bims-pideca Biomed News
on Class IA PI3K signalling in development and cancer
Issue of 2025–11–16
34 papers selected by
Ralitsa Radostinova Madsen, MRC-PPU



  1. J Biol Eng. 2025 Nov 13. 19(1): 102
      Cell fate decisions are regulated by intricate signaling networks, with Extracellular signal-Regulated Kinase (ERK) being a central node in the control of cell proliferation and differentiation. ERK typically cooperates with a network of other regulators, making it necessary to study multiple signaling pathways simultaneously at the single-cell level. Many existing fluorescent biosensors for ERK and other pathways have significant spectral overlap, limiting their utility for multiplexing. To address this limitation, we developed two novel red-FRET ERK biosensors, REKAR67 and REKAR76, which operate in the 670-720 nm range using the fluorescent proteins miRFP670nano3 and miRFP720. REKAR67 and REKAR76 differ in fluorophore position, which impacts biosensor characteristics; REKAR67 displayed a higher dynamic range but greater signal variance than REKAR76. In both polyclonal and clonal populations, REKAR67- or REKAR76-expressing cells displayed similar Signal-to-Noise ratios (SNR). Overall, the red-FRET ERK biosensors were highly consistent with existing CFP/YFP biosensors in reporting ERK activity. Both REKAR biosensors expand the available tools for measuring single-cell ERK activity by being spectrally compatible with other CFP/YFP FRET and cpGFP -based biosensors, allowing for multiplexed imaging.
    DOI:  https://doi.org/10.1186/s13036-025-00541-9
  2. Cell Rep Methods. 2025 Nov 10. pii: S2667-2375(25)00258-9. [Epub ahead of print] 101222
      Here, we introduce CRISPR and transcriptomics-assay for transposase-accessible chromatin (CAT-ATAC), a technique that adds CRISPR guide RNA (gRNA) capture to the existing 10× Genomics Multiome assay, generating linked transcriptome, chromatin accessibility, and perturbation identity data from the same individual cells. We demonstrate up to 77% capture rate for both arrayed and pooled delivery of lentiviral gRNAs in induced pluripotent stem cells (iPSCs) and cancer cell lines. This capability allows us to construct gene regulatory networks (GRNs) in cells under drug and genetic perturbations. By applying CAT-ATAC, we identified a GRN associated with dasatinib resistance, indirectly activated by the HIC2 gene. Using loss-of-function experiments, we further validated that ZFPM2, a component of the predicted GRN, also contributes to dasatinib resistance. CAT-ATAC can thus be used to generate high-content multidimensional genotype-phenotype maps to reveal gene and cellular interactions and functions.
    Keywords:  CP: biotechnology; CP: cancer biology; CRISPR; guide RNA; multiome; perturb-seq; single cell
    DOI:  https://doi.org/10.1016/j.crmeth.2025.101222
  3. Dis Model Mech. 2025 Nov 11. pii: dmm.052527. [Epub ahead of print]
      PTEN Hamartoma Tumour Syndrome (PHTS), a rare disease caused by germline heterozygous PTEN mutations, is associated with multi-organ/tissue overgrowth, autism spectrum disorder and increased cancer risk. Phenotypic variability in PHTS is partly due to diverse PTEN mutations and the protein's multifaceted functions. PTEN is primarily a PIP3 phosphatase regulating PI3K/AKT signalling but also maintains chromosomal stability through nuclear functions such as double-strand (ds) DNA damage repair. Here we show that PTEN-R173C, a pathogenic variant frequently found in PHTS and somatic cancer, has elevated PIP3 phosphatase activity that effectively regulates canonical PI3K/AKT signalling. However, PTEN-R173C is unstable and excluded from the nucleus. We generated Pten+/R173C mice which developed few tumours during their lifetime, aligning with normal PI3K/AKT signalling. However, they exhibit lymphoid hyperplasia, macrocephaly and brain abnormalities, associated with impaired nuclear functions of PTEN-R173C, demonstrated by reduced dsDNA damage repair. Integrating PHTS patient data with our mouse-model, we propose that defective nuclear functions of PTEN variants can predict the onset of PHTS phenotypes, and that late-onset cancer in these individuals may arise from secondary genetic alterations, facilitated by compromised dsDNA repair.
    Keywords:  ASD; Cancer; Macrocephaly; PHTS; PI3K; PTEN
    DOI:  https://doi.org/10.1242/dmm.052527
  4. Front Cell Dev Biol. 2025 ;13 1656051
      Our ever-growing capacity to observe dynamic processes at the single-cell level has highlighted how cells use complex signaling dynamics to provide adequate responses to intra- and extracellular cues. Specifically, there is increasing evidence that signaling dynamics can be functional in determining cell fate decisions. In this work, we provide an overview of the growing body of evidence supporting this idea across diverse biological contexts-including immune responses, reactions to DNA damage and growth factors, and embryonic development. In doing so, we aim to provide a precise conceptualization of what is meant when we say that signaling dynamics can determine cell fate, a unifying view of the methodologies used to sustain this claim and to identify some of the existing gaps in our mechanistic understanding of this process. We believe that the body of work hereby described strongly supports the importance of considering the temporal dimension of signaling when seeking to understand how cellular responses are regulated.
