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Bromodomain-containing protein 4 (BRD4) has been identified as a promising target in drug discovery, and the development of novel specific BRD4 bromodomain inhibitors will benefit anti-inflammatory drug discovery as well as bromodomain function role disclose. Herein, inspired by marine quinazolinone alkaloid penipanoid C, we designed and synthesized a series of quinazolin-4(3H)-ones with diverse linkers between two aromatic ring systems. Among them, compound 25 possessed good in vitro BRD4 inhibitory activities (IC 50  = 3.64 μM for BRD4 BD1 and IC 50  = 0.12 μM for BRD4 BD2) and anti-inflammatory activity (IC 50  = 1.98 μM for NO production assay). Meantime, 25 obviously suppressed the expression of TNF-α and IL-6 in LPS-stimulated Raw 264.7 and THP-1 cells. Notablely, 25 displayed in vivo therapeutic efficacies in an acute inflammation model without obvious cytotoxicity. These findings suggest that 25 is a selective BRD4 BD2 inhibitor which is a promising anti-inflammatory lead compound worthy for further investigation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

The cell nucleus contains distinct biomolecular condensates that form at specific genetic loci, organize chromosomes in 3D space, and regulate RNA processing. Among these, Cajal bodies (CBs) require key "scaffolding" proteins for their assembly, which is not fully understood. Here, we employ proximity biotinylation, mass spectrometry, and functional screening to comprehensively identify and test the functions of CB components. We document 144 protein interactors of coilin, of which 70 were newly detected, and establish 25 players needed for CB assembly and/or maintenance. Surprisingly, the depletion of nine coilin interactors-mostly constituents of the 60S ribosome (RPLs)-increased CB number and caused subdomains defined by coilin and the survival motor neuron protein (SMN) to merge. These phenotypes were traceable to altered nuclear levels of dimethylarginine. Our data implicate RPL24 and other players in the regulation of CBs by modulating posttranslational modifications. Moreover, the prevalence of transcription factors among the identified components highlights roles for gene activity in CB assembly and nuclear positioning., (© 2024 Arias Escayola et al.)

TWIST1 is aberrantly expressed in ovarian cancer (OC). MFAP2 is a downstream target of TWIST1, and we previously found MFAP2 facilitated OC development by activating FOXM1/β-catenin. We planned to investigate the mechanisms of TWIST1 in OC. GEPIA (a database for gene expression analysis) and UALCAN (a database containing comprehensive cancer transcriptome and clinical patient data) investigated TWIST1's connection to MFAP2 and patient survival in ovarian serous cystadenocarcinoma (OV). Human OC cells (A2780 and CAOV3) were transfected with si-TWIST1, oe-TWIST1, oe-MFAP2, or si-TWIST1 + oe-MFAP2. Cellular apoptosis, viability, migration, and invasion were detected. TWIST1, MFAP2, FOXM1, and β-catenin protein expressions were tested. Dual-luciferase and ChIP-qPCR validated the correlation between MFAP2 and TWIST1. Moreover, OC mice were established by injecting OC cells subcutaneously. The pathology, apoptosis, as well as Ki67, TWIST1, MFAP2, FOXM1, and β-catenin protein levels of tumors were assessed. TWIST1 expression positively correlated with MFAP2 expression, but negatively related to patients' survival in OV. TWIST1 overexpression promoted malignant behaviors, and increased MFAP2, FOXM1, and β-catenin protein levels for OC cells. TWIST1 knockdown exhibited the opposite trend. In vivo, TWIST1 knockdown disrupted tissue structure, induced apoptosis, decreased Ki67, TWIST1, MFAP2, FOXM1, and β-catenin protein levels in tumor. Interestingly, MFAP2 overexpression reversed the effects of TWIST1 knockdown in vitro and in vivo. Additionally, dual-luciferase and ChIP-qPCR confirmed MFAP2 was a downstream target for TWIST1 in OC. TWIST1 regulated FOXM1/β-catenin to promote the growth, migration, and invasion of OC cells by activating MFAP2, indicating that targeting TWIST1 may be effective for treating OC., (© 2025 Wiley Periodicals LLC.)

Introduction: A number of immunohistochemical stains have been examined for utility in establishing the site of origin for metastatic well-differentiated neuroendocrine tumors (NETs). In the gastrointestinal (GI) tract, distinguishing metastatic duodenal NETs from jejunoileal and other GI NETs is important for clinical work-up, prognosis, and therapy. A recent study indicated that prohormone convertase 2 (PCSK2 or PC2) had broad expression in small intestine and appendiceal NETs. Because the study did not include duodenal NETs, we examined PCSK2 expression in duodenal and other GI NETs., Methods: GI NETs (n = 69) and 13 corresponding lymph node metastases from stomach, duodenum, pancreas, ileum, appendix, and rectum were evaluated for the expression of PCSK2, along with ISL1, NKX2.2, CDX2, SATB2, and PAX8. Expression of each stain was evaluated using the H-score system, and differences in expression by site were evaluated by the chi square test., Results: PCSK2 was expressed at similar frequency in duodenal (50%), pancreatic (59%), and ileal NETs (40%). PCSK2 was infrequently expressed in stomach (0%), appendiceal (8%), and rectal (25%) NETs. However, incorporating PCSK2 into a panel including ISL1, NKX2.2, CDX2, and SATB2 allowed development of an algorithm which had 87% sensitivity and 93% specificity for classification of ileal NETs; and 68% sensitivity and 98% specificity for pancreaticoduodenal NETs., Conclusions: In contrast to previous findings, PCSK2 does not show specificity for any particular GI site. An algorithmic approach incorporating the expression of PCSK2 with that of ISL1, NKX2.2, CDX2, and SATB2 is useful in discriminating pancreatic, duodenal, ileal, appendiceal, and rectal NETs., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Bromodomain and extraterminal domain (BET) proteins, including BRD4, bind acetylated chromatin and coactivate gene transcription. A BET inhibitor, JQ1, prevents and reverses pathological cardiac remodeling in preclinical models of heart failure. However, the underlying cellular mechanisms by which JQ1 improves cardiac structure and function remain poorly defined. Here, we demonstrate that BRD4 knockdown reduced expression of genes encoding CC chemokines in cardiac fibroblasts, suggesting a role for this epigenetic reader in controlling fibroblast-immune cell cross talk. Consistent with this, JQ1 dramatically suppressed recruitment of monocytes to the heart in response to stress. Normal mouse hearts were found to have approximately equivalent numbers of major histocompatibility complex (MHC-II) high and MHC-II low resident macrophages, whereas MHC-II low macrophages predominated following JQ1 treatment. Single-cell RNA-seq data confirmed that JQ1 treatment or BRD4 knockout in CX3CR1 + cells reduced MHC-II gene expression in cardiac macrophages, and studies with cultured macrophages further illustrated a cell autonomous role for BET proteins in controlling the MHC-II axis. Bulk RNA-seq analysis demonstrated that JQ1 blocked pro-inflammatory macrophage gene expression through a mechanism that likely involves repression of NF-κB signaling. JQ1 treatment reduced cardiac infarct size in mice subjected to ischemia/reperfusion. Our findings illustrate that BET inhibition affords a powerful pharmacological approach to manipulate monocyte-derived and resident macrophages in the heart. Such an approach has the potential to enhance the reparative phenotype of macrophages to promote wound healing and limit infarct expansion following myocardial ischemia. NEW & NOTEWORTHY BRD4 inhibition blocks stress-induced recruitment of pro-inflammatory monocytes to the heart. BRD4 inhibition reprograms resident cardiac macrophages toward a reparative phenotype marked by reduced NF-κB signaling and diminished MHC-II expression. BRD4 inhibition reduces infarct size in an acute model of ischemia/reperfusion injury in mice.

