High Enhancer Of Zeste Homolog 2 Research Articles

The potential of EZH2 expression to facilitate treatment choice in stage II colorectal adenocarcinoma.

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. 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. 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. 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.

MicroRNA let-7c-5p Alleviates in Hepatocellular Carcinoma by Targeting Enhancer of Zeste Homolog 2: A Study Intersecting Bioinformatic Analysis and Validated Experiments.

Enhancer of zeste homolog 2 (EZH2)gene has a prognostic role in hepatocellular carcinoma (HCC). This study aimed to identify the role of microRNAs (miRNAs) let-7c-5p by targeting EZH2 in HCC. We downloaded gene and miRNA RNA-seq data from The Cancer Genome Atlas (TCGA) database. Differences in EZH2 expression between different groups were analyzed and the association of EZH2 expression with HCC prognosis was detected using Cox regression analysis. The miRNA-EZH2-pathway network was constructed. Dual-luciferase reporter assay was performed to detect the hsa-let-7c-5p-EZH2. Cell proliferation, migration, invasion, and apoptosis were detected by CCK-8, Wound healing, Transwell, and Flow cytometry, respectively. RT-qPCR and Western blot were used to detect the expression of let-7c-5p and EZH2. EZH2 was upregulated in HCC tumors (P < 0.0001). Cox regression analysis showed that TCGA HCC patients with high EZH2 expression levels showed a short survival time [hazard ratio (HR) = 1.677, 95% confidence interval (CI) 1.316-2.137; P < 0.0001]. Seven miRNAs were negatively correlated with EZH2 expression and were significantly downregulated in HCC tumor samples (P < 0.0001), in which hsa-let-7c-5p was associated with prognosis in HCC (HR = 0.849 95% CI 0.739-0.975; P = 0.021). We identified 14 immune cells that showed significant differences in EZH2 high- and low-expression groups. Additionally, let-7c-5p inhibited HCC cell proliferation, migration, and invasion and reversed the promoted effects of EZH2 on HCC cell malignant characteristics. hsa-let-7c-5p-EZH2 significantly suppressed HCC malignant characteristics, which can be used for HCC prognosis.

Comparative analysis of EZH2, p16 and p53 expression in uterine carcinosarcomas.

Introduction: The role of p16 and p53 immunohistochemistry in the diagnosis of rare and aggressive uterine carcinosarcoma (UCS) has been well established. However, enhancer of zeste homolog 2 (EZH2), a histone methyltransferase and a member of the polycomb group family is a relatively new biomarker, with limited published data on its significance in this tumor type. The goal of this study was to examine EZH2 expression in UCS and its components, in correlation with morphological features, and p16 and p53 staining patterns. Methods: Twenty-eight UCSs were included in the study. EZH2, p16 and p53 immunoreactivity were assessed independently by two pathologists in both tumor components (epithelial and mesenchymal). EZH2 and p16 immunostains were scored semiquantitatively: based on the percentage and intensity of tumor cell staining a binary staining index ("high- or low-expressing") was calculated. The p53 staining pattern was evaluated as wild-type or aberrant (diffuse nuclear, null, or cytoplasmic expression). Statistical tests were used to evaluate the correlation between staining patterns for all three markers and the different tumor components and histotypes. Results: High EZH2 and p16 expression and aberrant p53 patterns were present in 89.3% 78.6% and 85.7% of the epithelial component and in 78.6%, 62.5% and 82.1% of the mesenchymal component, respectively. Differences among these expression rates were not found to be significant (p > 0.05). Regarding the epithelial component, aberrant p53 pattern was found to be significantly (p = 0.0474) more frequent in the serous (100%) than in endometrioid (66.6%) histotypes. Within the mesenchymal component, p53 null expression pattern occurred significantly (p = 0.0257) more frequently in heterologous sarcoma components (71.4%) compared to the homologous histotype (18.8%). Conclusion: In conclusion, EZH2, p16 and p53 seem to play a universal role in the pathogenesis of UCS; however, a distinctive pattern of p53 expression appears to exist between the serous and endometrioid carcinoma components and also between the homologous and heterologous sarcoma components.

