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Diabetes mellitus has been widely acknowledged to have a negative effect on the osteoblastic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). However, the underlying epigenetic mechanisms associated with this process remain to be elucidated. The goal of the present study was to investigate the effect of diabetes mellitus on the osteoblastic differentiation of BMSCs and assess the role of histone methylation in the observed phenomena. The osteoblastic differentiation ability of BMSCs was shown to be decreased in diabetes mellitus, as indicated by alkaline phosphatase activity and the mRNA levels of osteoblast-related genes. Furthermore, diabetes mellitus caused an increased expression of the histone methylase EZH2 and the levels of H3K27Me3 and decreased the expression of the histone demethylase KDM6B, as demonstrated by qRT-PCR and western blotting. Furthermore, immunofluorescence staining suggested that both EZH2 and H3K27Me3 were primarily localized in the nucleus. In addition, chromatin immunoprecipitation assays indicated an increased presence of H3K27Me3 on the promoter region of the BMP4 gene. In summary, in the present study, we demonstrated that the osteoblastic differentiation of BMSCs is dramatically reduced in diabetes mellitus. In addition, upregulation of EZH2 expression and downregulation of KDM6B expression may not be enough to eliminate transcriptional repression mediated by H3K27Me3 on the promoter region of the BMP4 gene during the osteoblastic differentiation of BMSCs in diabetes mellitus., 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.)

Synovial sarcoma (SS) is driven by a unique t(18;X) chromosomal translocation resulting in expression of the SS18-SSX fusion oncoprotein, a transcriptional regulator with both activating and repressing functions. However, the manner in which SS18-SSX contributes to the development of SS is not entirely known. Here, we show that SS18-SSX drives the expression of Preferentially Expressed Antigen in Melanoma (PRAME), which is highly expressed in SS but whose function remains poorly understood. The fusion protein directly binds and activates the PRAME promoter and we found that expression of SS18-SSX and PRAME are positively correlated. We provide evidence that PRAME modulates retinoic acid (RA) signaling, forming a ternary complex with the RA receptor α (RARα) and the Enhancer of Zeste Homolog 2 (EZH2). Knockdown of PRAME suppressed the response to all-trans retinoic acid (ATRA) supporting PRAME's role in modulating RA-signaling. Notably, we demonstrate that combined pharmacological inhibition of EZH2 and treatment with ATRA reconstituted RA signaling followed by reduced proliferation and induction of cellular senescence. In conclusion, our data provides new insights on the role of the SS18-SSX fusion protein in regulation of PRAME expression and RA signaling, highlighting the therapeutic potential of disrupting the RARα-PRAME-EZH2 complex in SS. Schematic presentation of the proposed model. A The RARα-PRAME-EZH2 ternary complex in SS. The fusion SS18-SSX oncoprotein binds to the PRAME promoter and activates its expression. PRAME in turn interacts with RARα-RXR heterodimers as well as with EZH2, and the complex binds to retinoic acid response elements (RAREs) in the DNA. This results in transcriptional repression of retinoic acid (RA) responsive genes and thus inhibition of RA-signaling, allowing tumor cell proliferation. B Therapeutic strategy. Treatment with an EZH2 inhibitor, such as GSK343, or activation of RAR receptors via all-trans retinoic acid (ATRA), disrupts the RARα-PRAME-EZH2 ternary complex and restores RA-signaling. Exposure to GSK343 or ATRA results in inhibition of cell proliferation and induction of cellular senescence, where GSK343 shows a dominant effect. The Figure was created with Biorender.com., Competing Interests: Competing interests The authors declare no competing interests. Ethics approval and consent to participate This study does not involve any human participants, animals, or identifiable personal data, and thus did not require ethics committee approval or informed consent. The data analyzed were publicly available, and no new data collection from individuals was conducted. We have ensured that our study adheres to all relevant ethical standards., (© 2024. The Author(s).)

Enhancer of zeste homolog 2 (EZH2) is a histone methyltransferase that plays an important role in cancer cells biology. However, present EZH2 inhibitors in clinic have not achieved satisfactory efficacy. Herein, a number of EZH2-targeted PROTAC compounds were designed and synthesized by selecting different linkers, using Tazemetostat as the protein of interest (POI) portion of PROTAC molecules, hoping to improve the defects of existing EZH2 inhibitors effectively. Among all the target compounds, ZJ-20 showed the best performance with an IC 50 value of 5.0 nM against MINO cells, good pharmacokinetics parameters and a limited acceptable oral bioavailability. Significantly, ZJ-20 could achieve degradation of the entire PRC2 complex by targeting EZH2, which can serve as a lead compound for further study., 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 Ltd. All rights reserved.)

Enhancer of zeste homolog 2 (EZH2), a key protein implicated in various cancers including hepatocellular carcinoma (HCC), is recognized for its association with epigenetic dysregulation and pathogenesis. Despite clinical explorations into EZH2-targeting therapies, the mechanisms underlying its role in gene suppression in HCC have remained largely unexplored. Here, we integrate epigenomic and transcriptomic analyses to uncover the transcriptional landscape modulated by selective EZH2 inhibition in HCC. By reanalyzing transcriptomic data of HCC patients, we demonstrate that EZH2 overexpression correlates with poor patient survival. Treatment with the EZH2 inhibitor tazemetostat restored expression of genes involved in cysteine-methionine metabolism and lipid homeostasis, while suppressing angiogenesis and oxidative stress-related genes. Mechanistically, we demonstrate EZH2-mediated H3K27me3 enrichment at cis-regulatory elements of transsulfuration pathway genes, which is reversed upon inhibition, leading to increased chromatin accessibility. Among 16 EZH2-targeted candidate genes, BHMT and CDO1 were notably correlated with poor HCC prognosis. Tazemetostat treatment of HCC cells increased BHMT and CDO1 expression while reducing levels of ferroptosis markers FSP1, NFS1, and SLC7A11. Functionally, EZH2 inhibition dose-dependently reduced cell viability and increased lipid peroxidation in HCC cells. Our findings reveal a novel epigenetic mechanism controlling lipid peroxidation and ferroptosis susceptibility in HCC, providing a rationale for exploring EZH2-targeted therapies in this malignancy., (© 2024. The Author(s).)

RE-1 silencing transcription factor (REST) is a key repressor of neural genes. REST is upregulated under stress signals, aging and neurodegenerative diseases, but although it is upregulated, its function is lost in Alzheimer's Disease. However, why it becomes inactive remains unclear. Here, we show that the NAD-dependent deacetylase SIRT6 regulates REST expression, location and activity. In the absence of SIRT6, REST is overexpressed but mislocalized, leading to a partial loss of its activity and causing it to become toxic. SIRT6 deficiency abrogates REST and EZH2 interaction, perturbs the location of REST to the heterochromatin Lamin B ring, and leads to REST target gene overexpression. SIRT6 reintroduction or REST methyl-mimic K494M expression rescues this phenotype, while an acetyl-mimic mutant loses its function even in WT cells. Our studies define a novel regulatory switch where, depending on SIRT6 presence, the function of REST is regulated by post-translational modifications on K494 (Ac/me), affecting neuronal gene expression. In WT cells (left), REST functions as a repressor due to its methylation, which allows proper localization and interaction with EZH2. In SIRT6 KO cells (right), REST is overexpressed, but it is mislocalized and acetylated instead of methylated, impairing its interaction with EZH2. REST localizes in the cytoplasm in autophagosomes. The overall increase in REST without SIRT6 results in non-functional and toxic REST proteins. During aging, SIRT6 declines in the brain, while REST is upregulated to protect it. In pathological aging, where SIRT6 levels are very low, the increase in REST without SIRT6 results in non-functional and toxic REST., (© 2024. The Author(s).)

The persistence of cancer stem cells (CSC) is believed to contribute to resistance to platinum-based chemotherapy and disease relapse in ovarian cancer, the fifth leading cause of cancer-related death among US women. HOXC transcript antisense RNA (HOTAIR) is a long, noncoding RNA (lncRNA) overexpressed in high-grade serous ovarian cancer and linked to chemoresistance. However, HOTAIR impacts chromatin dynamics in ovarian CSCs. Oncogenic lncRNA's contributions to drug-resistant disease are incompletely understood. Here, we generated HOTAIR knockout (KO) high-grade serous ovarian cancer cell lines using paired CRISPR guide RNA design to investigate the function of HOTAIR. We show the loss of HOTAIR function resensitized ovarian cancer cells to platinum treatment and decreased the population of ovarian CSCs. Furthermore, HOTAIR KO inhibited the development of stemness-related phenotypes, including spheroid formation ability and expression of key stemness-associated genes ALDH1A1, NOTCH3, SOX9, and PROM1. HOTAIR KO altered the cellular transcriptome and chromatin accessibility landscape of multiple oncogenic-associated genes and pathways, including the NF-kB pathway. HOTAIR functions as an oncogene by recruiting enhancer of zeste homolog 2 (EZH2) to catalyze H3K27 trimethylation to suppress downstream tumor suppressor genes, and it was of interest to inhibit both HOTAIR and EZH2. In vivo, combining a HOTAIR inhibitor with an EZH2 inhibitor and platinum chemotherapy decreased tumor formation and increased survival. These results suggest a key role for HOTAIR in ovarian CSCs and malignant potential. Targeting HOTAIR in combination with epigenetic therapies may represent a therapeutic strategy to ameliorate ovarian cancer progression and resistance to platinum-based chemotherapy., (©2024 American Association for Cancer Research.)