Unfolded protein response (UPR) is activated in cells under endoplasmic reticulum (ER) stress. One sensor protein involved in this response is PERK, which is activated through its redox-dependent oligomerization. Prolonged UPR activation is associated with the development and progression of various diseases, making it essential to understanding the redox regulation of PERK. Sulfane sulfur, such as polysulfides and persulfides, can modify the cysteine residues and regulate the function of various proteins. However, the regulatory mechanism and physiological effects of sulfane sulfur on the PERK-eIF2α-ATF4 pathway remain poorly understood. This study focuses on the persulfidation of PERK to elucidate the effects of polysulfides on the PERK-eIF2α-ATF4 pathway and investigate its cytoprotective mechanism. Here, we demonstrated that polysulfide treatment promoted the oligomerization of PERK and PTP1B in neuronal cells using western blotting under nonreducing conditions. We also observed that l-cysteine, a biological source of sulfane sulfur, promoted the oligomerization of PERK and the knockdown of CBS and 3-MST, two sulfane sulfur-producing enzymes, and reduced PERK oligomerization induced by l-cysteine treatment. Furthermore, the band shift assay and LC-MS/MS studies revealed that polysulfides and persulfides induce PTP1B and PERK persulfidation. Additionally, polysulfides promoted eIF2α phosphorylation and ATF4 accumulation in the nucleus, suggesting that polysulfides activate the PERK-eIF2α-ATF4 pathway in neuronal cells. Moreover, polysulfides protected neuronal cells from methylglyoxal-induced toxicity, and this protective effect was reduced when the expression of Sestrin2, regulated by ATF4 activity, was suppressed. This study identified a novel mechanism for the activation of the PERK-eIF2α-ATF4 pathway through persulfidation by polysulfides and persulfides. Interestingly, activation of this pathway overcame the toxicity of methylglyoxal in dependence on Sestrin2 expression. These findings deepen our understanding of neuronal diseases involving ER stress and UPR disturbance and may inspire new therapeutic strategies., Competing Interests: Declaration of competing interest The authors claim no conflict of interest., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

To ensure that the embryo can package exponentially increasing amounts of DNA, replication-dependent histones are some of the earliest transcribed genes from the zygotic genome. However, how the histone genes are identified is not known. The Drosophila melanogaster pioneer factor CLAMP regulates the embryonic histone genes and helps establish the histone locus body, a suite of factors that controls histone mRNA biosynthesis, but CLAMP is not unique to the histone genes. Zelda collaborates with CLAMP across the genome to regulate zygotic genome activation and target early activated genes. We hypothesized that Zelda helps identify histone genes for early embryonic expression. We found that Zelda targets the histone gene locus early during embryogenesis, prior to histone gene expression. However, depletion of zelda in the early embryo does not affect histone mRNA levels or prevent the recruitment of other factors. These results suggest the earliest events responsible for specifying the zygotic histone genes remain undiscovered., Competing Interests: Conflicts of interest: The authors declare no financial conflicts of interest.

Mitophagy serves as a mitochondrial quality control mechanism to maintain the homeostasis of mitochondria and the intracellular environment. Studies have shown that there is a close relationship between mitophagy and apoptosis. Sestrin2 (Sesn2) is a highly conserved class of stress-inducible proteins that play important roles in reducing oxidative stress damage, inflammation, and apoptosis. However, the potential mechanism of how Sesn2 regulates mitophagy and apoptosis in severe acute pancreatitis (SAP) remains unclear. In the study, RAW264.7 (macrophage cell Line) cellular inflammation model established by lipopolysaccharide (LPS) treatment as well as LPS and CAE-induced SAP mouse model (wild-type and Sen2 Knockout mouse) were used. Our study showed that LPS stimulation significantly increased the level of Sesn2 in RAW264.7 cells, Sesn2 increased mitochondrial membrane potential, decreased inflammation levels, mitochondrial superoxide levels and apoptosis, and also promoted monocyte macrophages toward the M2 anti-inflammatory phenotype, suggesting a protective effect of Sesn2 on mitochondria. Further, Sesn2 increased mitophagy and decreased apoptosis via modulating the PINK1-Parkin signaling. Meanwhile, knockout of Sesn2 exacerbated pancreatic, mitochondrial damage and inflammation in a mouse model of SAP. In addition, the protective effect of Sesn2 against SAP was shown to be associated with mitophagy conducted by the PINK1-Parkin pathway via inhibiting apoptosis. These findings reveal that Sesn2 in balancing mitochondrial autophagy and apoptosis by modulating the PINK1-Parkin signaling may present a new therapeutic strategy for the treatment of SAP., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The role of TGF-β signaling in the epigenetic modifications involved in ovarian cancer is not fully understood. This study investigated the relationship between TGF-β signaling, epigenetic modifications, and cellular behaviors in ovarian cancer. We found that E-cadherin, a key cell adhesion molecule, underwent epigenetic silencing via promoter DNA hypermethylation in ovarian cancer cell lines and that this was accompanied by the upregulation of vimentin, which is indicative of a mesenchymal and invasive phenotype. DNA-demethylating agents restored E-cadherin expression, which suggests that TGF-β signaling mediates this epigenetic silencing. Overexpression of SMAD7, an inhibitory component of TGF-β signaling, reversed E-cadherin silencing, which suggests a role of SMAD7 in modulating the epigenetic status. Functionally, SMAD7 overexpression inhibited the migration and invasion in ovarian cancer cells, which suggests its therapeutic potential for suppressing metastasis. Clinically, ovarian cancer patients with high SMAD7 expression had significantly longer disease-free survival. Mechanistically, SMAD7 overexpression decreased the acetylation of H3K9 and the binding of the transcriptional repressor TWIST1 at the E-cadherin promoter, which promoted its demethylation and reactivation. Disruption of TGF-β signaling upregulated SMAD4 target genes, which are silenced by epigenetic mechanisms, a finding that suggests broader therapeutic implications. Overall, our results provide insights into the role of TGF-β-mediated epigenetic regulation in ovarian cancer metastasis and underscore the therapeutic potential of targeting TGF-β signaling and its downstream effectors. Further research is needed to elucidate the underlying mechanisms and validate these therapeutic strategies., (© 2024 Wiley Periodicals LLC.)

Ribosome biogenesis (RB) is an intricate and evolutionarily conserved process that takes place mainly in the nucleolus and is required for eukaryotic cells to maintain homeostasis, grow in size, and divide. Our laboratory has identified the NUF2 protein, part of the mitotic kinetochore, in a genome-wide siRNA screen for proteins required for making ribosomes in MCF10A human breast epithelial cells. After rigorous validation and using several biochemical and cell-based assays, we find a role for NUF2 in pre-rRNA transcription, the primary and rate-limiting step of RB. siRNA depletion of other components of the NUF2 kinetochore sub-complex, NDC80, SPC24, and SPC25, also reduce pre-rRNA transcription. Interestingly, essential protein components for pre-rRNA transcription, including the largest subunit of RNA polymerase I, POLR1A, are reduced upon siRNA depletion of NUF2 and its protein partners. Their reduced levels are a likely mechanism for the decrease in pre-rRNA transcription. siRNA depletion of NUF2 and NDC80 also cause increased TP53 and CDKN1A (p21) mRNA levels, which can be restored by codepletion of RPL5, indicating activation of the nucleolar stress pathway (NSP). These results reveal a new connection between proteins with a known role in mitosis to the function of the nucleolus in RB during interphase., Competing Interests: Conflicts of interest: The authors declare no financial conflict of interest.

Advanced prostate cancer (PCa) remains a significant clinical challenge, and docetaxel plays a significant role in disease management. Despite the efficacy of docetaxel as a first-line chemotherapy, resistance often develops. We developed three clinically relevant in vitro PCa cell models and transcriptomic analysis identified that the Paf1/RNA polymerase II complex component (PAF1)-associated pluripotent-transcription factor (TF), SOX2, plays a crucial role in docetaxel resistance. The cancer stem cell (CSC) transcriptional master regulator PAF1 is significantly higher in PCa cell lines, tumor tissues, and docetaxel resistant (DR) PCa cells than in age-matched control cells. To determine the molecular underlying and functional characteristics of PAF1 in resistance mechanisms, we performed coimmunoprecipitation, embryonic stem cell network proteins, in vitro tumor-initiating ability, and 3D multicellular organoid growth using PAF1 knockdown cells. Tet-inducible PAF1 depletion reduced the drug-efflux phenotype, tumor-initiating frequencies, and three-dimensional organoid growth of the docetaxel-resistant PCa cell lines. Functional studies also showed restoration of docetaxel sensitivity in a 3D tumorsphere model upon PAF1 depletion. PAF1 depletion was also associated with decreased pluripotent TFs and other CSC markers. This study provides a novel regulatory mechanism of docetaxel resistance in PCa through PAF1., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: SKB is a founding member of Sanguine Diagnostics and Therapeutics, Inc. Other authors have nothing to disclose., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Benign prostatic hyperplasia (BPH), characterized as a chronic disease with unregulated enlargement of prostatic gland, is commonly observed in elderly men leading to lower urinary tract dysfunction. Sestrin2 plays a role in the maintenance of cellular homeostasis and protects organisms from various stimuli. The exact role of Sestrin2 in the etiology of BPH, a common age-related disease, remains unknown. Here, we explored the regulatory function of Sestrin2 in modulating autophagy and its therapeutic role in spontaneous BPH. In vivo study, the 3-month-old (3 M) and 24-month-old (24 M) mice were used, and the 24 M mice were additionally administered recombinant Sestrin2 protein (rp-Sestrin2) for consecutive 14 days. In vitro, BPH-1 cells were transfected with an empty or Sestrin2 overexpression vector. Sestrin2 expression in mice prostate was gradually declined with age. Administration of rp-Sestrin2 to these mice suppressed prostatic hyperplasia, restored the balance between proliferation and apoptosis, and reduced prostatic fibrosis. Moreover, rp-Sestrin2 treatment enhanced autophagy by activating AMP-activated protein kinase (AMPK)/ mammalian target of rapamycin (mTOR) signaling pathway, as evidenced by increased autophagosome and autolysosome formation, along with a decrease in degradation marker such as p62. Our findings were further supported by in vitro studies, where Sestrin2 overexpression induced autophagy via AMPK/mTOR signaling pathway. These results suggest that Sestrin2 plays a critical role in attenuating spontaneous BPH by regulating autophagy through AMPK/mTOR signaling pathway. This study provides novel insights into the therapeutic potential of Sestrin2 in age-related spontaneous BPH., Competing Interests: Declarations. Competing interests: The authors declare no competing interests. Ethical approval: All animal experimental protocols were approved by the Institutional Animal Ethics Committee of the Chungnam National University (202307A-CNU-136). This study was conducted in accordance with the Guide for the Care and Use of Laboratory Animals of National Institutes of Health., (© 2025. The Author(s), under exclusive licence to Springer Nature B.V.)

