Epigenetic mechanisms of cancer progression and therapy resistance in estrogen-receptor (ER+) breast cancer

Estrogen receptor-positive (ER+) breast cancer is the most frequent breast cancer subtype. Agents targeting the ER signaling pathway have been successful in reducing mortality from breast cancer for decades. However, mechanisms of resistance to these treatments arise, especially in the metastatic setting. Recently, it has been recognized that epigenetic dysregulation is a common feature that facilitates the acquisition of cancer hallmarks across cancer types, including ER+ breast cancer. Alterations in epigenetic regulators and transcription factors (TF) coupled with changes to the chromatin landscape have been found to orchestrate breast oncogenesis, metastasis, and the development of a resistant phenotype. Here, we review recent advances in our understanding of how the epigenome dictates breast cancer tumorigenesis and resistance to targeted therapies and discuss novel therapeutic interventions for overcoming resistance.

Key chromatin regulator-related genes associated with the risk of coronary artery disease regulate the expression of HCFC1, RNF8, TNP1 and SET

Chromatin regulators are indispensable upstream epigenetic regulators.The emergence and progression of atherosclerosis has been demonstrated to be influenced by smooth muscle-related chromatin regulators, such as ZEB2 and MAFF. However, specific chromatin regulators and their possible roles have not been clarified. Information was gathered from 51 patients diagnosed with coronary artery disease (CAD) and 50 individuals in good health from the GEO database. 440 genes were identified as having differential expression across the two datasets, and these genes were linked to cellular reactions. Enrichment of pathways related to histone modification and transcriptional regulatory factors was observed in GO and KEGG analyses. Four machine learning models (RF, SVM, GLM, and XGB) were developed using the expression profiles of 440 chromatin-associated genes in the CAD cohort to pinpoint genes with significant diagnostic potential. After evaluating residuals, root mean square errors, receiver operating characteristic curves, and immune-infiltration, four key genes (HCFC1, RNF8, TNP1, and SET) were identified. Gene expression in different blood vessel levels in atherosclerotic plaques in a mouse model of coronary artery disease showed significant variations. The gene expression levels in macrophages aligned with clinical data from the GEO database as expected. This discovery is crucial for future analysis and the prediction of drug and miRNA targets. In conclusion, we found that the four hub genes are important in the mechanism of CAD. These findings provide new ideas for the study of potential epigenetic predictive markers and therapeutic targets to be used in determining a treatment strategy for CAD.

The roles of chromatin regulatory factors in endometriosis

PURPOSE

Endometriosis is an estrogen-dependent inflammatory disease and one of the most common gynecological diseases in women of reproductive age. The aim of the review was to explore the relationship between the chromatin regulatory factors and endometriosis.

METHODS

By searching for literature on chromatin regulators and endometriosis in PuMed. Finally, 98 documents were selected.

RESULTS

Chromatin regulators (CRs) are essential epigenetic regulatory factors that can regulate chromatin structure changes and are usually divided into three categories: DNA methylation compounds, histone modification compounds, and chromatin remodeling complexes. Noncoding RNAs are also chromatin regulators and can form heterochromatin by binding to protein complexes. Chromatin regulators cause abnormal gene expression by regulating chromatin structure, thereby affecting the occurrence and development of endometriosis.

CONCLUSION

This review summarizes the participation of chromatin regulators in the mechanisms of endometriosis, and these changes in related chromatin regulators provide a comprehensive reference for diagnosis and treatment of endometriosis.

Development of Chromatin Regulator-related Molecular Subtypes and a Signature to Predict Prognosis and Immunotherapeutic Response in Head and Neck Squamous Cell Carcinoma

BACKGROUND

Chromatin regulators (CRs) serve as indispensable factors in tumor biological processes by influencing tumorigenesis and the immune microenvironment and have been identified in head and neck squamous cell carcinoma (HNSCC). Hence, CR-related genes (CRRGs) are considered potential biomarkers for predicting prognosis and immune infiltration in HNSCC. In this study, we established a novel signature for predicting the prognosis and immunotherapeutic response of HSNCC.