EZH2 as a prognostic-related biomarker in lung adenocarcinoma correlating with cell cycle and immune infiltrates

BackgroundsIt has been observed that high levels of enhancer of zeste homolog 2 (EZH2) expression are associated with unsatisfactory prognoses and can be found in a wide range of malignancies. However, the effects of EZH2 on Lung Adenocarcinoma (LUAD) remain elusive. Through the integration of bioinformatic analyses, the present paper sought to ascertain the effects of EZH2 in LUAD.MethodsThe TIMER and UALCAN databases were applied to analyze mRNA and protein expression data for EZH2 in LUAD. The result of immunohistochemistry was obtained from the HPA database, and the survival curve was drawn according to the library provided by the HPA database. The LinkedOmics database was utilized to investigate the co-expressed genes and signal transduction pathways with EZH2. Up- and down-regulated genes from The Linked Omics database were introduced to the CMap database to predict potential drug targets for LUAD using the CMap database. The association between EZH2 and cancer-infiltrating immunocytes was studied through TIMER and TISIDB. In addition, this paper explores the relationship between EZH2 mRNA expression and NSCLC OS using the Kaplan–Meier plotter database to further validate and complement the research. Furthermore, the correlation between EZH2 expression and EGFR genes, KRAS genes, BRAF genes, and smoking from the Cancer Genome Atlas (TCGA) database is analyzed.ResultsIn contrast to paracancer specimens, the mRNA and protein levels of EZH2 were higher in LUAD tissues. Significantly, high levels of EZH2 were associated with unsatisfactory prognoses in LUAD patients. Additionally, the coexpressed genes of EZH2 were predominantly associated with numerous cell growth-associated pathways, including the cell cycle, DNA replication, RNA transport, and the p53 signaling pathway, according to Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways. The results of TCGA database revealed that the expression of EZH2 was lower in normal tissues than in lung cancer tissues (p < 0.05). Smoking was associated with elevated EZH2 expression (p < 0.001). EZH2 was highly expressed in lung cancers with positive KRAS expression, and the correlation was significant in lung adenocarcinoma (r = 0.3129, p < 0.001). CMap was applied to determine the top 15 positively correlated drugs/molecules and the top 15 negatively correlated drugs/molecules. MK-1775, MK-5108, fenbendazole, albendazole, BAY-K8644, evodiamine, purvalanol-a, mycophenolic-acid, PHA-793887, and cyclopamine are potential drugs for patients with lung adenocarcinoma and high EZH2 expression.ConclusionsHighly expressed EZH2 is a predictor of a suboptimal prognosis in LUAD and may serve as a prognostic marker and target gene for LUAD. The underlying cause may be associated with the synergistic effect of KRAS, immune cell infiltration, and metabolic processes.

EZH2-regulated immune risk score prognostic model predicts outcome of clear cell renal cell carcinoma.

The enhancer of zeste homolog 2 (EZH2) plays an important role in the tumor microenvironment (TME), and EZH2 in shaping the epigenetic landscape of CD8+ T cell fate and function, with a particular emphasis on cancer. Here, high EZH2 expression always leads to less CD8+ T cell infiltration. However, clear cell renal cell carcinoma (ccRCC) is reportedly a "hot" tumor, with contradictory high EZH2 expression. Our goal was to construct a EZH2-regulated immune risk score prognostic model to predict ccRCC outcomes, and provide a prospect of clinical EZH2 inhibitors in fine-tuning T cell responses with immune therapy. We downloaded and analyzed The Cancer Genome Atlas (TCGA), Cancer Cell Line Encyclopedia (CCLE), TISIDB database, and WebGestalt for ccRCC patients, EZH2-related tumor-infiltrating lymphocytes and immunomodulators. R packages "limma", "BiocManager", and "preprocessCore", etc. were downloaded to prepare CIBERSORT files, immune cells heatmap, multivariable Cox model and survival analysis. The EZH2-regulated immune risk model's prognostic ability was calculated by receiver operating characteristic (ROC) and area under the curve (AUC) analyses in R studio. EZH2 was highly expressed and related to poor outcome in ccRCC. However, high-expression EZH2 was not related to a "cool" tumor. Of the 49 immunomodulators significantly regulated by EZH2, forest plot showed 26 immunomodulators signatures independently associated with overall survival. The EZH2-regulated immune-risk score prognostic model was an independent prognostic factor (AUC =0.816), especially combined with clinicopathologic parameters in ccRCC overall survival prediction. The EZH2-regulated immune-risk score prognostic model was an independent prognostic factor, with good accuracy and predictability, and could provide experimental data to the clinical area.

