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 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 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 changes of the epigenetic regulator enhancer of zeste homolog 2 (EZH2) during pulp inflammation and the effect of EZH2 on macrophages migration. METHODS: Rat dental pulp was stimulated with 10 g/L lipopolysaccharide (LPS) to establish a model of rat pulpitis at different stages of inflammation. Immunohistochemical staining was used to detect the expression changes of EZH2 during the progression of pulp inflammation. Immunofluorescence double staining was used to detect the expression of EZH2, CD68 and their colocalization. To screen the appropriate concentration of EZH2 recombinant protein to stimulate hDPCs and human leukaemia-derived monocytic cell line (THP-1) cells, the effects of different concentrations (1, 10, 20, 40, and 100 μg/L) of EZH2 recombinant protein on proliferation of human dental pulp cells (hDPCs) and human monocyte cell line THP-1 were detected by cell counting kit-8 (CCK-8). Transwell migration assay was used to detect the effect of supernatants of hDPCs treated with EZH2 recombinant protein on the migration of THP-1 cells. RESULTS: HE staining results showed that in the model of rat pulp inflammation induced by LPS, with the prolongation of LPS stimulation, the inflammation response of pulp gradually increased. Immunohistochemical results showed that EZH2 expression decreased within 8 h of LPS-induced dental pulp inflammation; but after 1, 3, and 7 d of stimulation, EZH2 expression gradually increased with the extension of the stimulation time. As for the normal rat dental pulp tissue, the positive expression of EZH2 was scattered in the odontoblast cell layer and the pulp proper. Compared with the control group, LPS stimulated the expression of EZH2 and CD68 in the infected dental pulp, and the colocalization of EZH2 and CD68 could be detected in macrophages. The results of CCK-8 suggested that the appropriate concentration of EZH2 recombinant protein to stimulate hDPCs and THP-1 cells was 20 μg/L. Transwell cell migration assay confirmed that compared with the supernatant of EZH2 untreated HDPCs group, the supernatant of EZH2treated hDPCs significantly promoted macrophage chemotaxis. CONCLUSION EZH2 is involved in the development of pulpitis and promotes the chemotaxis of macrophages, which suggests that EZH2 may play an important regulatory role in the development of pulp inflammation.
Animals ; Cells, Cultured ; Chemotaxis ; Dental Pulp ; Enhancer of Zeste Homolog 2 Protein ; Humans ; Inflammation ; Macrophages ; Rats

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

Enhancer of zeste homolog 2(EZH2) is a histone methyltransferase which regulate gene expression through epigenetic machinery. The abnormal expression of EZH2 has been described in many cancer types. With in-depth study, it was found that EZH2 is involved in the occurrence and development in many kinds of malignant hematologic disease which may play a dual role of oncogenes and tumor suppressor genes. In recent years, the emergence of EZH2 inhibitors provide a new option for the future treatment of hematological malignancies. In this review, the expression and clinical significance of EZH2 in various of hematological tumors were summarized briefly.
Enhancer of Zeste Homolog 2 Protein/genetics* ; Hematologic Neoplasms/genetics* ; Humans ; Neoplasms ; Oncogenes ; Research

