Lower Methylation Levels Research Articles

Alu methylation level, morphological, and senescence changes during in vitro aging of human dental pulp stem cells

IntroductionHuman dental pulp stem cells (DPSCs) are pivotal in tissue engineering and cell-based therapies due to their significant differentiation potential and accessibility. A major challenge in in vitro cell expansion is their replicative senescence, which impacts their regeneration and differentiation capabilities. While genetic factors influence these processes, epigenetic regulations such as Alu methylation also play crucial roles. Changes in Alu methylation have been associated with human aging and age-related diseases, contributing to cellular dysfunction and stem cell senescence. Despite this, the implications of Alu methylation alterations in stem cell senescence remain underexplored. This study focuses on examining Alu methylation during the replicative senescence of DPSCs. MethodsThe methylation status of Alu elements in serially passaged, long-term cultured human DPSCs was assessed using combined bisulfite restriction analysis. Morphological changes and indicators of replicative senescence were also evaluated. DPSCs were divided into three passage groups for analysis: early, middle, and late. Methylation levels across these groups were compared to identify trends correlating with passage number. ResultsSignificant morphological changes and markers of replicative senescence were observed predominantly in the late-passage DPSCs. These cells exhibited notably lower levels of Alu methylation and higher proportions of hypomethylated Alu CpG sites compared to those in early passages. ConclusionThe study confirmed that alterations in Alu methylation are evident in the replicative senescence of human DPSCs, suggesting that epigenetic modifications could influence the aging process of these cells and potentially impact their therapeutic efficacy.

DNA methylation-mediated suppression of TUSC1 expression regulates the malignant progression of esophagogastric junction cancer

BackgroundEsophagogastric junction cancer (EJC) refers to malignant tumors that develop at the junction between the stomach and the esophagus. TUSC1 is a recently identified tumor suppressor gene known for its involvement in various types of cancer. The objective of this investigation was to elucidate the regulatory influence of DNA methylation on TUSC1 expression and its role in the progression of EJC.MethodsBioinformatics software was utilized to analyze the expression of TUSC1, enriched pathways, and highly methylated sites in the promoter region. TUSC1 expression in EJC was assessed using quantitative reverse transcription polymerase chain reaction (qRT-PCR), western blot (WB), and immunohistochemistry. Methylation-specific PCR was employed to detect the methylation level of TUSC1. To analyze the effects of TUSC1 and 5-AZA-2 on tumor cell proliferation, migration, invasion, cell cycle, and apoptosis, several assays including CCK-8, colony formation, transwell, and flow cytometry were conducted. The expression of MDM2 was assessed using qRT-PCR and WB. WB detected the expression of p53, and p-p53, markers for EJC cell proliferation, epithelial-mesenchymal transition, and apoptosis. The role of TUSC1 in tumor occurrence in vivo was examined using a xenograft mouse model.ResultsTUSC1 expression was significantly downregulated in EJC. Overexpression of TUSC1 and treatment with 5-AZA-2 inhibited the malignant progression of EJC cells. In EJC, low methylation levels promoted the expression of TUSC1. Upregulation of TUSC1 suppressed the expression of MDM2 and activated the p53 signaling pathway. Inactivation of this pathway attenuated the inhibitory effect of TUSC1 overexpression on EJC cell proliferation, migration, invasion, and other behaviors. Animal experiments demonstrated that TUSC1 overexpression inhibited EJC tumor growth and metastasis in vivo.ConclusionTUSC1 was commonly downregulated in EJC and regulated by methylation. It repressed the malignant progression of EJC tumors by mediating the p53 pathway, suggesting its potential as a diagnostic and therapeutic target for EJC.

DNA methylation profile of inflammatory breast cancer and its impact on prognosis and outcome