Adult T-cell leukemia (ATL) is an aggressive malignancy caused by human T-cell leukemia virus type 1 (HTLV-1) infection. Enhancer of zeste homolog 2 (EZH2) has been implicated in the development and progression of multiple cancers, including virus-induced malignancies. However, the potential function of EZH2 in HTLV-1-induced oncogenesis has not been clearly elucidated. In the present study, we showed that EZH2 was overexpressed and activated in HTLV-1-infected cell lines, potentially due to the activation of EZH2 promoter by HTLV-1 Tax and NF-κB p65 subunit. In addition, we found that EZH2 enhanced the HBZ-induced activation of TGF-β signaling in a histone methyltransferase-independent manner. As a mechanism for these actions, we found that EZH2 targeted Smad3/Smad4 to form a ternary complex, and the association between Smad3 and Smad4 was markedly enhanced in the presence of EZH2. Knockdown of EZH2 in ATL cells indeed repressed the expressions of the TGF-β target genes. In particular, EZH2 synergistically enhanced the HBZ/TGF-β-induced Foxp3 expression. Treatment of 3-Deazaneplanocin A, a specific inhibitor of EZH2 significantly inhibited the Foxp3 expression. Taken together, our results suggest that EZH2 may be involved in the differentiation of regulatory T cells through activating the HBZ-Smad3-TGF-β signaling axis, which is considered to be a key strategy for viral persistence., (© 2024 Wiley Periodicals LLC.)

Background: The child cancer, neuroblastoma (NB), is characterised by a low incidence of mutations and strong oncogenic embryonal driver signals. Many new targeted epigenetic modifier drugs have failed in human trials as monotherapy., Methods: We performed a high-throughput, combination chromatin-modifier drug screen against NB cells. We screened 13 drug candidates in 78 unique combinations., Results: We found that the combination of two histone methyltransferase (HMT) inhibitors: GSK343, targeting EZH2, and SGC0946, targeting DOT1L, demonstrated the strongest synergy across 8 NB cell lines, with low normal fibroblast toxicity. High mRNA expression of both EZH2 and DOT1L in NB tumour samples correlated with the poorest patient survival. Combination HMT inhibitor treatment caused activation of ATF4-mediated endoplasmic reticulum (ER) stress responses. In addition, glutathione and several amino acids were depleted by HMT inhibitor combination on mass spectrometry analysis. The combination of SGC0946 and GSK343 reduced tumour growth in comparison to single agents., Conclusion: Our results support further investigation of HMT inhibitor combinations as a therapeutic approach in NB., (© 2024 The Author(s). Cancer Medicine published by John Wiley & Sons Ltd.)

Sepsis-induced acute lung injury (SI-ALI) leads to significant deaths in critically ill patients worldwide. This study explores the mechanism of EZH2 regulating ferroptosis of alveolar epithelial cells (AECs) in SI-ALI. In vitro cell model and in vivo mouse lung injury model of sepsis were established. EZH2 expression in lung tissues was intervened by sh-EZH2, followed by H&E staining observation of lung tissue pathological changes. EZH2, H3K27me3, USP10, GPX4, and ACSL4 expressions were determined by qRT-PCR or Western blot. ROS, GSH, and iron ion levels were detected using fluorescent labeling and reagent kits, respectively. ChIP analyzed the enrichment of EZH2 and H3K27me3 on USP10 promoter. The binding between USP10 and GPX4, and the ubiquitination level of GPX4 were detected using Co-IP. EZH2 was highly expressed in lung tissues of SI-ALI mice. EZH2 silencing alleviated ALI and ferroptosis of AECs; EZH2 increased the H3K27me3 level on USP10 promoter through histone methylation. USP10 stabilized GPX4 protein expression through ubiquitination; inhibition of USP10 partially reversed the inhibitory effect of EZH2 silencing on ferroptosis of AECs. In conclusion, EZH2 depresses USP10 expression by promoting histone H3K27me3 modification on USP10 promoter, thereby enhancing ubiquitination degradation of GPX4 and ultimately facilitating ferroptosis of AECs in sepsis., (© 2024 Wiley Periodicals LLC.)

It is established that neurogenesis of dentate gyrus is increased after ischemic insult, although the regulatory mechanisms have not yet been elucidated. In this study, we focused on Ezh2 which suppresses gene expression through catalyzing trimethylation of lysine 27 of histone 3. Male gerbils were injected with adeno-associated virus (AAV) carrying shRNA targeting to Ezh2 into right dentate gyrus 2 weeks prior to forebrain ischemia. One week after ischemia, animals were injected with thymidine analogue to label proliferating cells. Three weeks after ischemia, animals were killed for histological analysis. AAV-mediated knockdown of Ezh2 significantly decreased the ischemia-induced increment of proliferating cells, and the proliferated cells after ischemia showed significantly longer migration from subgranular zone (SGZ), compared to the control group. Furthermore, the number of neural stem cells in SGZ significantly decreased after ischemia with Ezh2 knockdown group. Of note, Ezh2 knockdown did not affect the number of proliferating cells or the migration from SGZ in the non-ischemic condition. Our data showed that, specifically after ischemia, Ezh2 knockdown shifted the balance between self-renewal and differentiation toward differentiation in adult dentate gyrus., (© 2024. The Author(s).)

This study investigates the role and molecular mechanism of EZH2 in glioma cell proliferation, invasion, and migration. EZH2, miR-142-3p, lncRNA KCNQ1OT1, LIN28B, and HMGB3 expressions in glioma tissues and cells were determined using qRT-PCR or Western blot, followed by CCK-8 assay detection of cell viability, Transwell detection of invasion and migration, ChIP analysis of the enrichment of EZH2 and H3K27me3 on miR-142-3p promoter, dual-luciferase reporter assay and RIP validation of the binding of miR-142-3p-KCNQ1OT1 and KCNQ1OT1-LIN28B, and actinomycin D detection of KCNQ1OT1 and HMGB3 mRNA stability. A nude mouse xenograft model and a lung metastasis model were established. EZH2, KCNQ1OT1, LIN28B, and HMGB3 were highly expressed while miR-142-3p was poorly expressed in gliomas. EZH2 silencing restrained glioma cell proliferation, invasion, and migration. EZH2 repressed miR-142-3p expression by elevating the H3K27me3 level. miR-142-3p targeted KCNQ1OT1 expression, and KCNQ1OT1 bound to LIN28B to stabilize HMGB3 mRNA, thereby promoting its protein expression. EZH2 silencing depressed tumor growth and metastasis in nude mice via the miR-142-3p/KCNQ1OT1/HMGB3 axis. In conclusion, EZH2 curbed miR-142-3p expression, thereby relieving the inhibition of KCNQ1OT1 expression by miR-142-3p, enhancing the binding of KCNQ1OT1 to LIN28B, elevating HMGB3 expression, and ultimately accelerating glioma cell proliferation, invasion, and migration., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background and Objective: Non-small cell lung cancer (NSCLC) is a pernicious tumor with high incidence and mortality rates. The incidence rate of NSCLC increases with age and poses a serious danger to human health. The aim of this study was to determine the mechanism by which (-)-epicatechin (EC) alleviates NSCLC., Methods: Twenty-four pairs of NSCLC tissues and cancer-adjacent tissues were collected, and A549 and H460 radiotherapy-resistant strains were generated by repeatedly irradiating A549 and H460 cells with dose-gradient X-rays. Radiotherapy-resistant H460 cells were successfully injected subcutaneously into the left dorsal side of nude mice at a dose of 1 × 10 5 to establish an NSCLC animal model. The levels of interrelated genes and proteins were detected by RT‒qPCR and Western blotting, and cell proliferation and apoptosis were evaluated by CCK‒8 assay, Transwell assay, flow cytometry, and TUNEL staining., Results: LOC107986454 was highly expressed in NSCLC patients, while miR-143-3p was expressed at low levels and was negatively correlated with LOC107986454. Functionally, EC promoted autophagy and apoptosis induced by radiotherapy, restrained cell proliferation and migration, and ultimately enhanced the radiosensitivity of NSCLC cells. A downstream mechanistic study showed that EC facilitated miR-143-3p expression by inhibiting LOC107986454 and then restraining the expression of EZH2, which ultimately facilitated autophagy and apoptosis in cancer cells, inhibited proliferation and migration, and enhanced the radiosensitivity of NSCLC cells., Conclusion: EC can enhance the radiosensitivity of NSCLC cells by regulating the LOC107986454/miR-143-3p/EZH2 axis., Competing Interests: Competing interests The authors declare that they have no competing financial interests., (Copyright © 2024 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.)

Acute myeloid leukemia (AML) is a heterogeneous hematological malignancy that starts from bone marrow and spreads to other organs. At the time of diagnosis, both innate and defective natural killer (NK) cells are present in AML patients. The dysfunction of the NK cells is due to the absence of NK cell receptors such as NKG2D on tumor cells that help with tumor immune escape, and also the polycomb protein, EzH2, which plays an important role in the commitment and differentiation of NK cells. The inhibition of EzH2 activates NK cells towards enhanced lytic activity. However, the adoptive transfer of NK cells for cancer treatment is still under scrutiny due to limitations like production cost, vein-to-vein time, and complicated experimental procedures. In order to circumvent these issues, here, in vivo CD56 + NK cell genetic engineering is hypothesized through the CD56-directed delivery of the pSMP-EzH2 shRNA plasmid encapsulated in chitosan nanoparticles (pEzH2@CSNPs@CD56). The pSMP-EzH2 shRNA plasmid was encapsulated in chitosan nanoparticles followed by CD56 antibody conjugation through EDC-NHS chemistry. CD56 antibody-conjugated nanoparticles selectively target CD56 + NK cells and downregulate EzH2 expression in CD56 + NK cells of human PBMCs. The in vitro CD56 + CD3 - NK cells were enriched and stably suppressed EzH2 expression to prepare adoptive CD56 + CD3 - NK (EzH2 - ) cells for anti-AML immunotherapy. The in vitro NK (EzH2 - ) cells and pEzH2@CSNPs@CD56 reduced splenomegaly while immunophenotyping revealed in vivo downregulation of the c-Kit + leukemia stem cell population along with upregulation of the differentiation markers CD11b and Gr-1 in the peripheral blood and bone marrow of AML1-ETO9a-induced xenograft nude mice. CD56 + CD3 - and CD56 + CD38 + cell populations were significantly increased in the peripheral blood and bone marrow, which indicated NK cell-mediated AML cell killing took place suggesting that use of pEzH2@CSNPs@CD56 is a safe and viable strategy for NK cell-mediated anti-AML immunotherapy.

