Robust expression of EZH2 in endocervical neoplastic lesions

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 and POU2F3 Can Aid in the Distinction of Thymic Carcinoma from Thymoma

Thymic carcinoma is an aggressive malignancy that can be challenging to distinguish from thymoma using histomorphology. We assessed two emerging markers for these entities, EZH2 and POU2F3, and compared them with conventional immunostains. Whole slide sections of 37 thymic carcinomas, 23 type A thymomas, 13 type B3 thymomas, and 8 micronodular thymomas with lymphoid stroma (MNTLS) were immunostained for EZH2, POU2F3, CD117, CD5, TdT, BAP1, and MTAP. POU2F3 (≥10% hotspot staining), CD117, and CD5 showed 100% specificity for thymic carcinoma versus thymoma with 51%, 86%, and 35% sensitivity, respectively, for thymic carcinoma. All POU2F3 positive cases were also positive for CD117. All thymic carcinomas showed >10% EZH2 staining. EZH2 (≥80% staining) had a sensitivity of 81% for thymic carcinoma and a specificity of 100% for thymic carcinoma versus type A thymoma and MNTLS but had poor specificity (46%) for thymic carcinoma versus B3 thymoma. Adding EZH2 to a panel of CD117, TdT, BAP1, and MTAP increased cases with informative results from 67/81 (83%) to 77/81 (95%). Overall, absent EZH2 staining may be useful for excluding thymic carcinoma, diffuse EZH2 staining may help to exclude type A thymoma and MNTLS, and ≥10% POU2F3 staining has excellent specificity for thymic carcinoma versus thymoma.

Evaluation of Immunohistochemical Expression of Enhancer of Zeste Homolog 2 (EZH2) and Its Association With Clinicopathological Variables in Carcinoma Cervix

INTRODUCTION

 Carcinoma cervix is the fourth most common cancer worldwide and is one of the leading causes of cancer death in women. Recently, immunohistochemical expression of biomarkers has been utilized as indicators of disease progression, aggressiveness for predicting the prognosis in various cancers. DNA methylation of genes plays an important role in pathogenesis of carcinoma cervix and detection of aberrant methylation can be utilized for detection of carcinoma cervix and monitoring of its progression. Enhancer of Zeste Homolog 2 (EZH2) is a histone methyltransferase and catalyzes methylation of histone H3 and plays an important role in tumor cell proliferation, invasion, and metastasis. The aim of this study was to analyze the pattern, distribution, and grade of immunohistochemical expression of EZH2 in carcinoma cervix and study its association with clinico-pathological variables such as age, site and size of tumor, type of growth, tumor grade, histological subtype, lymph node metastasis, and stage of the tumor according to the Federation of Gynaecology and Obstetrics (FIGO).

MATERIALS AND METHODS

 This observational study was carried out in the Department of Pathology & Lab Medicine, at our institute. A total of 60 consecutive histopathologically confirmed cases of carcinoma cervix from January 2018 to June 2022 were subjected to immunohistochemistry (IHC) for EZH2. The immunohistochemical score for each case was obtained by multiplying the intensity and percentage of positive cells for EZH2. An immunohistochemical score of four or greater than four was considered as high immunoexpression. The immunohistochemical results were correlated with clinico-pathological variables.

RESULTS

 The data were analyzed using relevant statistical methods using SPSS version 23 (IBM Corp., Armonk, NY). To find the significant difference (p value) and association, chi-square test along with Pearson chi-square were used, wherever necessary. A p value of <0.05 was considered as significant. High immunoexpreesion of EZH2 exhibited a significant association (p < 0.05) with the tumor grade, histologic subtype, lymphnode metastasis, and FIGO stage.

CONCLUSIONS

 The results of our study affirm that a significant association exists between immunohistochemical expression of EZH2 with tumor grade, histological subtype, lymphnode metastasis, and FIGO stage which can be utilized in future studies with larger sample size to further strengthen the association of EZH2 immunoexpression in cancer cervix patients that may aid in the development of the targeted therapy in near future.