Background: The high mortality rate of metastatic colorectal cancer (CRC) is primarily attributed to resistance to chemotherapy, where cancer stem cells (CSCs) play a crucial role. Deubiquitinating enzymes are essential regulators of CSC maintenance, making them potential targets for eliminating CSCs and overcoming chemotherapy resistance. This study aims to identify key deubiquitinating enzymes regulating CSCs and drug resistance of CRC., Methods: RNA sequencing was performed to examine the mRNA expression of known deubiquitinating enzymes in CRC tissues from patients with alternate response to chemotherapy. Gain- and loss-of-function experiments were performed to evaluate the function of USP4 in regulation of stemness and drug sensitivity in CRC. High-throughput virtual screening and target management assays were conducted to identify small molecule inhibitor targeting USP4. Cell lines, organoids and animal models were used to evaluate the function of USP4 and its small molecule inhibitor in stemness and chemotherapy response., Results: The expression of USP4 was significantly elevated in CRC samples from progressive disease (PD) or stable disease (SD) patients compared to partial response (PR) specimen. USP4 promoted stemness by stabilizing the β-catenin and Twist1 proteins in CRC cells. A natural small molecule product U4-I05 diminished the stem-like features of CSCs and enhanced their sensitivity to oxaliplatin and 5-fluorouracil by targeting inhibition of its deubiquitinating enzyme activity through binding the catalytic domain of USP4 (311 cysteine site) at nanomolar concentrations, triggering proteasome-mediated degradation of β-catenin and Twist1. Treatment with U4-I05 also inhibited tumor metastasis and extended survival in a genetically engineered CRC mouse model., Conclusions: This study identifies U4-I05 as a USP4 inhibitor with significant therapeutic efficacy against CRC, offering a promising avenue for the development of new treatments targeting cancer stemness and chemotherapy resistance., Competing Interests: Declarations. Ethics statement: All experiments involving human samples were conducted in compliance with the Code of Ethics of the World Medical Association (Declaration of Helsinki) and received approval from the institutional review board of Sun Yat-sen University (SL-B2024-610-02). Information consent was obtained from all human subjects participating in the experiments. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Maintaining genome integrity is an essential and challenging process. RAD51 recombinase, the central component of several crucial processes in repairing DNA and protecting genome integrity, forms filaments on DNA, which are tightly regulated. One of these RAD51 regulators is FIGNL1 (fidgetin-like 1), which prevents RAD51 genotoxic chromatin association in normal cells and persistent RAD51 foci upon DNA damage. The cryogenic electron microscopy-imaged structure of FIGNL1 in complex with RAD51 reveals that FIGNL1 forms a nonplanar hexamer and encloses RAD51 N terminus in the FIGNL1 hexamer pore. Mutations in pore loop or catalytic residues of FIGNL1 render it defective in filament disassembly and are lethal in mouse embryonic stem cells. Our study reveals a distinct mechanism for removing RAD51 from bound substrates and provides the molecular basis for FIGNL1 in maintaining genome stability.

Background: This study aimed to analyze the functional role of Brd4 in colorectal cancer (CRC) organoids. Brd4 was identified as a CRC-related gene by our previous Sleeping Beauty mutagenesis transposon screening in mice. Brd4 is a transcriptional regulator that recognizes acetylated histones and is known to be involved in inflammatory responses. The role of Brd4 in CRC development remains largely unknown., Methods: We knocked out Brd4 in tumor organoids carrying mutations in Apc and Kras to generate Brd4KO organoids, and performed RNA-seq. The response of Brd4KO organoids to IFNγ was analyzed via a cell viability assay, an apoptosis assay, and RNAseq. The results were validated by pharmacological inhibition experiments with JQ1 in human CRC organoids., Results: In Brd4KO organoids, the IFNγ signaling genes Il33 and Myc target genes were downregulated. The addition of IFNγ to the colon organoids induced apoptosis, but IFNγ-induced apoptosis was attenuated in the Brd4KO organoids compared with the control organoids (two-sided t-test, P < 0.05). Similar results were obtained from pharmacological inhibition with JQ1 in human CRC organoids; IL33 expression was decreased, and IFNγ-induced apoptosis was attenuated in the presence of JQ1., Conclusions: Our results showed that the inhibition of Brd4 suppressed IFNγ-induced cytotoxicity by modulating the Jak-Stat pathway. These data suggested that the inhibition of Brd4 could increase cell viability in the cancer microenvironment where IFNγ is abundant, revealing a new aspect of the molecular mechanism of CRC development. Our results may help in evaluating the application of Bet inhibitors in treating CRC. Additionally, our RNA-seq data sets will be helpful for clarifying the relationship between Brd4 and immunomodulators, such as Il33, or for studying the responses of colonic epithelial cells to IFNγ., Competing Interests: Declarations. Ethics approval and consent to participate: All experiments were performed in accordance with our institutional guidelines and regulations. All protocols for animal experiments were reviewed and approved by the institutional animal care and use committee of National Cancer Center (Study number: T19-006-M07). The study protocol for experiments on human-derived samples was approved by the Ethics Committees of the National Cancer Center (Study number: 2020 − 393, 2008-097). Written informed consent was obtained in advance for participants, and no compensation was paid. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Simultaneous inhibition of the bromodomain and extra-terminal domain and Aurora kinases is a promising anticancer therapeutic strategy. Based on our previous study on BET-kinase dual inhibitors, we employed the molecular docking approach to design novel dual BET-Aurora kinase A inhibitors. Through several rounds of optimization and with the guidance of the solved cocrystal structure of BRD4 bound to inhibitor 27 , we finally obtained a series of highly potent dual BET-Aurora kinase A inhibitors. Compound 38 exhibited strong affinity toward both BRD4 and Aurora kinase A. It also showed good antiproliferative activities on diverse cancer cell lines, good pharmacokinetic profiles, and favorable antitumor efficacy in renal cell cancer and colon cancer xenograft models with TGI of 45.99% and 53.06%, respectively. The development of compound 38 reinforces the concept that a rational design may achieve dual inhibitors targeting specific kinases and bromodomain proteins.

BRM (SMARCA2) and BRG1 (SMARCA4) are mutually exclusive ATPase subunits of the mSWI/SNF (BAF) chromatin remodeling complex. BAF is an attractive therapeutic target because of its role in transcription, and mutations in the subunits of BAF are common in cancer and neurological disorders. Herein, we report the discovery of compound 1 ( FHD-286 ) as a potent allosteric inhibitor of the dual ATPase subunits from a high-throughput screening hit with a BRM IC 50 of ∼27 μM. FHD-286 is an orally bioavailable compound with antitumor activity in mouse xenograft models of uveal melanoma and acute myeloid leukemia and is being evaluated in Phase 1 clinical trials.