The role and detailed mechanisms of lncRNAs in idiopathic pulmonary fibrosis (IPF) are not fully understood. qPCR was conducted to verify lncRNA FEZF1-AS1 expression in the transforming growth factor-beta 1 (TGF-β1)-stimulated human lung fibroblasts (HLF) and A549. The EMT-related proteins were performed by western blotting. Cell proliferation, migration, and transition were detected by CCK-8, colony formation, wound-healing and transwell assays. A dual-luciferase reporter assay was conducted to validate the target relationship of FEZF1-AS1 and miR-200c-3p. FEZF1-AS1 is highly expressed in the fibrotic A549 and HLF. in vitro experiments revealed that FEZF1-AS1 facilitates cell proliferation, migration and invasion. Knockdown of FEZF1-AS1 attenuated TGF-b1-induced fibrogenesis both in vitro. Moreover, silencing FEZF1-AS1 inhibited fibrogenesis through modulation of miR-200c-3p. In addition, inhibition of miR-200c-3p promoted fibrogenesis by regulation of Zinc finger E-box binding homeobox 1 (ZEB1). Mechanistically, FEZF1-AS1 promoted lung fibrosis by acting as a competing endogenous RNA (ceRNA) for miR-200c-3p. FEZF1-AS1 silencing increased the expression and activity of miR-200c-3p to inhibit ZEB1 and alleviate lung fibrogenesis in A549 and HLF. In addition, our study showed that FEZF1-AS1 can regulate enhancer of zeste homolog2 (EZH2) to upregulate fibrosis-related proteins and promote lung fibrosis. In summary, the results of our study revealed the pulmonary fibrogenic effect of FEZF1-AS1 in cellular experiments, demonstrating the potential roles and mechanisms of the FEZF1-AS1/miR-200c-3p/ZEB1 and FEZF1-AS1/EZH2 pathways, which provides a novel and potential therapeutic target to lung fibrosis., (© 2024. The Author(s).)

Inactivating mutations in SMARCB1 confer an oncogenic dependency on EZH2 in atypical teratoid rhabdoid tumors (ATRTs), but the underlying mechanism has not been fully elucidated. We found that the sensitivity of ATRTs to EZH2 inhibition (EZH2i) is associated with the viral mimicry response. Unlike other epigenetic therapies targeting transcriptional repressors, EZH2i-induced viral mimicry is not triggered by cryptic transcription of endogenous retroelements, but rather mediated by increased expression of genes enriched for intronic inverted-repeat Alu (IR-Alu) elements. Interestingly, interferon-stimulated genes (ISGs) are highly enriched for dsRNA-forming intronic IR-Alu elements, suggesting a feedforward loop whereby these activated ISGs may reinforce dsRNA formation and viral mimicry. EZH2i also upregulates the expression of full-length LINE-1s, leading to genomic instability and cGAS/STING signaling in a process dependent on reverse transcriptase activity. Co-depletion of dsRNA sensing and cytoplasmic DNA sensing completely rescues the viral mimicry response to EZH2i in SMARCB1-deficient tumors., (© 2024. The Author(s).)

Background: Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a prevalent genetic disorder characterized by the formation of renal cysts leading to kidney failure. Despite known genetic underpinnings, the variability in disease progression suggests additional regulatory layers, including epigenetic modifications., Methods: We utilized various ADPKD models, including Pkd1 and Ezh2 conditional knockout (Pkd1 delta/delta :Ezh2 delta/delta ) mice, to explore the role of Enhancer of Zeste Homolog 2 (EZH2) in cystogenesis. Pharmacological inhibition of EZH2 was performed using GSK126 or EPZ-6438 across multiple models., Results: EZH2 expression was significantly upregulated in Pkd1 -/- cells, Pkd1 delta/delta mice, and human ADPKD kidneys. EZH2 inhibition attenuates cyst development in MDCK cells and a mouse embryonic kidney cyst model. Both Ezh2 conditional knockout and GSK126 treatment suppressed renal cyst growth and protected renal function in Pkd1 delta/delta mice. Mechanistically, cAMP/PKA/CREB pathway increased EZH2 expression. EZH2 mediated cystogenesis by enhancing methylation and activation of STAT3, promoting cell cycle through p21 suppression, and stimulating non-phosphorylated β-catenin in Wnt signaling pathway. Additionally, EZH2 enhanced ferroptosis by inhibiting SLC7A11 and GPX4 in ADPKD., Conclusion: Our findings elucidate the pivotal role of EZH2 in promoting renal cyst growth through epigenetic mechanisms and suggest that EZH2 inhibition or ablation may serve as a novel therapeutic approach for managing ADPKD., (© 2024. The Author(s).)

Polycomb repressive complex 2 (PRC2) is an epigenetic regulator that trimethylates lysine 27 of histone 3 (H3K27me3) and is essential for embryonic development and cellular differentiation. H3K27me3 is associated with transcriptionally repressed chromatin and is established when PRC2 is allosterically activated upon methyl-lysine binding by the regulatory subunit EED. Automethylation of the catalytic subunit enhancer of zeste homolog 2 (EZH2) stimulates its activity by an unknown mechanism. Here, we show that human PRC2 forms a dimer on chromatin in which an inactive, automethylated PRC2 protomer is the allosteric activator of a second PRC2 that is poised to methylate H3 of a substrate nucleosome. Functional assays support our model of allosteric trans-autoactivation via EED, suggesting a previously unknown mechanism mediating context-dependent activation of PRC2. Our work showcases the molecular mechanism of auto-modification-coupled dimerization in the regulation of chromatin-modifying complexes., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

There is documented sex disparity in cutaneous melanoma incidence and mortality, increasing disproportionately with age and in the male sex. However, the underlying mechanisms remain unclear. While biological sex differences and inherent immune response variability have been assessed in tumor cells, the role of the tumor-surrounding microenvironment, contextually in aging, has been overlooked. Here, we show that skin fibroblasts undergo age-mediated, sex-dependent changes in their proliferation, senescence, ROS levels, and stress response. We find that aged male fibroblasts selectively drive an invasive, therapy-resistant phenotype in melanoma cells and promote metastasis in aged male mice by increasing AXL expression. Intrinsic aging in male fibroblasts mediated by EZH2 decline increases BMP2 secretion, which in turn drives the slower-cycling, highly invasive, and therapy-resistant melanoma cell phenotype, characteristic of the aged male TME. Inhibition of BMP2 activity blocks the emergence of invasive phenotypes and sensitizes melanoma cells to BRAF/MEK inhibition., Competing Interests: Declaration of interests A.T.W. is on the board of reGAIN Therapeutics and the Melanoma Research Foundation. E.M.J. reports other support from Abmeta, personal fees from Genocea, personal fees from Achilles, personal fees from DragonFly, personal fees from Candel Therapeutics, other support from the Parker Institute, grants and other support from Lustgarten, personal fees from Carta, grants and other support from Genentech, grants and other support from AstraZeneca, personal fees from NextCure, and grants and other support from Break Through Cancer outside of the submitted work. D.J.Z. reports grant funding (paid to Johns Hopkins University) from Roche/Genentech. Y.C. and M.E.F. are affiliated with the Cancer Signaling and Microenvironment program, FoxChase Cancer Center, Philadelphia, PA, USA., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: The molecular biology mechanisms underlying postoperative cognitive dysfunction (POCD) remain unclear, resulting in a lack of specific therapeutic targets and limited clinical treatment options. The NLRP3 pyroptotic pathway, induced by neuroinflammation, is known to promote the development of POCD. Research has shown that lncRNA MEG3 exacerbates cell pyroptosis in various neurological injuries, though the precise mechanism remains to be investigated., Methods: In vitro and in vivo models of POCD were established through treatment with sevoflurane. Gene and protein expression were investigated using qRT-PCR, Western blot analysis, ELISA, and histological staining. Additionally, cell viability and injury were assessed through CCK-8 and LDH assays. Hippocampal-dependent memory and cognitive abilities were evaluated using the Morris Water Maze (MWM) test. Furthermore, the interactions between MEG3 and EZH2/YTHDC1 were validated through RNA immunoprecipitation (RIP) and chromatin immunoprecipitation (ChIP)., Results: Our findings reveal that sevoflurane significantly reduced MEG3 and pyroptosis-related proteins in mice. The overexpression of MEG3 protected mice against sevoflurane-induced cognitive dysfunction and reversed sevoflurane-induced pyroptosis in hippocampal neurons. MEG3 induced the downregulation of NLRP3 expression and reduced mRNA stability through its interaction with EZH2/YTHDC1., Conclusion: In conclusion, our study elucidates that MEG3 inhibits the NLRP3 inflammasome and hippocampal neuron pyroptosis through the recruitment of EZH2/YTHDC1. These findings shed light on the underlying mechanism of MEG3 in the regulation of POCD and suggest that MEG3 could serve as a potential therapeutic target for the treatment of POCD., 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.)

While cell fate determination and maintenance are important in establishing and preserving tissue identity and function during development, aberrant cell fate transition leads to cancer cell heterogeneity and resistance to treatment. Here, we report an unexpected role for the transcription factor p63 (Trp63/TP63) in the fate choice of the squamous versus neuroendocrine lineage in esophageal development and malignancy. Deletion of p63 results in extensive neuroendocrine differentiation in the developing mouse esophagus and esophageal progenitors derived from human embryonic stem cells. In human esophageal neuroendocrine carcinoma (eNEC) cells, p63 is transcriptionally silenced by EZH2-mediated H3K27 trimethylation (H3K27me3). Up-regulation of the major p63 isoform ΔNp63α, through either ectopic expression or EZH2 inhibition, promotes squamous transdifferentiation of eNEC cells. Together, these findings uncover p63 as a rheostat in coordinating the transition between squamous and neuroendocrine cell fates during esophageal development and tumor progression.