Non-coding RNAs-EZH2 regulatory mechanisms in cervical cancer: The current state of knowledge

Cervical cancer (CC) is among the leading causes of death in women worldwide. Both genetic and epigenetic regulators are required for the tumorigenesis and progression of CC. Non-coding RNAs (ncRNAs) are a group of RNAs that don't code for proteins yet constitute a large part of the human transcriptome, including long non-coding RNAs (lncRNAs), microRNAs (miRNAs), circular RNAs (circRNA), and other forms of non-coding RNAs. Deregulation of lncRNA, miRNA, and circRNA is implicated in the oncogenesis and development of cervical malignancies, acting as oncogenic drivers or tumor suppressors. Enhancer of zeste homolog 2 (EZH2) is the enzymatic subunit of Polycomb Repressive Complex 2 (PRC2), which functions to methylate histone H3 lysine 27 to silence gene transcription. Converging lines of evidence have revealed the oncogenic role played by EZH2 in cancers. EZH2 is upregulated in CC tissues with a robust correlation to the advanced stage, metastasis, and poor survival rate in patients. The elucidation of the roles of EZH2 in cancer has driven the development of therapeutic EZH2 inhibitors, which are approaching phase I or phase I/II clinical trials. Here we review the ncRNA-EZH2 regulatory pathways in CC that unify EZH2 and ncRNAs as an integrated system in the development of CC. Given the emerging findings for the role of the ncRNA-EZH2 regulatory axis in CC, it will be of great interest to develop novel therapeutic strategies based on their relationship.

The Role of Predictive Biomarkers in Endocervical Adenocarcinoma: Recommendations From the International Society of Gynecological Pathologists

To review the scientific evidence related to predictive biomarkers in cervical adenocarcinoma (ADC). The authors reviewed the literature regarding predictive biomarkers in cervical ADC. There were several limitations: (1) there is an overlap between predictive and prognostic biomarkers, as the vast majority of patients are treated with anticancer strategies; (2) in many studies and clinical trials, cervical ADC patients are included in a large series of patients predominantly composed of cervical squamous cell carcinomas; and (3) in most of the studies, and clinical trials, there is no distinction between human papillomavirus (HPV)-associated and HPV-independent cervical ADCs, or between various histologic subtypes. Results obtained from a small group of studies confirm that cervical ADCs exhibit distinct molecular features as compared with squamous carcinomas, and that there are different molecular features between different types of cervical ADCs. Promising areas of interest include ERBB2 (HER2) mutations and PD-L1 expression as predictive biomarkers for anti-HER2 treatment and immunotherapy, respectively. To date, no definitive data can be obtained from the literature regarding predictive biomarkers for cervical ADC. Clinical trials specifically designed for endocervical ADC patients are required to elucidate the predictive value of HER2 mutations and PD-L1 expression. The distinction between HPV-associated and HPV-independent cervical ADCs as well as early involvement of pathologists in the design of future clinical trials are needed to identify new predictive biomarkers in cervical ADC.

A microRNA-Messenger RNA Regulatory Network and Its Prognostic Value in Cervical Cancer

