or pharmacological approaches effectively restored the growth of Fsp1 KO tumors in vivo . Unlike GPX4 , FSP1 expression was prognostic for disease progression and poorer survival in LUAD patients, highlighting its potential as a viable therapeutic target. Moreover, given the critical role of GPX4 in multiple tissues, there is a greater therapeutic window for targeting FSP1. To this end, we demonstrated that pharmacologic inhibition of FSP1 had significant therapeutic benefit in pre-clinical lung cancer models. Our studies highlight the importance of ferroptosis suppression in vivo and pave the way for FSP1 inhibition as a therapeutic strategy to improve disease outcome in lung cancer patients.

DOI: https://doi.org/10.1101/2025.08.07.668766
FEBS J. 2025 Aug 17.

Mutant p53 affects the mitochondrial proteome, promoting mitochondrial fragmentation and OXPHOS in pancreatic ductal adenocarcinoma cells.

Maria Poles, Raffaella Pacchiana, Chiara Mortali, Barbara Cisterna, Nidula Mullappilly, Adriana Celesia, Federica Danzi, Martina Gaspari, Daniela Cecconi, Massimo Donadelli, Alessandra Fiore.

  Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal cancer marked by poor prognosis and frequent gain-of-function mutations in the TP53 tumor suppressor gene. Given the crucial role of mutant p53 in the context of metabolic reprogramming and aggressive tumor behavior, we explored its role on mitochondria, which may present a valuable therapeutic target. In this study, we characterized the unique mitochondrial proteome observed in PDAC cells harboring the gain-of-function TP53R273H mutation and discovered a strong mutant p53-dependent upregulation of myosin heavy chain 14 (MYH14), a nonmuscle myosin, implicated in mitochondrial dynamics. We deeply investigated the role of mutant p53 in the regulation of mitochondrial architecture and functionality in PDAC cells. Our morphological and morphometric analyses with transmission electron microscopy and three-dimensional confocal imaging revealed that mutant p53 induced marked mitochondrial fragmentation, whereas wild-type p53 stimulated mitochondrial elongation. Interestingly, the fragmented mitochondrial morphology is associated with higher mitochondrial respiration levels and more efficient mitochondrial cristae. These findings support the role of oncogenic mutant p53 isoforms in inducing mitochondrial fragmentation through a mechanism involving MYH14, resulting in an increased oxidative phosphorylation level that may support PDAC cell growth and aggressiveness.

Keywords:  MYH14; mitochondrial dynamics; mutant p53; pancreatic ductal adenocarcinoma cancer metabolism

DOI:  https://doi.org/10.1111/febs.70223
J Clin Invest. 2025 Aug 15. pii: e191945. [Epub ahead of print]135(16):

Experimental models of pancreas cancer: what has been the impact for precision medicine?

Vasiliki Pantazopoulou, Casie S Kubota, Satoshi Ogawa, Kevin Christian Montecillo Gulay, Xiaoxue Lin, Hyemin Song, Jonathan R Weitz, Hervé Tiriac, Andrew M Lowy, Dannielle D Engle.

Pancreatic cancer has a 5-year survival rate of approximately 13% and is projected to become the second-leading cause of cancer-related deaths by 2040. Despite advances in preclinical research, clinical translation remains challenging, and combination chemotherapy remains the standard of care. The intrinsic heterogeneity of pancreas cancer underscores the potential of precision medicine approaches to improve patient outcomes. However, clinical implementation faces substantial challenges, including patient performance status, metastatic disease at diagnosis, intrinsic drug resistance, and a highly complex tumor microenvironment. Emerging targeted therapies, such as RAS inhibitors, offer promise for personalized treatment. These developments have prompted precision medicine-focused clinical trials using molecular subtyping for patient stratification. Effective development of precision medicine therapies depends heavily on robust preclinical models capable of accurately recapitulating the complexities of the pancreatic tumor microenvironment. Two-dimensional, air-liquid interface, and patient-derived organoid cultures combined with in vivo genetically engineered mouse models and patient-derived xenografts represent valuable experimental systems. This Review critically examines the strengths and limitations of these experimental model systems. We highlight their relevance and utility for advancing precision medicine strategies in pancreas cancer.

DOI: https://doi.org/10.1172/JCI191945
mBio. 2025 Aug 18. e0118325

Role of listeriolysin O and phospholipases C in L. monocytogenes intercellular protrusion dynamics, resolution, and autophagy avoidance.

Madalyn Fields, Abigail Spencer, Sara J Mason, Christopher C Phelps, Xiaoli Zhang, Amal Amer, Stephanie Seveau.