Expression of EZH2 and H3K27me3 predicts tumor biology of urothelial carcinoma.

Enhancer of zeste homolog 2 (EZH2) is one of the major epigenetic modifiers involved in the transcriptional repression of target genes through trimethylation of H3K27 (lysine 27 residue of histone H3). Deregulated expression of both EZH2 and H3K27me3 has been implicated in the biological behavior and prognostic outcome of various malignancies. To assess the role of EZH2 and H3K27me3 in the carcinogenesis of urothelial carcinoma of urinary bladder. One hundred fifty consecutive urothelial carcinoma cases of urinary bladder (54.7% high-grade) were included in this study. Immunohistochemical analysis for EZH2 and H3K27me3 was performed on whole tissue sections. A multiplication score obtained by multiplying staining intensity and proportion of positively stained neoplastic cells was used for assessment. EZH2 showed a significant correlation with the tumor grade and lamina propria invasion (p < 0.001). The cases with high EZH2 expression showed a significantly high proliferative index (Mean- 32.7%; p < 0.001). In contrast, negative and low expression of H3K27me3 was significantly more common in high-grade cases (p = 0.006). The expression of H3K27me3 was significantly associated with lamina propria (p = 0.01) and deep muscle invasion (p = 0.007). EZH2 showed a significantly higher expression in the high-grade invasive areas as compared to the high-grade non-invasive areas of the same tumor (p = 0.03). This study establishes an important role of the key epigenetic regulators EZH2 and H3K27me3 in the pathobiology of urothelial carcinomas. Strong expression of EZH2 and weak expression of H3K27me3 are associated with higher grade, proliferative index and invasive behavior.

Mutually exclusive expression of EZH2 and H3K27me3 in non-small cell lung carcinoma

Enhancer of zeste homolog 2 (EZH2) epigenetically represses gene expression via trimethylation of lysine 27 on histone 3 (H3K27me3). Non-small cell carcinoma (NSCLC) has been reported to show high EZH2 and low H3K27me3 expression compared to normal lung tissues, but there are no studies examining the expression of EZH2 and H3K27me3 simultaneously with immunohistochemistry. In the present study, the expression of EZH2 and H3K27me3 was examined in surgically resected NSCLC. We enrolled 27 cases of squamous cell carcinoma (SCC), 73 cases of Lepidic, 77 of Papillary/Acinar, 51 of Solid, 31 of Micropapillary, and 12 of Mucinous subtypes of adenocarcinoma. First, we examined the expression of EZH2 and H3K27me3 in normal and metaplastic bronchial epithelium adjacent to NSCLC. Normal bronchial epithelium showed EZH2 expression in a limited number of basal cells and H3K27me3 expression in surface differentiated cells with cilia or mucus. In metaplastic bronchial epithelium, the number of EZH2-positive cells increased in multilayered basal cells, and H3K27me3-positive cells were observed in the superficial layer. Then, EZH2 and H3K27me3 expression was analyzed in NSCLC. Abundant EZH2 and rare H3K27me3 expression was detected in SCC, Papillary/Acinar, Solid and Micropapillary subtypes. In Mucinous subtype, EZH2 expression was hardly detected, and H3K27me3 expression was detected in almost all tumor cells. EZH2-expressing and H3K27me3-expressing tumor cells were similarly observed in Lepidic subtype, but double immunofluorescence revealed that EZH2 and H3K27me3 expression pattern was mutually exclusive. No co-expression of EZH2 and H3K27me3 was detected in all examined subtypes. To our knowledge, there have been no reports describing mutually exclusive expression pattern of EZH2 and H3K27me3.