    Keywords:  Hes1; MAPK; NF-kB; cell fate decisions; live-cell microscopy; p53; signaling dynamics
    DOI:  https://doi.org/10.3389/fcell.2025.1656051
  5. Cell. 2025 Nov 13. pii: S0092-8674(25)01151-1. [Epub ahead of print]188(23): 6393-6410
      Recent studies at molecular and genomic scales have enriched our understanding of life's most fundamental building block: the cell. However, bridging the gap between single-cell phenotypes and the emergent functions of tissues and organs remains a formidable challenge. Here, we suggest that the conceptual span from cells to tissues and organs is so large as to warrant intermediate stepping stones. Drawing inspiration from "network motifs"-discrete units of cell-level function that emerge from the interactions of a handful of genes or enzymes-we argue that similarly identifiable units of tissue-level function, which we term "mesoscale modules," emerge from coordinated "interactions" among relatively small numbers of cells and their extracellular milieu. We outline several such modules and propose that a concerted effort to study them will deepen our foundational understanding of tissue and organ functions. By developing these mesoscale insights, we anticipate a more tractable and mechanistic approach to complex human conditions rooted in tissue- and organ-scale dysregulation, including developmental defects, cancer, cardiovascular disease, immune-related disorders, infectious disease, and aging.
    Keywords:  emergent properties; mesoscale modules; network motifs; systems biology; tissue biology
    DOI:  https://doi.org/10.1016/j.cell.2025.10.012
  6. JCI Insight. 2025 Nov 11. pii: e189683. [Epub ahead of print]
      Insulin/insulin growth factor signaling is a conserved pathway that regulates lifespan. Yet, long-lived loss-of-function mutants often produce insulin-resistance, slow growth, and impair reproduction. Recently, a gain-of-function mutation in the kinase insert domain (KID) of the Drosophila insulin/IGF receptor was seen to dominantly extend lifespan without impairing insulin-sensitivity, growth and reproduction. This substitution occurs within residues conserved in mammalian insulin receptor (IR) and insulin growth factor-1 receptor (IGF-1R). We produced two knock-in mouse strains that carry the homologous KID Arg/Cys substitution in murine IR or IGF-1R, and we replicated these genotypes in human cells. Cells with heterodimer receptors of IR or IGF-1R induce receptor phosphorylation and phospho-Akt when stimulated with insulin or IGF. Heterodimer receptors of IR fully induce pERK but ERK was less phosphorylated in cells with IGF-1R heterodimers. Adults with a single KID allele (producing heterodimer receptors) have normal growth and glucose regulation. At four months, these mice variably display hormonal markers that associate with successful aging counteraction, including elevated adiponectin, FGF21, and reduced leptin and IGF-1. Livers of IGF-1R females show decreased transcriptome-based biological age, which may point toward delayed aging and warrants an actual lifespan experiment. These data suggest that KID mutants may slow mammalian aging while they avoid the complications of insulin resistance.
    Keywords:  Aging; Glucose metabolism; Insulin; Metabolism
    DOI:  https://doi.org/10.1172/jci.insight.189683
  7. J Biol Chem. 2025 Nov 07. pii: S0021-9258(25)02773-5. [Epub ahead of print] 110921
      Protein kinases function not only through their catalytic phospho-transfer activity but also by non-catalytic scaffold mechanisms. Introduction of mutations to inactivate catalysis provides a tool to differentiate between the two; however, kinase-inactivating mutations may alter the structure of the kinase domain and perturb scaffold functions. Here, we developed a strategy that prevents ATP binding, thereby preventing catalysis, while stabilizing the active conformation of the kinase domain. This approach leverages the structural role of ATP in assembling the catalytic spine (C-spine), a hydrophobic core essential for the active conformation. Specifically, we substituted Val or Ala residues proximal to the binding position of the adenosine ring of ATP with Phe in three protein kinase C isozymes (PKCβII, γ, θ) and Akt1. Structural modeling suggests that Phe substitutions at these positions are a surrogate for the adenosine ring of ATP to assemble the C-spine. Live-cell imaging using genetically encoded PKC and Akt activity reporters reveals that C-spine mutations abolish kinase activity. Furthermore, phosphorylation of the hydrophobic motif, an autophosphorylation site, is abolished in C-spine mutants of PKC family members and reduced in C-spine mutants of Akt1, independent of epidermal growth factor (EGF) stimulation. In PKCβII, these C-spine mutations accelerate plasma membrane translocation, consistent with impaired autoinhibition due to the lack of hydrophobic motif phosphorylation. Despite adopting reduced autoinhibition, turnover experiments with PKCθ reveal C-spine mutants do not impair the stability of the full-length PKC. The generation of pseudokinases by C-spine mutations provides a generalizable strategy for elucidating non-catalytic kinase functions.