BackgroundInflammatory breast cancer (IBC) is a rare disease characterized by rapid progression, early metastasis, and a high mortality rate.MethodsGenome-wide DNA methylation analysis (EPIC BeadChip platform, Illumina) and somatic gene variants (105 cancer-related genes) were performed in 24 IBCs selected from a cohort of 140 cases.ResultsWe identified 46,908 DMPs (differentially methylated positions) (66% hypomethylated); CpG islands were predominantly hypermethylated (39.9%). Unsupervised clustering analysis revealed three clusters of DMPs characterized by an enrichment of specific gene mutations and hormone receptor status. The comparison among DNA methylation findings and external datasets (TCGA-BRCA stages III-IV) resulted in 385 shared DMPs mapped in 333 genes (264 hypermethylated). 151 DMPs were associated with 110 genes previously detected as differentially expressed in IBC (GSE45581), and 68 DMPs were negatively correlated with gene expression. We also identified 4369 DMRs (differentially methylated regions) mapped on known genes (2392 hypomethylated). BCAT1, CXCL12, and TBX15 loci were selected and evaluated by bisulfite pyrosequencing in 31 IBC samples. BCAT1 and TBX15 had higher methylation levels in triple-negative compared to non-triple-negative, while CXCL12 had lower methylation levels in triple-negative than non-triple-negative IBC cases. TBX15 methylation level was associated with obesity.ConclusionsOur findings revealed a heterogeneous DNA methylation profile with potentially functional DMPs and DMRs. The DNA methylation data provided valuable insights for prognostic stratification and therapy selection to improve patient outcomes.Graphical

Differential expression of ADRB1 causes different responses to norepinephrine in adipocytes of Duroc-Landrace-Yorkshire pigs and min pigs

Research has shown that pigs from different regions exhibit varying responses to cold stimuli. Typically, cold stimuli induce browning of white adipose tissue mediated by adrenaline, promoting non-shivering thermogenesis. However, the molecular mechanisms underlying differential response of pig breeds to norepinephrine are unclear.The aim of this study was to investigate the differences and molecular mechanisms of the effects of norepinephrine (NE) treatment on adipocytes of Min pigs (a cold-resistant pig breed) and Duroc-Landrace-Yorkshire (DLY) pigs. Real time-qPCR, western blot, and immunofluorescence were performed following NE treatment on cell cultures of adipocytes originating from Min pigs (n = 3) and DLY pigs (n = 3) to assess the expressions of adipogenesis markers, beige fat markers, and mitochondrial biogenesis markers. The results showed that NE did not affect browning of adipocytes in DLY pigs, whereas promoted browning of adipocytes in Min pigs. Further, the expression of ADRB1 (Adrenoceptor Beta 1, ADRB1) was higher in subcutaneous adipose tissue and adipocytes of Min pigs than those of DLY pigs. Overexpression of ADRB1 in DLY pig adipocytes enhanced sensitivity to NE, exhibiting decreased adipogenesis markers, upregulated beige fat markers, and increased mitochondrial biogenesis. Conversely, adipocytes treated with ADRB1 antagonist in Min pigs resulted in decreased cellular sensitivity to NE. Further studies revealed differential CpG island methylation in ADRB1 promoter region, with lower methylation levels in Min pigs compared to DLY pigs. In conclusion, differential methylation of the ADRB1 promoter region leads to different ADRB1 expression, resulting in varying responsiveness to NE in adipocytes of two pig breeds. Our results provide new insights for further analysis of the differential cold responsiveness in pig breeds from different regions.

Hypermethylation of GSTM5 and its effect on oxidation in myelodysplastic syndrome

AbstractBackgroundHypermethylation of glutathione‐S‐transferase 5 (GSTM5) and its effect on oxidation in the pathogenesis of myelodysplastic syndrome (MDS) were investigated.MethodsGSTM5 methylation was detected in bone marrow (BM) samples from MDS patients, acute myeloid leukemia (AML) patients, and control individuals using methylation‐specific PCR and MassARRAY analysis. Bisulfite sequencing PCR was performed to verify methylation levels, while mRNA levels were determined using reverse transcription polymerase chain reaction. Correlations between GSTM5 methylation and clinical parameters were analyzed. The MDS cell line, SKM‐1, was treated with decitabine, buthionine sulfoximine, or overexpression of GSTM5, and the glutathione level and cell viability were detected.ResultsThe MassARRAY analysis revealed significant differences in GSTM5 methylation levels between the MDS and control groups. GSTM5 methylation levels were significantly increased in the high‐risk subgroup and showed a significant association with MDS progression to AML (hazard ratio = 3.6). Levels of GSTM5 mRNA were significantly decreased in the MDS group, exhibiting a negative correlation with the GSTM5 gene methylation level. Normal BM HS‐5 cells exhibited significantly lower levels of GSTM5 methylation than SKM‐1 cells. Overexpression of GSTM5 in SKM‐1 cells or treatment with buthionine sulfoximine or decitabine resulted in inhibition of proliferation and significantly decreased glutathione levels.ConclusionsGSTM5 plays an anti‐oxidative role in MDS and the tumor suppressor effect of GSTM5 may be mediated by reducing glutathione levels. GSTM5 hypermethylation and low levels of GSTM5 expression may be prognostic markers for MDS.