Combined Detection of RUNX3 and EZH2 in Evaluating Efficacy of Neoadjuvant Therapy and Prognostic Value of Middle and Low Locally Advanced Rectal Cancer.

ObjectiveThis article investigated whether Runt-Related Transcription Factor 3 (RUNX3) and enhancer of zeste homolog 2 (EZH2) can be used to evaluate the clinical efficacy of neoadjuvant therapy and prognosis of locally advanced rectal cancer (LARC). MethodsEighty LARC patients admitted to the Tianjin Medical University Cancer Institute/Hospital and First Affiliated Hospital of Hebei North University from Jan 2015 to Jan 2016 were enrolled. The patients were followed up for 60 months through hospital visits. All patients received neoadjuvant chemoradiotherapy (long range radiotherapy + oral capecitabine) + total mesorecta excision (TME) surgery. The clinical efficacy of the treatments was evaluated through endoscopic, radiography, and tumor regression grade (TRG). In addition, expression level of RUNX3 and EZH2 was quantified via immunohistochemistry. The association of RUNX3 and EZH2 with clinicopathological characteristics of advanced tumors and efficacy of neoadjuvant therapy was explored. Logistic regression analysis was performed to identify predictors of efficacy of neoadjuvant chemoradiotherapy. Survival curve was used to evaluate the impact of RUNX3 and EZH2 on the prognosis of LARC patients.ResultsA total of 80 patients diagnosed with LARC were enrolled in the study. Expression of RUNX3 was elevated in 25 (31.25%) patients, whereas expression of EZH2 was upregulated in 44 (55.00%) patients. Analysis of tumor regression identified 10 cases with TRG grade 0 (pathologic complete response, PCR), 24 cases with TRG grade 1, 35 cases with TRG grade 2, and 11 cases with TRG grade 3. Furthermore, 38 cases had significant down-staging, and 42 cases showed no significant down-staging as revealed by endoscopy and imaging. Patients with high expression of RUNX3 showed better tumor regression response and down-staging compared with those with low expression of RUNX3 (P < 0.001, P < 0.001). Moreover, patients with low EZH2 expression achieved TRG grade 0 and 1 response and down-staging effect compared with those with high expression of EZH2 (P < 0.001, P < 0.001). Logistic regression analysis showed that high expression of RUNX3, low expression of EZH2, and clinical N (cN) stage were good predictors of tumor regression response and down-staging. The 5-year disease free survival (DFS) and overall survival (OS) were 48.75 (39/80) and 58.75% (47/80), respectively. The 5-year DFS and OS of patients with high RUNX3 expression were significantly higher than low RUNX3 expression, whereas the 5-year DFS and OS of patients with high EZH2 expression were significantly lower than low EZH2 expression (P < 0.001). Univariate survival analysis showed that RUNX3 expression, EZH2 expression, cN, clinical T (cT), pathological T (pT) and pathological N (pN) were significantly correlated with the 5-year DFS and 5-year OS. Multivariate survival analysis showed that EZH2 expression and PN were good predictors of 5-year DFS and 5-year OS, whereas RUNX3 was a good predictor of 5-year DFS but not 5-year OS.ConclusionsExpression level of RUNX3 and EZH2 accurately predicts clinical efficacy of neoadjuvant chemoradiotherapy and the prognosis of LARC patients, suggesting that RUNX3 and EZH2 can be used as pivotal clinical predictors for LARC.

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

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(P=0.001)and increased positive protein expression rate of EZH2(P=0.022).The mRNA levels of RUNX3 and EZH2 in the cancer group were negatively correlated(r=-0.599,P=0.000).Twelve patients who received neoadjuvant chemotherapy reached TRG0-TRG2,and the overall effective rate of neoadjuvant chemotherapy was 46.15%(12/26).Compared with pre-neoadjuvant therapy group,the post-neoadjuvant therapy group had increased positive expression rate of RUNX3 protein(P=0.163)and decreased positive expression rate of EZH2 protein(P=0.095).In the pre-neoadjuvant therapy group,the effective rate of neoadjuvant chemotherapy was 75.00%(9/12)in patients with positive RUNX3 expression,77.78%(7/9)in patients with negative EZH2 expression,and 100%(7/7)in patients with positive expression of RUNX3 and negative expression of EZH2.Multivariate Logistic regression showed that the expression of RUNX3 protein was the factor influencing the efficacy of neoadjuvant chemotherapy. Conclusions The positive expression rate of RUNX3 in cancer tissue was lower than that in paracancerous tissue,while that of EZH2 showed the opposite trend.Neoadjuvant chemotherapy may affect the expression of RUNX3 and EZH2 in rectal cancer.The patients with high RUNX3 expression and low EZH2 expression in locally advanced rectal cancer were more sensitive to neoadjuvant chemotherapy with XELOX regimen.