    Keywords:  Akt; C-spine; kinase-dead; protein kinase C; pseudokinase
    DOI:  https://doi.org/10.1016/j.jbc.2025.110921
  8. Nucleic Acids Res. 2025 Nov 06. pii: gkaf1146. [Epub ahead of print]
      The ProteomeXchange consortium of proteomics resources (http://www.proteomexchange.org) was established to standardize open data practices in the mass spectrometry (MS)-based proteomics field. Here, we describe the main developments in ProteomeXchange in the last 3 years. The six member databases of ProteomeXchange, spread out in three different continents, are the PRIDE database, PeptideAtlas, MassIVE, jPOST, iProX, and Panorama Public. We provide updated data submission statistics, showcasing that the number of datasets submitted to ProteomeXchange resources has continued to accelerate every year. Through June 2025, 64 330 datasets had been submitted to ProteomeXchange resources, and from those, 30 097 (47%) just in the last 3 years. We also report on the improvements in the support for the standards developed by the Proteomics Standards Initiative, e.g. for Universal Spectrum Identifiers and for SDRF (Sample and Data Relationship Format)-Proteomics. Additionally, we highlight the increase in data reuse activities of public datasets, including targeted reanalyses of datasets of different proteomics data types, and the development of novel machine learning approaches. Finally, we summarize our plans for the near future, covering the development of resources for controlled-access human proteomics data, and for the support of non-MS proteomics approaches.
    DOI:  https://doi.org/10.1093/nar/gkaf1146
  9. Nat Biotechnol. 2025 Nov 11.
      A standardized 'parts list' of sequences for genetic engineering of microbes has been indispensable to progress in synthetic biology, but few analogous parts exist for mammalian systems. Here we design libraries of extant, ancestral, mutagenized or miniaturized variants of polymerase III promoters and guide RNA (gRNA) scaffolds and quantify their abilities to mediate precise edits to the mammalian genome through multiplex prime editing. We identify thousands of parts for reproducible editing in human and mouse cell lines, including hundreds with greater activity than commonly used sequences. Saturation mutagenesis screens identify tolerated sequence variants that further enhance sequence diversity. In an application to molecular recording, we design a 'ten key' array that, in mammalian cells, achieves balanced activity of pegRNAs as predicted by the activity of the component parts. The data reported here will aid the design of synthetic loci encoding arrays of gRNAs exhibiting predictable, differentiated levels of activity for applications in multiplexed perturbation, biological recorders and complex genetic circuits.
    DOI:  https://doi.org/10.1038/s41587-025-02896-2
  10. Cell Chem Biol. 2025 Nov 12. pii: S2451-9456(25)00345-9. [Epub ahead of print]
      Phenotypic screens carried out with functional genomics or small molecules have led to novel biological insights, revealed previously unknown targets for drug discovery programs, and provided starting points for the development of first-in-class therapies. Despite being valuable research tools, genetic and compound screening also have significant limitations. This perspective aims to shed a light on those limitations and provide mitigation strategies when available, with a goal of helping phenotypic screening practitioners gain an understanding of how and when to best utilize either approach.
    Keywords:  functional genomics; phenotypic drug discovery; phenotypic screening; target identification
    DOI:  https://doi.org/10.1016/j.chembiol.2025.10.008
  11. Nat Commun. 2025 Nov 13. 16(1): 9902
      Understanding kinase action requires precise quantitative measurements of their activity in vivo. In addition, the ability to capture spatial information of kinase activity is crucial to deconvolute complex signaling networks, interrogate multifaceted kinase actions, and assess drug effects or genetic perturbations. Here we develop a proteomic kinase activity sensor technique (ProKAS) for the analysis of kinase signaling using mass spectrometry. ProKAS is based on a tandem array of peptide sensors with amino acid barcodes that allow multiplexed analysis for spatial, kinetic, and screening applications. We engineered a ProKAS module to simultaneously monitor the activities of the DNA damage response kinases ATR, ATM, and CHK1 in response to genotoxic drugs, while also uncovering differences between these signaling responses in the nucleus, cytosol, and replication factories. Furthermore, we developed an in silico approach for the rational design of specific substrate peptides expandable to other kinases. Overall, ProKAS is a versatile system for systematically and spatially probing kinase action in cells.
    DOI:  https://doi.org/10.1038/s41467-025-65950-2
  12. iScience. 2025 Nov 21. 28(11): 113717
      Aging ovaries exhibit increased oxidative stress, contributing to infertility through cellular and hormonal changes. Nuclear factor E2-related factor 2 (NRF2), a key transcription factor, regulates antioxidant responses. This study investigates NRF2 in dormant (primordial) ovarian follicles to determine if NRF2 activation accounts for primordial follicle activation. We show that trigonelline (TRG) transiently activates NRF2, promoting primordial follicle activation in the non-hormonal phase of follicle development. Indeed, TRG enhances egg quality in aged mice. In human ovarian tissues, TRG increased activation of primordial follicles, resulting in more primary and secondary follicles. Mechanistically, TRG induces NRF2 nuclear translocation and upregulates NRF2-responsive genes, including Egf. Elevated epidermal growth factor (EGF) levels activate EGF receptor (EGFR), increasing protein kinase B (AKT) phosphorylation, which leads to FOXO3A nuclear extrusion and primordial follicle activation. These findings demonstrate that transient NRF2 activation is sufficient to initiate primordial follicle activation and follicle growth and development.