We describe the identification of selective SMARCA2, VHL-based heterobifunctional degraders. Structurally novel indolo[1,2- a ]quinazolin-5(7 H )-one SMARCA bromodomain binders were optimized and then converted to SMARCA2 degraders by linking them to well-defined VHL ligands. Our exploration led to the discovery of potent and selective degraders of SMARCA2 over the SMARCA4 paralog, leading to potent and selective growth inhibition of SMARCA4 mutant versus wild type cell lines. We further highlight the optimization of the pharmacokinetic profile of a subset of compounds leading to potent and selective degradation of SMARCA2 in the xenograft model. These compounds provide valuable tools with desirable properties for continued exploration of the biology defining the susceptibility of SMARCA4 mutant cancers to selective loss of SMARCA2.

In the SWI/SNF chromatin-remodeling complex, the mutually exclusive catalytic ATPase subunits SMARCA2 and SMARCA4 proteins have a synthetic-lethal relationship. Selectively targeting SMARCA2 for degradation is a promising and new therapeutic strategy for human cancers harboring inactivated mutated SMARCA4. In this study, we report the design, synthesis, and biological evaluation of novel SMARCA2/4 ligands and our subsequent design of PROTAC degraders using high-affinity SMARCA ligands and VHL-1 ligands. Our efforts led to the discovery of high-affinity SMARCA2/4 bromodomain ligands and the development of a potent and selective SMARCA2 degrader and a highly potent SMARCA2/4 and PBRM1 degrader.

SMARCA2 is an attractive synthetic lethal target in human cancers with mutated, inactivated SMARCA4. We report herein the discovery of highly potent and selective SMARCA2 PROTAC degraders, as exemplified by SMD-3236, which was designed using a new, high-affinity SMARCA ligand and a potent VHL-1 ligand. SMD-3236 achieves DC 50 < 1 nM and D max > 95% against SMARCA2 and >2000-fold degradation selectivity over SMARCA4. SMD-3236 potently inhibits cell growth in a panel of SMARCA4-deficient cell lines and displays minimal activity in SMARCA4 wild-type cell lines. SMD-3236 induces profound and persistent SMARCA2 depletion in tumor tissues for 1 week with a single administration, while sparing SMARCA4 protein. SMD-3236 effectively inhibits tumor growth with weekly administration in the H838 SMARCA4-deficient human cancer xenograft model at well-tolerated dose schedules. SMD-3236 represents a promising SMARCA2 degrader for extensive evaluation as a new therapy for the treatment of SMARCA4-deficient human cancers.

Background: Sepsis is a systemic inflammatory syndrome that can cause coagulation abnormalities, leading to damage in multiple organs. Vascular endothelial cells (VECs) are crucial in the development of sepsis-induced coagulopathy (SIC). The role of Parthenolide (PTL) in regulating SIC by protecting VECs remains unclear., Methods: The study utilized septic rats and lipopolysaccharide (LPS)-stimulated VECs to simulate a SIC model and observe the therapeutic effects of PTL. Additionally, nanotechnology was employed to produce Nano-PTL (N-PTL), to observe whether it has advantages over PTL in treating SIC., Results: PTL has been shown to mitigate lung injury in septic rats, significantly reduce tumor necrosis factor-α (TNF-α) levels, and increase survival rates. PTL treatment also enhances coagulation function, augments vascular endothelial cell (VEC) function, reduces mitochondrial fragmentation, and increases both mitochondrial oxygen consumption rate (OCR) and mitochondrial membrane potential (MMP), while inhibiting reactive oxygen species (ROS) production. By increasing BRD4/BCL-xL levels, PTL can prevent mitochondrial-mediated apoptosis in VECs, improve VEC function, and consequently ameliorate SIC. Additionally, nanotechnology-synthesized N-PTL further enhances the protective effects on VECs and coagulation function., Conclusions: This study clarifies the therapeutic effects and mechanisms of PTL on SIC, offering new strategies and directions for the treatment of sepsis., Competing Interests: Declarations. Ethics approval and consent to partcicipate: Experiments involving animals were conducted in strict adherence to the guidelines provided by the Animal Research: Reporting of In Vivo Experiments (ARRIVE). The procedures were reviewed and approved by the Laboratory Animal Welfare and Ethics Committee of the Army Medical University (Approval No. AMUWEC20237118). Consent for publication: Not applicable. Competing interests: All authors declare no competing interests., (© 2025. The Author(s).)

Induction of senescence by chemotherapeutic agents arrests cancer cells and activates immune surveillance responses to contribute to therapy outcomes. In this investigation, we searched for ways to enhance the NK-mediated elimination of senescent cells. We used a staggered screen approach, first identifying siRNAs potentiating the secretion of immunomodulatory cytokines to later test for their ability to enhance NK-mediated killing of senescent cells. We identified that genetic or pharmacological inhibition of SMARCA4 enhanced senescent cell elimination by NK cells. SMARCA4 expression is elevated during senescence and its inhibition derepresses repetitive elements, inducing the SASP via activation of cGAS/STING and MAVS/MDA5 pathways. Moreover, a PROTAC targeting SMARCA4 synergized with cisplatin to increase the infiltration of CD8 T cells and mature, activated NK cells in an immunocompetent model of ovarian cancer. Our results indicate that SMARCA4 inhibitors enhance NK-mediated surveillance of senescent cells and may represent senotherapeutic interventions for ovarian cancer.

Mutations or homozygous deletions of MHC class II (MHC-II) genes are commonly found in B cell lymphomas that develop in immune-privileged sites and have been associated with patient survival. However, the mechanisms regulating MHC-II expression, particularly through genetic and epigenetic factors, are not yet fully understood. In this study, we identified a key signaling pathway involving the histone H2AK119 deubiquitinase BRCA1 associated protein 1 (BAP1), the interferon regulatory factor interferon regulatory factor 1 (IRF1), and the MHC-II transactivator class II transactivator (CIITA), which directly activates MHC-II gene expression. Disruption of the BAP1/IRF1/CIITA axis leads to a functional attenuation of MHC-II expression and MHC-II-dependent immune cell infiltration, leading to accelerated tumor growth in immunocompetent mice. Additionally, we demonstrated that pharmacological inhibition of polycomb repressive complex 1 (PRC1) - which deposits histone H2K119Ub and opposes BAP1 activity - can restore MHC-II gene expression in BAP1-deficient B cell lymphoma cells. These findings suggest that BAP1 may function as a tumor suppressor by regulating the tumor microenvironment and immune response. Our study also establishes the rationale for therapeutic strategies to restore tumor-specific MHC-II expression and enhance immunotherapy outcomes at epigenetic levels in B cell lymphoma treatment.

The Human Silencing Hub (HUSH) guards the genome from the pathogenic effects of retroelement expression. Composed of MPP8, TASOR, and Periphilin-1, HUSH recognizes actively transcribed retrotransposed sequences by the presence of long (>1.5-kb) nascent transcripts without introns. HUSH recruits effectors that alter chromatin structure, degrade transcripts, and deposit transcriptionally repressive epigenetic marks. Here, we report the crystal structure of the C-terminal domain (CTD) of MPP8 necessary for HUSH activity. The MPP8 CTD consists of five ankyrin repeats followed by a domain with structural homology to the PINIT domains of Siz/PIAS-family SUMO E3 ligases. AlphaFold3 modeling of the MPP8-TASOR complex predicts that a SPOC domain and a domain with a novel fold in TASOR form extended interaction interfaces with the MPP8 CTD. Point mutations at these interfaces resulted in loss of HUSH-dependent transcriptional repression in a cell-based reporter assay, validating the AlphaFold3 model. The MPP8 chromodomain, known to bind the repressive mark H3K9me3, bound with similar or higher affinity to sequences in the H3K9 methyltransferase subunits SETDB1, ATF7IP, G9a, and GLP. Hence, MPP8 promotes heterochromatinization by recruiting H3K9 methyltransferases. Our work identifies novel structural elements in MPP8 required for HUSH complex assembly and silencing, thereby fulfilling vital functions in controlling retrotransposons., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: “Y.M. is a consultant for Related Sciences LLC. None of the other authors have any conflicts of interest”., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Of the seven in absentia homologue (SIAH) family, three members have been identified in the human genome. In contrast to the E3 ubiquitin ligase encoding SIAH1 and SIAH2, little is known on the regulation and function of SIAH3 in tumorigenesis. In this study, we reveal that SIAH3 is frequently epigenetically silenced in different cancer entities, including cutaneous melanoma, lung adenocarcinoma and head and neck cancer. Low SIAH3 levels correlate with an impaired survival of cancer patients. Additionally, induced expression of SIAH3 reduces cell proliferation and induces cell death. Functionally, SIAH3 negatively affects cellular metabolism by shifting cells form aerobic oxidative phosphorylation to glycolysis. SIAH3 is localized in the mitochondrion and interacts with proteins involved in mitochondrial ribosome biogenesis and translation. We also report that SIAH3 interacts with ubiquitin ligases, including SIAH1 or SIAH2, and is degraded by them. These results suggest that SIAH3 acts as an epigenetically controlled tumor suppressor by regulating cellular metabolism through the inhibition of oxidative phosphorylation., (© 2024 The Author(s). International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)