METHODS

A total of 870 CRRGs were obtained according to previous studies. Subsequently, patients in the TCGA-HNSC cohort were divided into different clusters based on the expression of prognostic CRRGs. Kaplan‒Meier (K‒M) survival analysis was conducted to compare the prognosis in clusters, and the CIBERSORT and ssGSEA methods assessed the immune infiltration status. In addition, the differences in immunotherapeutic responses were determined based on the TICA database. Furthermore, the differentially expressed CRRGs between clusters were identified, and the predictive signature was established according to the results of univariate Cox, least absolute shrinkage and selection operator regression analysis, and multivariate Cox. The predictive effects of the risk model were evaluated according to the area under the receiver operating characteristic (ROC) curve (AUC) in both the training and external test cohorts. A nomogram was established, and survival comparisons, functional enrichment analyses, and immune infiltration status and clinical treatment assessments were performed. In addition, the hub gene network and related analysis were conducted with the Cytohubba application.

RESULTS

Based on the expression of prognostic CRRGs, patients were divided into two clusters, in which Cluster 1 exhibited a better prognosis, more enriched immune infiltration, and a better immunotherapeutic response but exhibited chemotherapy sensitivity. The AUC values of the 1-, 3- and 5- year ROC curves for the risk model were 0.673, 0.732, and 0.692, respectively, as well as 0.645, 0.608, and 0.623 for the test set. In addition, patients in the low-risk group exhibited more immune cell enrichment and immune function activation, as well as a better immunotherapy response. The hub gene network indicated ACTN2 as the core gene differentially expressed between the two risk groups.

CONCLUSIONS

We identified molecular subtypes and established a novel predictive signature based on CRRGs. This effective CRRS system can possibly provide a novel research direction for exploring the correlation between CRs and HNSCC and requires further experimental validation.

Identification and validation of chromatin regulator-related signatures as a novel prognostic model for low-grade gliomas using translational bioinformatics

AIMS

The purpose of this study is to explore the potential biological role and prognostic significance of chromatin regulators (CRs) in low-grade gliomas (LGGs).

MAIN METHODS

CRs were obtained from the FACER database. Transcription profiles of LGG patients were collected from the TCGA and CGGA databases. Differentially expressed CRs (DECRs) between LGGs and normal controls were identified using DESeq2. The consensus clustering algorithm was employed to distinguish subtypes of LGGs based on prognosis-related DECRs. The differences in clinical and molecular characteristics between different subtypes were explored. R packages, GSVA, ssGSEA, and ESTIMATE were utilized to elucidate the tumor microenvironment and activated pathways in different subtypes. Subsequently, a CRs-related signature was developed using LASSO Cox regression. Its performance was evaluated by Kaplan-Meier curve and ROC curve analyses. In vitro experiments were performed to explore the function of JADE3 in LGGs, which predominantly expressed in glioma cells.

KEY FINDINGS

We identified 43 DECRs and two CRs-related subtypes of LGGs. The subtype characterized by shorter survival displayed significant enrichment for pathways associated with DNA damage response and repair, along with heightened immune cell infiltration. Furthermore, the CRs-based signature exhibited excellent prognostic performance in both the TCGA and CGGA databases. Knockdown of JADE3 significantly increased the invasion, migration, and proliferation abilities of Hs683.

SIGNIFICANCE

Our study reveals the aberrant expression and prognostic value of CRs in LGGs. It emphasizes the potential regulatory role of CRs in the microenvironment and DNA damage repair in LGGs. JADE3 could be a possible therapeutic target for LGGs.

Machine learning and experimental screening of chromatin regulator signatures and potential drugs in hepatitis B related hepatocellular carcinoma

Many evidences have confirmed that chromatin regulator factors (CRs) are involved in the progression of cancer, but its potential mechanism of affecting hepatitis B related hepatocellular carcinoma still needs to be studied. Our study detected the CRs that affect hepatitis B related hepatocellular carcinoma (HBV-HCC) through machine learning analysis, conducted the analysis of immune cells, constructed the relevant risk model and immune function infiltration, and predicted the potential therapeutic drugs. We found that these CRs were significantly related to the immune cells of Macrophages, B cells, CD8+T cells, etc., and PBK, AURKA, TOP2A and AURKB were the potential risk CRs of HBV-HCC. The expression levels of these four CRs increased in HepG2.2.15 cells and the liver of HBV-HCC patients, consistent with the predicted risk model. Subsequently, ten potential drugs closely related to the risk CRs were finally obtained, experimental research on resveratrol has shown that it can inhibit the proliferation of HepG2.2.15 cells and potentially inhibit the occurrence and development of HBV-HCC. Our study provides novel insights into the function of CRs in HBV-HCC and certain ideas for more accurate targeted therapy.Communicated by Ramaswamy H. Sarma.

