Epigenetic down-regulation of the HIST1 locus predicts better prognosis in acute myeloid leukemia with NPM1 mutation

Histone HIST1 genes and tumor-infiltrating lymphocytes in a child with γδ T cell acute lymphoblastic leukemia by single-cell sequencing

γδ T cell acute lymphoblastic leukemia (γδ T-ALL) represents a rare subset of T-ALL and is correlated with high rates of induction failure, relapse, and increased mortality. γδ T-ALL lacks a biologically informed framework for guiding its classification and treatment strategies. In this report, we detail a case of child with γδ T-ALL who underwent induction chemotherapy and intensification treatment, followed by haploidentical hematopoietic stem cell transplantation. The patient achieved a clinical complete remission and remains minimal residual disease negative with chidamide maintenance post-transplantation. Single-cell RNA sequencing revealed a connection between histone HIST1 genes and γδ T-ALL and identified potential effector functions of γδ T cells in combating this leukemia. This case carries significant implications for managing γδ T-ALL, highlighting the relationship between histone modification patterns and γδ tumor-infiltrating lymphocytes in γδ T-ALL cells for developing novel therapeutic approaches.

Mapping chromatin remodelling in glioblastoma identifies epigenetic regulation of key molecular pathways and novel druggable targets

BACKGROUND

Glioblastoma is the most common and aggressive malignant brain tumour in the adult population and its prognosis is dismal. The heterogeneous nature of the tumour, to which epigenetic dysregulation significantly contributes, is among the main therapeutic challenges of the disease.

RESULTS

We have leveraged SYNGN, an experimental pipeline enabling the syngeneic comparison of glioblastoma stem cells and expanded potential stem cell (EPSC)-derived neural stem cells to identify regulatory features driven by chromatin remodelling specifically in glioblastoma stem cells.

CONCLUSIONS

We show epigenetic regulation of the expression of genes and related signalling pathways contributing to glioblastoma development. We also identify novel epigenetically regulated druggable target genes on a patient-specific level, including SMOX and GABBR2.

Microbial signatures in head and neck squamous cell carcinoma: an in silico study

OBJECTIVES

The oral cavity harbors a plethora of bacterial species. Dysbiosis of oral and gut microbiota is associated with several oral and systemic pathologies, such as cancer, obesity, diabetes, atherosclerosis and gastrointestinal diseases. Imbalance in the oral-gut microbial axis has been associated with head and neck squamous cell carcinoma (HNSCC). This study aims to analyze the bacterial profile of HNSCC across various taxonomic units, investigate molecular patterns associated with prevalent bacterial phylum in HNSCC, and compare the bacterial profile in HNSCC and gastrointestinal (GI) carcinoma using computational analysis.

METHODOLOGY

The microbe-host transcriptomic, proteomic, and epigenetic analyses of HNSCC and GI carcinomas were performed using The Cancer Microbiome Atlas (TCMA) database. The differential expression of the host's mRNA transcripts and proteins associated with tumor microbiome were analyzed using The University of Alabama at Birmingham Cancer data analysis (UALCAN) and Clinical Proteomic Tumor Analysis Consortium (CPTAC) websites.

RESULTS

A decrease in Actinobacteria and an enrichment of Flavobacteria at the class level, Neisseriales, Pasteurellales, and Campylobacterales at the order level, Pasteurellaceae, Flavobacteriaceae, Campylobacteraceae, and Peptoniphilaceae at the family level, and Hemophilus, Porphyromonas, and Leptotrichia at the genus level were observed in HNSCC compared to the normal mucosa. RICTOR protein, mRNA transcripts (HIST1H2BB, SCARNA11, TBC1D21 gene), and hsa-miR-200a-5p miRNA were significantly correlated with prevalent bacterial species in HNSCC. A major increase in Actinobacteria, Fusobacteria, and Spirochaetes was observed in HNSCC compared to GI carcinoma.