FcMET1 mediates low DNA methylation and promotes peel coloring in Ficus carica

Fig (Ficus carica L.) with purple-red peel cultivars are popular among consumers and exhibit better storability. While DNA methylation influences fruit ripening and color development, its specific role in fig fruit remains unclear. This study explores the impact of DNA methylation on the fig peel coloration. Enzymatic colorimetric detection revealed that the level of ‘Purple Peel’ fig DNA methylation decreases with fig fruit ripening and coloring. Treatment of young fruit with the DNA-methylation inhibitor azacytidine induced peel coloration, suggesting that a decrease in DNA-methylation level promotes fig peel coloration. Seven members of DNA methyltransferases and three members of DNA demethylases were identified from a high-level fig genome, highlighting FcMET1 and FcDRM2 as stable proteins, ensuring functional expression. Reference to the Arabidopsis protein interaction network map predicted that FcMET1 is in a central position, suggesting a crucial regulatory role in multiple biological processes. Correlation analysis revealed a positive correlation between FcMET1 expression during peel development and the level of total DNA methylation. Weighted gene co-expression network analysis identified co-expression of FcMET1 with the color-related transcription factors MYB, bHLH and WD40, as well as with eight structural genes in the flavonoid-biosynthesis pathway. The expression of FcUFGT3 was negatively correlated with that of FcMET1. McrBC-PCR and Bisulfite Sequencing detection showed that a low methylation level of the FcUFGT3 promoter corresponds with its high expression in colored fig. This investigation of the mechanism of DNA methylation provides a theoretical basis for understanding the role of DNA-methylation modifications in fig ripening and coloring.

Single-stranded pre-methylated 5mC adapters uncover the methylation profile of plasma ultrashort Single-stranded cell-free DNA.

Whole-genome bisulfite sequencing (BS-Seq) measures cytosine methylation changes at single-base resolution and can be used to profile cell-free DNA (cfDNA). In plasma, ultrashort single-stranded cfDNA (uscfDNA, ∼50 nt) has been identified together with 167 bp double-stranded mononucleosomal cell-free DNA (mncfDNA). However, the methylation profile of uscfDNA has not been described. Conventional BS-Seq workflows may not be helpful because bisulfite conversion degrades larger DNA into smaller fragments, leading to erroneous categorization as uscfDNA. We describe the '5mCAdpBS-Seq' workflow in which pre-methylated 5mC (5-methylcytosine) single-stranded adapters are ligated to heat-denatured cfDNA before bisulfite conversion. This method retains only DNA fragments that are unaltered by bisulfite treatment, resulting in less biased uscfDNA methylation analysis. Using 5mCAdpBS-Seq, uscfDNA had lower levels of DNA methylation (∼15%) compared to mncfDNA and was enriched in promoters and CpG islands. Hypomethylated uscfDNA fragments were enriched in upstream transcription start sites (TSSs), and the intensity of enrichment was correlated with expressedgenesof hemopoietic cells. Using tissue-of-origin deconvolution, we inferred that uscfDNA is derived primarily from eosinophils, neutrophils, and monocytes. As proof-of-principle, we show that characteristics of the methylation profile of uscfDNA can distinguish non-small cell lung carcinoma from non-cancer samples. The 5mCAdpBS-Seq workflow is recommended for any cfDNA methylation-based investigations.

Identification of epigenetic silencing of the SFRP2 gene in colorectal cancer as a clinical biomarker and molecular significance