    Keywords:  Cell biology; Reproductive medicine
    DOI:  https://doi.org/10.1016/j.isci.2025.113717
  13. Cancer Discov. 2025 Nov 17.
      Loss of tumor suppressor PTEN drives cancer progression and therapeutic resistance, yet no targeted therapies exist for PTEN-deficient tumors. Here, we identify a critical druggable mechanism where PTEN-loss induces PI3Kβ phosphorylation for tumorigenesis. Using BioID interactome, we uncovered phosphorylation-dependent PI3Kβ-EPHA2 interaction in PTEN-null cells, driven by p-PI3KβY962. PTEN functions as a tyrosine phosphatase that normally dephosphorylates p-PI3KβY962. In PTEN-deficient contexts, enhanced p-PI3KβY962 forms a complex with EPHA2 and SRC, where both kinases contribute to PI3Kβ phosphorylation, activating oncogenic pERK/c-MYC and pAKT pathways. We developed a selective p-PI3KβY962 antibody detecting p-PI3KβY962 in PTEN-deficient tumors across preclinical models and clinical tumor specimens. Disrupting p-PI3KβY962 suppressed tumor growth in multiple PTEN-null models. Dasatinib, an FDA-approved SRC/EPHA2 inhibitor, effectively reduced p-PI3KβY962 and inhibited tumor progression in PTEN-null but not PTEN-WT tumors. These findings establish p-PI3KβY962 as a druggable target and biomarker for developing targeted therapy in PTEN-deficient cancers beyond conventional PI3K kinase inhibition.
    DOI:  https://doi.org/10.1158/2159-8290.CD-25-1126
  14. Nat Methods. 2025 Nov;22(11): 2386-2399
      Cell segmentation is the foundation of a wide range of microscopy-based biological studies. Deep learning has revolutionized two-dimensional (2D) cell segmentation, enabling generalized solutions across cell types and imaging modalities. This has been driven by the ease of scaling up image acquisition, annotation and computation. However, three-dimensional (3D) cell segmentation, requiring dense annotation of 2D slices, still poses substantial challenges. Manual labeling of 3D cells to train broadly applicable segmentation models is prohibitive. Even in high-contrast images annotation is ambiguous and time-consuming. Here we develop a theory and toolbox, u-Segment3D, for 2D-to-3D segmentation, compatible with any 2D method generating pixel-based instance cell masks. u-Segment3D translates and enhances 2D instance segmentations to a 3D consensus instance segmentation without training data, as demonstrated on 11 real-life datasets, comprising >70,000 cells, spanning single cells, cell aggregates and tissue. Moreover, u-Segment3D is competitive with native 3D segmentation, even exceeding when cells are crowded and have complex morphologies.
    DOI:  https://doi.org/10.1038/s41592-025-02887-w
  15. Brain Commun. 2025 ;7(6): fcaf408
      We aimed to decipher the natural history of paediatric cerebral and intraspinal medullary cavernous malformations and their genetic background, with an emphasis on the effect of mutational burden on their radiological features and haemorrhagic risk. We retrospectively collected clinical and radiological data and the natural history of the disease during the follow-up of all consecutive patients with cavernous malformations over the last 2 decades at a unique paediatric centre. We created an MRI atlas after lesion segmentation and normalization to perform voxel-based lesion symptom mapping. Targeted germline DNA sequencing of CCM1-3 genes and somatic lesions and targeted sequencing of RAS and PI3 K pathway genes were performed. In total, 257 patients carrying 786 brain and 14 spinal cavernous malformations were analysed. Age at diagnosis was 9.5 ± 5 years. Follow-up data were available for 718 lesions with a mean follow-up of 5.59 ± 3.28 years. Then, 134 brain (80 with focal onset seizures) and 10 spinal cavernous malformations were surgically excised. Furthermore, 95 of the/144 DNA extracted from lesions were successfully sequenced for somatic variants (PIK3CA, MAP3K3, KRIT1 and KRAS). We found an annual haemorrhagic risk of 1.9%, which was increased by type (sporadic or postradiation), location (brainstem or spinal), and radiological parameters (extracapsular haemorrhage, volume, signal, or presence of developmental venous anomaly). Cavernous malformations symptoms and radiological features were highly dependent on brain location. Surgical risk for cortical brain lesions was 0.9%, with 85% international league against epilepsy score grade of 1-2. Furthermore, 62% of operated lesions carried a pathogenic PIK3CA variant. The MAP3K3 somatic variant alone or in association with a PIK3CA variant decreased the annual haemorrhagic risk by 4.8 ± 1.5 (P < 0.05). We confirmed that 96% of cavernous malformations that are satellites of a developmental venous anomaly carried a PIK3CA variant and increased the relative haemorrhagic risk by 3 ± 0.31 (P = 3.8.10-3). We report an annual haemorrhagic risk of 1.9%, which is modulated by radiological features (i.e. extracapsular haemorrhage, volume, signal, and location) and lesion type. Here, we describe the first MRI atlas. Surgery yields excellent general outcomes in supratentorial superficial lesions, unlike deep-seated cavernous malformations, which is associated with high morbidity. Molecular diagnosis of operated lesions highlighted PIK3CA as a factor associated with aggressiveness in both sporadic and familial cavernous malformations. MAP3K3 decreased the risk. Finally, we confirmed that developmental venous anomaly is a radiological landmark of PIK3CA.