Prognostic significance of EZH2 and ARID1A expression in urothelial carcinoma: an immunohistochemical study

ABSTRACT Enhancer of zeste homolog 2 (EZH2) and AT-rich interactive domain 1A (ARID1A) expression in urothelial carcinoma (UC) has not been well studied. ARID1A is a novel tumor suppressor gene coding for a chromatin remodeling protein that is mutated in urinary bladder cancer. The enhancer of zeste homolog 2 (EZH2) is a transcriptional repressor involved in gene silencing. Amplification of EZH2 has been reported in several malignancies. This study analyzed the immunohistochemical expression of EZH2 and ARID1A in 56 cases of UC that included (n = 21) cases of radical cystectomy and (n = 35) cases of transurethral resections of bladder tumor (TURBT) with muscle fibers and immunotherapy with adjuvant intravesical bacillus Calmette-Guerin (BCG). The predicting role of both markers for tumor recurrence and recurrence-free survival (RFS) was also analyzed. High EZH2 marker expression was observed in 75% of cases while 78.6% of cases had low ARID1A marker expression. There was a significant negative correlation between the two markers where high EZH2 and low ARID1A expression was significantly associated with higher tumor grade, stage, presence of muscle invasion, lymph node metastasis, presence of concomitant carcinoma in situ (CIS) and higher incidence of recurrence with shorter RFS rate. It was concluded that EZH2 and ARID1A play a role in tumor carcinogenesis and differentiation and could be considered as independent prognostic factors in UC and for use as a potential therapeutic target.

Druggable epigenetic suppression of interferon-induced chemokine expression linked to MYCN amplification in neuroblastoma

BackgroundAmplification of the MYCN oncogene is a molecular hallmark of aggressive neuroblastoma (NB), a childhood cancer of the sympathetic nervous system. There is evidence that MYCN promotes a non-inflamed and...

The significance of enhancer of zeste homolog 2 (EZH2) expression in spindle cell lesions of the breast.

Spindle cell lesions of the breast are rare entities and pose a diagnostic challenge for pathologists due to overlapping morphologic and immunohistochemical features. We evaluated EZH2 expression in various benign (fibromatosis (n = 8), myofibroblastoma (n = 7), neurofibroma (n = 1), nodular fasciitis (n = 5), benign phyllodes tumor (n = 18)) and malignant (malignant phyllodes tumor (n = 8), metaplastic breast carcinoma (n = 16) and angiosarcoma (n = 8)) spindle cell lesions as a potential diagnostic and therapeutic marker. The EZH2 expression was evaluated semi-quantitatively to categorize the cases as 'low' and 'high' expression. All benign lesions showed low EZH2 expression, whereas high EZH2 expression was observed in the majority (28/32; 88%) of malignant lesions. The study results suggest that EZH2 may be used both as an additional diagnostic tool to reach an accurate diagnosis of the spindle cell lesions of the breast and as a therapeutic target for the malignant lesions.

Evaluation of EZH2 and ERRα in colorectal carcinoma: an immunohistochemical study.

