Epigenetic modifications promote the expression of the orphan nuclear receptor NR0B1 in human lung adenocarcinoma cells

Studies in Cancer Epigenetics through a Sex and Gendered Lens: A Comprehensive Scoping Review

Background: Sex and gender are vitally important in the study of epigenetic mechanisms for various types of cancer. However, little has been done to assess the state of sex and gender-based analyses (SGBA) in this field. The aim was to undertake a critical evaluation of sex and gender representation, discussion, and data analysis within the cancer epigenetics field since 2010. Methods: A PRISMA-ScR scoping review was conducted with 111 peer-reviewed studies comprising of colorectal, gastric, head and neck, hepatocellular carcinoma, and lung cancers. Data extraction and a quality appraisal were performed by a team of epidemiologists and bioethicists. Results: Of the 111 included studies, only 17 studies (15.3%) explicitly stated sex and gender analysis to be their primary aim. A total of 103 studies (92.8%) provided a detailed analysis of sex/gender as a biological or social variable, while the remaining 8 studies (7.2%) only stratified results by sex/gender. Although sex and gender were a key facet in all the eligible studies, only 7 studies (6.3%) provided an explicit definition of the terms "sex" or "gender", while the remaining 104 studies (93.7%) used the words "sex" or "gender" without providing a definition. A total of 84 studies (75.7%) conflated the concepts of "sex" and "gender", while 44 studies (39.6%) were inconsistent with their usage of the "sex" and "gender" terms. Conclusions: Very few studies offered a robust analysis of sex/gender data according to SAGER guidelines. We call for clear and directed guidelines regarding the use of sex/gender as a variable in epigenetics research.

Targeting Nuclear Receptors in Lung Cancer—Novel Therapeutic Prospects

Lung cancer, the second most commonly diagnosed cancer, is the major cause of fatalities worldwide for both men and women, with an estimated 2.2 million new incidences and 1.8 million deaths, according to GLOBOCAN 2020. Although various risk factors for lung cancer pathogenesis have been reported, controlling smoking alone has a significant value as a preventive measure. In spite of decades of extensive research, mechanistic cues and targets need to be profoundly explored to develop potential diagnostics, treatments, and reliable therapies for this disease. Nuclear receptors (NRs) function as transcription factors that control diverse biological processes such as cell growth, differentiation, development, and metabolism. The aberrant expression of NRs has been involved in a variety of disorders, including cancer. Deregulation of distinct NRs in lung cancer has been associated with numerous events, including mutations, epigenetic modifications, and different signaling cascades. Substantial efforts have been made to develop several small molecules as agonists or antagonists directed to target specific NRs for inhibiting tumor cell growth, migration, and invasion and inducing apoptosis in lung cancer, which makes NRs promising candidates for reliable lung cancer therapeutics. The current work focuses on the importance of various NRs in the development and progression of lung cancer and highlights the different small molecules (e.g., agonist or antagonist) that influence NR expression, with the goal of establishing them as viable therapeutics to combat lung cancer.

A New Risk Score Based on Eight Hepatocellular Carcinoma- Immune Gene Expression Can Predict the Prognosis of the Patients

Background

Hepatocellular carcinoma (HCC) is one of the malignant tumors with high morbidity and mortality worldwide. Immunotherapy has emerged as an increasingly important cancer treatment modality. However, the potential relationship between immune genes and HCC still needs to be explored. The purpose of this study is to construct a new prognostic risk signature to predict the prognosis of HCC patients based on the expression of immune-related genes (IRGs) and explore its potential mechanism.

Methods

We analyzed the gene expression data of 332 HCC patient samples and 46 adjacent normal tissues samples (Solid Tissue Normal including cirrhotic tissue) in The Cancer Genome Atlas (TCGA) database and clinical characteristics. We analyzed the gene expression data, identified differentially expressed IRGs in HCC tissues, filtered IRGs with prognostic value to construct an IRG signature, and classified patients into high and low gene expression groups based on the expression of IRGs in their tumor tissues. We also investigated the potential molecular mechanisms of IRGs through a bioinformatics approach using Protein-Protein Interaction (PPI) network, Kyoto Encyclopedia of Genes and Genomes (KEGG) database analysis and Gene Ontology (GO) database analysis. Differentially expressed IRGs associated with significant clinical outcomes (SIRGs) were identified by univariate Cox regression analysis. An immune-related risk score model (IRRSM) was established based on Lasso Cox regression analysis and multivariate Cox regression analysis. Based on the IRRSM, the immune score of the patients was calculated, and the patients were divided into high-risk and low-risk patients according to the median score, and the differences in survival between the two groups were compared. Then, the correlation analysis between the IRRSM and clinical characteristics was performed, and the IRRSM was validated using the International Cancer Genome Consortium (ICGC) database.

Results

The IRRSM was eventually constructed and confirmed to be an independent prognostic model for HCC patients. The IRRSM was shown to be positively correlated with the infiltration of four types of immune cells.

Conclusion

Our results showed that some SIRGs have potential value for predicting the prognosis and clinical outcomes of HCC patients. IRGs affect the prognosis of HCC patients by regulating the tumor immune microenvironment (TIME). This study provides a new insight for immune research and treatment strategies in HCC patients.

Model based on five tumour immune microenvironment-related genes for predicting hepatocellular carcinoma immunotherapy outcomes

BACKGROUND

Although the tumour immune microenvironment is known to significantly influence immunotherapy outcomes, its association with changes in gene expression patterns in hepatocellular carcinoma (HCC) during immunotherapy and its effect on prognosis have not been clarified.