CONCLUSION

The oral-gut microbial dysbiosis, as reflected by the differential abundance of bacterial species in oral and GI carcinomas, suggests the implication of tumor microbiome and their genomic interactions with the host in carcinogenesis.

Quantification of Histone H1 Subtypes Using Targeted Proteomics

Histone H1 is involved in the regulation of chromatin structure. Human somatic cells express up to seven subtypes. The variability in the proportions of somatic H1s (H1 complement) is one piece of evidence supporting their functional specificity. Alterations in the protein levels of different H1 subtypes have been observed in cancer, suggesting their potential as biomarkers and that they might play a role in disease development. We have developed a mass spectrometry-based (MS) parallel reaction monitoring (PRM) assay suitable for the quantification of H1 subtypes. Our PRM method is based on the quantification of unique peptides for each subtype, providing high specificity. Evaluation of the PRM performance on three human cell lines, HeLa, K562, and T47D, showed high reproducibility and sensitivity. Quantification values agreed with the electrophoretic and Western blot data, indicating the accuracy of the method. We used PRM to quantify the H1 complement in peripheral blood samples of healthy individuals and chronic myeloid leukemia (CML) patients. In CML, the first line of therapy is a tyrosine kinase inhibitor, imatinib. Our preliminary data revealed differences in the H1 complement in CML patients between imatinib responders and non-responders. These results support further research to determine if the H1 content or subtype composition could help predict imatinib response.

m5 C regulator-mediated methylation modification patterns and tumor microenvironment infiltration characteristics in acute myeloid leukemia

BACKGROUND

Recently, many studies have been conducted to examine immune response modification at epigenetic level, but the candidate effect of RNA 5-methylcytosine (m5 C) modification on tumor microenvironment (TME) of acute myeloid leukemia (AML) is still unknown at present.

METHODS

We assessed the patterns of m5 C modification among 417 AML cases by using nine m5 C regulators. Thereafter, we associated those identified modification patterns with TME cell infiltration features. Additionally, stepwise regression and LASSO Cox regression analyses were conducted for quantifying patterns of m5 C modification among AML cases to establish the m5 C-score. Meanwhile, we validated the expression of genes in the m5C-score model by qRT-PCR. Finally, the present work analyzed the association between m5 C-score and AML clinical characteristics and prognostic outcomes.

RESULTS

In total, three different patterns of m5 C modification (m5 C-clusters) were identified, and highly differentiated TME cell infiltration features were also identified. On this basis, evaluating patterns of m5 C modification in single cancer samples was important for evaluating the immune/stromal activities in TME and for predicting prognosis. In addition, the m5 C-score was established, which showed a close relation with the overall survival (OS) of test and training set samples. Moreover, multivariate Cox analysis suggested that our constructed m5 C-score served as the independent predicting factor for the prognosis of AML (hazard ratio = 1.57, 95% confidence interval = 1.38-1.79, p < 1e-5 ).

CONCLUSIONS

This study shows that m5 C modification may be one of the key roles in the formation of diversity and complexity of TME. Meanwhile, assessing the patterns of m5 C modification among individual cancer samples is of great importance, which provides insights into cell infiltration features within TME, thereby helping to develop relevant immunotherapy and predict patient prognostic outcomes.

Histone Variants and Their Chaperones in Hematological Malignancies

Epigenetic regulation occurs on the level of compacting DNA into chromatin. The functional unit of chromatin is the nucleosome, which consists of DNA wrapped around a core of histone proteins. While canonical histone proteins are incorporated into chromatin through a replication-coupled process, structural variants of histones, commonly named histone variants, are deposited into chromatin in a replication-independent manner. Specific chaperones and chromatin remodelers mediate the locus-specific deposition of histone variants. Although histone variants comprise one of the least understood layers of epigenetic regulation, it has been proposed that they play an essential role in directly regulating gene expression in health and disease. Here, we review the emerging evidence suggesting that histone variants have a role at different stages of hematopoiesis, with a particular focus on the histone variants H2A, H3, and H1. Moreover, we discuss the current knowledge on how the dysregulation of histone variants can contribute to hematopoietic malignancies.