    Keywords:  brain mosaicism; brain probability atlas; paediatric intracranial haemorrhage; stroke; vascular malformation
    DOI:  https://doi.org/10.1093/braincomms/fcaf408
  16. Sci Adv. 2025 Nov 14. 11(46): eadz3889
      Continuous glucose monitors have proven invaluable for monitoring blood glucose levels for diabetics, but they are of limited use for observing glucose dynamics at the cellular (or subcellular) level. We have developed a second generation, genetically encoded intensity-based glucose sensing fluorescent reporter (iGlucoSnFR2). We show that when it is targeted to the cytosol, it reports intracellular glucose consumption and gluconeogenesis in cell culture, along with efflux from the endoplasmic reticulum. It outperforms the original iGlucoSnFR in vivo when observed by fiber photometry in mouse brain and reports transient increase in glucose concentration when stimulated by noradrenaline or electrical stimulation. Last, we demonstrate that membrane localized iGlucoSnFR2 can be calibrated in vivo to indicate absolute changes in extracellular glucose concentration in awake mice. We anticipate iGlucoSnFR2 facilitating previously unobservable measurements of glucose dynamics with high spatial and temporal resolution in living mammals and other experimental organisms.
    DOI:  https://doi.org/10.1126/sciadv.adz3889
  17. Elife. 2025 Nov 14. pii: RP101613. [Epub ahead of print]13
      Plasma membrane potential has been linked to cell proliferation for over 40 years in vertebrate cells. In this study, we experimentally demonstrated that membrane depolarization promotes mitosis and that this process depends on the voltage-dependent activation of extracellular signal-regulated kinase (ERK) in human cells. Notably, ERK activity showed a clear dependence on the membrane potential, independent of growth factor stimulation. This voltage dependence was observed even near the resting membrane potential, indicating that small shifts in the resting potential can influence proliferative activity. Voltage-dependent ERK activity is derived from the altered dynamics of phosphatidylserine and is not mediated by calcium influx from the extracellular space. These findings suggest that fundamental biological processes such as cell proliferation are regulated by the physicochemical properties of membrane lipids. This study highlights the broader physiological roles of membrane potentials beyond action potentials, which are well-established in neural systems.
    Keywords:  ERK; cell biology; human; human cells; imaging; membrane potential; proliferation
    DOI:  https://doi.org/10.7554/eLife.101613
  18. Stem Cell Reports. 2025 Nov 13. pii: S2213-6711(25)00317-0. [Epub ahead of print] 102713
      Perturb-seq is a powerful approach to systematically assess how genes and enhancers impact the molecular and cellular pathways of development and disease. However, technical challenges have limited its application in stem-cell-based systems. Here, we benchmarked Perturb-seq across multiple CRISPRi modalities, on diverse genomic targets, in multiple human pluripotent stem cells, during directed differentiation to multiple lineages, and across multiple single guide RNA (sgRNA) delivery systems. To ensure cost-effective production of large-scale Perturb-seq datasets as part of the Impact of Genomic Variants on Function (IGVF) consortium, our optimized protocol dynamically assesses experiment quality across the weeks-long procedure. Our analysis of 1,996,260 sequenced cells across benchmarking datasets reveals shared regulatory networks linking disease-associated enhancers and genes with downstream targets during cardiomyocyte differentiation. This study establishes open tools and resources for interrogating genome function during stem cell differentiation.
    Keywords:  CRISPR/Cas9; Perturb-seq; cardiomyocytes; human pluripotent stem cells; neural progenitor cells; single-cell genomics
    DOI:  https://doi.org/10.1016/j.stemcr.2025.102713
  19. Curr Opin Struct Biol. 2025 Nov 12. pii: S0959-440X(25)00205-2. [Epub ahead of print]95 103187
      Receptor tyrosine kinases (RTKs) control myriads of cellular functions. RTKs are paradigmatic examples of receptors where activity is directly dependent on quaternary structure. In most cases, the monomeric RTK is inactive, and function arises only after a ligand binding event leads the RTK to bind to another copy of itself, activating trans-autophosphorylation of tyrosine residues. Such RTK homodimerization can be accompanied by the formation of homomers of higher stoichiometry. However, RTK monomers can also bind to a second type of RTK, forming heterodimers. RTK heteromerization is believed to result in different signaling than homomerization. Despite its importance, we have a poor understanding of the factors that define if an RTK will form homomers or heteromers. This short review covers recent discoveries on the heteromerization of RTK, in what is called the RTK interactome. We discuss its translational potential, and how ligands and membrane lipids affect heteromer formation.
    DOI:  https://doi.org/10.1016/j.sbi.2025.103187
  20. Mol Cell Proteomics. 2025 Nov 12. pii: S1535-9476(25)00565-1. [Epub ahead of print] 101466
       BACKGROUND: Juvenile-type granulosa cell tumors (JGCTs) manifest during the prepubertal period as precocious pseudo-puberty and/or dysmenorrhea. We have previously identified pathogenic variants in AKT1 in JGCTs. This study aims to understand how these variants affect cellular function at the phenotypic and molecular levels using a Drosophila model.
    METHODS: Transgenic Drosophila models expressing wild-type (WT) AKT1 and four pathogenic variants were created under the control of tissue-specific promoters. Phenotypic effects were studied by assessing Drosophila wings for cell division and growth using wing surface and trichome density and ovarian follicular cells were examined for subcellular localization and morphology. Molecular analyses included Mass Spectrometry (MS) to identify differentially expressed proteins (DEPs) and phospho-peptides, along with RNAseq to characterize transcriptomic changes.