A prognosis prediction chromatin regulator signature for patients with severe asthma

Severe asthma imposes a physical and economic burden on both patients and society. As chromatin regulators (CRs) influence the progression of multiple diseases through epigenetic mechanisms, we aimed to study the role of CRs in patients with severe asthma. Transcriptome data (GSE143303) from 47 patients with severe asthma and 13 healthy participants was downloaded from the Gene Expression Omnibus database. Enrichment analysis was performed to investigate the functions of differentially expressed CRs between the groups. We identified 80 differentially expressed CRs; they were mainly enriched in histone modification, chromatin organization, and lysine degradation. A protein-protein interaction network was then constructed. The analyzed immune scores were different between sick and healthy individuals. Thus, CRs with a high correlation in the immune analysis, SMARCC1, SETD2, KMT2B, and CHD8, were used to construct a nomogram model. Finally, using online prediction tools, we determined that lanatoside C, cefepime, and methapyrilene may be potentially effective drugs in the treatment of severe asthma. The nomogram constructed using the four CRs, SMARCC1, SETD2, KMT2B, and CHD8, may be a useful tool for predicting the prognosis of patients with severe asthma. This study provided new insights into the role of CRs in severe asthma.

Establishing a prognostic model of chromatin modulators and identifying potential drug candidates in renal clear cell patients

BACKGROUND

Renal carcinoma is a common malignant tumor of the urinary system. Advanced renal carcinoma has a low 5-year survival rate and a poor prognosis. More and more studies have confirmed that chromatin regulators (CRs) can regulate the occurrence and development of cancer. This article investigates the functional and prognostic value of CRs in renal carcinoma patients.

METHODS

mRNA expression and clinical information were obtained from The Cancer Genome Atlas database. Univariate Cox regression analysis and LASSO regression analysis were used to select prognostic chromatin-regulated genes and use them to construct a risk model for predicting the prognosis of renal cancer. Differences in prognosis between high-risk and low-risk groups were compared using Kaplan-Meier analysis. In addition, we analyzed the relationship between chromatin regulators and tumor immune infiltration, and explored differences in drug sensitivity between risk groups.

RESULTS

We constructed a model consisting of 11 CRs to predict the prognosis of renal cancer patients. We not only successfully validated its feasibility, but also found that the 11 CR-based model was an independent prognostic factor. Functional analysis showed that CRs were mainly enriched in cancer development-related signalling pathways. We also found through the TIMER database that CR-based models were also associated with immune cell infiltration and immune checkpoints. At the same time, the genomics of drug sensitivity in cancer database was used to analyze the commonly used drugs of renal clear cell carcinoma patients. It was found that patients in the low-risk group were sensitive to medicines such as axitinib, pazopanib, sorafenib, and gemcitabine. In contrast, those in the high-risk group may be sensitive to sunitinib.

CONCLUSION

The chromatin regulator-related prognostic model we constructed can be used to assess the prognostic risk of patients with clear cell renal cell carcinoma. The results of this study can bring new ideas for targeted therapy of clear cell renal carcinoma, helping doctors to take corresponding measures in advance for patients with different risks.

Identification of Chromatin Regulatory Factors Related to Immunity and Treatment of Alzheimer's Disease

Alzheimer's disease is one of the common neurodegenerative diseases in the elderly, which mainly manifests as progressively severe cognitive impairment, which seriously affects the quality of life of patients. Chromatin regulators have been shown to be associated with a variety of biological processes, and we mainly explore the relationship between chromatin regulators and Alzheimer's disease. Eight hundred seventy chromatin regulators were collected from previous studies, and data related to Alzheimer's disease patients were downloaded from the GEO database. Finally, we screened chromatin regulators related to Alzheimer's disease immunity, established prediction models, and screened related drugs and miRNAs. We screened 160 differentially expressed CRs, constructed an interaction network, obtained 10 hub genes, successfully constructed a prediction model based on immune-related 5 CRs, and obtained 520 related drugs and 3 related miRNA, which provided an idea for the treatment of Alzheimer's disease. Our study identified 5 chromatin regulators related to Alzheimer's disease, which are expected to be new targets for Alzheimer's disease immunotherapy.

