Avaliação da expressão da proteína EZH2 em carcinoma adenoide cístico e adenoma pleomórfico / EZH2 immunoexpression in adenoid cystic carcinoma and pleomorphic adenoma

As neoplasias de glândulas salivares apresentam comportamentos diferenciados, que não seguem os padrões clássicos das neoplasias benignas e malignas. A raridade de algumas destas lesões dificulta ainda mais o entendimento dos mecanismos envolvidos na etiopatogenia. Marcadores moleculares como a proteína EZH2 têm sido utilizados na investigação de alterações epigenéticas em diferentes neoplasias, auxiliando na definição do diagnóstico e prognóstico das lesões. O objetivo do presente trabalho é avaliar a expressão da proteína EZH2 e descrever as características clínicas e microscópicas de amostras de carcinoma adenoide cístico (CAC) e adenoma pleomórfico (AP) com ênfase na importância da definição da malignidade da lesão. A análise dos cortes microscópicos corados em Hematoxilina e Eosina dos casos de Adenoma pleomórfico mostraram células epiteliais e mioepiteliais glandulares dispostas em lençóis e estruturas ductiformes em meio a estroma variável. Os casos de Carcinoma adenoide cístico mostraram três padrões distintos de crescimento incluindo formações tubulares, cribriformes e sólidas. Todos os casos de AP e CAC foram positivos para reação imuno-histoquímica para EZH2. As amostras de CAC apresentaram expressão de EZH2 significativamente maior comparado ao AP. As covariáveis metástase em linfonodos, recorrência, padrão histológico, presença de áreas sólidas e invasão perineural foram descritas em relação à marcação de EZH2 em amostras de CAC. Dessa forma, os resultados do estudo melhoram o entendimento das características clínicas e histológicas do CAC, assim como sobre o comportamento das lesões. Além disso, a análise mostra que o EZH2 é um potencial marcador de malignidade e ressalta a importância da validação de marcadores moleculares de alterações epigenéticas.

Salivary gland neoplasms present different behaviors, which do not follow the classic patterns of benign and malignant neoplasms. The rarity of some of these lesions makes it even more difficult to understand the mechanisms involved in the etiopathogenesis. Molecular markers such as the EZH2 protein have been used to investigate epigenetic changes in different neoplasms, helping to define the diagnosis and prognosis of the lesions. The aim of the study was to evaluate the expression of the EZH2 protein and to describe the clinical and microscopic characteristics of adenoid cystic carcinoma (ACC) and pleomorphic adenoma (PA) which emphasizes the importance of defining the malignancy of the neoplasm. Histopathological analysis of PA cases showed myoepithelial and glandular epithelial cells arranged as duct-like structures and sheets intermingled in the variable stroma and ACC cases showed the three growth patterns, tubular, cribriform and solid forms. All ACC and PA cases were positive for EZH2, with diffuse nuclear staining in neoplastic cells. The ACC samples showed significantly higher EZH2 expression compared to the PA. The covariables nodal metastasis, recurrence, growth pattern, presence of solid areas and perineural invasion have been described in relation to EZH2 staining in ACC samples. The results of the study improve the understanding of the clinical and histological characteristics of ACC, as well as on the behavior of lesions. In addition, the analysis showed that EZH2 is a potential marker of malignancy and highlights the importance of validating molecular markers of epigenetic alterations.

Relationship between Expression of Runt-related Transcription Factor 3 and Enhancer of zeste Homolog 2 Proteins and Sensitivity to Neoadjuvant Chemotherapy in Locally Advanced Rectal Cancer / 中国医学科学院学报

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(

Analysis of the Predictive Value of EZH2 Expression Level on the Clinical Efficacy and Long-term Prognosis of Patients with Primary Gastrointestinal Diffuse Large B-cell Lymphoma / 中国实验血液学杂志

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.

Expression and Clinical Significance of EZH2 in Patients with Diffuse Large B Cell Lymphoma Accompanied by HBV Infection / 中国实验血液学杂志

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.

Research Progress of Expression and Clinical Significant of EZH2 in Hematological Malignancies--Review / 中国实验血液学杂志

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 affects dental pulp inflammation by regulating macrophage chemotaxis / 北京大学学报(医学版)

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.

