Prognostic Value of EZH2 in Non-Small-Cell Lung Cancers: A Meta-Analysis and Bioinformatics Analysis

Assessment of targeted therapy opportunities in sinonasal cancers using patient-derived functional tumor models

Malignant tumors derived from the epithelium lining the nasal cavity region are termed sinonasal cancers, a highly heterogeneous group of rare tumors accounting for 3 - 5 % of all head and neck cancers. Progress with next-generation molecular profiling has improved our understanding of the complexity of sinonasal cancers and resulted in the identification of an increasing number of distinct tumor entities. Despite these significant developments, the treatment of sinonasal cancers has hardly evolved since the 1980s, and an advanced sinonasal cancer presents a poor prognosis as targeted therapies are usually not available. To gain insights into potential targeted therapeutic opportunities, we performed a multiomics profiling of patient-derived functional tumor models to identify molecular characteristics associated with pharmacological responses in the different subtypes of sinonasal cancer.

METHODS

Patient-derived ex vivo tumor models representing four distinct sinonasal cancer subtypes: sinonasal intestinal-type adenocarcinoma, sinonasal neuroendocrine carcinoma, sinonasal undifferentiated carcinoma and SMARCB1 deficient sinonasal carcinoma were included in the analyses. Results of functional drug screens of 160 anti-cancer therapies were integrated with gene panel sequencing and histological analyses of the tumor tissues and the ex vivo cell cultures to establish associations between drug sensitivity and molecular characteristics including driver mutations.

RESULTS

The different sinonasal cancer subtypes display considerable differential drug sensitivity. Underlying the drug sensitivity profiles, each subtype was associated with unique molecular features. The therapeutic vulnerabilities correlating with specific genomic background were extended and validated with in silico analyses of cancer cell lines representing different human cancers and with reported case studies of sinonasal cancers treated with targeted therapies.

CONCLUSION

The results demonstrate the importance of understanding the differential biology and the molecular features associated with the different subtypes of sinonasal cancers. Patient-derived ex vivo tumor models can be a powerful tool for investigating these rare cancers and prioritizing targeted therapeutic strategies for future clinical development and personalized medicine.

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

BACKGROUNDS

It 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.

METHODS

The 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.

RESULTS

In 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.

CONCLUSIONS

Highly 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.

The pharmacological and biological importance of EZH2 signaling in lung cancer

Up to 18% of cancer-related deaths worldwide are attributed to lung tumor and global burden of this type of cancer is ascending. Different factors are responsible for development of lung cancer such as smoking, environmental factors and genetic mutations. EZH2 is a vital protein with catalytic activity and belongs to PCR2 family. EZH2 has been implicated in regulating gene expression by binding to promoter of targets. The importance of EZH2 in lung cancer is discussed in current manuscript. Activation of EZH2 significantly elevates the proliferation rate of lung cancer. Furthermore, metastasis and associated molecular mechanisms including EMT undergo activation by EZH2 in enhancing the lung cancer progression. The response of lung cancer to therapy can be significantly diminished due to EZH2 upregulation. Since EZH2 increases tumor progression, anti-cancer agents suppressing its expression reduce malignancy. In spite of significant effort in understanding modulatory function of EZH2 on other pathways, it appears that EZH2 can be also regulated and controlled by other factors that are described in current review. Therefore, translating current findings to clinic can improve treatment and management of lung cancer patients.

Squamous cell lung cancer: Current landscape and future therapeutic options

Squamous cell lung cancers (lung squamous cell carcinomas [LUSCs]) are associated with high mortality and a lack of therapies specific to this disease. Although recurrent molecular aberrations are present in LUSCs, efforts to develop targeted therapies against receptor tyrosine kinases, signaling transduction, and cell cycle checkpoints in LUSCs were met with significant challenges. The present therapeutic landscape focuses on epigenetic therapies to modulate the expression of lineage-dependent survival pathways and undruggable oncogenes. Another important therapeutic approach is to exploit metabolic vulnerabilities unique to LUSCs. These novel therapies may synergize with immune checkpoint inhibitors in the right therapeutic context. For example, the recognition that alterations in KEAP1-NFE2L2 in LUSCs affected antitumor immune responses created unique opportunities for targeted, metabolic, and immune combinations. This article provides a perspective on how lessons learned from the past influence the current therapeutic landscape and opportunities for future drug development for LUSCs.

Analysis of the correlation between Zeste enhancer homolog 2 (EZH2) mRNA expression and the prognosis of mesothelioma patients and immune infiltration