Pyroptosis-related gene-based prognostic signature for predicting the overall survival of oral squamous cell carcinoma patients

Purpose

Oral squamous cell carcinoma (OSCC) is the most common oral cancer worldwide. Pyroptosis is a type of programmed cell death mediated by caspase, accompanied by an inflammatory response, and plays an important role in cancer progression. The purpose of this study was to explore and identify potential biomarkers and further elucidate the potential role of cell pyroptosis in OSCC.

Methods

We regarded the samples from The Cancer Genome Atlas database as a training dataset, screened differentially expressed genes (DEGs), and further screened out OSCC phenotypic characteristic genes by using weighted gene co-expression network analysis. The analysis of 42 known pyroptosis-related genes showed that Psuch genes were widely expressed, mutated, and methylated in OSCC samples.

Results

Through correlation analysis, we identified our OSCC pyroptosis-related DEGs. To further evaluate the prognostic value of pyroptosis-related regulators, we constructed a seven gene-based prognostic signature using Cox univariate analysis and least absolute shrinkage and selection operator Cox regression analysis. Meanwhile, we found that patients in the low-risk group had higher immune infiltration. Moreover, our results also indicated significant differences in sensitivity to cisplatin and gefitinib between the high-risk and low-risk groups.

Conclusion

Our study successfully constructed the pyroptosis-related prognostic signature, which might play a potential prediction role in OSCC prognosis. Our findings also suggested that pyroptosis-related regulators might be novel biomarkers for tumor diagnosis and treatment in OSCC.

Epigenetic programming underpins B-cell dysfunction in peanut and multi-food allergy

OBJECTIVE

Rates of IgE-mediated food allergy (FA) have increased over the last few decades, and mounting evidence implicates disruption of epigenetic profiles in various immune cell types in FA development. Recent data implicate B-cell dysfunction in FA; however, few studies have examined epigenetic changes within these cells.

METHODS

We assessed epigenetic and transcriptomic profiles in purified B cells from adolescents with FA, comparing single-food-allergic (peanut only), multi-food-allergic (peanut and ≥1 other food) and non-allergic (control) individuals. Adolescents represent a phenotype of persistent and severe FA indicative of a common immune deviation.

RESULTS

We identified 144 differentially methylated probes (DMPs) and 116 differentially expressed genes (DEGs) that distinguish B cells of individuals with FA from controls, including differential methylation of the PM20D1 promoter previously associated with allergic disorders. Subgroup comparisons found 729 DMPs specific to either single-food- or multi-food-allergic individuals, suggesting epigenetic distinctions between allergy groups. This included two regions with increased methylation near three S100 genes in multi-food-allergic individuals. Ontology results of DEGs specific to multi-food-allergic individuals revealed enrichment of terms associated with myeloid cell activation. Motif enrichment analysis of promoters associated with DMPs and DEGs showed differential enrichment for motifs recognised by transcription factors regulating B- and T-cell development, B-cell lineage determination and TGF-β signalling pathway between the multi-food-allergic and single-food-allergic groups.

CONCLUSION

Our data highlight epigenetic changes in B cells associated with peanut allergy, distinguishing features of the epigenome between single-food- and multi-food-allergic individuals and revealing differential developmental pathways potentially underpinning these distinct phenotypes.

The missing linker: emerging trends for H1 variant-specific functions

In this review, Prendergast and Reinberg discuss the likelihood that the family of histone H1 variants may be key to understanding several fundamental processes in chromatin biology and underscore their particular contributions to distinctly significant chromatin-related processes.