Pellino1 (PELI1) is a key regulator of inflammatory and autoimmune diseases. The role of PELI1 in juvenile idiopathic arthritis (JIA) is unclear. The correlation between serum PELI1 mRNA levels and clinical indicators of JIA patients was evaluated by Pearson correlation analysis. The percentage of Th1, Th2, Th17 and Treg cells was analyzed by flow cytometry. ELISA kits were used to detect cytokine levels in serum and cell supernatants. Co-immunoprecipitation experiments were performed to validate PELI1 and TCF-1 interactions. The protein and ubiquitination levels of TCF-1 were detected by western blot. The results showed that JIA patients have high serum PELI1 levels. PELI1 levels were positively correlated with erythrocyte sedimentation rate, C-reactive protein levels and JADAS27 scores in JIA patients. Interfering with PELI1 promoted naïve CD4 + T cell differentiation to Th2 and Treg cells and increased IL-4 and IL-10 levels, while inhibiting their differentiation to Th1 and Th17 cells and decreasing IFN-γ and IL-17 levels. PELI1 increased TCF-1 ubiquitination levels and accelerated its degradation. Inhibition of TCF-1 reduced the effects of interfering with PELI1 on cell differentiation and cytokine levels. In conclusion, Silencing of PELI1 facilitated the naïve CD4 + T cell differentiation into Th2 and Treg cells by TCF-1., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Bromodomain-containing protein 4 (BRD4) plays a vital role in fibrosis of various organs. However, the underlying mechanism of BRD4 in renal fibrosis remains unclear. To construct in vitro and in vivo models of renal fibrosis, TCMK-1 cells were subjected to TGF-β1 treatment and mice were subjected to UUO surgery and adenine induction. IP assay was used for arginine asymmetric dimethylation (ADMA) level, ubiquitination degradation of Snail, and acetylation level of Snail test. Co-IP was used to validate the interactions of BRD4, protein arginine methyltransferase-1 (PRMT1), and Snail. HE staining and Masson staining were used for morphological examination of renal tissue. BRD4 was abnormally overexpressed during renal fibrosis. TGF-β1-induced fibrosis and partial epithelial-mesenchymal transition (pEMT) could be inhibited by BRD4 silencing. PRMT1 mediated ADMA level of BRD4 to enhance BRD4 phosphorylation and its protein stability. Snail protein degradation was attenuated by BRD4 overexpression in an acetylation-dependent manner in TCMK-1 cells. Furthermore, PRMT1 inhibitor abolished BRD4 overexpression-induced fibrosis and pEMT in TGF-β1-treated TCMK-1 cells and Snail overexpression reversed BRD4 silencing-induced inhibition of fibrosis and pEMT. What's more, the reduction of BRD4 arginine methylation inhibited BRD4 phosphorylation and Snail expression to alleviate renal fibrosis in UUO surgery and adenine induction mice. Collectively, PRMT1-mediated BRD4 arginine methylation and phosphorylation promoted pEMT and renal fibrosis through regulation of Snail expression., (© 2025 Federation of American Societies for Experimental Biology.)

SMAD3 plays a crucial role in TGF-β, regulating various normal developmental mechanisms and disease pathogenesis. Here, we report that SMAD3 directly interacts with Nucleostemin (NS), leading to nuclear translocation and affecting SMAD3 activity after TGF-β1 stimulation. Moreover, NS acts as a competitor, preventing PPM1A from recognizing and dephosphorylating SMAD3. Experimental investigations have demonstrated that NS significantly enhances cellular migration and invasion by promoting the EMT mechanism in vitro. NS knockdown notably suppresses tumor metastasis in the lungs and liver in vivo. Importantly, NS expression is significantly elevated in numerous human malignancies, correlating with a poorer prognosis. The collective evidence from these studies suggests that NS exhibits oncogenic characteristics, supporting further exploration of NS as a potential target for tumor treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The human silencing hub (HUSH) complex is a transcription-dependent, epigenetic repressor complex that provides a genome-wide immunosurveillance system for the recognition and silencing of newly-integrated retroelements. The core HUSH complex of TASOR, MPP8 and Periphilin, represses these retroelements through SETDB1-mediated H3K9me3 deposition and MORC2-dependent chromatin compaction. HUSH-dependent silencing is RNA-mediated, yet no HUSH component contains a recognised RNA-binding domain. Here we used an unbiased approach to identify which HUSH component was able to bind RNA and determine whether RNA-binding was essential for HUSH function. We identify Periphilin as the major RNA-binding component of the HUSH complex and show that Periphilin's N-terminal domain is essential for both RNA binding and HUSH function. Periphilin binding to RNA was independent of its interaction with TASOR or MPP8, as its N-terminal domain was sufficient for RNA targeting. The artificial tethering of Periphilin to a HUSH-insensitive, nascent transcript, enabled the HUSH-dependent silencing of the transcript. This tethering of Periphilin allowed the RNA-binding region of Periphilin to be removed such that only its C-terminal domain was required for oligomerisation and interaction with TASOR. We therefore show that Periphilin is the predominant RNA-binding protein of the HUSH complex and this RNA-binding is essential for HUSH activity., (© The Author(s) 2024. Published by Oxford University Press on behalf of Nucleic Acids Research.)

Balanced self-renewal and differentiation of stem cells are crucial for maintaining tissue homeostasis, but the underlying mechanisms of this process remain poorly understood. Here, from an RNA interference (RNAi) screen in adult Drosophila intestinal stem cells (ISCs), we identify a factor, Pax, which is orthologous to mammalian PXN, coordinates the proliferation and differentiation of ISCs during both normal homeostasis and injury-induced midgut regeneration in Drosophila. Loss of Pax promotes ISC proliferation while suppressing its differentiation into absorptive enterocytes (ECs). Mechanistically, our findings demonstrate that Pax is a conserved target gene of the Hippo signaling pathway in both Drosophila and mammals. Subsequent investigations have revealed Pax interacts with Yki and enhances its cytoplasmic localization, thereby establishing a feedback regulatory mechanism that attenuates Yki activity and ultimately inhibits ISCs proliferation. Additionally, Pax induces the differentiation of ISCs into ECs by activating Notch expression, thus facilitating the differentiation process. Overall, our study highlights Pax as a pivotal component of the Hippo and Notch pathways in regulating midgut homeostasis, shedding light on this growth-related pathway in tissue maintenance and intestinal function., Competing Interests: Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Esophageal cancer (EC) is associated with high mortality rates and widespread resistance to chemotherapeutic agents, like paclitaxel (PTX), posing a significant global public health challenge. ANP32E is a member of the acidic nuclear phosphoprotein 32 family, its specific biological functions and mechanisms in EC remain unclear. Through bioinformatics analysis and clinical tissue sample studies, we observed a marked upregulation of ANP32E expression in EC tissues. Utilizing ANP32E knock-out EC cell models and xenograft experiments in nude mice, we demonstrated that the absence of ANP32E significantly inhibits tumor progression and migration, whereas its overexpression exacerbates tumor growth. Transcriptomic sequencing (RNA-seq) further revealed activation of the ferroptosis pathway in ANP32E deficient cells, which was confirmed through experiments showing enhanced ferroptosis that could be reversed by the ferroptosis inhibitor ferrostatin-1. At the molecular level, ANP32E regulates EC progression and ferroptosis via the p53/SLC7A11 axis. ANP32E depletion resulted in increased p53 expression level, while inhibition of p53 partially restored the suppressed cell proliferation and increased ferroptosis in ANP32E-depleted cells. Additionally, knocking out ANP32E significantly enhanced EC cell sensitivity to PTX, Combining PTX with the ferroptosis inducer erastin was more effective in inhibiting tumor growth. In vivo, we confirmed the synergistic effect of ANP32E knock-out combined with PTX demonstrating superior tumor suppressing. Overall, our findings suggest that ANP32E regulates EC progression and ferroptosis through the p53/SLC7A11 axis, offering a potential molecular target for overcoming PTX resistance in EC treatment., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Aerobic glycolysis is a hallmark of many viral infections, leading to substantial accumulation of lactate. However, the regulatory roles of lactate during viral infections remain poorly understood. Here, we report that human cytomegalovirus (HCMV) infection leverages lactate to induce widespread protein lactylation and promote viral spread. We establish that lactyllysine is enriched in intrinsically disordered regions, regulating viral protein condensates and immune signaling transduction. Dynamic lactylation of immune factors suppresses immunity, a feature we show to be shared for HCMV and herpes simplex virus 1 infections, through regulation of RNA binding protein 14 and interferon-γ-inducible protein 16 (IFI16). K90 lactylation of the viral DNA sensor IFI16 inhibits recruitment of the DNA damage response kinase DNA-PK, preventing IFI16-driven virus gene repression and cytokine induction. Together, we characterize global protein lactylation dynamics during virus infection, finding that virus-induced lactate contributes to its immune evasion through direct inhibition of immune signaling pathways.