Background: Research has elucidated that homeobox B9 (HOXB9), an important transcriptional activator, plays a pivotal role in promoting the invasion and metastasis of hepatocellular carcinoma (HCC) cells. However, the mechanism by which HOXB9 promotes the invasion and metastasis of HCC cells is incompletely understood and needs further exploration., Methods: HOXB9 and snail family transcriptional repressor 2 (SNAI2) expression were analyzed using qRT-PCR and western blotting. The invasion and metastasis of hepatocellular carcinoma (HCC) cells were investigated using in vitro and in vivo assays. The H3K27me3 enrichment and HOXB9 interaction with microRNA 203a (MIR203A) or SNAI2 were detected using ChIP-qPCR. Transcriptional activities of SNAI2 and MIR203A promoter were detected using dual-luciferase reporter assays. Co-IP and GST pull-down assays were performed to confirm the binding between HOXB9 and EZH2., Results: HOXB9 and SNAI2 were highly expressed in HCC tissues and their expression was positively intercorrelated and associated with poor prognosis in patients with HCC. In vitro and in vivo experiments confirmed that HOXB9 can upregulate the expression of SNAI2 to promote the invasion and metastasis of HCC cells. Furthermore, HOXB9 elevated SNAI2 expression by inhibiting MIR203A expression, a tumor suppressor gene, in HCC cells. Mechanistically, HOXB9 recruited enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) through interaction with its WD-binding domain, which increased EZH2-mediated histone H3 lysine 27 trimethylation (H3K27me3) at the MIR203A promoter region, in turn repressing the transcriptional activity and expression of MIR203A and consequently increasing the SNAI2 level in HCC cells. Finally, empirical evidence from in vitro and in vivo studies confirmed that mitigation of the HOXB9-mediated enhancement of epigenetic silencing of MIR203A inhibited SNAI2 expression, impeding the invasion and metastasis of HCC cells., Conclusions: Our study reveals a novel mechanism by which HOXB9 promotes the invasion and metastasis of HCC cells and expands the understanding of the function of HOXB9 in tumor progression and provides a novel therapeutic strategy for curtailing HCC invasion and metastasis., (© 2024. The Author(s).)

The retinoblastoma gene product (Rb1), a master regulator of the cell cycle, plays a prominent role in cell differentiation. Previously, by analyzing the differentiation of cells transiently overexpressing the ΔS/N DN Rb1 mutant, we demonstrated that these cells fail to differentiate into mature adipocytes and that they constitutively silence Pparγ2 through CpG methylation. Here, we demonstrate that the consequences of the transient expression of ΔS/N DN Rb1 are accompanied by the retention of Cebpa promoter methylation near the TSS under adipogenic differentiation, thereby preventing its expression. The CGIs of the promoters of the Rb1 , Ezh2 , Mll4 , Utx , and Tet2 genes, which are essential for adipogenic differentiation, have an unmethylated status regardless of the cell differentiation state. Moreover, Dnmt3a, a de novo DNA methyltransferase, is overexpressed in undifferentiated ΔS/N cells compared with wild-type cells and, in addition to Dnmt1, Dnmt3a is significantly upregulated by adipogenic stimuli in both wild-type and ΔS/N cells. Notably, the chromatin modifier Ezh2, which is also involved in epigenetic reprogramming, is highly induced in ΔS/N cells. Overall, we demonstrate that two major genes, Pparγ2 and Cebpa , which are responsible for terminal adipocyte differentiation, are selectively epigenetically reprogrammed to constitutively silent states. We hypothesize that the activation of Dnmt3a, Rb1, and Ezh2 observed in ΔS/N cells may be a consequence of a stress response caused by the accumulation and malfunctioning of Rb1-interacting complexes for the epigenetic reprogramming of Pparγ2/Cebpa and prevention of adipogenesis in an inappropriate cellular context. The failure of ΔS/N cells to differentiate and express Pparγ2 and Cebpa in culture following the expression of the DN Rb1 mutant may indicate the creation of epigenetic memory for new reprogrammed epigenetic states of genes.

Isl1 has been described as an embryonic master control gene expressed in the pericloacal mesenchyme. Deletion of Isl1 from the genital mesenchyme in mice leads to an ectopic urethral opening and epispadias-like phenotype. Using genome wide association methods, we identified ISL1 as the key susceptibility gene for classic bladder exstrophy (CBE), comprising epispadias and exstrophy of the urinary bladder. The most significant marker (rs6874700) identified in our recent GWAS meta-analysis achieved a p value of 1.48 × 10 - 24 within the ISL1 region. In silico analysis of rs6874700 and all other genome-wide significant markers in Linkage Disequilibrium (LD) with rs6874700 (D' = 1.0; R 2  > 0.90) revealed marker rs2303751 (p value 8.12 × 10 - 20 ) as the marker with the highest regulatory effect predicted. Here, we describe a novel 1.2 kb intragenic promoter residing between 6.2 and 7.4 kb downstream of the ISL1 transcription starting site, which is located in the reverse DNA strand and harbors a binding site for EZH2 at the exact region of marker rs2303751. We show, that EZH2 silencing in HEK cells reduces ISL1 expression. We show that ezh2 -/- knockout (KO) zebrafish larvae display tissues specificity of ISL1 regulation with reduced expression of Isl1 in the pronephric region of zebrafish larvae. In addition, a shorter and malformed nephric duct is observed in ezh2 -/- ko zebrafish Tg(wt1ß:eGFP) reporter lines. Our study shows, that Ezh2 is a key regulator of Isl1 during urinary tract formation and suggests tissue specific ISL1 dysregulation as an underlying mechanism for CBE formation., (© 2024. The Author(s).)

Background: SUZ12 is one of the core members of the polycomb repressive complex 2 (PRC2), but its expression and role in lung adenocarcinoma (LUAD) are unclear. We aimed to explore the expression, prognosis, biological functions and roles of SUZ12 in LUAD., Methods: The expression of SUZ12 was detected by immunohistochemical staining, qRT-PCR, and western blotting in LUAD tissues and cells. The biological functions and molecular mechanisms of SUZ12 were characterized by a range of in vitro and in vivo experiments., Results: SUZ12 was overexpressed in LUAD tissues, and high SUZ12 expression was correlated with worse clinicopathological features and a poorer prognosis. Knockdown of SUZ12 significantly inhibited cell growth, colony formation, invasion, and migration, and induced apoptosis and G1/S phase arrest, while overexpression of SUZ12 had the opposite effects. Knockdown of SUZ12 decreased the tumorigenic capacity of A549 cells in vivo. The expression of key signaling molecules related to the cell cycle, apoptosis, migration, and immunity were altered by the knockdown or overexpression of SUZ12. SUZ12 can directly bind to the Bax promoter region, EZH2 and H3K27me3 levels dependents on SUZ12. The expression levels of SUZ12 and Bax were negatively correlated in LUAD tissues., Conclusions: SUZ12 is a new oncogene related to the poor prognosis of LUAD. SUZ12 regulates LUAD progression by regulating the expression of related signaling molecules, and as a part of the PRC2 complex, it may bind to the Bax promoter to silence Bax expression., (© 2024 The Author(s). Cancer Medicine published by John Wiley & Sons Ltd.)

Background: Small-cell lung cancer (SCLC) shows high enhancer of zeste homolog 2 (EZH2) expressions. EZH2-mediated epigenetics promote epithelial-mesenchymal transition (EMT), enhancing invasive and metastatic potential in malignancies. MicroRNAs (miRNAs), small noncoding RNAs, modulate EMT, determining tumor phenotypes. However, the association between miRNAs and EZH2 in SCLC remains to be clarified-we aimed to identify a novel tumorigenic mechanism through miRNAs, EZH2, and EMT in SCLC, leading to future therapeutic applications., Methods: We analyzed EZH2 and E-cadherin expressions in lung cancer cell lines and tumor tissues from 34 SCLC patients and confirmed EZH2 siRNA-mediated EMT inhibition. miRNA expression profiles were compared between EZH2 knockdown SCLC cells and negative control SCLC cells using miRNA array. We identified a target miRNA of EZH2 showing expressional differences in EZH2-knockdown cells and analyzed the impact of the miRNA on EZH2-mediated EMT and tumorigenesis., Results: All SCLC cells showed increased EZH2 and decreased E-cadherin expressions. SCLC tissues had higher EZH2 and lower E-cadherin expressions than other lung cancer tissues. miRNA array revealed that miR-4448 expression increased in EZH2-knockdown SCLC cells. miR-4448 overexpression reduced tumor cell growth and prevented EMT. miR-4448 bound to the 3'UTR of the girdin gene and suppressed its expression, thereby decreasing Akt phosphorylation at Ser473. Attenuated Akt phosphorylation resulted in AMP-activated protein kinase (AMPK) phosphorylation at Thr172 and 183, enhancing EZH2 phosphorylation at Thr311., Conclusion: SCLC characterized high EZH2 expression and promoted EMT, compared with non-small cell lung cancer. miR-4448 inhibited Girdin expression, reducing Akt phosphorylation, and enhancing AMPK and EZH2 phosphorylation. Eventually, miR-4448 prevented EZH2-mediated EMT and tumorigenesis by modulating the Girdin/Akt/AMPK axis in SCLC. miR-4448 might be a potential SCLC inhibitor., (© 2024 The Author(s). Cancer Medicine published by John Wiley & Sons Ltd.)