The combined immunohistochemical evaluation of EZH2 (enhancer of zeste homolog 2) and ERRα (estrogen-related receptor α), in relation to clinicopathological prognostic factors and patients' outcome, has not been performed yet in colorectal carcinoma (CRC). In order to achieve this aim, 120 samples were extracted; 60 cases of CRC; and 60 samples from normal colonic tissue. Our study showed that 63.3% and 38.3% of CRC cases reveal high EZH2 and high ERRα nuclear expression, respectively. 6.6% and 8.3% of normal colonic mucosa samples express low EZH2 and low ERRα nuclear expression, respectively. High EZH2 and high ERRα expression correlate with late tumor stages (p = 0.001 each), high grade (p = 0.001, p = 0.009 respectively), positive lymph node involvement (p = 0.001, p = 0.002 respectively) and larger tumor size (p = 0.001 each). There is a moderate highly statistically significant agreement (κ = 0.467, p = 0.001) between EZH2 and ERRα immunohistochemical expression. By Kaplan Meier analysis, high EZH2 and high ERRα show statistically significant shorter overall survival, and progression free survival than cases with low EZH2 and low ERRα immunohistochemical expression, respectively. Thus, EZH2 and ERRα might serve as potential promising prognostic markers in CRC.

EZH2 is a negative prognostic biomarker associated with immunosuppression in hepatocellular carcinoma.

The enhancer of zeste homolog 2 (EZH2) plays a critical role in different components of anti-tumor immunity. However, the specific role of EZH2 in modulating MHC Class I antigen presentation and T cell infiltration have not been investigated in HCC. This study analyzed the expression and clinical significance of EZH2 in HCC. The EZH2 genetic alterations were identified using cBioPortal. The EZH2 mRNA and protein levels were found to be significantly higher in HCC than in adjacent normal liver tissues in multiple datasets from the GEO and TCGA databases. High expression of EZH2 was significantly correlated with poor overall survival, disease-specific survival, progression-free survival, and relapse-free survival in almost all patients with HCC. The gene set variance analysis (GSVA) showed that the expression of EZH2 is positively correlated with an immunosuppressive microenvironment and negatively correlated with major MHC class I antigen presentation molecules. Gene set enrichment analysis (GSEA) showed that high EZH2 expression is positively associated with the MYC and glycolysis signaling pathway and negatively associated with the interferon-gamma signaling pathway in HCC tissues. These findings demonstrate that EZH2 is a potential prognostic biomarker and therapeutic target in HCC.

EZH2 Contributes To Cisplatin Resistance In Breast Cancer By Epigenetically Suppressing miR-381 Expression.

BackgroundEmerging evidence reveals the vital role of enhancer of zeste homolog 2 (EZH2) in cancer chemoresistance. However, its function and molecular mechanisms in breast cancer chemoresistance remain largely unknown.MethodsGene expression was evaluated using quantitative real-time PCR (qRT-PCR) and Western blot analysis. The functional roles of EZH2 and miR-381 in breast cancer were explored using cell MTT assay and flow cytometry analysis. The effect of EZH2 on miR-381 expression in transcriptional level was determined using Chromatin immunoprecipitation (ChIP) assay and Luciferase reporter assay.ResultsIn this study, we found that EZH2 was up-regulated in CDDP-resistant breast cancer tissues and cell lines. Breast cancer patients with high EZH2 expression had a poor prognosis. EZH2 silencing improved the sensitivity of MCF-7/CDDP and MDA-MB-231/CDDP cells towards CDDP. Moreover, EZH2 could epigenetically silence miR-381. miR-381 overexpression could overcome CDDP resistance in CDDP-resistant breast cancer cells. miR-381 knockdown weakened the inductive effect of EZH2 silencing on CDDP sensitivity of MCF-7/CDDP and MDA-MB-231/CDDP cells. Furthermore, EZH2 knockdown facilitated CDDP sensitivity of CDDP-resistant breast cancer cells in vivo.ConclusionsCollectively, EZH2 depletion overcame CDDP resistance of breast cancer through epigenetically silencing miR-381, providing a novel therapeutic target for breast cancer chemoresistance.

EZH2 Expression in Intestinal Neuroendocrine Tumors.

