BACKGROUND: Knee osteoarthritis (OA) is still challenging to prevent or treat. Enhanced endoplasmic reticulum (ER) stress and increased pyroptosis in chondrocytes may be responsible for cartilage degeneration. This study aims to investigate the effect of ER stress on chondrocyte pyroptosis and the upstream regulatory mechanisms, which have rarely been reported. METHODS: The expression of the histone methyltransferase enhancer of zeste homolog 2 (EZH2), microRNA-142-3p (miR-142-3p), and high mobility group box 1 (HMGB1) and the levels of ER stress, pyroptosis, and metabolic markers in normal and OA chondrocytes were investigated by western blotting, quantitative polymerase chain reaction, immunohistochemistry, fluorescence in situ hybridization, fluorescein amidite-tyrosine-valine-alanine-aspartic acid-fluoromethyl ketone (FAM-YVAD-FMK)/Hoechst 33342/propidium iodide (PI) staining, lactate dehydrogenase (LDH) release assays, and cell viability assessments. The effects of EZH2, miR-142-3p, and HMGB1 on ER stress and pyroptosis and the hierarchical regulatory relationship between them were analyzed by chromatin immunoprecipitation, luciferase reporters, gain/loss-of-function assays, and rescue assays in interleukin (IL)-1β-induced OA chondrocytes. The mechanistic contribution of EZH2, miR-142-3p, and HMGB1 to chondrocyte ER stress and pyroptosis and therapeutic prospects were validated radiologically, histologically, and immunohistochemically in surgically induced OA rats. RESULTS: Increased EZH2 and HMGB1, decreased miR-142-3p, enhanced ER stress, and activated pyroptosis in chondrocytes were associated with OA occurrence and progression. EZH2 and HMGB1 exacerbated and miR-142-3p alleviated ER stress and pyroptosis in OA chondrocytes. EZH2 transcriptionally silenced miR-142-3p via H3K27 trimethylation, and miR-142-3p posttranscriptionally silenced HMGB1 by targeting the 3'-UTR of the HMGB1 gene. Moreover, ER stress mediated the effects of EZH2, miR-142-3p, and HMGB1 on chondrocyte pyroptosis. In vivo experiments mechanistically validated the hierarchical regulatory relationship between EZH2, miR-142-3p, and HMGB1 and their effects on chondrocyte ER stress and pyroptosis. CONCLUSIONS A novel EZH2/miR-142-3p/HMGB1 axis mediates chondrocyte pyroptosis and cartilage degeneration by regulating ER stress in OA, contributing novel mechanistic insights into OA pathogenesis and providing potential targets for future therapeutic research.
Enhancer of Zeste Homolog 2 Protein/genetics* ; Osteoarthritis, Knee/pathology* ; Chondrocytes/metabolism* ; Pyroptosis/physiology* ; HMGB1 Protein/genetics* ; MicroRNAs/metabolism* ; Endoplasmic Reticulum Stress/genetics* ; Humans ; Animals ; Rats ; Male ; Rats, Sprague-Dawley ; Middle Aged