BackgroundSeveral studies have suggested secreted frizzled-related protein 2 (SFRP2) gene as a potential clinical biomarker in colorectal cancer (CRC). However, its diagnostic role remains unclear. In this study, we aimed to investigate the significance of SFRP2 methylation levels in a large cohort of biological specimens (including blood, adipose and colonic tissues) from patients with CRC, thereby potentially identifying new biomarker utility.MethodsWe examined the expression (by qPCR) and methylation status (by 450 K DNA array and DNA pyrosequencing) of the SFRP2 gene in healthy participants (N = 110, aged as 53.7 (14.2), 48/62 males/females) and patients with CRC (N = 85, aged 67.7 (10.5), 61/24 males/females), across different biological tissues, and assessing its potential as a biomarker for CRC. Additionally, we investigated the effect of recombinant human SFRP2 (rhSFRP2) as a therapeutic target, on cell proliferation, migration, and the expression of key genes related to carcinogenesis and the Wnt pathway.ResultsOur findings revealed that SFRP2 promoter methylation in whole blood could predict cancer stage (I + II vs. III + IV) (AUC = 0.653), lymph node invasion (AUC = 0.692), and CRC recurrence (AUC = 0.699) in patients with CRC (all with p < 0.05). Furthermore, we observed a global hypomethylation of SFRP2 in tumors compared to the adjacent area (p < 0.001). This observation was validated in the TCGA-COAD and TCGA-READ cohorts, demonstrating overall hypermethylation (both with p < 0.001) and low expression (p < 0.001), as shown in publicly available scRNA-Seq data. Notably, neoadjuvant-treated CRC patients exhibited lower SFRP2 methylation levels compared to untreated patients (p < 0.05) and low promoter SFRP2 methylation in untreated patients was associated with poor overall survival (p < 0.05), when compared to high methylation. Finally, treatment with 5 µg of rhSFRP2 treatment in CRC cells (HCT116 cells) inhibited cell proliferation (p < 0.001) and migration (p < 0.05), and downregulated the expression of AXIN2 (p < 0.01), a gene involved in Wnt signaling pathway.ConclusionsThese findings establish promoter methylation of the SFRP2 gene as a prognostic candidate in CRC when assessed in blood, and as a therapeutic prognostic candidate in tumors, potentially valuable in clinical practice. SFRP2 also emerges as a therapeutic option, providing new clinical and therapeutical avenues.

Low methylation marker levels among human papillomavirus-vaccinated women with cervical high-grade squamous intraepithelial lesions.

Cervical cancer screening programs, including triage tests, need redesigning as human papillomavirus (HPV)-vaccinated women are entering the programs. Methylation markers offer a potential solution to reduce false-positive rates by identifying clinically relevant cervical lesions with progressive potential. In a nested case-control study, 9242 women who received the three-dose HPV16/18-vaccine at ages 12-15 or 18 in a community-randomized trial were included. Subsequently, they were re-randomized for either frequent or infrequent cervical cancer screening trials. Over a 15-year post-vaccination follow-up until 2022, 17 high-grade squamous intraepithelial lesion (HSIL) and 15 low-grade (LSIL) cases were identified at the 25-year screening round, alongside 371 age and community-matched HPV16/18-vaccinated controls. Methylation analyses were performed on cervical samples collected at age 25, preceding histologically confirmed LSIL or HSIL diagnoses. DNA methylation of viral (HPV16/18/31/33) and host-cell genes (EPB41L3, FAM19A4, and miR124-2) was measured, along with HPV-genotyping. No HPV16/18 HSIL cases were observed. The predominant HPV-genotypes were HPV52 (29.4%), HPV59/HPV51/HPV58 (each 23.5%), and HPV33 (17.7%). Methylation levels were generally low, with no significant differences in mean methylation levels of viral or host-cell genes between the LSIL/HSIL and controls. However, a significant difference in methylation levels was found between HSIL cases and controls when considering a combination of viral genes and EPB41L3 (p value = .0001). HPV-vaccinated women with HSIL had HPV infections with uncommon HPV types that very rarely cause cancer and displayed low methylation levels. Further investigation is warranted to understand the likely regressive nature of HSIL among HPV-vaccinated women and its implications for management.

Integrated analysis of the DNA methylome and RNA transcriptome during the development of skeletal muscle in Duroc pigs.

Skeletal muscle development plays a crucial role in yield and quality of pork; however, this process is influenced by various factors. In this study, we employed whole-genome bisulfite sequencing (WGBS) and transcriptome sequencing to comprehensively investigate the longissimus dorsi muscle (LDM), aiming to identify key genes that impact the growth and development of Duroc pigs with different average daily gains (ADGs). Eight pigs were selected and divided into two groups based on ADGs: H (774.89 g) group and L (658.77 g) group. Each pair of the H and L groups were half-siblings. The results of methylation sequencing revealed 2631 differentially methylated genes (DMGs) involved in metabolic processes, signalling, insulin secretion, and other biological activities. Furthermore, a joint analysis was conducted on these DMGs and the differentially expressed genes (DEGs) obtained from transcriptome sequencing of the same individual. This analysis identified 316 differentially methylated and differentially expressed genes (DMEGs), including 18 DMEGs in promoter regions and 294 DMEGs in gene body regions. Finally, LPAR1 and MEF2C were selected as candidate genes associated with muscle development. Bisulfite sequencing PCR (BSP) and quantitative real-time PCR (qRT-PCR) revealed that the promoter region of LPAR1 exhibited significantly lower methylation levels (P < 0.05) and greater expression levels (P < 0.05) in the H group than in the L group. Additionally, hypermethylation was observed in the gene body region of MEF2C, as was a low expression level, in the H group (P < 0.05). These results suggest that the differences in the ADGs of Duroc pigs fed the same diet may be influenced by the methylation levels and expression levels of genes related to skeletal muscle development.