  Cell-to-cell spread is a major mechanism used by the bacterial pathogen Listeria monocytogenes to disseminate within its host. In this mechanism, bacteria are directly transferred from the cytosol of an infected donor cell to a recipient cell via formation of an intercellular protrusion. The intercellular protrusion resolves into a vacuole that is disrupted by L. monocytogenes to reach the cytosol of the recipient cell, where it divides and starts new cell-to-cell spread cycles. Here, we studied the spatiotemporal dynamics of the donor and recipient host cell plasma membranes during intercellular protrusion formation, resolution, and disruption, as well as the role of the bacterial pore-forming toxin listeriolysin O (LLO) and two phospholipases C in these dynamics. Leveraging three-dimensional live-cell microscopy, we co-cultured and imaged infected epithelial cells expressing different fluorescent plasma membrane markers to distinguish donor from recipient cell membranes. We characterized, for the first time, the dynamics of the canonical cell-to-cell spread pathway in which protrusions resolve into double-membrane vacuoles, followed by the successive disruption of donor and recipient membranes. We found that LLO controls protrusion resolution into a double-membrane vacuole and disruption of donor and recipient membranes, whereas the phospholipases C (PLCs) control donor membrane disruption and prevent bacterial entrapment into autophagosomes. Furthermore, we identified a second, more efficient "non-canonical" cell-to-cell spread pathway strictly requiring LLO/PLCs cooperation, which resolves into a single-membrane vacuole that is rapidly disrupted. Altogether, this study provides the first detailed analysis of membrane dynamics within intercellular protrusions and vacuoles, establishing an advanced model for L. monocytogenes cell-to-cell spread.IMPORTANCEIntracellular bacterial pathogens, including L. monocytogenes, spread from cell to cell to effectively disseminate within host tissues and cause systemic infections. We developed a fluorescence microscopy-based method to visualize and distinguish in real time the dynamics of donor and recipient host cell plasma membranes during the different stages of the cell-to-cell spread process: (i) formation of the intercellular protrusion-containing L. monocytogenes, (ii) protrusion resolution into a vacuole, and (iii) disruption of the vacuolar membranes until the bacterium is released into the cytosol of the recipient cell. We measured the kinetics of the two identified-canonical and non-canonical-cell-to-cell spread pathways of L. monocytogenes in epithelial cells. This work also revealed that the virulence factors listeriolysin O and phospholipases C differentially control donor and recipient membrane remodeling and bacterial capture into autophagosomes, providing an advanced model for L. monocytogenes cell-to-cell spread.

Keywords:  Listeria monocytogenes; Listeria protrusion; bacterial intercellular spreading; cell-to-cell spreading; listeriolysin O; phospholipase C

DOI:  https://doi.org/10.1128/mbio.01183-25
Biophys J. 2025 Aug 18. pii: S0006-3495(25)00529-6. [Epub ahead of print]

Vesicle tension in porous membranes: aspiration, spreading, and tube extraction.

Grégory Beaune, Françoise Brochard-Wyart.

We review recent theoretical and experimental advances in understanding the mechanical tension of porous vesicles. Focusing on three key deformation processes, aspiration, spreading, and tube extrusion, we show how membrane porosity introduces novel timescales and feedback mechanisms that alter vesicle behavior. In particular, we highlight how tube extrusion from porous membranes demonstrates the vesicle's ability to regulate internal volume and dynamically modulate membrane tension. This regulation enables the sustained elongation of membrane tubes under milder mechanical conditions than those required for non-porous vesicles. These findings provide new insight into biologically relevant processes such as organelle shaping, intracellular transport, and mechanosensitive remodeling, emphasizing the crucial role of membrane permeability in cellular morphodynamics.

DOI: https://doi.org/10.1016/j.bpj.2025.08.017
Redox Biol. 2025 Aug 16. pii: S2213-2317(25)00339-8. [Epub ahead of print]86 103826

Macrophages and macrophage extracellular vesicles confer cancer ferroptosis resistance via PRDX6-mediated mitophagy inhibition.

Naisheng Zheng, Fuli Li, Qing Huang, Xian Huang, Tomasz Maj.