OBJECTIVE: To investigate the expression levels of EZH2 and KMT2D in patients with diffuse large B-cell lymphoma (DLBCL) and their relationship with pathological features. METHODS: 84 patients with DLBCL treated in our hospital from January 2021 to June 2022 were selected as the study subjects, and clinical characteristics such as sex, age and pathological classification of the patients were collected. Immunohistochemistry was used to detecet the expression of KMT2D and EZH2 proteins in tumor tissue cells of the DLBCL patients. The differential expression of KMT2D and EZH2 in subgroups of different sexes, ages, primary sites, clinical stages, Hans subtypes, etc. were compared. The correlation between the expression of KMT2D and EZH2 protein and BCL-6, CD79A was analyzed and validated through the interaction of protein molecular structures. We followed up and recorded the survival status of the patients for 12 months, and analyzed the factors that affect the mortality of DLBCL patients. RESULTS: The positive rate of KMT2D and EZH2 was high (over 95%) in DLBCL patients. There was no significant difference in the expression of EZH2 and KMT2D among subgroups of different sexes, ages and stages (P >0.05). However, patients with different levels of BCL-6 and CD79A expression showed differences in EZH2 and KMT2D expression (P < 0.05). EZH2 and KMT2D were positively correlated with BCL-6 (r =0.391, r =0.332) and CD79A (r =0.309, r =0.258), respectively, and there were interactions in the protein molecular structures. The risk factors for mortality in DLBCL patients include male sex (OR =1.106, 95%CI : 1.082-1.130, P < 0.001), stage II (OR =1.778, 95%CI : 1.567-2.016, P < 0.001), stage IV (OR =2.233, 95%CI : 2.021-2.467, P < 0.001), EZH2 positive (OR =2.762, 95%CI : 1.304-5.850, P =0.008), BCL-6 positive (OR =7.309, 95%CI : 1.340-39.859, P =0.022), age≥74 years (OR =3.080, 95%CI : 1.658-5.723, P < 0.001), and 63-73 years old (OR =2.400, 95%CI : 1.564-3.682, P < 0.001), while KMT2D positive (OR =0.180, 95%CI : 0.054-0.608, P =0.006) and 41-51 years old (OR =0.406, 95%CI : 0.274-0.603, P < 0.001) were factors which could reduce the risk of mortality. CONCLUSION EZH2 and KMT2D are highly expressed in patients with DLBCL, and they are positively correlated with BCL-6 and CD79A, and affect the prognosis of DLBCL patients.
Humans ; Enhancer of Zeste Homolog 2 Protein/metabolism* ; Lymphoma, Large B-Cell, Diffuse/metabolism* ; DNA-Binding Proteins/metabolism* ; Female ; Male ; Middle Aged ; Adult ; Neoplasm Proteins/metabolism* ; Aged ; Immunohistochemistry ; Proto-Oncogene Proteins c-bcl-6/metabolism* ; Prognosis

OBJECTIVES: Esophageal squamous cell carcinoma (ESCC) is characterized by complex pathogenesis and poor prognosis. In recent years, epithelial-mesenchymal transition (EMT) in tumor initiation and progression has attracted increasing attention. Enhancer of zeste homolog 2 (EZH2), which is aberrantly expressed in various tumors, may be closely related to the EMT process. This study aims to examine the expression and correlation of EZH2 and EMT markers in ESCC cells and tissues, evaluate the effects of EZH2 knockdown on ESCC cell proliferation, invasion, and migration, and explore how EZH2 contributes to the malignant biological behavior of ESCC. METHODS: Bioinformatics analyses were used to assess EZH2 expression levels in ESCC. Small interfering RNA was used to knock down EZH2 in ESCC cell lines EC109 and EC9706. Cell proliferation, invasion, and migration were evaluated using cell counting kit-8 (CCK-8), wound healing, and Transwell assays. Protein and mRNA expression levels of EZH2, E-cadherin (E-cad), and vimentin (Vim) were detected by Western blotting and real time fluorogenic quantitative PCR (RT-qPCR), respectively. Immunohistochemical (IHC) staining was performed on 70 ESCC tissue samples and 40 paired adjacent normal tissues collected from the First Affiliated Hospital of Shihezi University between 2010 and 2016 to assess the expression of EZH2, E-cad, and Vim, and to analyze their associations with clinicopathological feature and patient prognosis. RESULTS: Bioinformatics analysis showed that EZH2 was highly expressed in ESCC (P<0.001), and high EZH2 expression was associated with worse prognosis (P<0.001). CCK-8, wound healing, and Transwell assays demonstrated that EZH2 knockdown significantly suppressed the proliferation, invasion, and migration of ESCC cells (P<0.001). In addition, Vim expression was significantly reduced, while E-cad expression was significantly increased at both protein and mRNA levels in EZH2-silenced cells (all P<0.05). IHC staining analysis revealed higher expression of EZH2 and Vim and lower expression of E-cad in ESCC tissues compared to adjacent normal tissues. Kaplan-Meier survival analysis showed that low expression of EZH2 and Vim and high expression of E-cad were associated with longer survival (all P<0.05). CONCLUSIONS EZH2 promotes malignant biological behavior in ESCC by mediating EMT. Elevated EZH2 expression is associated with poor prognosis in ESCC patients.
Humans ; Enhancer of Zeste Homolog 2 Protein/physiology* ; Esophageal Squamous Cell Carcinoma/pathology* ; Epithelial-Mesenchymal Transition/genetics* ; Esophageal Neoplasms/metabolism* ; Cell Proliferation ; Cell Line, Tumor ; Cell Movement ; Cadherins/genetics* ; Vimentin/genetics* ; Male ; Female ; Middle Aged ; Neoplasm Invasiveness ; Prognosis ; RNA, Small Interfering/genetics* ; Gene Expression Regulation, Neoplastic