Neuroendocrine tumors (NETs) arise from the cells present throughout the diffuse endocrine system. These neoplasms were previously regarded as rare, but in fact are increasing in incidence (3.65/100 000 individuals/y). Enhancer of zeste homolog 2 (EZH2) plays a crucial role in cell cycle regulation, and it was reported to be overexpressed in several tumors. The aim of the study was to investigate EZH2 expression, also related with proliferation rate, and p53 expression in NETs of the intestine encompassing a group of tumors primary to the stomach, appendix, small intestine, and colon. The specimens from 33 patients with neuroendrocrine tumors were investigated by immunohistochemistry for EZH2, p53, and Ki-67. Only 10 of 33 (30.3%) cases showed high EZH2 expression. High EZH2 levels significantly associated with elevated proliferation rates (P=0.0012) and with elevated percentage of positive cells for p53 (P=0.011). Our results suggest an association between p53 and the EZH2 pathway in NETs. EZH2 could represent a potential target antigen in cancer immunotherapy.

Oncogenic enhancer of zeste homolog 2 is an actionable target in patients with non-small cell lung cancer.

BackgroundThe aims of this study were to investigate the link between enhancer of zeste homolog 2 (EZH2) and histone deacetylase (HDAC) in preclinical studies and in human lung cancer tissue microarrays.MethodsEnhancer of zeste homolog 2 and HDAC1 mRNA expression in two lung adenocarcinoma (LUAD) datasets (MDACC and TCGA) were correlated with patient outcomes. We evaluated the association of EZH2 and HDAC1 expression with response to the HDAC1 inhibitor, suberoylanilide hydroxamic acid (SAHA). The response to SAHA was assessed at baseline and after alteration of EZH2 or HDAC mRNA expression in LUAD cell lines.ResultsDirect correlation was found between EZH2 and HDAC1 expression (P < 0.0001). When EZH2 expression was knocked down‐ or upregulated, there was a corresponding decrease or increase in expression of HDAC expression, respectively. Cell lines with high EZH2 expression responded to SAHA treatment with a mean inhibition rate of 73.1% compared to 43.2% in cell lines with low EZH2 expression (P < 0.0001). This correlation was confirmed in non‐small cell lung cancer (NSCLC) specimens from MDACC (Spearman's correlation r = 0.416; P < 0.0001) and TCGA datasets (r = 0.221; P < 0.0001). Patients with high EZH2 and high HDAC1 expression in stage I NSCLC specimens of both datasets had the lowest survival compared to the patients with low expression of either or both markers.ConclusionOur findings show that overexpression of EZH2 is a negative prognostic indicator. Increased EZH2 expression predicts for response to HDAC inhibitors and thus could serve as a biomarker for selecting NSCLC patients for treatment with HDAC inhibitors.

Loss of enhancer of zeste homologue 2 (EZH2) at tumor invasion front is correlated with higher aggressiveness in colorectal cancer cells

PurposeEnhancer of zeste homolog 2 (EZH2) is associated with epigenetic gene silencing and aggressiveness in many tumor types. However, the prognostic impact of high EZH2 expression is controversially discussed for colorectal cancer. For this reason, we immunohistochemically analyzed EZH2 expression in 105 specimens from colon cancer patients separately for tumor center and invasion front.MethodsAll sections from tissue microarrays were evaluated manually and digitally using Definiens Tissue Studio software (TSS). To mirror-image the EZH2 status at the tumor invasion front, we treated HCT116 colon cancer cells with the EZH2 inhibitor 3-Deazaneplanocin A (DZNep) and studied the growth of in ovo xenografts in the chorioallantoic membrane (CAM) assay.ResultsWe showed a significant decrease in EZH2 expression and the repressive H3K27me3 code at the tumor invasion front as supported by the TSS-constructed heatmaps. Loss of EZH2 at tumor invasion front, but not in tumor center was correlated with unfavorable prognosis and more advanced tumor stages. The observed cell cycle arrest in vitro and in vivo was associated with higher tumor aggressiveness. Xenografts formed by DZNep-treated HCT116 cells showed loosely packed tumor masses, infiltrative growth into the CAM, and high vessel density.ConclusionThe differences in EZH2 expression between tumor center and invasion front as well as different scoring and cutoff values can most likely explain controversial literature data concerning the prognostic value of EZH2. Epigenetic therapies using EZH2 inhibitors have to be carefully evaluated for each specific tumor type, since alterations in cell differentiation might lead to unfavorable results.

Clinical significance of enhancer of zeste homolog 2 and histone deacetylases 1 and 2 expression in peripheral T-cell lymphoma.