ATPase family AAA domain-containing protein 2 (ATAD2) is significantly up-regulated in many cancer types and contributes to poor patient outcomes. ATAD2 exhibits a multidomain architecture comprising an N-terminal acidic domain, two AAA+ ATPase domains, a bromodomain, and a C-terminal domain. The AAA+ ATPase domain facilitates protein oligomerization and ATP binding, while the bromodomain recognizes acetylated lysine in histones and nonhistone proteins. ATAD2 involvement in cancer extends across multiple signaling pathways, such as Rb-E2F1, PI3K/AKT, and TGF-β1/Smad3, which promotes cell proliferation and cancer progression. Herein, we report that ATAD2 directly interacts with TWIST1, and both N-terminal regions of proteins mediate the interaction. Immunofluorescence experiments suggested that ATAD2 and TWIST1 primarily colocalize in the nucleus. Notably, our qPCR results revealed the functional significance of ATAD2-TWIST1 interaction by demonstrating their synergistic effect on the transcriptional activation of MYC in colorectal carcinoma cell lines. Moreover, the ChIP-qPCR result further indicates that ATAD2 and TWIST1 significantly localize in the promoter of the MYC gene. In addition, analysis of The Cancer Genome Atlas (TCGA) and Clinical Proteomic Tumor Analysis Consortium (CPTAC) data suggests a correlation between ATAD2, TWIST1, and MYC overexpression and poor survival rates in colorectal carcinoma. Lastly, the overexpression of ATAD2 and TWIST1 enhances cell proliferation, emphasizing their role in colorectal carcinoma progression through MYC activation. Together, these results suggest that ATAD2 is a crucial factor in TWIST1-dependent MYC gene activation, resulting in an active ATAD2-TWIST1-MYC axis that contributes to colon cancer cell proliferation.

Background: Polymerase delta-interacting protein 2 (Poldip2) is a novel regulator of vascular permeability that has been shown to be involved in aggravating blood-brain barrier (BBB) disruption following stroke; however, the underlying mechanisms are unknown. While endothelial tight junctions (TJ) are critical mediators of BBB permeability, the effect of Poldip2 on TJ function has not been elucidated yet. Here, we aim to define the mechanism by which Poldip2 mediates BBB disruption, specifically focusing on phosphorylation and stabilization of the TJ integral protein ZO-1., Methods and Results: Cerebral ischemia was induced in endothelial-specific Poldip2 knockout mice and controls. Cerebral vascular permeability was assessed by Evans blue dye extravasation. Endothelial-specific Poldip2 deletion abolished Evans blue dye extravasation after ischemia induction. In vitro permeability assays demonstrated that Poldip2 knockdown suppressed TNF-α-induced endothelial cell (EC) permeability. Immunofluorescence staining showed that Poldip2 depletion prevented TNF-α-induced ZO-1 disruption at interendothelial junctions. Conversely, Poldip2 overexpression increased endothelial permeability, loss of ZO-1 localization at cell-cell junctions and enhanced reactive oxygen species (ROS) production. Treatment with the antioxidant N-acetyl cysteine (NAC) reduced Poldip2-induced ZO-1 disruption at inter interendothelial junctions. Immunoprecipitation studies demonstrated Poldip2 overexpression induced tyrosine phosphorylation of ZO-1, which was prevented by treatment with NAC or MitoTEMPO, a mitochondrial ROS scavenger., Conclusions: These data reveal a novel mitochondrial ROS-driven mechanism by which Poldip2 induces ZO-1 tyrosine phosphorylation and promotes EC permeability following cerebral ischemia., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Exiting a germinal zone (GZ) initiates a cascade of events that promote neuronal maturation and circuit assembly. Developing neurons and their progenitors must interpret various niche signals-such as morphogens, guidance molecules, extracellular matrix components, and adhesive cues-to navigate this region. How differentiating neurons in mouse brains integrate and adapt to multiple cell-extrinsic niche cues with their cell-intrinsic machinery in exiting a GZ is unknown. We establish cooperation between cell polarity-regulated adhesion and Netrin-1 signaling comprises a coincidence detection circuit repelling maturing neurons from their GZ. In this circuit, the Partitioning defective 3 (Pard3) polarity protein and Junctional adhesion molecule-C (JamC) adhesion molecule promote, while the Seven in absentia 2 (Siah2) ubiquitin ligase inhibits, Deleted in colorectal cancer (Dcc) receptor surface recruitment to gate differentiation linked repulsion to GZ Netrin-1. These results demonstrate cell polarity as a central integrator of adhesive- and guidance cues cooperating to spur GZ exit., Competing Interests: Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

The histone locus body (HLB) is a membraneless organelle that determines the transcription of replication-dependent histones. However, the mechanisms underlying the appropriate formation of the HLB in the nucleus but not in the cytoplasm remain unknown. HLB formation is dependent on the scaffold protein NPAT. We identify KPNA3 as a specific importin that drives the nuclear import of NPAT by binding to the nuclear localization signal (NLS) sequence. NPAT undergoes phase separation, which is inhibited by KPNA3-mediated impairment of self-association. In this, a C-terminal self-interaction facilitator (C-SIF) motif, proximal to the NLS, binds the middle 431-1,030 sequence to mediate the self-association of NPAT. Mechanistically, the anchoring of KPNA3 to the NPAT-NLS sterically blocks C-SIF motif-dependent NPAT self-association. This leads to the suppression of aberrant NPAT condensation in the cytoplasm. Collectively, our study reveals a previously unappreciated role of KPNA3 in modulating HLB formation and delineates a steric hindrance mechanism that prevents inappropriate cytoplasmic NPAT condensation., (© 2024 Xu et al.)

The nuclear envelope (NE) is a double-membrane structure critical for genome maintenance and cellular function, composed of the inner and outer nuclear membranes. In fission yeast, the inner nuclear membrane (INM) proteins Lem2 and Bqt4 are essential for maintaining NE integrity. The study published by Hiraoka group explores the interactions between Lem2 and Bqt4 with lipid synthesis enzymes, addressing their roles in NE maintenance. The authors identified Lem2- and Bqt4-binding proteins using immunoprecipitation and mass spectrometry, revealing that Lem2 interacts with lipid synthesis enzymes, whilst Bqt4 binds to an enzyme that involves in glucosylceramide synthesis. These findings suggest that Lem2 and Bqt4 independently contribute to NE structure and its integrity through distinct lipid metabolic pathways, highlighting their complementary roles in nuclear membrane homeostasis. This study represents a significant step forward in the field of NE biology to unravel the complexities of nuclear membrane dynamics., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.)