Tissue formation and organ homeostasis are achieved by precise coordination of proliferation and differentiation of stem cells and progenitors. While deregulation of these processes can result in degenerative disease or cancer, their molecular interplays remain unclear. Here we show that the switch of human pluripotent stem cell (hPSC) self-renewal to differentiation is associated with the induction of distinct cyclin-dependent kinase inhibitors (CDKIs). In hPSCs, Activin/Nodal/TGFβ signaling maintains CDKIs in a poised state via SMAD2/3-NANOG-OCT4-EZH2-SNON transcriptional complex. Upon gradual differentiation, CDKIs are induced by successive transcriptional complexes between SMAD2/3-SMYD2 and developmental regulators such as EOMES, thereby lengthening the G1 phase. This, in turn, induces SMAD2/3 transcriptional activity by blocking its linker phosphorylation. Such SMAD2/3-CDKI positive feedback loops drive the exit from pluripotency and stepwise cell-fate specification that could be harnessed for producing cells for therapeutic applications. Our study uncovers fundamental mechanisms of how cell-fate specification is interconnected to cell-cycle dynamics and provides insight into autonomous circuitries governing tissue self-formation.
Humans ; Smad2 Protein/genetics* ; Smad3 Protein/genetics* ; Cell Differentiation ; Pluripotent Stem Cells/metabolism* ; Signal Transduction ; Octamer Transcription Factor-3/genetics* ; Enhancer of Zeste Homolog 2 Protein/genetics* ; Nanog Homeobox Protein/genetics* ; Phosphorylation

Humans ; Cardiovascular Diseases ; Enhancer of Zeste Homolog 2 Protein/metabolism* ; Histones ; Methyltransferases

Humans ; Cardiovascular Diseases ; Enhancer of Zeste Homolog 2 Protein/metabolism* ; Histones ; Methyltransferases

The histone methyltransferase enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2)-mediated trimethylation of histone H3 lysine 27 (H3K27me3) regulates neural stem cell proliferation and fate specificity through silencing different gene sets in the central nervous system. Here, we explored the function of EZH2 in early post-mitotic neurons by generating a neuron-specific Ezh2 conditional knockout mouse line. The results showed that a lack of neuronal EZH2 led to delayed neuronal migration, more complex dendritic arborization, and increased dendritic spine density. Transcriptome analysis revealed that neuronal EZH2-regulated genes are related to neuronal morphogenesis. In particular, the gene encoding p21-activated kinase 3 (Pak3) was identified as a target gene suppressed by EZH2 and H3K27me3, and expression of the dominant negative Pak3 reversed Ezh2 knockout-induced higher dendritic spine density. Finally, the lack of neuronal EZH2 resulted in impaired memory behaviors in adult mice. Our results demonstrated that neuronal EZH2 acts to control multiple steps of neuronal morphogenesis during development, and has long-lasting effects on cognitive function in adult mice.
Animals ; Mice ; Enhancer of Zeste Homolog 2 Protein/metabolism* ; Histone Methyltransferases/metabolism* ; Histones/genetics* ; Morphogenesis ; Neuronal Plasticity ; Neurons/metabolism*

OBJECTIVE: To investigate the predictive value of methyltransferase EZH2 expression level on the clinical efficacy and long-term prognosis of patients with primary gastrointestinal diffuse large B-cell lymphoma (PGI-DLBCL). METHODS: 161 patients with newly treated PGI-DLBCL in our hospital from August 2013 to July 2019 were selected. The expression level of EZH2 protein was detected by immunohistochemistry, and the short-term efficacy and long-term survival differences of patients with different levels of EZH2 were compared. The predictive values of EZH2 expression level on the short-term efficacy and long-term prognosis of PGI-DLBCL patients were analyzed by Log-rank test and COX risk proportional regression model. Chi-square test and Logistic regression analysis were used to analyze the influencing factors of EZH2 expression level. RESULTS: The complete response (CR) and overal response(OR) rates of those with high EZH2 expression were significantly lower than those with low EZH2 expression (P<0.001). The median OS and PFS of EZH2 high-level and low-level expression group was 37, 31 months and 49, 42 months, respectively. The cumulative OS and PFS rates of the high-level expression group were significantly lower than those of the low-level expression group, and the differences were statistically significant (P<0.05). The high expression levels of H3K27me3, EZH2, BCL-2, BCL-6, c-MYC were closely related to the shortening of OS and PFS, while the high expression level of Ki-67 was closely related to the shortening of OS (P<0.05), of which the high expression levels of H3K27me3, EZH2, BCL-2, and BCL-6 were independent risk factors for shortening of OS and PFS. The expression level of EZH2 was positively correlated with the expression level of H3K27me3, BCL-6, c-MYC and Ki-67 (r=0.741, r=0.837, r=0.809, r=0.772), and the high expression levels of H3K27me3, BCL-6 and Ki-67 were independent factors influencing the high expression of EZH2. CONCLUSION In patients with PGI-DLBCL, the high expression of EZH2 significantly reduces the short-term CR and OR rates, which is an independent risk factor for the shortening of long-term OS and PFS rates, and it is independently related to the high expression of H3K27me3 and BCL6.
Enhancer of Zeste Homolog 2 Protein ; Humans ; Immunohistochemistry ; Lymphoma, Large B-Cell, Diffuse ; Prognosis ; Remission Induction ; Retrospective Studies ; Treatment Outcome