Knockdown of long non-coding RNA HOTAIR reverses cisplatin resistance of ovarian cancer cells through inhibiting miR-138-5p-regulated EZH2 and SIRT1

BACKGROUND: Cisplatin resistance (DDP-resistance) remains one of the major causes of poor prognosis in females with ovarian cancer. Long non-coding RNAs (lncRNAs) have been shown to participate in the regulation of cellular processes, including chemoresistance. The aim of this study was to explore the role of HOX transcript antisense RNA (HOTAIR) in DDP-resistant ovarian cancer cells. METHODS: DDP-resistant ovarian cancer cell lines (SKOV3/DDP and A2780/DDP) were established. Real-time PCR, western blot, dual-luciferase reporter assay, and flow cytometry were then used to evaluate the effect of HOTAIR/miR-138-5p axis on chemoresistance of DDP-resistant ovarian cancer cells to DDP. RESULTS: We found that HOTAIR was upregulated in DDP-resistant cells, while miR-138-5p was downregulated. Knockdown of HOTAIR increased the expression of miR-138-5p in DDP-resistant cells and miR-138-5p is directly bound to HOTAIR. Upregulation of miR-138-5p induced by HOTAIR siRNA or by its mimics enhanced the chemosensitivity of DDP-resistant cells and decreased the expression of EZH2 (enhancer of zeste 2 polycomb repressive complex 2 subunit) and SIRT1 (sirtuin 1). Furthermore, the HOTAIR silencing-induced chemosensitivity of DDP-resistant cells was weakened by miR-138-5p inhibitor. CONCLUSIONS: These data demonstrate that HOTAIR acts as a sponge of miR-138-5p to prevent its binding to EZH2 and SIRT1, thereby promoting DDP-resistance of ovarian cancer cells. Our work will shed light on the development of therapeutic strategies for ovarian cancer treatment.

Expression of MiR101 and EZH2 in Patients with Mantle Cell Lymphoma and Its Clinical Significance / 中国实验血液学杂志

OBJECTIVE@#To investigate the expression of miR-101 and EZH2 in patients with mantle cell lymphoma(MCL) and to analyze its correlation with clinical prognosis of MCL patients.@*METHODS@#RQ-PCR and S-P immunohistochemistry were used to detect the expressions of miR-101 and EZH2 in tissue of MCL patients. CCK-8 was used to assay the effect of miR-100 minics on the proliferation of Jeko-1 and Mino cells; the flow cytometry with Annexin V/PI double staining was used to assay the apoptosis; Western blot was used to assay the effect of miR-101 minics on the expression of EZH2 protein in Jeko-1 and Mino cells.@*RESULTS@#Compared with control group, miR-101 lowly expressed, and EZH2 protein highly expressed in MCL group, with very statistically significant difference(P<0.01).There was negative correlation between miR-101 and EZH2 expression(r=-0.638，P<0.05). The expression of miR-101 and EZH2 significantly correlated with B symptoms, International Prognostic Index(IPI) and Ann Arbor stage, respectively. Survival analysis showed that the overall survival(OS) rate of patients with low expression of miR-101 were significantly lower than that of patients with high miR-101 expression (P=0.0014), the OS rate of patients with EZH2 high expression were significantly lower than that of patients with EZH2 low expression (P=0.0093). The miR-100 minics could inhibit the proliferation of Jeko-1 and Mino cells, and increase the apoptotic rate. The expression of EZH2 protein was markedly suppressed by the miR-100 minics.@*CONCLUSION@#The expression of miR-101 and EZH2 is different in MCL patients with different clinical stage and prognosis. The miR-101 can inhibit the cell proliferation and induce cell apoptosis of mantle cell lymphoma by targeting EZH2.

Role of EZH2 Inhibitor Combined with Gefitinib in EGFR-TKIs Resistant Lung Cancer Cells / 中国肺癌杂志

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.