Identification of molecular subtypes based on chromatin regulator and tumor microenvironment infiltration characterization in papillary renal cell carcinoma

BACKGROUND

Papillary renal cell carcinoma (pRCC) is the second most common histological type of renal cell carcinoma. The prognosis of local pRCC is better than that of ccRCC, but the situation has changed greatly after pRCC metastasis. Chromatin regulators (CRs) are indispensable in epigenetic regulation, and their abnormal expression in tumors leads to the occurrence and development of tumor. However, the role of CRs in pRCC has not been studied yet.

MATERIALS AND METHODS

291 samples were obtained from TCGA-KIPR cohort. Unsupervised clustering analysis was utilized to divide the patients of pRCC into two subtypes. Lasso Cox regression analysis was performed to construct a CRs_score model for predicting OS. The unique characteristics of different molecular subtypes were determined by TME cell infiltration analysis, GO and KEGG analysis and drug sensitivity analysis. We also carried out drug sensitivity experiments in vitro to verify the effect of signature genes on drug sensitivity to sunitinib.

RESULTS

We described the transcriptional and genetic alteration of 19 prognosis-related CRs genes in 291 cases of TCGA-KIRP cohort. We identified two distinct molecular subtypes, which have significant differences in prognosis, clinicopathological features and tumor immune microenvironment (TME). Then, four signature genes were selected by lasso regression analysis to construct a CRs_score for predicting OS, and its predictive ability for patients with pRCC was verified. A nomogram was established to improve the clinical applicability of CRs_score. We found that there was a significant difference in the proportion of immune cell infiltration between high- and low-CRs_score. In addition, CRs_score was significantly correlated with chemosensitivity. Finally, we found that SK-RC-39 cell lines were more sensitive to sunitinib after knocking down the signature gene CDCA3, PDIA4, or SUCNR1.

CONCLUSIONS

Our comprehensive analysis of CRs gene in pRCC showed that CRs gene plays a potential role in TME, prognosis and drug resistance in pRCC. These findings may lay a foundation for further study of the regulatory role of CRs gene in pRCC, and provide a new method for evaluating prognosis and developing more effective targeted therapy.

Bioinformatics-based analysis of potential candidates chromatin regulators for immune infiltration in osteoarthritis

BACKGROUND

Through the bioinformatics analysis to screen out the potential chromatin regulators (CRs) under the immune infiltration of osteoarthritis (OA), thus providing some theoretical support for future studies of epigenetic mechanisms under OA immune infiltration.

METHODS

By integrating CRs and the OA gene expression matrix, we performed weighted gene co-expression network analysis (WGCNA), differential analysis, and further screened Hub genes by protein-protein interaction (PPI) analysis. Using the OA gene expression matrix, immune infiltration extraction and quantification were performed to analyze the correlations and differences between immune infiltrating cells and their functions. By virtue of these Hub genes, Hub gene association analysis was completed and their upstream miRNAs were predicted by the FunRich software. Moreover, a risk model was established to analyze the risk probability of associated CRs in OA, and the confidence of the results was validated by the validation dataset.

RESULTS

This research acquired a total of 32 overlapping genes, and 10 Hub genes were further identified. The strongest positive correlation between dendritic cells and mast cells and the strongest negative correlation between parainflammation and Type I IFN reponse. In the OA group DCs, iDCs, macrophages, MCs, APC co-inhibition, and CCR were significantly increased, whereas B cells, NK cells, Th2 cells, TIL, and T cell co-stimulation were significantly decreased. The risk model results revealed that BRD1 might be an independent risk factor for OA, and the validation dataset results are consistent with it. 60 upstream miRNAs of OA-related CRs were predicted by the FunRich software.