    RESULTS: Wings expressing mutated AKT1 showed increased surface area and reduced trichome density, indicating larger cells. In ovarian follicular cells, WT AKT1 localized primarily to the cytoplasm, while mutated AKT1 variants were associated with the plasma membrane, leading to morphological abnormalities and increased cell size. MS revealed numerous DEPs and phospho-peptides, highlighting changes in pathways such as glycolysis and Rho GTPase signaling. Transcriptomics demonstrated a clear gain-of-function for mutated AKT1 in activating a subset of genes. However, several genes up-regulated by WT AKT1 were less effectively activated by the mutants, indicating a potential loss-of-function in transcriptional regulation for this subset, revealing an unexpected mechanistic complexity.
    CONCLUSIONS: Network analysis of interactions involving DEPs, phosphorylated proteins, and transcription factors suggests these elements mediate the observed proteomic and transcriptional alterations. Taken together, the results underscore the utility of Drosophila models in unraveling the biological relevance of AKT1 pathogenic variants in cancer.
    DOI:  https://doi.org/10.1016/j.mcpro.2025.101466
  21. Am J Med Genet A. 2025 Nov 11. e64307
      Smith-Kingsmore syndrome (SKS) is a rare autosomal dominant condition characterized by neurodevelopmental differences, macrocephaly/megalencephaly, describable facial features, sleep-wake abnormalities, hyperphagia, and overgrowth. SKS is caused by pathogenic gain-of-function variants in MTOR which lead to hyperactivation of the mTOR pathway. In this review, we discuss the history, epidemiology, molecular basis, clinical features, and management considerations for Smith-Kingsmore syndrome. In addition, we provide insight on early developmental milestones through a report on 14 individuals with a confirmed diagnosis of SKS. Among these individuals, 8/12 (67%) achieved crawling at an average age of 23 months, 9/14 (64%) achieved walking with an average age of 32 months, 5/9 (56%) achieved a pincer grasp at an average age of 23 months, 8/12 (67%) achieved the ability to use a device or utensil with an average age of 3.4 years, 10/13 (77%) achieved babbling at an average age of 20 months, 8/14 (57%) achieved their first word at an average age of 34 months, and 4/14 (29%) achieved the use of short phrases at an average age of 4.6 years. This review highlights advances in characterizing the natural history of SKS since it was first described 12 years ago and the need for additional research to inform genotype-phenotype correlations and targeted therapies to support individuals with SKS.
    Keywords:  MTOR gene; MTORopathy; Smith‐Kingsmore syndrome; developmental delay
    DOI:  https://doi.org/10.1002/ajmg.a.64307
  22. Cancer Res. 2025 Nov 13.
      Single-cell RNA-sequencing (scRNA-seq) facilitates the discovery of gene expression signatures that define cell states across patients, which could be used in patient stratification and precision oncology. However, the lack of standardization in computational methodologies that are used to analyze these data impedes the reproducibility of signature detection. To address this, we developed CanSig, a comprehensive benchmarking tool that evaluates methods for identifying transcriptional signatures in cancer. CanSig integrates metrics for batch correction and biological signal conservation with a transcriptional signature correlation metric to score methods according to signature rediscovery, cross-dataset reproducibility, and clinical relevance. CanSig was applied to thirteen methods on twelve scRNA-seq datasets from five human cancer types-glioblastoma, breast cancer, lung adenocarcinoma, rhabdomyosarcoma, and cutaneous squamous cell carcinoma-representing 185 patients and 174,000 malignant cells. The signatures identified with these methods correlated with clinically relevant outcomes, including patient survival and lymph node metastasis. These results identified Harmony, BBKNN, and fastMNN as the highest-scoring integration methods for discovering shared transcriptional states in cancer. Overall, CanSig provides a standardized, reproducible framework for uncovering clinically relevant cancer cell states in single-cell transcriptomics.
    DOI:  https://doi.org/10.1158/0008-5472.CAN-25-0940
  23. Cancer Heterog Plast. 2025 ;2(4):
      The inaugural FASEB Science Research Conference (SRC) on Cellular Plasticity in Cancer was held in May 2025 in Hong Kong SAR, China. This event brought together leading experts to discuss cutting-edge research centered on cancer cell plasticity. The conference featured comprehensive presentations covering a broad spectrum of topics, including oncofetal reprogramming in tumor development and progression, mechanisms regulating cancer cell plasticity, metabolic reprogramming and its role in tumor progression, cancer cell plasticity during metastasis, cancer stem cell programs within the tumor microenvironment, tumor plasticity and immune evasion, as well as innovative therapeutic strategies aimed at targeting stem cell-like states, modulating cancer cell states, and effectively controlling disease progression. It is anticipated that the insights gained from this meeting will catalyze further advancements in cancer biology and therapy.