Effect of enhancer of zeste homolog 2 on the expression of glial cell line-derived neurotrophic factor family receptor α-1 in the colon tissue of children with Hirschsprung's disease / 中国当代儿科杂志

OBJECTIVE@#To study the expression levels of glial cell line-derived neurotrophic factor family receptor α-1 (GFRα1) and enhancer of zeste homolog 2 (EZH2) in the intestinal tissue of children with Hirschsprung's disease (HSCR), as well as the role of EZH2 in the regulation of GFRα1 gene expression and the pathogenesis of HSCR.@*METHODS@#The samples of colon tissue with spasm from 24 children with HSCR after radical treatment of HSCR were selected as the experimental group, and the samples of necrotized colon tissue from 18 children with neonatal necrotizing enterocolitis after surgical resection were selected as the control group. Real-time PCR and Western blot were used to measure the expression levels of GFRα1 and EZH2 in colon tissue in both groups. Human neuroblastoma SH-SY5Y cells were divided into an EZH2 over-expression group and a negative control group. The cells in the EZH2 over-expression group were transfected with pCMV6-EZH2 plasmid, and those in the negative control group were transfected with pCMV6 plasmid. The expression levels of EZH2 and GFRα1 were measured after transfection.@*RESULTS@#Compared with the control group, the experimental group had significant reductions in the mRNA and protein expression levels of GFRα1 and EZH2 in colon tissue (P<0.05), and the protein expression of EZH2 was positively correlated with that of GFRα1 (r=0.606, P=0.002). Compared with the negative control group, the EZH2 over-expression group had significant increases in the expression levels of EZH2 and GFRα1 after SH-SY5Y cells were transfected with EZH2 over-expression plasmid (P<0.05).@*CONCLUSIONS@#Low expression of EZH2 in the colon tissue of children with HSCR may be one of the causes of inadequate expression of GFRα1 and onset of HSCR.

Effect of lincRNA PVT1 associated with Enhancer of Zeste homolog 2 (EZH2) and with androgen receptor (AR) on the large-scale gene expression in LNCaP prostate cancer cells

O lincRNA PVT1 (Plasmacytoma Variant Translocation 1) é um RNA longo não codificador de proteínas (ncRNA) descrito como um oncogene sendo superexpresso em vários tipos de cânceres. LincRNA PVT1 está localizado na região genômica 8q24, também conhecida como 'gene desert'. O nível de expressão do lincRNA PVT1 está associado ao aumento do risco de câncer de próstata (PCa) e está correlacionado com os níveis de expressão do receptor de andrógeno (AR). No entanto, o mecanismo do envolvimento do lincRNA PVT1 com o AR no desenvolvimento de câncer de próstata ainda não está bem esclarecido. Aqui, nós testamos a hipótese que a formação do complexo AR-EZH2-PVT1 participa na regulação da expressão gênica em câncer de próstata, nas células LNCaP. A imunoprecipitação de ribonucleoproteínas seguida de PCR quantitativo (RIP-qPCR) revelou que o lincRNA PVT1 está associado fisicamente ao AR (12% do input) e à metiltransferase EZH2, proteína componente do complexo repressor Polycomb 2 (36% do input) sob condições suplementadas com andrógeno (+R1881). O lincRNA PVT1 também está associado fisicamente ao AR (10% de input) e à EZH2 (42% de input) em condições de privação de andrógeno (-R1881). Assim, a associação física entre lincRNA PVT1, AR e EZH2 é independente do hormônio andrógeno. Usando uma abordagem de estudo em larga-escala de perda e ganho de função, nossos resultados mostraram que o silenciamento do lincRNA PVT1 em células LNCaP na presença de andrógeno restaura a expressão parcialmente, totalmente ou causa superexpressão de 160 genes que tiveram a expressão inibida por andrógeno. Entre esses genes, destacamos genes envolvidos na regulação da diferenciação celular, em componentes da junção célula-célula, na inibição da migração e invasão celular e no desencadeamento da via apoptótica. Imunoprecipitação da cromatina seguida de PCR quantitativo (ChIP-qPCR), em cultura de células LNCaP suplementada com andrógeno sob silenciamento do lincRNA PVT1, mostrou aumento significativo na ocupação pela marca de histona ativadora H3K27Ac do promotor do gene NOV, um dos genes que tiveram sua expressão aumentada com o silenciamento de PVT1. O ChIP-qPCR também mostrou, após o silenciamento do lincRNA PVT1, um aumento significativo da marca H3K27me3 na região enhancer do gene NOV, uma característica de enhancers poised (prontos para ativação). Em conclusão, nós fornecemos a primeira evidência experimental para um mecanismo de ação do oncogene lincRNA PVT1 em células de câncer de próstata e demonstramos que sua ação inibidora da expressão afeta genes alvo que facilitam a proliferação e migração de células do câncer de próstata, sugerindo que o lincRNA PVT1 é um novo agente no complexo mecanismo de repressão transcricional envolvendo um RNA silenciador, o receptor de andrógeno (AR) e o potenciador de Zeste homólogo 2 (EZH2) no remodelamento da cromatina em células LNCaP