Epigenetics serve a key role in peripheral T cell lymphoma (PTCL). The purpose of the present study was to investigate the clinical significance of enhancer of zeste homolog 2 (EZH2) and histone deacetylase 1 and 2 (HDAC1/2) expression in PTCL. A total of 82 patients were enrolled in the present study, including 43 with PTCL not otherwise specified (PTCL-NOS), 10 with angioimmunoblastic T-cell lymphoma (AITL), 14 with natural killer/T-cell lymphoma (NK/TCL) and 15 with anaplastic large cell lymphoma (ALCL). EZH2 and HDAC1/2 expression was detected by immunohistochemistry and any correlations between them were evaluated. Additionally, any correlations between EZH2 or HDAC1/2 expression and a number of clinicopathological characteristics were analyzed, and survival curves were created. Results revealed that 55.8% of patients with PTCL-NOS, 57.1% of patients with NK/TCL, 86.7% of patients ALCL and 50% of patients with AITL highly expressed HDAC1. Furthermore, 58.1% of patients with PTCL-NOS, 57.1% of patients with NK/TCL, 53.3% of patients with ALCL and 60% of patients with AITL highly expressed HDAC2. Additionally, 67.5% of patients with PTCL-NOS, 50% of patients with NK/TCL, 73.3% of patients with ALCL and 60% of patients with AITL highly expressed EZH2. EZH2 expression was significantly correlated with the presence of B symptoms, elevated LDH and elevated β2 microglobulin (B2M; P<0.05), and HDAC2 expression was significantly correlated with sex, advanced clinical stages, high international prognostic index scores and elevated B2M levels (P<0.05) in all the patients with PTCL. However, different subtypes of PTCL are correlated with different clinical characteristics. Patients with PTCL highly expressing EZH2 or HDAC2 exhibit a poorer overall survival rate. In conclusion, EZH2 and HDAC1/2 were frequently upregulated in patients with PTCL, and the patients with a higher EZH2 and HDAC2 expression usually exhibited a poorer survival rate. Therefore, EZH2 and HDAC2 may be prognostic markers in patients with PTCL, particularly in those with PTCL-NOS.

Immunostaining of Increased Expression of Enhancer of Zeste Homolog 2 (EZH2) in Diffuse Midline Glioma H3K27M-Mutant Patients with Poor Survival

Introduction: The interaction of K27M mutation in histone H3 (H3K27M mutation) with polycomb repressive complex 2 (PRC2) is facilitated by the enhancer of zeste homolog 2 (EZH2). Subsequently, this interaction leads to the global reduction level of H3K27me3. We analyzed the EZH2 expression level in H3K27M mutation-positive tumors and revealed the association of high EZH2 expression with poor survival. Methods: Our study included 12 patients, with an age range of 6–56 years and treated between 2007 and 2016. All patients underwent MRI study for nonenhanced T1, T2, diffusion, gadolinium-enhanced T1-weighted imaging, and fluid-attenuated inversion recovery (FLAIR). Immunohistochemical staining was performed against H3K27M, H3K27me3, EZH2, EED, mutant isocitrate dehydrogenase 1 (IDH1), α-thalassemia X-linked intellectual disability (ATRX), p53, O6-methylguanine-DNA methyltransferase (MGMT), and Ki-67 antibodies. Results: All patients were negative for IDH1R132H and H3K27me3, but H3K27M-positive. Staining against EZH2 was negative in all histological features of grade II cases (3/12) and positive in grade III and IV cases; EZH2 positivity is associated with poor prognosis (p = 0.0082). EZH2 positivity was not associated with EED positivity. Retained ATRX staining was found mostly in grade III and IV cases (6/12). P53 was predominantly positive in cases of astrocytoma and glioblastoma (8/12). The labeling index of Ki-67 was 1.2–31.4% for grade II and III histological features and 11.2–24.8% for grade IV. Conclusion: We suggest that the expression of EZH2 is not associated with the PRC2 pathway and increases in patients with H3K27M-mutant diffuse midline glioma and a poor prognosis. Further studies are necessary to understand the mechanism involved.