    Keywords:  cancer cell plasticity; cancer stem cells; cellular plasticity; immune evasion; phenotypic switching; therapy resistance; tumor microenvironment
    DOI:  https://doi.org/10.47248/chp2502040018
  24. J Biol Chem. 2025 Nov 12. pii: S0021-9258(25)02774-7. [Epub ahead of print] 110922
      The mammalian microtubule-associated serine/threonine (MAST) kinases are a highly conserved subfamily of AGC kinases that are implicated as therapeutic targets for cancer and diabetes. However, the activity, regulation, and substrates of MAST kinases are poorly understood. We examined the biochemical activity of Mast2, as a representative of the MAST family. The domain of unknown function (DUF1908) is necessary for Mast2 kinase activity in vitro, while the PDZ domain is dispensable. Mast2 kinase activity does not appear to be compatible with the AGC kinase model of T-loop phospho-activation. Instead, it contains a unique insertion that is likely stabilized by ion-pair interactions. The C-terminus of the kinase domain contains motifs regulated by mTOR in other AGC kinases, and mutation of these conserved residues reduces Mast2 kinase activity. Consistent with mTOR regulation, Mast2 purified from insulin-stimulated cells has increased activity compared to serum-starved cells, and this increase in activity is dependent on mTOR. Finally, stable 18O-ATP labeled kinase assay linked phospho-proteomics (SIKALIP) identifies a collection of putative Mast2 substrates, including the PP2A inhibitor, endosuphine-α (ENSA). Our results develop a biochemical profile of the MAST Kinases, provide insight into their regulatory mechanisms, and begin to identify the cellular function of MAST2.
    Keywords:  AGC; AlphaFold; DUF 1908; ENSA; MAST1; MAST2; MAST3; MAST4; kinase; mTOR; phosphorylation; signal transduction
    DOI:  https://doi.org/10.1016/j.jbc.2025.110922
  25. Mol Cell. 2025 Nov 07. pii: S1097-2765(25)00856-1. [Epub ahead of print]
      Harnessing DNA double-strand breaks (DSBs) is a powerful approach for gene editing, but it may provoke loss of heterozygosity (LOH), a common feature of tumor genomes. To interrogate this risk, we developed a flow cytometry-based system (Flo-LOH), detecting LOH in ∼5% of mouse embryonic and human epithelial cells following a DSB. Inhibition of both non-homologous end joining (NHEJ) and microhomology-mediated end joining (MMEJ) massively increases LOH, although the dependence on individual pathways differs in the two cell types. Multiple mechanisms lead to LOH, including chromosome truncations with de novo telomere addition and whole chromosome loss. LOH spans megabases distal from the DSB but also frequently tens of megabases centromere-proximal, which can arise from breakage-fusion-bridge events. Unlike DSBs, Cas9 nicks and adenine base editing did not noticeably impact LOH. The capacity for large-scale LOH must therefore be considered when using DSB-based gene editing, especially in conjunction with end-joining inhibition.
    Keywords:  BLM; CRISPR-Cas9; DNA double-strand break; HDR; MMEJ; breakage-fusion-bridge cycle; genomic instability; inter-homolog homologous recombination; loss of heterozygosity; nickase
    DOI:  https://doi.org/10.1016/j.molcel.2025.10.015
  26. PLoS Comput Biol. 2025 Nov 10. 21(11): e1013666
      Recent advances in single-cell and spatial transcriptomics have revolutionized our understanding of cellular heterogeneity. However, translating high-dimensional data into functional pathway insights remains challenging. To address this obstacle, we developed PaaSc (Pathway activity analysis of Single-cell), a computational method for inferring pathway activity at single-cell resolution. PaaSc employs multiple correspondence analysis to simultaneously project cells and genes into a common latent space and selects pathway-associated dimensions through linear regression to infer pathway activity scores. We validated PaaSc across diverse benchmarking datasets, including those that jointly profiled protein and RNA levels, as well as large-scale cancer scRNA-seq cohorts. Compared with state-of-the-art methods, PaaSc demonstrated superior performance in multiple applications: scoring cell type-specific gene sets, identifying cell senescence-associated pathways, and exploring GWAS trait-associated cell types. Importantly, PaaSc maintained accuracy despite batch effects and demonstrated robust performance across different data modalities, including scATAC-seq and spatial transcriptomics data. Our results demonstrate that PaaSc accurately captures dynamic cellular states and spatial patterns, thereby advancing our understanding of cellular dynamics, aging, and disease mechanisms.
    DOI:  https://doi.org/10.1371/journal.pcbi.1013666
  27. Nat Biotechnol. 2025 Nov 11.
      Single-cell sequencing characterizes biological samples at unprecedented scale and detail, but data interpretation remains challenging. Here, we present CellWhisperer, an artificial intelligence (AI) model and software tool for chat-based interrogation of gene expression. We establish a multimodal embedding of transcriptomes and their textual annotations, using contrastive learning on 1 million RNA sequencing profiles with AI-curated descriptions. This embedding informs a large language model that answers user-provided questions about cells and genes in natural-language chats. We benchmark CellWhisperer's performance for zero-shot prediction of cell types and other biological annotations and demonstrate its use for biological discovery in a meta-analysis of human embryonic development. We integrate a CellWhisperer chat box with the CELLxGENE browser, allowing users to interactively explore gene expression through a combined graphical and chat interface. In summary, CellWhisperer leverages large community-scale data repositories to connect transcriptomes and text, thereby enabling interactive exploration of single-cell RNA-sequencing data with natural-language chats.