Long non-coding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) is an oncogene known to be overexpressed in various types of cancer. PVT1 lincRNA is located in the wellknown cancer-related genomic region 8q24, also known as 'gene desert. PVT1 lincRNA level of expression is associated with increased prostate cancer (PCa) risk and is correlated with androgen receptor (AR) expression levels. However, the mechanism of PVT1 and AR involvement in the development of prostate cancer is still unclear. Here, we tested the hypothesis that formation of the complex AR-EZH2-PVT1 participates in the regulation of gene expression in prostate cancer, in LNCaP cells. Ribonucleoprotein immunoprecipitation followed by quantitative PCR (RIP-qPCR) revealed that PVT1 lincRNA binds both the AR (12 % of PVT1 input) and the methyltransferase EZH2 from the Polycomb repressive complex 2 (36 % of input) under androgen-supplemented conditions (+R1881). PVT1 also binds both AR (10 % of input) and EZH2 (42 % of input) under androgen-deprived conditions (-R1881). Thus, PVT1 binding to AR and EZH2 is independent of the androgen hormone. Using a large-scale loss and gain of function approach, our results show that PVT1 knockdown (KD) in LNCaP in the presence of androgen restores the expression partially, fully or causes overexpression of 160 genes that are inhibited by androgen. Among these genes, we highlight genes involved in regulation of cell differentiation, in components of cell-cell junction, in inhibition of cell migration and invasion and in triggering of the apoptotic pathway. Chromatin immunoprecipitation followed by quantitative PCR (ChIP-qPCR) with LNCaP cells in androgen-supplemented cultures under PVT1 lincRNA knockdown showed a significant increase in occupancy by the histone activation mark H3K27Ac of the promoter region of the NOV gene, one of the genes that had an increased expression upon PVT1 silencing. ChIPqPCR also showed a significant increase upon PVT1 lincRNA silencing of the H3K27me3 histone mark in the enhancer region of the NOV gene, a distinct feature of poised enhancers. In conclusion, we provide first experimental evidence for a mechanism of action of PVT1 lincRNA oncogene in prostate cancer cells, and show that its inhibitory action affects targetgenes that facilitate proliferation and migration of prostate cancer cells, thus suggesting PVT1 lincRNA as a novel lncRNA player in the complex mechanism of transcriptional repression involving a silencer RNA, the androgen receptor (AR) and the Enhancer of zeste homolog 2 (EZH2) in chromatin remodeling in LNCaP cells

Rapamycin Induces Apoptosis of K562 Cells through EZH2/Hedgehog Signaling Pathway / 中国实验血液学杂志

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.

mA Regulates Neurogenesis and Neuronal Development by Modulating Histone Methyltransferase Ezh2 / 基因组蛋白质组与生物信息学报·英文版

N-methyladenosine (mA), catalyzed by the methyltransferase complex consisting of Mettl3 and Mettl14, is the most abundant RNA modification in mRNAs and participates in diverse biological processes. However, the roles and precise mechanisms of mA modification in regulating neuronal development and adult neurogenesis remain unclear. Here, we examined the function of Mettl3, the key component of the complex, in neuronal development and adult neurogenesis of mice. We found that the depletion of Mettl3 significantly reduced mA levels in adult neural stem cells (aNSCs) and inhibited the proliferation of aNSCs. Mettl3 depletion not only inhibited neuronal development and skewed the differentiation of aNSCs more toward glial lineage, but also affected the morphological maturation of newborn neurons in the adult brain. mA immunoprecipitation combined with deep sequencing (MeRIP-seq) revealed that mA was predominantly enriched in transcripts related to neurogenesis and neuronal development. Mechanistically, mA was present on the transcripts of histone methyltransferase Ezh2, and its reduction upon Mettl3 knockdown decreased both Ezh2 protein expression and consequent H3K27me3 levels. The defects of neurogenesis and neuronal development induced by Mettl3 depletion could be rescued by Ezh2 overexpression. Collectively, our results uncover a crosstalk between RNA and histone modifications and indicate that Mettl3-mediated mA modification plays an important role in regulating neurogenesis and neuronal development through modulating Ezh2.