Diabetic nephropathy (DN), an eminent etiology of renal disease in patients with diabetes, involves intricate molecular mechanisms. Recent investigations have elucidated microRNA-193a (miR-193a) as a pivotal modulator in DN, although its precise function in podocyte impairment remains obscure. The present study investigated the role of miR-193a in podocyte injury via the WT1/EZH2/β-catenin/NLRP3 pathway. This study employed a comprehensive experimental approach involving both in vitro and in vivo analyses. We utilized human podocyte cell lines and renal biopsy samples from pediatric patients with DN. The miR-193a expression levels in podocytes and glomeruli were quantified via qRT‒PCR. Western blotting and immunofluorescence were used to assess the expression of WT1, EZH2, β-catenin, and NLRP3 inflammasome components. Additionally, the study used luciferase reporter assays to confirm the interaction between miR-193a and WT1. The impact of miR-193a manipulation was observed by overexpressing WT1 and inhibiting miR-193a in podocytes, followed by analysis of downstream pathway activation and inflammatory markers. We found upregulated miR-193a in podocytes and glomeruli, which directly targeted and suppressed WT1, a crucial podocyte transcription factor. WT1 suppression, in turn, activated the EZH2/β-catenin/NLRP3 pathway, leading to inflammasome assembly and proinflammatory cytokine production. Overexpression of WT1 or inhibition of miR-193a attenuated these effects, protecting podocytes from injury. This study identified a novel mechanism by which miR-193a-mediated WT1 suppression triggers podocyte injury in DN via the EZH2/β-catenin/NLRP3 pathway. Targeting this pathway or inhibiting miR-193a may be potential therapeutic strategies for DN., 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.)

Human pancreatic cancer is characterized by the molecular diversity encompassing native duct-like and squamous cell-like identities, but mechanisms underlying squamous transdifferentiation have remained elusive. To comprehensively capture the molecular diversity of human pancreatic cancer, we here profiled 65 patient-derived pancreatic cancer organoid lines, including six adenosquamous carcinoma lines. H3K27me3-mediated erasure of the ductal lineage specifiers and hijacking of the TP63-driven squamous-cell programme drove squamous-cell commitment, providing survival benefit in a Wnt-deficient environment and hypoxic conditions. Gene engineering of normal pancreatic duct organoids revealed that GATA6 loss and a Wnt-deficient environment, in concert with genetic or hypoxia-mediated inactivation of KDM6A, facilitate squamous reprogramming, which in turn enhances environmental fitness. EZH2 inhibition counterbalanced the epigenetic bias and curbed the growth of adenosquamous cancer organoids. Our results demonstrate how an adversarial microenvironment dictates the molecular and histological evolution of human pancreatic cancer and provide insights into the principles and significance of lineage conversion in human cancer., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Background: Spinal cord injury (SCI) is a destructive neurological and pathological state that causes major motor, sensory and autonomic dysfunctions. Bone marrow mesenchymal stem cells (BMSCs)-derived exosomes show great therapeutic potential for SCI. Exosomes derived from miR-26a-modified MSCs promote axonal regeneration following SCI. Our study aims to uncover the mechanisms by which BMSC-derived exosomes carrying miR-26a-5p regulate SCI., Methods: BMSCs and BMSC-derived exosomes were isolated and characterized by Oil Red O and alizarin red staining, transmission electron microscopy, flow cytometry, nanoparticle tracking analysis and Western blotting. PC12 cells were treated with lipopolysaccharides (LPS), and SCI was established through laminectomy with contusion injury in rats. Annexin-V staining, CCK-8 and EdU incorporation were applied to determine cell apoptosis, viability, and proliferation. Hematoxylin and Eosin, Nissl and TUNEL staining was used to evaluate SCI injury and apoptosis in the spinal cord. Luciferase and chromatin immunoprecipitation assays were applied to evaluate gene interaction., Results: BMSC-derived exosomes facilitated LPS-treated PC12 cell proliferation and inhibited apoptosis by delivering miR-26a-5p. Moreover, BMSC-derived exosomal miR-26a-5p alleviated SCI. Furthermore, miR-26a-5p inhibited EZH2 expression by directly binding to EZH2, and EZH2 inhibited BDNF expression via promoting H3K27me3. Increased phosphorylated CREB enhanced KCC2 transcription and expression by binding to its promoter. Knockdown of miR-26a-5p abrogated BMSC-derived exosome-mediated protection in LPS-treated PC12 cells, but it was reversed by KCC2 overexpression., Conclusion: BMSC-derived exosomes carrying miR-26a-5p repressed EZH2 expression to promote BDNF and TrkB expression and CREB phosphorylation and subsequently increase KCC2 expression, thus protecting PC12 cells and ameliorating SCI., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Ankylosing spondylitis (AS) is a common chronic progressive inflammatory autoimmune disease. T helper 17 (Th17) cells are the major effector cells mediating AS inflammation. Histone 3 Lys 27 trimethylation (H3K27me3) is an inhibitory histone modification that silences gene transcription and plays an important role in Th17 differentiation. The objective of this study was to investigate the expression of H3K27me3 in patients with AS and to explore its epigenetic regulation mechanism of Th17 differentiation during AS inflammation. We collected serum samples from 45 patients with AS at various stages and 10 healthy controls to measure their Interleukin-17 (IL-17) levels using ELISA. A quantitative polymerase chain reaction was used to quantify the mRNA levels of RORc and the signaling molecules of the JAK2/STAT3 pathway, JMJD3, and EZH2. Additionally, Western blot analysis was performed to quantify the protein levels of H3K27me3, RORγt, JAK2, STAT3, JMJD3, and EZH2 in cell protein extracts. The results showed that H3K27me3 expression in peripheral blood mononuclear cells (PBMCs) was significantly lower in patients with active AS compared to both the normal control groups and those with stable AS. Moreover, a significant negative correlation was observed between H3K27me3 expression and the characteristic transcription factor of Th17 differentiation, RORγt. We also discovered that patients with active AS exhibited significantly higher levels of JMJD3, an inhibitor of H3K27 demethylase, compared to the normal control group and patients with stable AS, while the expression of H3K27 methyltransferase (EZH2) was significantly lower. These findings suggest that H3K27me3 may be a dynamic and important epigenetic modification in AS inflammation, and JMJD3/EZH2 regulates the methylation level of H3K27me3, which may be one of the key regulatory factors in the pathogenesis of AS. These findings contribute to our understanding of the role of epigenetics in AS and may have implications for the development of novel therapeutic strategies for AS., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objective: To explore the relationship between the expression of placental growth factor (PLGF) and Zeste homolog enhancer 2 (EZH2) in placental tissues of women with gestational diabetes (GDM), placental function, and pregnancy outcome., Methods: Select 100 women with GDM diagnosed in our hospital from January 2019 to May 2020 as the GDM group and 100 women with normal pregnancy at the same time as the control group. Detection and analysis of the expression levels of PLGF and EZH2 proteins in placental tissue after delivery of the two components. Observation of the expression of different PLGF and EZH2 proteins using an electron microscope, and analyze the ultrastructural changes in placental tissue of women with GDM. Finally, assess the differences in pregnancy outcomes., Results: The expression intensity of PLGF protein in the GDM group was higher than that in the control group (P < .001), and the expression intensity of EZH2 protein in the GDM group was lower than that in the control group (P < .001); the positive rate of PLGF protein in the GDM group was 67.00% higher than that of the control group 35.00% (P < .001), the positive rate of EZH2 protein in the GDM group was 15.00% lower than 33.00% in the control group (P = .003); the placental ultrastructural change rate of PLGF-positive GDM women was 71.64% higher than that in the negative expression group 45.45 % (P = .011); the placental ultrastructural change rate of EZH2 protein-positive GDM mothers was 33.33% lower than that of negative expression of A mixed 68.24% (P = .01); the incidence of premature infants (26.87%) and fetal respiratory distress (13.43%) in the PLGF-positive GDM group, the rate was higher than that in the negative expression group (9.09%, 0%) (P = .027, .04); the incidence of preterm infants in the EZH2 protein-positive GDM group (0.00%) was lower than that in the negative expression group (24.71%) (P = .03)., Conclusion: The expression of PLGF is up-regulated and the expression of EZH2 is down-regulated in the placental tissue of GDM women, which causes ultrastructural changes in the placental tissue and increases the incidence of preterm birth and fetal respiratory distress to a certain extent.

Background: The current selection criteria of patients with stage II colorectal carcinoma (CRC) suitable for adjuvant therapy are not satisfactory. Enhancer of zeste homolog 2 (EZH2) has been demonstrated to be over-expressed in CRC. However, data regarding the role of EZH2 in CRC survival remains controversial, and little is known about it in stage II CRC. Thus, we conducted this study to investigate the clinical significance of EZH2 expression in stage II CRC., Methods: Cases with stage II CRC resected between 2015 and 2018 were retrospectively reviewed. EZH2 expression was analyzed by immunohistochemistry using tissue microarrays. The relationship between EZH2 expression and clinicopathological variables was analyzed. Survival curves were estimated by the Kaplan-Meier approach., Results: We found high EZH2 expression in 134 of 221 analyzable stage II tumors (60.63%). No significant associations were observed between EZH2 expression and common clinicopathological factors. Survival analyses showed that cases receiving surgery alone had inferior overall survival (OS) than those receiving surgery and chemotherapy ( P=0.0075 ) in stage II CRC with high EZH2 expression, however, metastasis-free survival (MFS) was similar between these two subgroups. Treatment choice had no impact on the survival of stage II CRC with low EZH2 expression., Conclusion: The OS of stage II CRC with high EZH2 expression improved more strikingly with surgery and adjuvant chemotherapy than with surgery alone, which suggests the potential of EZH2 expression as a biomarker to help identify a subgroup of early-stage CRC benefiting from surgery and adjuvant chemotherapy. More large-scale studies are warranted to corroborate this finding and to further evaluate the predictive nature of EZH2., (©The Author(s) 2024. Open Access. This article is licensed under a Creative Commons CC-BY International License.)