Radiation therapy is a common treatment modality for lung cancer, and resistance to radiation can significantly affect treatment outcomes. We recently described that lung cancer cells that express more germ cell cancer genes (GC genes, genes that are usually restricted to the germ line) can repair DNA double-strand breaks more rapidly, show higher rates of proliferation and are more resistant to ionizing radiation than cells that express fewer GC genes. The gene encoding TRIP13 appeared to play a large role in this malignant phenotype. However, the molecular regulatory mechanism of TRIP13 in radiation resistance remained largely unknown. Here, we show that TRIP13 is a key contributor to non-small cell lung cancer (NSCLC) treatment resistance, particularly in patients following radiation treatment, for whom levels of TRIP13 expression are correlated with a poor prognosis. Repeated irradiation of led to an increase of basal TRIP13 levels and radioresistance. This effect of radioresistance could be enhanced or abrogated by overexpressing or knocking out TRIP13. Elevated TRIP13 is also correlated with enhanced repair of radiation-induced DNA damage. We further showed the proteins NBS1 and RAD51 (homologous recombination. HR) and XRCC5 (non-homologous end-joining, NHEJ) to act downstream of TRIP13, although inhibition of TRIP13 mostly reduced the HR associated proteins in response to induced resistance to irradiation. This study elucidates a novel mechanism of treatment resistance in NSCLC cells, in which TRIP13 promotes HR mediated DNA repair and resistance to ionizing radiation., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Identifying novel targets for molecular radiosensitization is critical for improving the efficacy of colorectal cancer (CRC) radiotherapy. Alpha-thalassemia/mental retardation X-linked (ATRX), a member of the SWI/SNF-like chromatin remodeling protein family, functions in the maintenance of genomic integrity and the regulation of apoptosis and senescence. However, whether ATRX is directly involved in the radiosensitivity of CRC remains unclear. Our results showed that silencing ATRX increased the radiosensitivity of HCT116 CRC cells, which was further strengthened when p53 was depleted. To explore the potential mechanism, we focused on the impact of the ionizing radiation (IR)-induced DNA damage response (DDR), apoptosis, and senescence and the activation of the Daxx/MDM2/p53 pathway caused by ATRX loss. The results showed that IR induced DNA damage and G2/M arrest after depleting ATRX, especially in p53-depleted HCT116 cells, and inhibited ATM/Chk2 pathway activation, indicating that ATRX loss leads to failure of triggering the ATM/Chk2 pathway. Accordingly, ATRX loss promotes cell apoptosis and attenuates cell senescence. Interestingly, our results indicate that ATRX loss upregulates p53 function via the Daxx/MDM2 pathway to mediate radiosensitivity. Thus, ATRX may represent a novel radiosensitizing target for CRC, particularly p53-deficient CRC., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

The mechanisms underlying the establishment of asymmetric structures during development remain elusive. The wing of Drosophila is asymmetric along the Anterior-Posterior (AP) axis, but the developmental origins of this asymmetry is unknown. Here, we investigate the contribution of cell recruitment, a process that drives cell fate differentiation in the Drosophila wing disc, to the asymmetric shape and pattern of the adult wing. Genetic impairment of cell recruitment in the wing disc results in a significant gain of AP symmetry, which results from a reduction of the region between longitudinal vein 5 and the wing margin (L5-M) in the adult wing. Morphometric analysis confirms that blocking of cell recruitment results in a more symmetric wing with respect to controls, suggesting a contribution of cell recruitment to the establishment of asymmetry in the adult wing. In order to verify if this phenotype is originated during the time in which cell recruitment occurs during larval development, we examined the expression of a reporter for the selector gene vestigial (vg) in the corresponding pro-vein regions of the wing disc, but our findings could not explain our findings in adult wings. However, the circularity of the Vg pattern significantly increases in recruitment-impaired wing discs, suggesting that cell recruitment may contribute to AP asymmetries in the adult wing shape by altering the roundness of the Vg pattern. We conclude that cell recruitment, a widespread mechanism that participates in growth and patterning of several developing systems, may contribute, at least partially, to the asymmetric shape of the Drosophila wing., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2025 Reyes et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Chronic hepatitis B virus (HBV) infection can significantly increase the incidence of cirrhosis and liver cancer, and there is no curative treatment. The persistence of HBV covalently closed circular DNA (cccDNA) is the major obstacle of antiviral treatments. cccDNA is formed through repairing viral partially double-stranded relaxed circular DNA (rcDNA) by varies host factors. However, the detailed mechanisms are not well characterized. To dissect the biogenesis of cccDNA, we took advantage of an in vitro rcDNA repair system to precipitate host factors interacting with rcDNA and identified co-precipitated proteins by mass spectrometry. Results revealed the MRE11-RAD50-NBS1 (MRN) complex as a potential factor. Transiently or stably knockdown of MRE11, RAD50 or NBS1 in hepatocytes before HBV infection significantly decreased viral markers, including cccDNA, while reconstitution reversed the effect. Chromatin immunoprecipitation assay further validated the interaction of MRN complex and HBV DNA. However, MRN knockdown after HBV infection showed no effect on viral replication, which indicated that MRN complex inhibited the formation of cccDNA without affecting its stability or transcriptional activity. Interestingly, Mirin, a MRN complex inhibitor which can inhibit the exonuclease activity of MRE11 and MRN-dependent activation of ATM, but not ATM kinase inhibitor KU55933, could decrease cccDNA level. Likewise, the MRE11 endonuclease activity inhibitor PFM01 treatment decreased cccDNA. MRE11 nuclease assays indicated that rcDNA is a substrate of MRE11. Furthermore, the inhibition of ATR-CHK1 pathway, which is known to be involved in cccDNA formation, impaired the effect of MRN complex on cccDNA. Similarly, inhibition of MRE11 endonuclease activity mitigated the effect of ATR-CHK1 pathway on cccDNA. These findings indicate that MRN complex cooperates with ATR-CHK1 pathway to regulate the formation of HBV cccDNA. In summary, we identified host factors, specifically the MRN complex, regulating cccDNA formation during HBV infection. These findings provide insights into how HBV hijacks host enzymes to establish chronic infection and reveal new therapeutic opportunities., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2025 Zhao et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Replication fork collision with a DNA nick can generate a one-ended break, fostering genomic instability. The opposing fork's collision with the nick could form a second DNA end, enabling conservative repair by homologous recombination (HR). To study mechanisms of nickase-induced HR, we developed the Flp recombinase "step arrest" nickase in mammalian cells. A Flp-nick induces two-ended, BRCA2/RAD51-dependent short tract gene conversion (STGC), BRCA2/RAD51-independent long tract gene conversion, and discoordinated two-ended invasions. HR pathways induced by a replication-independent break and the Flp-nickase differ in their dependence on BRCA1, MRE11, and CtIP. To determine the origin of the second DNA end during Flp-nickase-induced STGC, we blocked the opposing fork using a Tus/Ter replication fork barrier (RFB). Flp-nickase-induced STGC remained robust and two ended. Thus, a single replication fork's collision with a Flp-nick triggers two-ended HR, possibly reflecting replicative bypass of lagging strand nicks. This response may limit genomic instability during replication of nicked DNA., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The DNA damage checkpoint is a highly conserved signaling pathway induced by genotoxin exposure or endogenous genome stress. It alters many cellular processes such as arresting the cell cycle progression and increasing DNA repair capacities. However, cells can downregulate the checkpoint after prolonged stress exposure to allow continued growth and alternative repair. Strategies that can dampen the DNA damage checkpoint are not well understood. Here, we report that budding yeast employs a pathway composed of the scaffold protein Rtt107, its binding partner Mms22, and an Mms22-associated ubiquitin ligase complex to downregulate the DNA damage checkpoint. Mechanistically, this pathway promotes the proteasomal degradation of a key checkpoint factor, Rad9. Furthermore, Rtt107 binding to Mms22 helps to enrich the ubiquitin ligase complex on chromatin for targeting the chromatin-bound form of Rad9. Finally, we provide evidence that the Rtt107-Mms22 axis operates in parallel with the Rtt107-Slx4 axis, which displaces Rad9 from chromatin. We thus propose that Rtt107 enables a bifurcated "anti-Rad9" strategy to optimally downregulate the DNA damage checkpoint., Competing Interests: Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

ATP-dependent chromatin remodeling protein ATRX is an essential regulator involved in maintenance of DNA structure and chromatin state and regulation of gene expression during development. ATRX was originally identified as the monogenic cause of X-linked α-thalassemia mental retardation (ATR-X) syndrome. Affected individuals display a variety of developmental abnormalities and skeletal deformities. Studies from others investigated the role of ATRX in skeletal development by tissue-specific Atrx knockout. However, the impact of ATRX during early skeletal development has not been examined. Using preosteoblast-specific Atrx conditional knockout mice, we observed increased trabecular bone mass and decreased osteoclast number in bone. In vitro coculture of Atrx conditional knockout bone marrow stromal cells (BMSCs) with WT splenocytes showed impaired osteoclast differentiation. Additionally, Atrx deletion was associated with decreased receptor activator of nuclear factor κ-B ligand (Rankl)/ osteoprotegerin (Opg) expression ratio in BMSCs. Notably, Atrx-deficient osteolineage cells expressed high levels of the neuropeptide cocaine- and amphetamine-regulated transcript prepropeptide (Cartpt). Mechanistically, ATRX suppresses Cartpt transcription by binding to the promoter, which is otherwise poised for Cartpt expression by RUNX2 binding to the distal enhancer. Finally, Cartpt silencing in Atrx conditional knockout BMSCs rescued the molecular phenotype by increasing the Rankl/Opg expression ratio. Together, our data show a potent repressor function of ATRX in restricting Cartpt expression during skeletal development.