Construction of EZH2 Knockout Animal Model by CRISPR/Cas9 Technology / 中国肺癌杂志

BACKGROUND@#It has been proven that CRISPR/Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated 9) system was the modern gene-editing technology through the constitutive expression of nucleases Cas9 in the mammalian, which binds to the specific site in the genome mediated by single-guide RNA (sgRNA) at desired genomic loci. The aim of this study is that the animal model of EZH2 gene knockout was constructed using CRISPR/Cas9 technology.@*METHODS@#In this study, we designed two single-guide RNAs targeting the Exon3 and Exon4 of EZH2 gene. Then, their gene-targeting efficiency were detected by SURVEYOR assay. The lentivirus was perfused into the lungs of mice by using a bronchial tube and detected by immunohistochemistry and qRT-PCR.@*RESULTS@#The experimental results of NIH-3T3 cells verify that the designed sgEZH2 can efficiently effect the cleavage of target DNA by Cas9 in vitro. The immunohistochemistry and qRT-PCR results showed that the EZH2 expression in experimental group was significantly decreased in the mouse lung tissue.@*CONCLUSIONS@#The study successfully designed two sgRNA which can play a knock-out EZH2 function. An EZH2 knockout animal model was successfully constructed by CRISPR/Cas9 system, and it will be an effective animal model for studying the functions and mechanisms of EZH2.

Therapeutic effect of enhancer of Zeste homolog 2 inhibitor GSK343 on periodontitis by regulating macrophage differentiation / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To explore the therapeutic effect of enhancer of Zeste homolog 2 (EZH2) inhibitor GSK343 on periodontitis by regulating microphage differentiation.</p><p><b>METHODS</b>Macrophage RAW264.7 cells were divided into the blank (A group), control (B group), lipopolysaccharide (LPS) stimulation (C group), and LPS+GSK343 (D group) groups. Phenotype transformations was determined through Western blot analysis and enzyme-linked immunosorbent assay by detecting the differentiation of phenotypic biological markers, including tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), interleukin-10 (IL-10), and Arginase-1 (Arg-1). Metergasis was identified by performing a phagocytosis test on Escherichia coli (E. coli).</p><p><b>RESULTS</b>Macrophage RAW264.7 cells produced classical phenotypic biomarkers (M1) TNF-α and iNOS under LPS stimulation. The expression levels of IL-10 and Arg-1 increased after adding GSK343 into the culture medium. GSK343 also induced the conversion of M1 macrophages into M2 macrophages. Macrophage RAW264.7 cells exerted a phagocytic effect on E. coli, and this effect was enhanced after adding LPS into the culture medium. GSK343 regulated the macrophage RAW264.7 phagocytosis of E. coli.</p><p><b>CONCLUSIONS</b>GSK343 possibly participates in the regulation of macrophage differentiation and, consequently, in the latent treatment of periodontitis.</p>

EZH2 Protein Expression and Tumor Response to Neoadjuvant Chemotherapy in Locally Advanced Breast Cancer / Expressão da proteína EZH2 e resposta tumoral à quimioterapia neoadjuvante no câncer de mama localmente avançado

Abstract Introduction Neoadjuvant chemotherapy (NAC) is the standard treatment for locally advanced breast cancer. However, some tumors will not respond to this treatment due to histological and molecular features. The protein EZH2 (enhancer of zest homolog 2) is a histone methyltransferase that is correlated with poorly differentiated breast carcinomas and aggressive tumor behavior. Purpose The present study evaluated the association between EZH2 expression and response to NAC, and its correlation with HER2 overexpression, estrogen and progesterone receptors (ER, PR) and Ki-67 proliferation index. Methods A total of 60 patients with locally advanced breast cancer treated with NAC were selected for this study. Twenty-three paraffin blocks had not enough material for tissue resection, and were not evaluated. A tissue microarray based in immunohistochemistry (IHC) analysis of EZH2 was performed for the remaining 37 specimens. Patients were divided into two groups based on response to NAC. Results EZH2 expression was significantly associated with markers of poor prognosis such as ER negativity (p = 0.001), PR negativity (p = 0.042) and high Ki-67 proliferation index (p = 0.002). High EZH2 expression was not correlated with the response to NAC. Conclusions Our data suggested that EZH2 protein expression may not correlate with the clinical response to NAC. Other studies with more patients are needed to confirm this observation.