METHODS

A total of 365 HCC samples from The Cancer Genome Atlas liver hepatocellular carcinoma (TCGA-LIHC) dataset were stratified into training datasets and verification datasets. In the training datasets, immune-related genes were analysed through univariate Cox regression analyses and least absolute shrinkage and selection operator (LASSO)-Cox analyses to build a prognostic model. The TCGA-LIHC, GSE14520, and Imvigor210 cohorts were subjected to time-dependent receiver operating characteristic (ROC) and Kaplan-Meier survival curve analyses to verify the reliability of the developed model. Finally, single-sample gene set enrichment analysis (ssGSEA) was used to study the underlying molecular mechanisms.

RESULTS

Five immune-related genes (LDHA, PPAT, BFSP1, NR0B1, and PFKFB4) were identified and used to establish the prognostic model for patient response to HCC treatment. ROC curve analysis of the TCGA (training and validation sets) and GSE14520 cohorts confirmed the predictive ability of the five-gene-based model (AUC > 0.6). In addition, ROC and Kaplan-Meier analyses indicated that the model could stratify patients into a low-risk and a high-risk group, wherein the high-risk group exhibited worse prognosis and was less sensitive to immunotherapy than the low-risk group. Functional enrichment analysis predicted potential associations of the five genes with several metabolic processes and oncological signatures.

CONCLUSIONS

We established a novel five-gene-based prognostic model based on the tumour immune microenvironment that can predict immunotherapy efficacy in HCC patients.

Eight immune-related genes predict survival outcomes and immune characteristics in breast cancer

Advancements in immunotherapy have improved our understanding of the immune characteristics of breast cancer. Here, we analyzed gene expression profiles and clinical data obtained from The Cancer Genome Atlas database to identify genes that were differentially expressed between breast tumor tissues and normal breast tissues. Comparisons with the Immunology Database and Analysis Portal (ImmPort) indicated that many of the identified differentially expressed genes were immune-related. Risk scores calculated based on an eight-gene signature constructed from these immune-related genes predicted both overall survival and relapse-free survival outcomes in breast cancer patients. The predictive value of the eight-gene signature was validated in different breast cancer subtypes using external datasets. Associations between risk score and breast cancer immune characteristics were also identified; in vitro experiments using breast cancer cell lines confirmed those associations. Thus, the novel eight-gene signature described here accurately predicts breast cancer survival outcomes as well as immune checkpoint expression and immune cell infiltration processes.

DNA demethylation facilitates the specific transcription of the mouse X-linked Tsga8 gene in round spermatids†

Some X-linked genes necessary for spermiogenesis are specifically activated in the postmeiotic germ cells. However, the regulatory mechanism about this activation is not clearly understood. Here, we examined the potential mechanism controlling the transcriptional activation of the mouse testis specific gene A8 (Tsga8) gene in round spermatids. We observed that the Tsga8 expression was negatively correlated with the methylation level of the CpG sites in its core promoter. During spermatogenesis, the Tsga8 promoter was methylated in spermatogonia, and then demethylated in spermatocytes. The demethylation status of Tsga8 promoter was maintained through the postmeiotic germ cells, providing a potentially active chromatin for Tsga8 transcription. In vitro investigation showed that the E12 and Spz1 transcription factors can enhance the Tsga8 promoter activity by binding to the unmethylated E-box motif within the Tsga8 promoter. Additionally, the core Tsga8 promoter drove green fluorescent protein (GFP) expression in the germ cells of Tsga8-GFP transgenic mice, and the GFP expression pattern was similar to that of endogenous Tsga8. Moreover, the DNA methylation profile of the Tsga8-promoter-driven transgene was consistent with that of the endogenous Tsga8 promoter, indicating the existence of a similar epigenetic modification for the Tsga8 promoter to ensure its spatiotemporal expression in vivo. Taken together, this study reports the details of a regulatory mechanism that includes DNA methylation and transcription factors to mediate the postmeiotic expression of an X-linked gene.

DAX1 promotes cervical cancer cell growth and tumorigenicity through activation of Wnt/β-catenin pathway via GSK3β

DAX1 is well known for its fundamental role in several types of cancer, while its biological role in cervical cancer remains largely unexplored. The expression of DAX1 in cervical carcinoma tissue was examined using immunohistochemistry and western blot. The effects of DAX1 silencing on the cell growth, tumor formation, and CSC (cancer stem cell) characteristics were also investigated. DAX1 expressed a gradual increase from normal cervix to high-grade squamous intraepithelial lesions, and consequently to cervical cancer. Silence of DAX1 significantly inhibited the cell growth, tumorigenicity, and tumorsphere formation. Furthermore, the TOP/FOP-Flash reporter assay revealed that Wnt/β-catenin pathway was significantly inactivated in DAX1-silenced cervical cancer cells with the downregulation of Wnt/β-catenin targeting genes, including cyclinD1 and c-myc. Moreover, dual-luciferase reporter and chromatin immunoprecipitation (ChIP) assay confirmed that DAX1 transcriptionally repressed glycogen synthase kinase 3β (GSK3β), an inhibitor of the Wnt/β-catenin pathway, by physically interacting with -666~-444 motif on the GSK3β promoter. Additionally, the blockage of GSK3β by CHIR-99021 resulted in a significant increase of CSC characteristics induced by the silence of DAX1. Our data demonstrated that DAX1 is overexpressed in cervical cancer, and that it promotes cell growth and tumorigenicity through activating Wnt/β-catenin pathway mediated by GSK3β.