Mesothelioma lies one of the most malignant tumors, in which the identification of the corresponding biomarkers is extremely critical. This study aims to investigate the prognostic value of enhancer homolog 2 (EZH2) mRNA expression in mesothelioma patients accompanied with its immune infiltration analysis. Gene expression, clinical information and enrichment analysis were obtained based on the Cancer Genome Atlas (TCGA), the immune infiltration analysis and bioinformatics analysis were performed. Clinical information and gene expression were obtained from 86 patients with mesothelioma based on TCGA database. Survival analysis, GSEA enrichment analysis, and immune infiltration analysis of EZH2 expression were carried out using R (version 3.6.3) (statistical analysis and visualization). The correlation of EZH2 expression with immune cell infiltration in mesothelioma was analyzed according to the TIMER database (Fig. https://cistrome.shinyapps.io/timer/). A univariate and multivariate analysis of general data obtained from the TCGA database was performed, involving age, gender, stage, pathological type, and whether they had received radiotherapy, the results indicated the association of high expression of EZH2 with poor prognosis in mesothelioma patients, with the worse prognosis in the High group (HR = 2.75, 95% CI 1.68–4.52, P < 0.010). Moreover, ROC curves showed that EZH2 expression predicted 1-year survival with an AUC of 0.740, 2-year survival with an AUC of 0.756, and 3-year survival with an AUC of 0.692, suggesting a robust predictive effect of EZH2 expression on prognosis. KEGG pathway analysis indicated five pathways showing the strongest positive correlation with EZH2 expression: cell cycle, DNA replication, Cell adhesion molecules cams, Primary immuno deficiency, Tsate transduction, and five pathways showing the strongest negative correlation with EZH2 expression: Glycolysis gluconeogenesis, Drug metabolism, cytochrome P450, retinol metabolism, fatty acid metabolism ribosome. We investigated the correlation between EZH2 expression and the level of immune infiltration in mesothelioma tissues. The results indicated that EZH2 expression played a critical role in immune infiltration, of which the high expression was correlated with the reduced number of NK cells, Mast cells, and Th17 cells. Moreover, mesothelioma patients with high EZH2 expression differ from those with low EZH2 expression in their tumor immune microenvironment. EZH2, as a new prognostic biomarker for mesothelioma, contributes to elucidating how changes in the immune environment promote the development of mesothelioma. Further analysis, EZH2 may serve as a biological test to predict the prognosis of mesothelioma.

FAK Executes Anti-Senescence via Regulating EZH2 Signaling in Non-Small Cell Lung Cancer Cells

Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase overexpressed in various cancer types that plays a critical role in tumor progression. Accumulating evidence suggests that targeting FAK, either alone or in combination with other agents, may serve as an effective therapeutic strategy for numerous cancers. In addition to retarding proliferation, metastasis, and angiogenesis, FAK inhibition triggers cellular senescence in lung cancer cells. However, the detailed mechanism remains enigmatic. In the present study, we found that FAK inhibition not only elicits DNA-damage signaling but also downregulates enhancer of zeste homolog 2 (EZH2) expression. The manipulation of FAK expression influences EZH2 expression and corresponding signaling in vitro. Immunohistochemistry shows that active FAK signaling corresponds with the activation of the EZH2-mediated signaling cascade in lung-cancer-cells-derived tumor tissues. We also found that ectopic EZH2 expression attenuates FAK-inhibition-induced cellular senescence in lung cancer cells. Our results identify EZH2 as a critical downstream effector of the FAK-mediated anti-senescence pathway. Targeting FAK-EZH2 axis-induced cellular senescence may represent a promising therapeutic strategy for restraining tumor growth.

Targeting EZH2 to overcome the resistance to immunotherapy in lung cancer

Unleashing the immune system to fight cancer has been a major breakthrough in cancer therapeutics since 2014 when anti-PD-1 antibodies (pembrolizumab and nivolumab) were approved for patients with metastatic melanoma. Therapeutic indications have rapidly expanded for many types of advanced cancer, including lung cancer. A variety of antibodies targeting the PD-1/PD-L1 checkpoint are contributing to this paradigm shift. The field now confronts two salient challenges: first, to improve the therapeutic outcome given the low response rate across the histologies; second, to identify biomarkers for improved patient selection. Pre-clinical and clinical studies are underway to evaluate combinatorial treatments to improve the therapeutic outcome paired with correlative studies to identify the factors associated with response and resistance. One of the emerging strategies is to combine epigenetic modifiers with immune checkpoint blockade (ICB) based on the evidence that targeting epigenetic elements can enhance anti-tumor immunity by reshaping the tumor microenvironment (TME). We will briefly review pleotropic biological functions of enhancer of zeste homolog 2 (EZH2), the enzymatic subunit of polycomb repressive complex 2 (PRC2), clinical developments of oral EZH2 inhibitors, and potentially promising approaches to combine EZH2 inhibitors and PD-1 blockade for patients with advanced solid tumors, focusing on lung cancer.

The combined use of long non-coding RNA HOTAIR and polycomb group protein EZH2 as a prognostic marker of lung adenocarcinoma

BACKGROUND

The long non-coding RNA Hox transcript antisense intergenic RNA (HOTAIR) and polycomb group protein Enhancer of zeste homolog 2 (EZH2) function cooperatively in carcinogenesis. However, their combined usage as prognostic markers for lung adenocarcinoma remains unverified.

MATERIALS AND METHODS

To validate their combined usage, we measured the expression of both genes in the surgical samples from 83 adenocarcinoma cases using quantitative real-time PCR and analyzed the association between the gene expressions and various clinicopathological factors. We also examined the EZH2 protein levels using immunohistochemistry. Finally, we analyzed the association between their expression status and the overall survival using 54 stage I cases.

RESULTS

Both genes were expressed at significantly higher levels in adenocarcinoma tissues than normal lung. EZH2 expression, but not HOTAIR expression, was significantly higher in solid adenocarcinoma than in other subtypes. In the survival analysis using stage-I cases, both HOTAIR expression and EZH2 protein levels were associated with a worse prognosis. The overall survival was highest in the low-HOTAIR and low-EZH2 group (low-low), followed by the high-low or low-high group and the high-high group. According to the multivariate analysis, the high-high status of HOTAIR-EZH2 (protein) was significantly associated with a worse prognosis than the low-low group.

CONCLUSION

More accurate prognoses would be possible by simultaneously measuring both genes than measuring either. The high-HOTAIR and high-EZH2 (protein) status, compared to the low-low, is proposed as an independent prognostic marker for stage I cases. Thus, it would serve as a potential biomarker for anti-EZH2 therapy.