Resumo Introdução A quimioterapia neoadjuvante é o tratamento padrão para os cânceres de mama localmente avançados. Entretanto, apenas uma porcentagem desses tumores irá responder ao tratamento, devido a características histológicas e moleculares. A proteína EZH2 (enhancer of zest homolog 2) é uma histona metiltransferase associada a tumores mal diferenciados e de comportamento agressivo. Objetivo O presente estudo teve como objetivo avaliar a associação entre a expressão da proteína EZH2 e a resposta à quimioterapia neoadjuvante, além da correlação dessa proteína com hiper-expressão de HER2, receptores de estrogênio e progesterona, e o marcador de proliferação Ki-67. Métodos Um total de 60 pacientes com câncer de mama localmente avançado tratadas com quimioterapia neoadjuvante foram selecionadas para esse estudo. Vinte e três blocos de parafina não continham material suficiente para ressecção e não foram avaliados. Foi realizado microarray baseado em análise imuno-histoquímica da proteína EZH2 para as 36 pacientes restantes. As pacientes foram divididas em dois grupos baseado na resposta à quimioterapia neoadjuvante. Resultados A expressão da proteína EZH2 foi significativamente associada com marcadores de pior prognóstico, como negatividade para receptor de estrogênio (p = 0,001) e progesterona (p = 0,042), além de alto Ki-67 (p = 0,002). Entretanto, a alta expressão da EZH2 não se correlacionou com a resposta à quimioterapia neoadjuvante. Conclusões Nossos dados sugerem que a expressão da proteína EZH2 pode não estar relacionada com a resposta clínica à quimioterapia neoadjuvante. Outros estudos com maior número de pacientes são necessários para confirmar esses achados.

Effect of a novel EZH2 inhibitor GSK126 on prostate cancer cells / 浙江大学学报·医学版

To investigate the effect of a novel EZH2 inhibitor GSK126 on cell growth, apoptosis and migration of prostate cancer cells.Prostate cancer PC-3 and DU145 cells were treated with GSK126 at different doses. Cell growth was detected by sulforhodamine assay. Cell apoptosis was assayed by Annexin V-/PI kit. Transwell chamber and wound healing assays were conducted to detect cell migration. The mRNA level was detected by quantitative PCR, and protein expression was detected by Western blot analysis.GSK126 showed significant effect on cell growth and apoptosis when the dose was higher than 50 μmol/L. Wound healing assay revealed that scratch space in PC-3 cells was significantly increased in a dose-dependent manner in GSK126-treated groups[(247.2±24.4),(347.2±19.2) and (410.5±18.1) μm in low, medium and high dose (5.0, 20.0, 50.0 μmol/L), respectively] as compared with the control group[(171.3±17.8) μm](all<0.05). Transwell assay showed that migrated PC-3 cells in control group was 322.0±17.9,while those in GSK126-treated groups were 198.3±15.4 (low),82.7±6.2 (medium) and 30.2±4.1 (high), and the differences between the control group and GSK126-treated groups were significant(all<0.05). In addition, GSK126 up-regulated E-cadherin mRNA expression and down-regulated N-cadherin and Vimentin mRNA expression, whereas had no significant effect on Snail, Fibronectin and VEGF-A mRNA expression. The protein expression of E-cadherin was elevated but VEGF-A protein did not change in GSK126-treated groups. Similar results were exhibited in DU145 cell.GSK126 can significantly inhibit cell migration and invasion in prostate cancer PC-3 and DU145 cells, which may be resulted from its effect on epithelial-mesenchymal transition. GSK126 may be used as a potential anti-prostate cancer dug in clinic.