Objective To investigate the expression and correlation of Runt-related transcription factor 3(RUNX3)and enhancer of zeste homolog 2(EZH2)in rectal cancer,and to reveal the relationship between the expression of RUNX3 and EZH2 and the sensitivity of XELOX regimen to neoadjuvant chemotherapy in locally advanced rectal cancer patients. Methods The carcinoma and paracancerous tissues of 31 patients with rectal adenocarcinoma and no preoperative antitumor therapy were selected as cancer group and paracancer group,respectively.The relative mRNA levels of RUNX3 and EZH2 in the two groups were measured by real-time quantitative reverse transcription-polymerase chain reaction,and the protein levels were determined by immunohistochemical assay.The expression of RUNX3 and EZH2 was compared between cancer tissue and paracancerous tissue.The pre-treatment wax blocks of 26 patients with locally advanced rectal cancer who received 3 cycles of XELOX regimen as neoadjuvant chemotherapy before surgery were selected as the pre-neoadjuvant therapy group,and the postoperative pathological wax blocks were selected as the post-neoadjuvant treatment group.Tumor regression grade(TRG)was determined to evaluate the efficacy of neoadjuvant therapy.Immunohistochemical assay was used to detect the protein levels of RUNX3 and EZH2 in the two groups,and then the relationship between the expression patterns of the two proteins and the efficacy of neoadjuvant chemotherapy was analyzed. Results Compared with paracancerous tissue,the cancer tissue showed down-regulated mRNA level and reduced positive protein expression rate of RUNX3,while up-regulated mRNA level(
Core Binding Factor Alpha 3 Subunit/genetics* ; Enhancer of Zeste Homolog 2 Protein/genetics* ; Humans ; Neoadjuvant Therapy ; Rectal Neoplasms/drug therapy* ; Transcription Factor 3

OBJECTIVE: To explore the expression and clinical significance of EZH2 in DLBCL patients accompanied by HBV infection. METHODS: The clinicopathological data of 59 patients with DLBCL accompanied by HBV infection in our hospital from February 2015 to October 2017 were analyzed retrospectively. The patients were divided into HBV negative and HBV positive groups by serological testing before surgery. The expression of EZH2 was detected by immumohistochemical staining, and the clinicopathological characteristics and survival were analyzed and compared between these two groups. RESULTS: There were 30 patients (50.8%) in the HBV negative group and 29 patients (49.2%)in the HBV positive group. The differences of age, LDH level and IPI score between two groups were statistically significant (P＜0.05). The expression of EZH2 in HBV- positive group was significantly higher than that in the HBV- negative group (P＜0.05), where the expression of EZH2 correlated with the expression of the BCL-6 (r=0.282, P＜0.05), especially in the GCB-DLBCL (r=0.549, P＜0.05). PFS was not significantly different between two groups of HBV (P＞0.05), while the PFS in the R-CHOP regimen group was higher than that in the CHOP regimen group (P＜0.05). COX multivariate analysis showed that both the chemotherapy regimen without R and the increased level of LDH were the risk factors affecting the prognosis of DLBCL patients (P＜0.05). CONCLUSION EZH2 highly expresses in HBV positive group, suggesting that the significance of EZH2 in DLBCL with HBV infection is worth further explore.
Antineoplastic Combined Chemotherapy Protocols ; Cyclophosphamide ; Doxorubicin ; Enhancer of Zeste Homolog 2 Protein ; genetics ; Hepatitis B ; complications ; Hepatitis B virus ; Humans ; Lymphoma, Large B-Cell, Diffuse ; complications ; genetics ; Prognosis ; Retrospective Studies ; Rituximab ; Vincristine