Background: Long non-coding RNA (lncRNA) zinc finger protein 667-antisense RNA 1 ( ZNF667-AS1 ) is closely related to the advancement of a variety of cancers, but its functional role in colorectal cancer remains unclear. This study was designed to explore the function and molecular mechanisms of lncRNA ZNF667-AS1 in colorectal cancer., Methods: Reverse transcriptase real-time quantitative polymerase chain reaction (RT-qPCR) was used for the detection of ZNF667-AS1 and proline-rich nuclear receptor co-activator protein 2 ( PNRC2 ) expression level. Cell counting kit-8 (CCK-8), 5-Ethynyl-2'- deoxyuridine (EdU), and colony formation assays were conducted to assess cell proliferation; flow cytometry and transwell invasion assay were performed separately to measure cell apoptosis and invasion. RNA immunoprecipitation (RIP) assay was utilized to analyze the relationship between ZNF667-AS1 and PNRC2 . Western blot was to test the PNRC2 protein expression. The in vivo role of ZNF667-AS1 in the advancement of colorectal cancer was evaluated by tumor xenograft assay., Results: LncRNA ZNF667-AS1 and PNRC2 were both decreased in colorectal cancer tissue samples and cells ( p < 0.05). ZNF667-AS1 overexpression remarkably restrained proliferation and invasion in HCT-116 and LOVO cells, but enhanced cell apoptosis ( p < 0.0001). Moreover, ZNF667-AS1 directly targeted PNRC2 , and positively regulated its expression. The influence of ZNF667-AS1 overexpression on invasion, apoptosis, and proliferation was suppressed by PNRC2 knockdown in HCT-116 and LOVO cells. Additionally, ZNF667-AS1 overexpression markedly inhibited tumor growth via upregulation of PNRC2 in mice in vivo ( p < 0.05)., Conclusion: LncRNA ZNF667-AS1 expressed low in colorectal cancer. LncRNA ZNF667-AS1 repressed proliferation and invasion, and enhanced apoptosis of colorectal cancer cells by targeting PNRC2 .

Gastric cancer (GC) remains the most common malignant tumor of the gastrointestinal tract and one of the leading causes of cancer-related deaths worldwide. Non-coding RNAs (ncRNAs), including microRNAs (miRNAs), are involved in the pathogenesis and progression of GC and, therefore, may be potential diagnostic and prognostic biomarkers. Our work was aimed at investigating the predicted regulation of ARID1A by miR-129-5p and miR-3613-3p and the clinical value of their aberrant expression in GC. The study included tumor and adjacent non-tumor tissues from 110 GC patients, 38 sectional normal gastric tissue samples, as well as 65 plasma samples of GC patients and 49 plasma samples of healthy donors. Expression levels of ARID1A and both miRNAs were quantified by reverse transcription-polymerase chain reaction (RT-PCR). We have identified significant associations of their expression with the clinical and pathological characteristics of GC patients both in tissues and plasma. To validate predicted target pairs miR-129-5p/ ARID1A and miR-3613-3p/ ARID1A , in vitro experiments on cancer cell lines were conducted. The obtained results suggest a complex role of ARID1A, miR-129-5p and miR-3613-3p in GC and potential regulation of ARID1A expression by both miRNAs.

Breast cancer continues to be a major health issue for women worldwide, with vimentin (VIM) identified as a crucial factor in its progression due to its role in cell migration and the epithelial-to-mesenchymal transition (EMT). This study focuses on elucidating VIM's regulatory mechanisms on the miR-615-3p/PICK1 axis. Utilizing the 4T1 breast cancer cell model, we first used RNA-seq and proteomics to investigate the changes in the APA of PICK1 following VIM knockout (KO). These high-throughput analyses aimed to uncover the underlying transcriptional and proteomic alterations associated with VIM's influence on breast cancer cells. RNA-seq and proteomic profiling revealed significant APA in PICK1 following VIM KO, suggesting a novel mechanism by which VIM regulates breast cancer progression. Validation experiments confirmed that VIM KO affects the miR-615-3p-PICK1 axis, with miR-615-3p's regulation of PICK1 being contingent upon the APA of PICK1. These findings highlight the complex interplay between VIM, miR-615-3p, and PICK1 in the regulation of breast cancer cell behavior. This study reveals that vimentin affects the miR-615-3p-PICK1 axis through APA, revealing the key role of VIM in cancer progression. Opened up new avenues for targeted cancer therapy, with a focus on regulating the interaction between APA and miR-615-3p-PICK1., (© 2025 The Author(s). BioFactors published by Wiley Periodicals LLC on behalf of International Union of Biochemistry and Molecular Biology.)

Triple-negative breast cancer (TNBC) is a highly aggressive subtype of breast cancer that lacks hormone receptors, which makes it more likely to metastasize and have a poor prognosis. Despite some effectiveness of chemotherapy, TNBC remains challenging to manage, with high relapse and mortality rates. Recent findings have highlighted the role of the ubiquitin-protease system in TNBC, with ABI2 identified as a significant regulator. Reduced ABI2 expression is associated with aggressive disease and poor outcomes, whereas ABI2 overexpression (OE-ABI2) inhibits TNBC cell proliferation by modulating the PI3K/Akt signaling pathway. Although ABI2 is not a nuclear protein, it influences critical nuclear functions such as DNA repair and gene expression. Nuclear proteins, particularly those in the nuclear pore complex and nuclear matrix, are essential for cellular functions and have been linked to various diseases, including cancer. This study used RNA sequencing (RNA-seq) to examine the gene expression in MDA-MB-231 cell line and ABI2-overexpressing cells. Differentially expressed genes were annotated, and a protein-protein interaction network was constructed. Network and enrichment analysis identified the nucleoporins NUP54 and NUP153 as potential novel targets for TNBC. This study emphasizes the impact of ABI2 on nuclear proteins and suggests that targeting NUP54 and NUP153 could offer new therapeutic options for TNBC., (Copyright © 2025. Published by Elsevier Inc.)

SMARCA4-deficient lung cancer, including thoracic SMARCA4-deficient undifferentiated tumors and SMARCA4-deficient nonsmall-cell lung carcinomas, is a rare and aggressive disease characterized by rapid progression and poor prognosis. This cancer was identified as a distinct entity with specific morphologic and molecular features in the 2021 WHO Classification of Thoracic Tumors. Molecular alterations in SMARCA4 are specific to this type of lung cancer. Deficiency in SMARCA4 suppresses the SWI/SNF tumor suppressor complex, driving tumor progression. Due to the lack of standardized treatment, most patients succumb to the disease within 6 months. This study provides a detailed analysis of the SMARCA4 pathway and its role in lung cancer. We analyzed potential therapeutic targets and agents to offer insights for the precise and effective treatment of SMARCA4-deficient lung cancer., (© 2025 Wiley Periodicals LLC.)

Background: Schlafen 11 (SLFN-11) has been identified as a sensitizer of tumor cells to DNA-damaging agents. However, the relationship between SLFN-11 expression and clinical outcomes in patients with small cell lung cancer (SCLC) remains unexplored. Thus, we aimed to evaluate the impact of SLFN-11 expression on survival in patients with limited-stage (LS) SCLC., Methods: We conducted a retrospective review of data from patients pathologically diagnosed with LS-SCLC post-surgery between January 2008 and December 2018. SLFN-11 expression was assessed using immunohistochemistry in tissue microarrays and scored using a histology (H)-score (range: 0-300)., Results: Overall, 86 patients were included in the analysis with a median H-score of 43 for SLFN-11 expression. Among the patients, 44 had high SLFN-11 expression (provisionally defined as H-score ≥ 43). No significant differences in clinical profiles were observed between the two groups (high and low SLFN expression). The median survival durations were not reached (NR; 95% confidence interval [CI]: 65.1 months to NR) and 33.5 months (95% CI: 24.2 months to NR) for patients with high and low SLFN-11 expression, respectively (hazard ratio [HR]: 0.40, 95% CI: 0.19-0.81; p = 0.012). Among patients who relapsed post-surgery (n = 21), the median survival durations were 22.0 (95% CI: 7.6-44.9 months) and 8.1 (95% CI: 1.8-24.6 months) months in patients with high and low SLFN-11 expression, respectively (HR: 0.22, 95% CI: 0.06-0.84; p = 0.026)., Conclusions: High SLFN-11 expression is associated with relatively longer survival in patients with LS-SCLC in both those undergoing surgery and those who have relapsed., (© 2025 The Author(s). Thoracic Cancer published by John Wiley & Sons Australia, Ltd.)