Cervical cancer (CC) is the fourth commonest cancer in women worldwide. Increasing evidence proves that microRNA (miRNA)-messenger RNA (mRNA) network is involved in CC. In this study, miRNA and mRNA expression profiles were downloaded from The Cancer Genome Atlas (TCGA) database. Differently expressed miRNAs (DE-miRNAs) and mRNAs (DE-mRNAs) were obtained by "Empirical Analysis of Digital Gene Expression Data in R (EdgeR)" package. Then, functional analyses were conducted. With Cytoscape software, a protein-protein interaction (PPI) network was established to identify hub genes that were used for building an miRNA-hub gene network. Next, a prognostic signature based on hub genes was constructed by Cox regression analysis, and its prognostic value was assessed by a nomogram. Finally, the relationship between immune cell infiltration and the three genes in the prognostic model was investigated by using the CIBERSORT algorithm. We screened out 5096 DE-mRNAs and 114 DE-miRNAs between healthy cervical and CC tissues. Then, 102 target DE-mRNAs of upregulated DE-miRNAs and 150 target DE-mRNAs of downregulated DE-miRNAs were obtained. PPI network demonstrated 20 hub nodes with higher connectivity. DE-mRNAs were mostly enriched in pathways in cancer, cell cycle, and proteoglycans in cancer. The miRNA-hub gene network showed that most hub genes could be potentially modulated by miR-200c-3p, miR-23b-3p, and miR-106b-5p. Quantitative real-time PCR proved that 10 miRNAs were downregulated and 6 mRNAs were upregulated markedly in CC tissues. Furthermore, a prognostic signature was established based on enhancer of zeste homolog 2 (EZH2), Fms-related tyrosine kinase 1 (FLT1), and glyceraldehyde 3-phosphate dehydrogenase (GAPDH). The area under the curve value of the 5-year receiver operating characteristic curve was 0.609. The three genes were also found to be related to the infiltration of six types of immune cells, including dendritic cells, macrophages M0 and M1, mast cells, and monocytes. In conclusion, the development of CC is regulated by the miRNA-mRNA network we proposed in this study.

Immune system‑associated genes increase malignant progression and can be used to predict clinical outcome in patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most malignant types of cancer, and is associated with high recurrence rates and a poor response to chemotherapy. Immune signatures in the microenvironment of HCC have not been well explored systematically. The aim of the present study was to identify prognostic immune signatures and build a nomogram for use in clinical evaluation. Using bioinformatics analysis, RNA‑seq data and overall survival (OS) information on 370 HCC cases from TCGA and 232 HCC cases from ICGC were analyzed. The differential expression of select immune genes, based on previously published studies, between HCC and adjacent tissue were analyzed using the limma package in R. Enrichment of pathways and gene ontology analysis was performed using clusterProfiler. Subsequently, univariate Cox regression analysis, Lasso penalty linear regression and multivariate Cox regression models were used to construct a model for immune risk score (IRS). The R packages, survival and survivalROC, were used to plot survival and the associated receiver operating characteristic curves. Infiltration of immune cells was calculated using Tumor IMmune Estimation Resource, with significance examined using a Pearson's correlation test. P<0.05 was considered significant. Based on the analysis, expression of 200 immune genes were upregulated and 47 immune genes were downregulated immune genes. In the multivariate Cox model, 5 genes (enhancer of zest homology 2, ferritin light chain, complement factor H related 3, isthmin 2, cyclin dependent kinase 5) were used to generate the IRS. By stratifying according to the median IRS, it was shown that patients with a high IRS had poor OS rates after 1, 2, 3 and 5 years, and this result was consistent across the testing, training and independent validation cohorts. Additionally, the IRS was correlated with the abundance of infiltrating immune cells. The nomogram built using IRS and clinical characteristics, was able to predict 1, 3 and 5 year OS with area under the curve values of >0.8. These results suggest that the model developed to calculate the IRS may be used to monitor the effectiveness of treatment strategies and for prognostic prediction.

Carcinogenic roles and therapeutic effects of EZH2 in gynecological cancers

Enhancer of Zeste Homolog 2 (EZH2) is highly expressed in kinds of malignant tumors and related to tumor occurrence, development, and prognosis. EZH2 is the catalytic subunit of the polycomb repressive complex 2 (PRC2), which promotes cell proliferation, migration, and invasion by epigenetic regulation of anti-tumor gene. It can activate numerous tumor-associated signaling pathways and interfere with DNA damage repair. In recent years, large amounts of studies have shown that EZH2 is closely related to gynecologic-related malignancies and can be used as a potential target gene for the treatment of gynecological-related malignancies. This review summarizes the oncogenic function of EZH2 and introduces the recent advances in the development of EZH2 inhibitors. On this basis, future research prospect of EZH2 is proposed.