CONCLUSION

This study identified certain potential CRs and miRNAs that could regulate OA immunity, thus providing certain theoretical supports for future epigenetic mechanism studies on the immune infiltration of OA.

A novel chromatin regulator-related immune checkpoint related gene prognostic signature and potential candidate drugs for endometrial cancer patients

Background

Endometrial cancer (EC) is the most common gynecologic malignancy in developed countries and its prevalence is increasing. As an emerging therapy with a promising efficacy, immunotherapy has been extensively applied in the treatment of solid tumors. In addition, chromatin regulators (CRs), as essential upstream regulators of epigenetics, play a significant role in tumorigenesis and cancer development.

Methods

CRs and immune checkpoint-related genes (ICRGs) were obtained from the previous top research. The Genome Cancer Atlas (TCGA) was utilized to acquire the mRNA expression and clinical information of patients with EC. Correlation analysis was utilized for screen CRs-related ICRGs (CRRICRGs). By Cox regression and least absolute shrinkage and selection operator (LASSO) analysis, prognosis related CRRICRGs were screened out and risk model was constructed. The Kaplan–Meier curve was used to estimate the prognosis between high- and low-risk group. By comparing the IC50 value, the drugs sensitivity difference was explored. We obtained small molecule drugs for the treatment of UCEC patients based on CAMP dataset.

Results

We successfully constructed a 9 CRRICRs-based prognostic signature for patients with UCEC and found the riskscore was an independent prognostic factor. The results of functional analysis suggested that CRRICRGs may be involved in immune processes associated with cancer. Immune characteristics analysis provided further evidence that the CRRICRGs-based model was correlated with immune cells infiltration and immune checkpoint. Eight small molecule drugs that may be effective for the treatment of UCEC patients were screened. Effective drugs identified by drug sensitivity profiling in high- and low-risk groups.

Conclusion

In summary, our study provided novel insights into the function of CRRICRGs in UCEC. We also developed a reliable prognostic panel for the survival of patients with UCEC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41065-022-00253-w.

A genetic map of the chromatin regulators to drug response in cancer cells

BACKGROUND

Diverse drug vulnerabilities owing to the Chromatin regulators (CRs) genetic interaction across various cancers, but the identification of CRs genetic interaction remains challenging.

METHODS

In order to provide a global view of the CRs genetic interaction in cancer cells, we developed a method to identify potential drug response-related CRs genetic interactions for specific cancer types by integrating the screen of CRISPR-Cas9 and pharmacogenomic response datasets.

RESULTS

Totally, 625 drug response-related CRs synthetic lethality (CSL) interactions and 288 CRs synthetic viability (CSV) interactions were detected. Systematically network analysis presented CRs genetic interactions have biological function relationship. Furthermore, we validated CRs genetic interactions induce multiple omics deregulation in The Cancer Genome Atlas. We revealed the colon adenocarcinoma patients (COAD) with mutations of a CRs set (EP300, MSH6, NSD2 and TRRAP) mediate a better survival with low expression of MAP2 and could benefit from taxnes. While the COAD patients carrying at least one of the CSV interactions in Vorinostat CSV module confer a poor prognosis and may be resistant to Vorinostat treatment.

CONCLUSIONS

The CRs genetic interaction map provides a rich resource to investigate cancer-associated CRs genetic interaction and proposes a powerful strategy of biomarker discovery to guide the rational use of agents in cancer therapy.

The role of MORC3 in silencing transposable elements in mouse embryonic stem cells

BACKGROUND

Microrchidia proteins (MORCs) are involved in epigenetic gene silencing in a variety of eukaryotic organisms. Deletion of MORCs result in several developmental abnormalities and their dysregulation has been implicated in developmental disease and multiple cancers. Specifically, mammalian MORC3 mutations are associated with immune system defects and human cancers such as bladder, uterine, stomach, lung, and diffuse large B cell lymphomas. While previous studies have shown that MORC3 binds to H3K4me3 in vitro and overlaps with H3K4me3 ChIP-seq peaks in mouse embryonic stem cells, the mechanism by which MORC3 regulates gene expression is unknown.