BACKGROUND: Lung cancer is one of the common malignant tumors that impair human health. With the development of epigenetics, the researchers found that enhancer of Zeste homolog 2 (EZH2) is highly expressed in lung cancer tissue and its expression is closely related to the prognosis. EZH2 inhibitor can also enhance the sensitivity of tumor cells to a variety of anti-tumor drugs. The purpose of this study is to investigate the effect of combination of EZH2 inhibitor and gefitinib on the proliferation, apoptosis and migration of Gefitinib-resistant lung cancer cells. METHODS: PC9 and PC9/AB2 cells were used for this study. CCK-8 and EdU experiment were used to detect combined treatment on cell viability and proliferation activity; Wound healing assay and Transwell chamber experiment were used to determine the effects of combination therapy on cell migration ability; Flow cytometry was used to detect the effect of combination therapy on EZH2 and apoptosis; Western blot was used to observe the effect of combination therapy on epidermal growth factor receptor (EGFR) signaling pathway-related proteins expression. RESULTS: In gefitinib-resistant cell line PC9/AB2, gefitinib combined with EZH2 inhibitor GSK343 can significantly inhibit cell viability, reduce cell migration and increase cell apoptosis. At the same time, combination therapy can significantly inhibit the expression of EZH2 and phosphorylation EGFR proteins. CONCLUSIONS The combination of EZH2 inhibitor GSK343 and gefitinib sensitize PC9/AB2 cell to gefitinib response. This study also suggests that synergistic therapy plays a role in the reversal of EGFR-tyrosine kinase inhibitor (EGFR-TKIs) resistance in lung cancer.
Antineoplastic Agents ; pharmacology ; Cell Line, Tumor ; Cell Movement ; drug effects ; Cell Proliferation ; drug effects ; Cell Survival ; drug effects ; Drug Resistance, Neoplasm ; drug effects ; Drug Synergism ; Enhancer of Zeste Homolog 2 Protein ; antagonists & inhibitors ; ErbB Receptors ; antagonists & inhibitors ; Gefitinib ; pharmacology ; Humans ; Lung Neoplasms ; pathology ; Protein Kinase Inhibitors ; pharmacology

OBJECTIVE: To investigate the mechanism of rapamycin-induced apoptosis of chronic myelogenous leukemia cells. METHODS: The chronic granulocytic leukemia K562 cells were divided into 3 groups: A, B and C group were treated with rapamycin of 10, 15 and 20 nmol/L, repectively for 24 h, while the K562 cells in control group were not treated with rapamycin. The effect of rapamycin on the proliferation of K562 cells was detected by MTT, and the effect of rapamycin on the apoptosis of K562 cells was detected by AnnexinV-FITC/PI double staining. The expression level of EZH2/Hedgehog signaling pathway genes in K562 cells was detected by RT-PCR, and Western blot was used to detect the levels of apoptotic protein and the related signaling pathway proteins in K562 cells. RESULTS: The MTT assay showed that the different concentration of rapamycin had obvious inhibitory effects on the cells, and the survival rate of cells in group C was 37.6%±3.4%, which was significantly lower than that of the other groups (P＜0.05). The apoptosis rate of cells in group C was 93.1%±8.1%, which was significantly higher than that of the other groups (P＜0.05). By Western blot, it was found that the relative expression levels of Caspase-3 and BAX protein in group C were 0.36 ± 0.04 and 0.39±0.06, respectively, which were significantly higher than those in other groups (P＜0.05), and the level of BCL-2 protein was 0.17±0.03, which was significantly lower than that of other groups (P＜0.05). By RT-PCR, it was found that the mRNA levels of EZH2 and Hedgehog genes in A, B and C groups were significantly lower than those in the control group (P＜0.05), but mRNA level of Ptch1 gene was significantly higher than that of the control (P＜0.05). By Western blot, it was found that the expression levels of EZH2 and Hedgehog protein in A, B and C groups were significantly lower than that in the control group (P＜0.05), but the level of Ptch1 protein was higher than that of the control (P＜0.05). The relative levels of EZH2 and Hedgehog protein in group C were 0.21 ±0.03 and 0.16±0.05 respectively, which were significantly lower than those in other groups (P＜0.05), and Ptch1 protein level were 0.46 ±0.06, significantly higher than that of other groups (P＜0.05). CONCLUSION Rapamycin can inhibit the protein expression of EZH2 in leukemic cells, thus interfere with the activation of Hedgehog signaling pathway, promote the expression of apoptotic protein, reduce the level of anti apoptotic protein, and eventually induce apoptosis of leukemia cells.
Apoptosis ; Cell Proliferation ; Enhancer of Zeste Homolog 2 Protein ; Hedgehog Proteins ; Humans ; K562 Cells ; Signal Transduction ; drug effects ; Sirolimus