The discussion in this review centers around the significant relationships between EZH2 and the initiation, progression, metastasis, metabolism, drug resistance, and immune regulation of cancer. Polycomb group (PcG) proteins, which encompass two primary Polycomb repressor complexes (PRC1 and PRC2), have been categorized. PRC2 consists mainly of four subunits, namely EZH2, EED, SUZ12, and RbAp46/48. As the crucial catalytic component within the PRC2 complex, EZH2 plays a pivotal role in controlling a wide range of biological processes. Overexpression/mutations of EZH2 have been detected in a wide variety of tumors. Several mechanisms of EZH regulation have been identified, including regulation EZH2 mRNA by miRNAs, LncRNAs, accessibility to DNA via DNA-binding proteins, post-translational modifications, and transcriptional regulation. EZH2 signaling triggers cancer progression and may intervene with anti-tumor immunity; therefore it has charmed attention as an effective therapeutic target in cancer therapy. Numerous nucleic acid-based therapies have been used in the modification of EZH2. In addition to gene therapy approaches, pharmaceutical compounds can be used to target the EZH2 signaling pathway in the treatment of cancer. EZH2-associated tumor cells and immune cells enhance the effects of the immune response in a variety of human malignancies. The combination of epigenetic modifying agents, such as anti-EZH2 compounds with immunotherapy, could potentially be efficacious even in the context of immunosuppressive tumors. Summary, understanding the mechanisms underlying resistance to EZH2 inhibitors may facilitate the development of novel drugs to prevent or treat relapse in treated patients., (© 2024 The Author(s). Clinical Genetics published by John Wiley & Sons Ltd.)

Metaplastic breast carcinomas (mBrCA) are a highly aggressive subtype of triple-negative breast cancer with histologic evidence of epithelial-to-mesenchymal transition and aberrant differentiation. Inactivation of the tumor suppressor gene cellular communication network factor 6 (CCN6; also known as Wnt1-induced secreted protein 3) is a feature of mBrCAs, and mice with conditional inactivation of Ccn6 in mammary epithelium (Ccn6-KO) develop spindle mBrCAs with epithelial-to-mesenchymal transition. Elucidation of the precise mechanistic details of how CCN6 acts as a tumor suppressor in mBrCA could help identify improved treatment strategies. In this study, we showed that CCN6 interacts with the Wnt receptor FZD8 and coreceptor LRP6 on mBrCA cells to antagonize Wnt-induced activation of β-catenin/TCF-mediated transcription. The histone methyltransferase EZH2 was identified as a β-catenin/TCF transcriptional target in Ccn6-KO mBrCA cells. Inhibiting Wnt/β-catenin/TCF signaling in Ccn6-KO mBrCA cells led to reduced EZH2 expression, decreased histone H3 lysine 27 trimethylation, and deregulation of specific target genes. Pharmacologic inhibition of EZH2 reduced growth and metastasis of Ccn6-KO mBrCA mammary tumors in vivo. Low CCN6 is significantly associated with activated β-catenin and high EZH2 in human spindle mBrCAs compared with other subtypes. Collectively, these findings establish CCN6 as a key negative regulator of a β-catenin/TCF/EZH2 axis and highlight the inhibition of β-catenin or EZH2 as a potential therapeutic approach for patients with spindle mBrCAs.  Significance: CCN6 deficiency drives metaplastic breast carcinoma growth and metastasis by increasing Wnt/β-catenin activation to upregulate EZH2, identifying EZH2 inhibition as a mechanistically guided treatment strategy for this deadly form of breast cancer., (©2024 American Association for Cancer Research.)

Background/objectives: Methyltransferase EZH2-mediated H3K27me3 is involved in liver inflammation and fibrosis, but its role in hepatic metabolic derangements is not yet clearly defined. We investigated if a high-fat diet (HFD) induced early changes in EZH2 expression and H3K27 me3 in the liver of mice., Methods: Five-week-old mice were fed an HFD or a low-fat diet (Control) for 2 weeks (2 W) or 8 weeks (8 W). Body weight was recorded weekly. Glycemia and oral glucose tolerance were assessed at baseline and after 2 W-8 W. Finally, livers were collected for further analysis., Results: As expected, mice that received 8 W HFD showed an increase in body weight, glycemia, and liver steatosis and an impairment in glucose tolerance; no alterations were observed in 2 W HFD mice. Eight weeks of HFD caused hepatic EZH2 nuclear localization and increased H3 K27me3; surprisingly, the same alterations occurred in 2 W HFD mice livers, even before overweight onset. We demonstrated that selective EZH2 inhibition reduced H3K27me3 and counteracted lipid accumulation in HUH-7 cells upon palmitic acid treatment., Conclusions: In conclusion, we point to EZH2/H3K27me3 as an early epigenetic event occurring in fatty-acid-challenged livers both in vivo and in vitro, thus establishing EZH2 as a potential pharmacological target for metabolic derangements.

The immunosuppressive function of regulatory T (Treg) cells is essential for maintaining immune homeostasis. Enhancer of zeste homolog 2 (EZH2), a histone H3 lysine 27 (H3K27) methyltransferase, plays a key role in maintaining Treg cell function upon CD28 co-stimulation, and Ezh2 deletion in Treg cells causes autoimmunity. Here, we assess whether increasing H3K27me3 levels, by using an Ezh2 Y641F gain-of-function mutation, will improve Treg cell function. We find that Treg cells expressing Ezh2 Y641F display an effector Treg phenotype, are poised for improved homing to organ tissues, and can accelerate remission from autoimmunity. The H3K27me3 landscape and transcriptome of naive Ezh2 Y641F Treg cells exhibit a redistribution of H3K27me3 modifications that recapitulates the gene expression profile of activated Ezh2 WT Treg cells after CD28 co-stimulation. Altogether, increased H3K27me3 levels promote the differentiation of effector Treg cells that can better suppress autoimmunity., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Objective: To investigate the effect and associated mechanism of tumor tissue-infiltrating NK cells after receiving radiotherapy for hepatocellular carcinoma (HCC). Methods: A HCC tumor-bearing mouse model was constructed using human hepatocellular carcinoma cell line (SK-Hep-1) and divided into four groups: control, radiotherapy, NK cell clearance, and NK clearance combined with radiotherapy. Tumor growth condition was simultaneously recorded. The NK cell ratio in peripheral blood and the NK cell intratumoral infiltration condition were detected by flow cytometry and immunohistochemistry. Lentiviral-constructed SK-Hep-1 cells was used to detect the effect of radiotherapy on the regulation of CXCL10 and NK cell chemotaxis following EZH2 overexpression. SK-Hep-1 cells were irradiated in vitro and in vivo . The expression levels of EZH2 and CXCL10 mRNA and protein in the two groups of cell lines and mouse tumor tissues were detected by reverse transcription polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), western blotting (WB), and immunohistochemistry. The chemotaxis and blocking experiments were used to validate the chemotaxis effect of CXCL10 on NK cells. The independent sample t-test was used to compare the groups. P <0.05 was considered statistically significant. Results: The HCC tumor-bearing mouse model experiment showed that HCC tumor growth was most remarkable in the NK clearance combined with the radiotherapy group compared to the radiotherapy group ( P <0.05). Compared with the control group, the number of NK cells in the peripheral blood of nude mice in the radiotherapy group was significantly reduced, while the NK cell intratumoral infiltration was significantly increased ( P <0.05). Flow cytometry and immunohistochemistry showed in vitro and in vivo expressional alterations. The average expression levels of EZH2 mRNA and protein in hepatocellular carcinoma cell lines and tumor tissues were decreased in the radiotherapy group than the control group and mouse tumor tissues ( P <0.05), while the mRNA and protein expression levels of CXCL10 increased ( P <0.05). The cell supernatant following radiotherapy enhanced NK cell chemotaxis but inhibited CXCL10 neutralization. EZH2 overexpression validated that radiotherapy up-regulated CXCL10 mRNA and down-regulated protein expression levels in in vitro and in vivo experiments ( P <0.05). The chemotactic effect on NK cells was significantly weakened with EZH2 overexpression following radiotherapy. Conclusion: NK cells, as immune effector cells, are directly involved in radiotherapy- activated anti-HCC immunity. Importantly, radiotherapy inhibits EZH2 expression in hepatocellular carcinoma, thereby upregulating CXCL10 expression and enhancing intratumoral NK cell invasion.

Primary Effusion Lymphoma (PEL) cells carry Kaposi's sarcoma-associated herpesvirus (KSHV) in a latent state, except for a small number of cells in which the virus replicates to ensure its persistence into the infected host. However, the lytic cycle can be reactivated in vitro by exposing these lymphoma cells to various treatments, leading to cell lysis. To restrict viral antigen expression, KSHV induces repressive epigenetic changes, including DNA methylation and histone modifications. Among the latter, histone deacetylation and tri-methylation of Histone H3 lisyne-27 (H3K27me3) have been reported to play a role. Here, we found that the inhibition of H3K27 tri-methylation by valemetostat DS3201 (DS), a small molecule that inhibits Enhancer of Zeste Homolog 2 (EZH2) methyltransferase, induced the KSHV lytic cycle in PEL cells, and that this effect involved the activation of the wtp53-p21 axis and autophagic dysregulation. DS also potentiated the lytic cycle activation mediated by the Histone deacetylases (HDAC) inhibitor Suberoylanilide hydroxamic acid (SAHA) and reinforced its cytotoxic effect, suggesting that such a combination could be used to unbalance the latent/lytic cycle and further impair the survival of PEL cells.