  Ferroptosis has emerged as a promising therapeutic target in cancer therapy, with the tumor microenvironment (TME) playing a pivotal role in regulating ferroptosis. Although macrophages contribute to ferroptosis regulation within TME, the underlying mechanisms remain unclear. In this study, we demonstrate that macrophages consistently attenuate GPX4 inhibitor-induced lipid peroxidation and cell death in various tumor cell lines, whereas their resistance to cysteine transport inhibitor-triggered ferroptosis varies across cell types. This tumor protection from ferroptosis is mediated through macrophage-tumor cell contact and the delivery of macrophage-derived extracellular vesicles (Mφ-EV). Transcriptomic and proteomic analyses revealed that macrophages and Mφ-EV enhance glutathione metabolism in tumor cells. Notably, Mφ-EV are uniquely enriched with the glutathione metabolism-related protein PRDX6. Mechanistically, the glutathione peroxidase activity of PRDX6 elevates intracellular reduced glutathione, suppresses lipid peroxidation, and thereby mitigates ferroptosis. Furthermore, macrophage-derived PRDX6 reduces mitochondrial superoxide accumulation, alleviates ferroptosis-induced mitophagy, and enhances tumor cell viability, ultimately promoting tumor growth. Together, our findings provide a novel mechanism of ferroptosis resistance in TME, wherein macrophages confer tumor cell resilience by bypassing GPX4 inhibition.

Keywords:  Extracellular vesicles; Ferroptosis; Macrophages; Mitophagy; Peroxiredoxin 6

DOI:  https://doi.org/10.1016/j.redox.2025.103826
bioRxiv. 2025 Aug 11. pii: 2025.08.07.669190. [Epub ahead of print]

Dehydration promotes intracellular lipid synthesis and accumulation.

Joshua S Carty, Jazlyn Selvasingh, Yvonne Zuchowski, Hyuck-Jin Nam, Clothilde Pénalva, Gayani Nanayakkara, Erin Q Jennings, Kelsey Voss, Edith T Adame, John T Tossberg, Wei Sheng Yap, Meiling Melzer, Olga Viquez, A Scott McCall, Elizabeth R Piotrowski, Ryoichi Bessho, Shirong Cao, Katrina L Leaptrot, Alexandra C Schrimpe-Rutledge, Simona G Codreanu, Stacy D Sherrod, John A McLean, Jonathan B Trapani, Matthew A Cottam, Ma Wan, Deepti Shrivastava, Don Delker, Matthew H Wilson, Clinton M Hasenour, Louise Lantier, Irene Chernova, Jamey D Young, Volker H Haase, Jose Pablo Vazquez-Medina, Dylan K Kosma, Peter Kim, Jean-Philippe Cartailler, Mingzhi Zhang, Roy Zent, Raymond C Harris, Jason A Watts, Andrew S Terker, Fabian Bock, Jeffrey C Rathmell, Aylin R Rodan, Juan P Arroyo.

Lipids can be considered a water reservoir used to offset dehydration stress as their oxidation by the mitochondria generates water. However, whether dehydration directly regulates lipid synthesis is unknown, which is the focus of this study. We found that dehydration stress decreases cellular oxygen consumption, increases intracellular lipid synthesis, and favors glutamine oxidation as a carbon precursor for lipid synthesis via remodeling mitochondrial metabolism. These findings provide a mechanism whereby cellular dehydration leads to intracellular lipid accumulation, functionally linking water availability to lipid storage.

DOI: https://doi.org/10.1101/2025.08.07.669190
Cancer Res. 2025 Aug 18.

Generations in Flux: Tracking the Birth of Cellular Heterogeneity in Cancer.

Aaron McKenna.

Intratumor heterogeneity is a hallmark of cancer, enabling subpopulations of cells to evade therapy, adapt to immune attack, and thrive in diverse microenvironments. While retrospective genomic and epigenomic analyses have mapped the large-scale histories of tumor evolution, they cannot capture the rapid, dynamic changes in cell state that occur as individual cells divide. Panagopoulos and colleagues recently developed a cellular platform to monitor the role of transient replication stress in real time, tracking sister cells as they divide and replicate. The authors use these techniques to show that daughter and granddaughter cells can inherit very different states, often leading to further cellular instability. This work broadens our understanding of how diverse cell states arise from oncogenic stress and how cellular heterogeneity emerges.

DOI: https://doi.org/10.1158/0008-5472.CAN-25-3601
Proc Natl Acad Sci U S A. 2025 Aug 26. 122(34): e2512404122

Systemic Kras ablation disrupts myeloid cell homeostasis in adult mice.

Elena Zamorano-Dominguez, Lucía Morales-Cacho, Rebeca Barrero, Silvia Jiménez-Parrado, Alma Dhawahir, Isabel Hernández-Porras, Lucía Simón-Carrasco, Sara Barrambana, Pian Sun, Ana Galván-Del-Rey, Blanca Rosas-Perez, Vasiliki Liaki, Matthias Drosten, Mónica Musteanu, Federico Virga, Eugenio Santos, Francisca Mulero, Eduardo Caleiras, Carmen Guerra, Mariano Barbacid.