miRNA-101 inhibits the expression of the enhancer of zeste homolog 2 in androgen-independent prostate cancer LNCaP cell line / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the effect of miRNA-101 on the expression of the enhancer of zeste homolog 2 (EXH2) in human androgen-independent prostated cancer LNCaP cells.</p><p><b>METHODS</b>We divided LNCaP cells into a blank control, a negative control, and a miRNA-l01 transfection group, constructed the vector by transfecting synthetic miRNA-101 mimics into the LNCaP cells, and evaluated the efficiency of transfection by fluorescence microscopy. Then we determined the expression level of EZH2 mRNA by qRT-PCR in the three groups of cells and that of the EZH2 protein in the negative control and transfection groups by Western blot.</p><p><b>RESULTS</b>Green fluorescence signals were observed in over 70% of the LNCaP cells in the transfection group after 24 hours of transfection. At 72 hours, the expression of miRNA-101 was significantly upregulated in the transfected cells (P < 0.01), that of EZH2 mRNA was remarkably lower in the transfection group (0.01 ± 0.10) than in the blank control (0.95 ± 0.40) and negative control (0.86 ± 0.30) groups (both P < 0.01), and that of the EZH2 protein was increased in the negative control but decreased in the transfection group with the extension of culture time.</p><p><b>CONCLUSION</b>miRNA-101, with its inhibitory effect on the expression of EZH2 in LNCaP cells, is a potential biotherapeutic for prostate cancer.</p>

Expression of enhancer of zeste homolog 2 in esophageal squamous cell carcinoma and its prognostic value in postoperative patients / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the expression of enhancer of zeste homolog 2 (EZH2) in esophageal squamous cell carcinoma and its association with the prognosis of postoperative patients.</p><p><b>METHODS</b>Surgical specimens were obtained from 102 patients with esophageal squamous cell carcinoma undergoing radical resection in our hospital from 1996 to 2006. Immunochemistry was employed to examine EZH2 protein expressions in the specimens, including 102 carcinoma tissue specimens, 30 adjacent tissue specimens and 30 normal esophageal tissue specimens. The expression levels of EZH2 were analyzed in relation to the clinicopathological parameters of the patients including gender, age, tumor differentiation, TNM, and lymph node metastasis. The postoperative patients were followed up to analyze the association of EZH2 expression with the clinical outcomes.</p><p><b>RESULTS</b>The esophageal squamous cell carcinoma tissue showed a higher EZH2 expression than the adjacent and normal esophageal tissues. EZH2 expression was higher in poorly differentiated carcinoma than in well differentiated tissue, and also higher in cases with lymph node metastasis than those without; the expression was higher in TNM stage II/III patients than in stage I patients but lower than in stage IV patients. The patients with low EZH2 expression was found to have a longer survival time than those with high EZH2 expression (P<0.05).</p><p><b>CONCLUSION</b>EZH2 plays an important role in the differentiation and metastasis of esophageal squamous cell carcinoma, and a high EZH2 expression is associated with a poor outcome in the the postoperative patients.</p>

Screening of novel miRNAs targeting EZH2 3' untranslated region using lentivirus miRNAs library and their expressions in breast cancer cells and tissues / 南方医科大学学报

<p><b>OBJECTIVE</b>To screen novel miRNAs targeting EZH2 3' untranslated region (UTR) in recombinational MCF-7 breast cancer cells over-expressing EZH2 3' UTR and quantitative analyze the expressions of the screened miRNA in breast cancer cells and tissues.</p><p><b>METHODS</b>A lentiviral library was transfected into the recombinant cell line MCF-7. The cells were screened with cytotoxic agents before extraction of the genome for amplification of the miRNA precursors using PCR. The screened miRNAs were identified with sequence analysis and their expressions were analyzed quantitatively with real-time PCR in breast cancer cells and tissues.</p><p><b>RESULTS</b>Seven miRNAs were screened from the recombinant MCF-7 cells, namely miR-15b, miR-16-2, miR-181b2, miR-217, miR-224, miR-329-1, and miR-487b, all of which failed to be predicted by bioinformatics software. Real-time PCR showed that miR-217, miR-329-1, and miR-487b were over-expressed in MCF-7 cells, and the expression of miR-15b and miR-16-2 was significantly increased in cancer tissues compared with the adjacent tissues (P<0.05).</p><p><b>CONCLUSION</b>Novel targeted miRNAs that can not be predicted by bioinformatics software were successfully screened from MCF-7 breast cancer cells over-expressing EZH2 3' UTR. These miRNAs are expressed differentially between normal breast cells and breast cancer tissues.</p>