Major advances in the chromatin and epigenetics fields have uncovered the importance of core histones, histone variants and their post-translational modifications (PTMs) in modulating chromatin structure. However, an acutely understudied related feature of chromatin structure is the role of linker histone H1. Previous assumptions of the functional redundancy of the 11 nonallelic H1 variants are contrasted by their strong evolutionary conservation, variability in their potential PTMs, and increased reports of their disparate functions, sub-nuclear localizations and unique expression patterns in different cell types. The commonly accepted notion that histone H1 functions solely in chromatin compaction and transcription repression is now being challenged by work from multiple groups. These studies highlight histone H1 variants as underappreciated facets of chromatin dynamics that function independently in various chromatin-based processes. In this review, we present notable findings involving the individual somatic H1 variants of which there are seven, underscoring their particular contributions to distinctly significant chromatin-related processes.

Towards understanding the Regulation of Histone H1 Somatic Subtypes with OMICs

Histone H1 is involved in the regulation of chromatin higher-order structure and compaction. In humans, histone H1 is a multigene family with seven subtypes differentially expressed in somatic cells. Which are the regulatory mechanisms that determine the variability of the H1 complement is a long-standing biological question regarding histone H1. We have used a new approach based on the integration of OMICs data to address this issue. We have examined the 3D-chromatin structure, the binding of transcription factors (TFs), and the expression of somatic H1 genes in human cell lines, using data from public repositories, such as ENCODE. Analysis of Hi-C, ChIP-seq, and RNA-seq data, have revealed that transcriptional control has a greater impact on H1 regulation than previously thought. Somatic H1 genes located in topologically associated domains (TADs) show higher expression than in boundary regions. H1 genes are targeted by a variable number of transcription factors including cell cycle-related TFs, and tissue-specific TFs, suggesting a fine-tuned, subtype-specific transcriptional control. We describe, for the first time, that all H1 somatic subtypes are under transcriptional co-regulation. The replication-independent subtypes, which are encoded in different chromosomes isolated from other histone genes, are also co-regulated with the rest of the somatic H1 genes, indicating that transcriptional co-regulation extends beyond the histone cluster. Transcriptional control and transcriptional co-regulation explain, at least in part, the variability of H1 complement, the fluctuations of H1 subtypes during development, and also the compensatory effects observed, in model systems, after perturbation of one or more H1 subtypes.

TNFRSF12A and a new prognostic model identified from methylation combined with expression profiles to predict overall survival in hepatocellular carcinoma

BACKGROUND

It has been proved that DNA methylation, as an epigenetic regulatory mode, plays a crucial role in the initiation, progression and invasion of hepatocellular carcinoma (HCC). However, there still are some pathways and factors that regulates the carcinogenesis of HCC remains unclear.

METHODS

The original datasets comparing DNA methylation, clinical information and transcriptome profiling between HCC and normal controls were downloaded from The Cancer Genome Atlas (TCGA) database. R software was used to screen for methylation-differential genes (MDGs) and methylation-driven genes. Gene-functional enrichment analysis, ConsensusPathDB pathway analysis, protein-protein interaction (PPI) network construction and survival analysis were performed; methylation-specific polymerase chain reaction (MSP) and real-time quantitative polymerase chain reaction (RT-qPCR) were used for validation.

RESULTS

One hundred and sixty-seven MDGs and 285 methylation-driven genes were identified. Function and pathway enrichment analysis revealed that they are associated with sequence-specific DNA binding, nuclear nucleosome, regulation of insulin-like growth factor transport, etc. An eight-gene (HIST1H1D, RP11-476B1.1, OR2AK2, TNFRSF12A, CTD-2313N18.8, AC133644.2, RP11-467L13.4 and LINC00989) prognostic model was identified from the MDGs; its methylation degree can strongly predict the overall survival of HCC. Among them, TNFRSF12A being the only one belongs to both MDGs and methylation-driver genes, shows a significant independent correlation with the prognosis of HCC. That was validated in further details.

CONCLUSIONS

Our research has identified a registry of novel genes and pathways that's important for regulating the carcinogenesis of HCC. In addition, we identified a strong molecular model for prognostic prediction. These findings will not only provide guidance for clinical individualized treatment, but also to set us targets for further research on the molecular mechanism of HCC.