  The KRAS oncogene has been associated with many types of cancer, including pancreatic, lung, and colorectal. For decades, its gene products were thought to be undruggable. However, during the last decade, a large battery of KRAS inhibitors selective against specific mutations (KRASG12C and KRASG12D), panKRAS inhibitors active against all KRAS isoforms, or even panRAS inhibitors, capable of inhibiting the three members of the RAS family, have been developed. In mice, the Kras locus is essential for embryonic development and can sustain adult homeostasis in the absence of Hras and Nras expression. Thus, we considered of interest to interrogate the role of the Kras locus in an experimental system to generate potentially relevant information regarding the use of panKRAS or panRAS inhibitors in the clinic. Here, we report that systemic ablation of Kras expression in adult mice does not induce significant changes in overall survival, body weight, glucose levels, metabolic profile, or heart function. In contrast, flow cytometry and histopathological analyses of organs such as blood, bone marrow, and spleen showed a significant increase of the myeloid lineage leading to myelomonocytic metaplasia. In this context, replacement of the KRAS isoforms by HRAS is sufficient to maintain adult homeostasis, suggesting that the unique properties of the Kras locus are primarily due to its pattern of expression rather than to the activity of its gene products.

Keywords:  Hras and Nras; Kras; myelomonocytic metaplasia; panRAS inhibitors; systemic ablation

DOI:  https://doi.org/10.1073/pnas.2512404122
Nat Genet. 2025 Aug 18.

Tracing the evolution of single-cell 3D genomes in Kras-driven cancers.

Miao Liu, Shengyan Jin, Sherry S Agabiti, Tyler B Jensen, Tianqi Yang, Jonathan S D Radda, Christian F Ruiz, Gabriel Baldissera, Moein Rajaei, Fang-Yong Li, Jeffrey P Townsend, Mandar Deepak Muzumdar, Siyuan Wang.

Although three-dimensional (3D) genome structures are altered in cancer, it remains unclear how these changes evolve and diversify during cancer progression. Leveraging genome-wide chromatin tracing to visualize 3D genome folding directly in tissues, we generated 3D genome cancer atlases of oncogenic Kras-driven mouse lung adenocarcinoma (LUAD) and pancreatic ductal adenocarcinoma. Here we define nonmonotonic, stage-specific alterations in 3D genome compaction, heterogeneity and compartmentalization as cancers progress from normal to preinvasive and ultimately to invasive tumors, discovering a potential structural bottleneck in early tumor progression. Remarkably, 3D genome architectures distinguish morphologic cancer states in single cells, despite considerable cell-to-cell heterogeneity. Analyses of genome compartmentalization changes not only showed that compartment-associated genes are more homogeneously regulated but also elucidated prognostic and dependency genes in LUAD, as well as an unexpected role for Rnf2 in 3D genome regulation. Our results highlight the power of single-cell 3D genome mapping to identify diagnostic, prognostic and therapeutic biomarkers in cancer.

DOI: https://doi.org/10.1038/s41588-025-02297-w
Nat Commun. 2025 Aug 19. 16(1): 7724

Quantifying collective interactions in biomolecular phase separation.

Hannes Ausserwöger, Ella de Csilléry, Daoyuan Qian, Georg Krainer, Timothy J Welsh, Tomas Sneideris, Titus M Franzmann, Seema Qamar, Nadia A Erkamp, Jonathon Nixon-Abell, Mrityunjoy Kar, Peter St George-Hyslop, Anthony A Hyman, Simon Alberti, Rohit V Pappu, Tuomas P J Knowles.

Biomolecular phase separation is an emerging theme for protein assembly and cellular organisation. The collective forces driving such condensation, however, remain challenging to characterise. Here we show that tracking the dilute phase concentration of only one component suffices to quantify composition and energetics of multicomponent condensates. Applying this assay to several disease- and stress-related proteins, we find that monovalent ions can either deplete from or enrich within the dense phase in a context-dependent manner. By analysing the effect of the widely used modulator 1,6-hexanediol, we find that the compound inhibits phase separation by acting as a solvation agent that expands polypeptide chains. Extending the strategy to in cellulo data, we even quantify the relative energetic contributions of individual proteins within complex condensates. Together, our approach provides a generic and broadly applicable tool for dissecting the forces governing biomolecular condensation and guiding the rational modulation of condensate behaviour.

DOI: https://doi.org/10.1038/s41467-025-62437-y