Background: The prognosis of breast cancer patients with visceral metastasis (VM) is significantly worse than that of patients without VM. We aimed to evaluate EZH2 (enhancer of zeste homolog 2) mutation as a biomarker associated with VM., Methods: Data from forty-nine patients with metastatic breast cancer (MBC) pathologically confirmed at our hospital between March 2016 and September 2018 were collected. Metastatic tissue samples were obtained via ultrasound-guided needle biopsy, and paired peripheral blood samples were also collected. Tissue and blood samples were subjected to targeted next-generation sequencing via a 247-gene panel. Stably transfected MDA-MB-231 cells expressing wild-type EZH2 (EZH2 WT ) or a mutant form of EZH2 (EZH2 K515R ) were generated. Cell proliferation, colony formation ability, migration and invasion abilities and apoptosis were assessed using CCK-8 assays, plate colony formation assays, Transwell chamber assays and flow cytometry., Results: The incidence of EZH2 mutations in the VM subgroup was greater than that in the non-VM subgroup in the entire cohort (n = 49, 42.3% vs. 13.0%, p = 0.024) and in the triple-negative breast cancer (TNBC) subgroup (n = 20, 50.0% vs. 10.0%, p = 0.05). Patients carrying EZH2 mutations had a significantly greater risk of developing VM than did those in the non-EZH2 mutation group in the entire cohort (HR 2.9) and in the TNBC subgroup (HR 6.45). Multivariate analysis revealed that EZH2 mutation was an independent prognostic factor for VM (HR 2.99, p = 0.009) in the entire cohort and in the TNBC subgroup (HR 10.1, p = 0.006). Data from cBioPortal also showed that patients with EZH2 mutations had a significantly greater risk of developing VM (HR 3.1), and the time to develop VM was significantly earlier in the EZH2 mutation group (31.5 months vs. 109.7 months, p = 0.008). Multivariate analysis revealed that EZH2 mutation (HR 2.73, p = 0.026) was an independent factor for VM after breast cancer surgery. There was no correlation between EZH2 mutations and BRCA1/2 mutations. Most of the patients (81.8%) in our cohort who developed VM carried the "c.1544A > G (p.K515R)" mutation. Compared with EZH2 WT MDA-MB-231 cells, EZH2 K515R MDA-MB-231 cells had greater colony formation rates (p < 0.01), greater migration and invasion rates (p < 0.001), and lower apoptosis rates (p < 0.01). The proportion of S + G2/M phase cells in the EZH2 K515R group was significantly greater than that in the EZH2 WT group., Conclusions: EZH2 mutation is associated with VM development in breast cancer patients. The EZH2 K515R mutation leads to VM and a poor prognosis by enhancing proliferation and invasion and inhibiting apoptosis in breast cancer cells., (© 2024. The Author(s).)

Alzheimer's disease (AD) is a common neurodegenerative disease. Previous studies have identified the critical role of astrocytes in the progression of AD. The focus of this study revolves around clarifying the regulatory mechanism of the STAT3/EZH2/BAI1 axis in astrocytes in AD. We successfully developed a rat model of AD, and measured the learning and cognitive ability of the rats by Morris water maze experiment. HE and Nissl's staining were used for histomorphological identification of the rat hippocampus. Meanwhile, immunofluorescence and immunohistochemistry were used to detect astrocyte activation and brain-specific angiogenesis inhibitor-1 (BAI1) expression in rat hippocampal tissue, respectively. The role of STAT3/EZH2/BAI1 regulating axis in astrocyte activation and neuronal cell apoptosis was verified by establishing the co-culture system of astrocytes and neuronal cells in vitro. Western Blot (WB) was used to detect the expression of associated proteins, and enzyme-linked immunosorbent assay (ELISA) was used to detect astrocyte neurotrophic factor secretion. Hochest/PI staining and flow cytometry were used to observe neuronal apoptosis. Compared with the sham group, AD rats showed significantly decreased cognitive and learning abilities, noticeable hippocampal tissue damage, and significantly low levels of BAI1 expression. In in vitro models, BAI1 was found to inhibit astrocyte activation and enhance the secretion of neurotrophins, resulting in decrease of neurone apoptosis. The regulation of BAI1 by the STAT3/EZH2 axis was shown to affect astrocyte activation and neuronal cell apoptosis. In conclusion, this study represents the pioneering discovery that regulated by the STAT3/EZH2 axis, BAI1 suppresses astrocyte activation, thus reducing neuronal apoptosis., 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.)

As histone modification enzymes, EZH2 mediates H3K27 trimethylation (H3K27me3), whereas LSD1 removes methyl groups from H3K4me1/2 and H3K9me1/2. Synergistic anticancer effects of combining inhibitors of these two enzymes are observed in leukemia and prostate cancer. Thus, a series of EZH2/LSD1 dual inhibitors are designed and synthesized to evaluate their anticancer activity. After the structure-activity study, one of the best compounds, ML234 , displayed excellent antiproliferative capacity against prostate cancer cell lines LNCAP, PC3, and 22RV1. Enzymatic assays ascertained that the anticancer potency of ML234 was mediated through coinhibition of EZH2 and LSD1. Moreover, the accumulation of H3K4me2 and H3K9me2 and the decrease of H3K27me3 induced by ML234 were verified by Western blot analysis. More importantly, the compound remarkably suppressed the tumor growth and enhanced the therapeutic efficacy of clinical drug enzalutamide in the 22RV1 xenograft mouse model, indicating that it may have potential as an anticancer agent in prostate cancer.

Epigenetic modifications to DNA and chromatin control oncogenic and tumor-suppressive mechanisms in melanoma. Ezh2, the catalytic component of the Polycomb Repressive Complex 2 (PRC2), which mediates methylation of lysine 27 on histone 3 (H3K27me3), can regulate both melanoma initiation and progression. We previously found that mutant Ezh2 Y641F interacts with the immune regulator Stat3 and together they affect anti-tumor immunity. However, given the numerous downstream targets and pathways affected by Ezh2, many mechanisms that determine its oncogenic activity remain largely unexplored. Using genetically engineered mouse models, we further investigated the role of pathways downstream of Ezh2 in melanoma carcinogenesis and identified significant enrichment in several autophagy signatures, along with increased expression of autophagy regulators, such as Atg7. In this study, we investigated the effect of Atg7 on melanoma growth and tumor immunity within the context of a wild-type or Ezh2 Y641F epigenetic state. We found that the Atg7 locus is controlled by multiple Ezh2 and Stat3 binding sites, Atg7 expression is dependent on Stat3 expression, and that deletion of Atg7 slows down melanoma cell growth in vivo, but not in vitro. Atg7 deletion also results in increased CD8 + T cells in Ezh2 Y641F melanomas and reduced myelosuppressive cell infiltration in the tumor microenvironment, particularly in Ezh2 WT melanomas, suggesting a strong immune system contribution in the role of Atg7 in melanoma progression. These findings highlight the complex interplay between genetic mutations, epigenetic regulators, and autophagy in shaping tumor immunity in melanoma., (© 2024. The Author(s).)

Purpose: To explore risk factors predicting poor prognosis of uveal melanoma in a Chinese population, with specific emphasis on monosomy 3, 8q gain, and EZH2 staining., Methods: Eighty-nine patients with uveal melanoma from 2012 to 2021 were reviewed. Clinical and pathological records were collected and analyzed. Immunohistochemical staining of EZH2, monosomy 3 and 8q gain were respectively conducted in 45, 54, and 57 cases. Survival was evaluated by Kaplan-Meier analysis and log-rank test. Cox proportional hazard regressions were employed to predict risk factors of distant metastasis., Results: The median follow-up was 44 months. Altogether, 16 % of patients developed distant metastases and died from disease-related causes. Disease-specific survival at one and three years was 96.6 % and 88.4 % while distant metastasis rates were 7.9 % and 12 %. Univariate Cox regression analysis revealed that age (HR: 1.04), tumor largest basal diameter (HR: 1.21), tumor thickness (HR: 1.21), ciliary body involvement (HR: 3.50), AJCC stage (HR: 5.68), epithelioid cell type (HR: 7.71), 8q gain (HR: 7.48), and high expression of EZH2 (HR: 6.09) were associated with distant metastasis. 8q gain was associated with epithelioid cell type and thicker tumor while EZH2 was correlated with epithelioid cell type. Monosomy 3 lacked a significant correlation with other factors., Conclusion: EZH2 and 8q gain could be taken into consideration when calculating poor prognosis in Chinese patients with uveal melanoma. Monosomy 3 showed no significance in distant metastasis, but this may be due to a small sample size., Competing Interests: Conflicts of interest disclosures 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 circular RNA (circRNA) plays a crucial role in various biological processes, particularly posttranscriptional regulation. However, the role of circRNA in the development of goat skeletal muscle has not been thoroughly explored. Here, we identified circPAPD7, which is a novel circular RNA that is preferentially expressed in the skeletal muscle. Functional assays demonstrated that circPAPD7 promoted proliferation and inhibited differentiation in goat skeletal muscle satellite cells (MuSCs). Mechanistically, it was discovered that circPAPD7 interacts with miR-26a-5p. Moreover, the rescue experiments indicated that the overexpression of circPAPD7 may reverse the inhibitory impact of miR-26a-5p on myoblast proliferation and the accelerated effects on differentiation. Furthermore, we provided evidence that circPAPD7 functions as a sponge for miR-26a-5p, thereby facilitating the upregulation of EZH2 expression in goat MuSCs. Together, the results revealed that circPAPD7 promote proliferation and inhibit differentiation of goat MuSCs via the miR-26a-5p/EZH2 pathway., Competing Interests: Declaration of competing interest All the authors declare that there is no conflict of interest in this research., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Bisphenol S (BPS), an alternative to bisphenol A (BPA), exerts proliferative effects similar to those of BPA. BPS is a representative endocrine disruptor associated with cancer progression. However, the mechanisms underlying BPS-induced glioblastoma progression are not fully understood. To investigate the effects of BPS on glioblastoma, U-87 MG cancer cell lines were exposed to BPS. The study focused on analyzing the proliferation and migration of U-87 MG cells. Furthermore, the involvement of the enhancer of the zeste homolog 2 (EZH2)-mediated phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of the rapamycin (mTOR) pathway was examined. Pharmacological approaches were employed to inhibit EZH2 activity and observe its effects on BPS-induced changes. The results indicated that BPS promoted the proliferation and migration of U-87 MG cells at a concentration of 0.1 µM. These changes appeared to be linked to the activation of the EZH2-mediated PI3K/AKT/mTOR pathway. Moreover, inhibiting EZH2 activity using pharmacological approaches restored the BPS-mediated induction of proliferation and migration. In conclusion, the results of this study indicated that BPS induces glioblastoma progression through EZH2 upregulation. Therefore, targeting the EZH2-mediated PI3K/AKT/mTOR pathway could be considered a potential therapeutic strategy for the treatment of glioblastoma., 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 B.V. All rights reserved.)