    DOI:  https://doi.org/10.1038/s41587-025-02857-9
  28. Cell Death Dis. 2025 Nov 14. 16(1): 829
      Tuberous sclerosis complex (TSC) is an autosomal dominant disorder caused by inactivating mutations in TSC1 or TSC2 gene, leading to mTORC1 hyperactivation. However, mTORC1-independent mechanisms in this disorder remain poorly understood. In the study, excess glycogen storage was found in Tsc1-/- cells, Tsc1+/- and Tsc1c.2500-2503delAACA mice, as well as in Tsc2-/- cells, Tsc2+/- and Tsc2c.1113delA mice, with more pronounced accumulation in models with TSC2 defects. Mechanistically, the deficiency of TSC1 or TSC2 gene caused redundant uncomplexed-TSC2 or TSC1 protein, respectively. Strikingly, only uncomplexed-TSC1 downregulated the histone demethylase KDM5A, which in turn increased H3K4me3 levels at the METTL3 promoter to enhance its expression. The upregulated m6A "writer" protein METTL3 cooperated with the "reader" protein IGF2BP2 to stabilize GYS2 mRNA, causing the upregulation of GYS2 resulting in the glycogen storage. Thus, our study uncovered a novel mTORC1 independent pathway (TSC1-KDM5A-METTL3-IGF2BP2-GYS2) that underlies the excess glycogen storage, and that synergy of mTORC1-dependent and independent pathways leads to the more pronounced glycogen storage with TSC2 defects compared to those with TSC1 defects, reflecting the more severer clinical phenotypes in TSC patients with TSC2 mutations. Importantly, the restoration of glycogen homeostasis and significant amelioration of liver lesion in TSC2 defect models after the combination treatment of pharmacological inhibitors targeting mTORC1 and METTL3, unveil a potential clinic intervention for TSC patients to whom mTORC1 inhibitors are less effective or even ineffective.
    DOI:  https://doi.org/10.1038/s41419-025-08161-3
  29. Proc Natl Acad Sci U S A. 2025 Nov 18. 122(46): e2511069122
      During autophagy, the contents enclosed within autophagosomes are degraded, while the outer membrane components are recycled from autolysosomes by the recycler complex through the recently discovered autophagosomal components recycling (ACR) process. This recycling is essential for maintaining autophagic activity. However, the molecular machinery and upstream regulatory mechanisms driving this recycling process remain poorly understood. Here, we identify SNX16 as a key component of the recycler complex, which localizes to autolysosomes and is required for ACR. SNX16 functions in ACR by regulating recycler complex formation, facilitating cargo recognition, and mediating the connection between STX17-SNX4-SNX5 and dynein-dynactin complexes. In addition, SNX16-cargo interactions are regulated by two ACR-related small GTPases, Rab32 and Rab38. Importantly, mTORC1 phosphorylates SNX16 to regulate ACR by inhibiting its interactions with STX17 and other recycler components, thus preventing recycler complex formation. Taken together, our findings identify SNX16 as a recycler component and establish a link between mTORC1 and ACR.
    Keywords:  SNX16; autophagosomal components recycling; autophagy
    DOI:  https://doi.org/10.1073/pnas.2511069122
  30. J Neurochem. 2025 Nov;169(11): e70281
      Synaptic plasticity and memory formation require de novo protein synthesis. The mechanistic/mammalian target of rapamycin complex 1 (mTORC1) promotes mRNA translation initiation in the central nervous system. Recent research has uncovered that excitatory neurons, inhibitory neurons, and glia play distinct roles in modulating synaptic strength and encoding long-term memory via mTORC1 signaling. In this review, we discuss the mechanisms by which mTORC1 regulates translation initiation in the brain and its cell type-specific roles in shaping distinct forms of synaptic plasticity and memory. We also consider how dysregulated translational control contributes to neurological disorders and explore emerging technologies for therapeutic modulation of the mTORC1 pathway.
    Keywords:  excitatory neurons; glia; interneurons; mTORC1; memory; synaptic plasticity; translation
    DOI:  https://doi.org/10.1111/jnc.70281
  31. Development. 2025 Nov 15. pii: dev204308. [Epub ahead of print]152(22):
      Here, we present MultiSite Assembly of Gateway Induced Clones (MAGIC), which leverages Gateway-based recombinatorial cloning technology for rapid, modular assembly of plasmids to facilitate transgenesis in cells and vertebrate animal models. The MAGIC collection of plasmids spans a range of in vitro and in vivo uses, from tools for optically and chemically tunable gene expression, to simultaneous expression of microRNAs and fluorescent reporters, to a suite of distinct subcellular compartmental fluorescent reporters, to Cre and Dre recombinase-dependent gene expression. MAGIC system components are compatible with existing MultiSite Gateway Tol2 systems currently used in zebrafish and mammalian lentiviral and adenoviral Destination vectors, allowing rapid cross-species experimentation. The kit also includes novel vectors for stable transgene integration into host genomes in vitro or in vivo when used with piggyBac transposase, I-Sce meganuclease or Tol2 transposase. Collectively, the MAGIC system facilitates transgenesis in cultured mammalian cells, mouse, chick and zebrafish embryos, enabling the rapid generation of innovative DNA constructs for biological research due to a shared, common plasmid platform.
    Keywords:   piggyBac ; Cloning; Cre/lox; Dre/rox; Fluorescence; Gateway; LexA/LexOp; Tet/dox
    DOI:  https://doi.org/10.1242/dev.204308