RESULTS

In this study, we identified that mutation in Morc3 results in a suppressor of variegation phenotype in a Modifiers of murine metastable epialleles Dominant (MommeD) screen. We also find that MORC3 functions as an epigenetic silencer of transposable elements (TEs) in mouse embryonic stem cells (mESCs). Loss of Morc3 results in upregulation of TEs, specifically those belonging to the LTR class of retrotransposons also referred to as endogenous retroviruses (ERVs). Using ChIP-seq we found that MORC3, in addition to its known localization at H3K4me3 sites, also binds to ERVs, suggesting a direct role in regulating their expression. Previous studies have shown that these ERVs are marked by the repressive histone mark H3K9me3 which plays a key role in their silencing. However, we found that levels of H3K9me3 showed only minor losses in Morc3 mutant mES cells. Instead, we found that loss of Morc3 resulted in increased chromatin accessibility at ERVs as measured by ATAC-seq.

CONCLUSIONS

Our results reveal MORC3 as a novel regulator of ERV silencing in mouse embryonic stem cells. The relatively minor changes of H3K9me3 in the Morc3 mutant suggests that MORC3 acts mainly downstream of, or in a parallel pathway with, the TRIM28/SETDB1 complex that deposits H3K9me3 at these loci. The increased chromatin accessibility of ERVs in the Morc3 mutant suggests that MORC3 may act at the level of chromatin compaction to effect TE silencing.

Automated in situ chromatin profiling efficiently resolves cell types and gene regulatory programs

BACKGROUND

Our understanding of eukaryotic gene regulation is limited by the complexity of protein-DNA interactions that comprise the chromatin landscape and by inefficient methods for characterizing these interactions. We recently introduced CUT&RUN, an antibody-targeted nuclease cleavage method that profiles DNA-binding proteins, histones and chromatin-modifying proteins in situ with exceptional sensitivity and resolution.

RESULTS

Here, we describe an automated CUT&RUN platform and apply it to characterize the chromatin landscapes of human cells. We find that automated CUT&RUN profiles of histone modifications crisply demarcate active and repressed chromatin regions, and we develop a continuous metric to identify cell-type-specific promoter and enhancer activities. We test the ability of automated CUT&RUN to profile frozen tumor samples and find that our method readily distinguishes two pediatric glioma xenografts by their subtype-specific gene expression programs.

CONCLUSIONS

The easy, cost-effective workflow makes automated CUT&RUN an attractive tool for high-throughput characterization of cell types and patient samples.

Comprehensive single cell-resolution analysis of the role of chromatin regulators in early C. elegans embryogenesis

Chromatin regulators are widely expressed proteins with diverse roles in gene expression, nuclear organization, cell cycle regulation, pluripotency, physiology and development, and are frequently mutated in human diseases such as cancer. Their inhibition often results in pleiotropic effects that are difficult to study using conventional approaches. We have developed a semi-automated nuclear tracking algorithm to quantify the divisions, movements and positions of all nuclei during the early development of Caenorhabditis elegans and have used it to systematically study the effects of inhibiting chromatin regulators. The resulting high dimensional datasets revealed that inhibition of multiple regulators, including F55A3.3 (encoding FACT subunit SUPT16H), lin-53 (RBBP4/7), rba-1 (RBBP4/7), set-16 (MLL2/3), hda-1 (HDAC1/2), swsn-7 (ARID2), and let-526 (ARID1A/1B) affected cell cycle progression and caused chromosome segregation defects. In contrast, inhibition of cir-1 (CIR1) accelerated cell division timing in specific cells of the AB lineage. The inhibition of RNA polymerase II also accelerated these division timings, suggesting that normal gene expression is required to delay cell cycle progression in multiple lineages in the early embryo. Quantitative analyses of the dataset suggested the existence of at least two functionally distinct SWI/SNF chromatin remodeling complex activities in the early embryo, and identified a redundant requirement for the egl-27 and lin-40 MTA orthologs in the development of endoderm and mesoderm lineages. Moreover, our dataset also revealed a characteristic rearrangement of chromatin to the nuclear periphery upon the inhibition of multiple general regulators of gene expression. Our systematic, comprehensive and quantitative datasets illustrate the power of single cell-resolution quantitative tracking and high dimensional phenotyping to investigate gene function. Furthermore, the results provide an overview of the functions of essential chromatin regulators during the early development of an animal.