Background: Clinical data demonstrate that chronic use of opioid analgesics increases neuropathic pain in people living with human immunodeficiency virus (HIV). Therefore, it is important to elucidate the molecular mechanisms of HIV-related chronic pain. In this study, we investigated the role of the transcription factor cMyc, epigenetic writer enhancer of zeste homology 2 (EZH2), and sirtuin 3 (Sirt3) pathway in HIV glycoprotein gp120 with morphine (gp120M)-induced neuropathic pain in rats., Methods: Neuropathic pain was induced by intrathecal administration of recombinant gp120 with morphine. Mechanical withdrawal threshold was measured using von Frey filaments, and thermal latency using the hotplate test. Spinal expression of cMyc, EZH2, and Sirt3 were measured using Western blots. Antinociceptive effects of intrathecal administration of antisense oligodeoxynucleotide against cMyc, a selective inhibitor of EZH2, or recombinant Sirt3 were tested., Results: In the spinal dorsal horn, gp120M upregulated expression of cMyc (ratio of gp120M versus control, 1.68 ± 0.08 vs 1.00 ± 0.14, P = .0132) and EZH2 (ratio of gp120M versus control, 1.76 ± 0.05 vs 1.00 ± 0.16, P = .006), and downregulated Sirt3 (ratio of control versus gp120M, 1.00 ± 0.13 vs 0.43 ± 0.10, P = .0069) compared to control. Treatment with intrathecal antisense oligodeoxynucleotide against cMyc, GSK126 (EZH2 selective inhibitor), or recombinant Sirt3 reduced mechanical allodynia and thermal hyperalgesia in this gp120M pain model. Knockdown of cMyc reduced spinal EZH2 expression in gp120M treated rats. Chromatin immunoprecipitation (ChIP) assay showed that enrichment of cMyc binding to the ezh2 gene promoter region was increased in the gp120M-treated rat spinal dorsal horn, and that intrathecal administration of antisense ODN against cMyc (AS-cMyc) reversed the increased enrichment of cMyc. Enrichment of trimethylation of histone 3 on lysine residue 27 (H3K27me3; an epigenetic mark associated with the downregulation of gene expression) binding to the sirt3 gene promoter region was upregulated in the gp120M-treated rat spinal dorsal horn; that intrathecal GSK126 reversed the increased enrichment of H3K27me3 in the sirt3 gene promoter. Luciferase reporter assay demonstrated that cMyc mediated ezh2 gene transcription at the ezh2 gene promoter region, and that H3K27me3 silenced sirt3 gene transcription at the gene promoter region., Conclusion: These results demonstrated that spinal Sirt3 decrease in gp120M-induced neuropathic pain was mediated by cMyc-EZH2/H3K27me3 activity in an epigenetic manner. This study provided new insight into the mechanisms of neuropathic pain in HIV patients with chronic opioids., (Copyright © 2024 International Anesthesia Research Society.)

Background: Glioma stem cells (GSCs), which are known for their therapy resistance, play a substantial role in treatment inefficacy for glioblastoma multiforme (GBM). TRIM37, a member of the tripartite motif (TRIM) protein family initially linked to a rare growth disorder, has been recognized for its oncogenic role. However, the mechanism by which TRIM37 regulates tumor growth in glioma and GSCs is unclear., Methods: For the in vitro experiments, gene expression was measured by western blotting, RT-qPCR, and immunofluorescence. Cell viability was detected by CCK-8, and cell apoptosis was detected by flow cytometry. The interaction between Enhancer of Zeste Homolog 2 (EZH2) and TRIM37 was verified by co-immunoprecipitation (Co-IP). The interaction between EZH2 and the PTCH1 promoter was verified using dual-luciferase reporter assay and chromatin immunoprecipitation (ChIP). For the in vivo experiments, an orthotopically implanted glioma mouse model was used to validate tumor growth., Results: The expression of TRIM37 is higher in GSCs compared with matched non-GSCs. TRIM37 knockdown promotes apoptosis, decreased stemness in GSCs, and reduces tumor growth in GSCs xenografts of nude mice. TRIM37 and EZH2 co-localize in the nucleus and interact with each other. TRIM37 knockdown or EZH2 inhibition downregulates the protein expressions associated with the Sonic Hedgehog (SHH) pathway. EZH2 epigenetically downregulates PTCH1 to activate SHH pathway in GSCs., Conclusions: TRIM37 maintains the cell growth and stemness in GSCs through the interaction with EZH2. EZH2 activates SHH stem cell signaling pathway by downregulating the expression of SHH pathway suppressor PTCH1. Our findings suggest that TRIM37 may be a potential therapeutic target for GBM., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Intestinal ischemia-reperfusion (IR) injury is a common gastrointestinal disease that induces severe intestinal dysfunction. Intestinal myenteric neurons participate in maintaining the intestinal function, which will be severely injured by IR. Macrophages are widely reported to be involved in the pathogenesis of organ IR injury, including intestine, which is activated by NLRP3 signaling. Lonicerin (LCR) is a natural extracted monomer with inhibitory efficacy against the NLRP3 pathway in macrophages. The present study aims to explore the potential protective function of LCR in intestinal IR injury. Myenteric neurons were extracted from mice. RAW 264.7 cells were stimulated by H/R with or without 10 μM and 30 μM LCR. Remarkable increased release of IL-6, MCP-1, and TNF-α were observed in H/R treated RAW 264.7 cells, along with an upregulation of NLRP3, cleaved-caspase-1, IL-1β, and EZH2, which were sharply repressed by LCR. Myenteric neurons were cultured with the supernatant collected from each group. Markedly decreased neuron number and shortened length of neuron axon were observed in the H/R group, which were signally reversed by LCR. RAW 264.7 cells were stimulated by H/R, followed by incubated with 30 μM LCR with or without pcDNA3.1-EZH2. The inhibition of LCR on NLRP3 signaling in H/R treated RAW 264.7 cells was abolished by EZH2 overexpression. Furthermore, the impact of LCR on neuron number and neuron axon length in myenteric neurons in the H/R group was abated by EZH2 overexpression. Collectively, LCR alleviated intestinal myenteric neuron injury induced by H/R treated macrophages via downregulating EZH2., (© 2024 Wiley Periodicals LLC.)

Despite the ongoing progress in detecting and treating cancer, there is still a need for extensive research into the molecular mechanisms involved in the emergence, progression, and resistance to recurrence of female reproductive tissue-specific cancers such as ovarian, breast, cervical, and endometrial cancers. The nuclear paraspeckle assembly transcript 1 (NEAT1) is a long non-coding RNA (lncRNA) that exhibits increased expression in female tumors. Moreover, elevated levels of NEAT1 have been associated with poorer survival outcomes in cancer patients. NEAT1 plays a pivotal role in driving tumor initiation through modulating the expression of genes involved in various aspects of tumor cell proliferation, epithelial-to-mesenchymal transition (EMT), metastasis, chemoresistance, and radio-resistance. Mechanistically, NEAT1 acts as a scaffold RNA molecule via interacting with EZH2 (Enhancer of Zeste 2 Polycomb Repressive Complex 2 Subunit), thereby influencing the expression of downstream effectors of EZH2. Additionally, NEAT1 functions as a competing endogenous RNA (ceRNA) by microRNAs (miRNAs) sponging, consequently altering the expression levels of their target genes during the development of female cancers. This comprehensive review aims to shed light on the latest insights regarding the expression pattern, biological functions, and underlying mechanisms governing the function and regulation of NEAT1 in tumors. Furthermore, particular emphasis is placed on its clinical significance as a novel diagnostic biomarker and a promising therapeutic target for female cancers., 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.)

Objective: The enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) can regulate osteogenesis and osteoclastogenesis. This study aimed to further explore the effects of EZH2 modification on ferroptosis and the osteoblast-osteoclast balance in rheumatoid arthritis (RA) in vitro and in vivo., Methods: Bone marrow mesenchymal stromal cells were transfected with EZH2 overexpression (oeEZH2) and EZH2 shRNA (shEZH2) plasmids with or without ferrostatin-1 (Fer-1) treatment and subjected to an osteoblast differentiation assay. The cells were then cocultured with bone marrow-derived macrophages and subjected to an osteoclast differentiation assay. Collagen-induced arthritis (CIA) mice were generated and injected with shEZH2 adeno-associated virus (AAV)., Results: OeEZH2 repressed osteoblast differentiation, as reflected by decreased ALP and Alizarin Red S staining and increased OPN, RUNX2, OPG and RANKL; however, shEZH2 had the opposite effects. Besides, oeEZH2 promoted osteoblast ferroptosis, as suggested by increased MDA, Fe 2+ , ROS, and PTGS2 but decreased GPX4 and SLC7A11; these effects could be attenuated by Fer-1 treatment. In contrast, shEZH2 ameliorated osteoblast ferroptosis. OeEZH2 subsequently increased osteoclast differentiation, as indicated by increased TRAP + multinucleated cells, NFATC1, CTSK, and c-FOS; however, shEZH2 had the opposite effect, except that it did not regulate CTSK. In CIA mice, shEZH2 AAV decreased the clinical symptom score, histological score of cartilage, and systemic inflammation (TNF-α and IL-6) and repressed bone ferroptosis and restored the osteoblast-osteoclast balance to some extent, as reflected by immunohistochemical staining of related markers., Conclusion: Targeting EZH2 attenuates the ferroptosis-mediated osteoblast-osteoclast imbalance in RA, revealing its potential as a treatment target., 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.)