Population genomics and epigenomics of Spirodela polyrhiza provide insights into the evolution of facultative asexuality

Many plants are facultatively asexual, balancing short-term benefits with long-term costs of asexuality. During range expansion, natural selection likely influences the genetic controls of asexuality in these organisms. However, evidence of natural selection driving asexuality is limited, and the evolutionary consequences of asexuality on the genomic and epigenomic diversity remain controversial. We analyzed population genomes and epigenomes of Spirodela polyrhiza, (L.) Schleid., a facultatively asexual plant that flowers rarely, revealing remarkably low genomic diversity and DNA methylation levels. Within species, demographic history and the frequency of asexual reproduction jointly determined intra-specific variations of genomic diversity and DNA methylation levels. Genome-wide scans revealed that genes associated with stress adaptations, flowering and embryogenesis were under positive selection. These data are consistent with the hypothesize that natural selection can shape the evolution of asexuality during habitat expansions, which alters genomic and epigenomic diversity levels.

Plexin domain-containing 1 may be a biomarker of poor prognosis in hepatocellular carcinoma patients, may mediate immune evasion.

For the first time, we investigated the oncological role of plexin domain-containing 1 (PLXDC1), also known as tumor endothelial marker 7 (TEM7), in hepatocellular carcinoma (HCC). To investigate the oncological profile of PLXDC1 in HCC. Based on The Cancer Genome Atlas database, we analyzed the expression of PLXDC1 in HCC. Using immunohistochemistry, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blotting, we validated our results. The prognostic value of PLXDC1 in HCC was analyzed by assessing its correlation with clinicopathological features, such as patient survival, methylation level, tumor immune microenvironment features, and immune cell surface checkpoint expression. Finally, to assess the immune evasion potential of PLXDC1 in HCC, we used the tumor immune dysfunction and exclusion (TIDE) website and immunohistochemical staining assays. Based on immunohistochemistry, qRT-PCR, and Western blot assays, overexpression of PLXDC1 in HCC was associated with poor prognosis. Univariate and multivariate Cox analyses indicated that PLXDC1 might be an independent prognostic factor. In HCC patients with high methylation levels, the prognosis was worse than in patients with low methylation levels. Pathway enrichment analysis of HCC tissues indicated that genes upregulated in the high-PLXDC1 subgroup were enriched in mesenchymal and immune activation signaling, and TIDE assessment showed that the risk of immune evasion was significantly higher in the high-PLXDC1 subgroup compared to the low-PLXDC1 subgroup. The high-risk group had a significantly lower immune evasion rate as well as a poor prognosis, and PLXDC1-related risk scores were also associated with a poor prognosis. As a result of this study analyzing PLXDC1 from multiple biological perspectives, it was revealed that it is a biomarker of poor prognosis for HCC patients, and that it plays a role in determining immune evasion status.

Multi-omics portrait of ductal carcinoma in situ in young women.

Young patients with breast ductal carcinoma in situ (DCIS) often face a poorer prognosis. The genomic intricacies in young-onset DCIS, however, remain underexplored. To address this gap, we undertook a comprehensive study encompassing exome, transcriptome, and vmethylome analyses. Our investigation included 20 DCIS samples (including 15 young-onset DCIS) and paired samples of normal breast tissue and blood. Through RNA sequencing, we identified two distinct DCIS subgroups: "immune hot" and "immune cold". The "immune hot" subgroup was characterized by increased infiltration of lymphocytes and macrophages, elevated expression of PDCD1 and CTLA4, and reduced GATA3 expression. This group also exhibited active immunerelated transcriptional regulators. Mutational analysis revealed alterations in TP53 (38%), GATA3 (25%), and TTN (19%), with two cases showing mutations in APC, ERBB2, and SMARCC1. Common genomic alterations, irrespective of immune status, included gains in copy numbers at 1q, 8q, 17q, and 20q, and losses at 11q, 17p, and 22q. Signature analysis highlighted the predominance of signatures 2 and 1, with "immune cold" samples showing a significant presence of signature 8. Our methylome study on 13 DCIS samples identified 328 hyperdifferentially methylated regions (DMRs) and 521 hypo-DMRs, with "immune cold" cases generally showing lower levels of methylation. In summary, the molecular characteristics of young-onset DCIS share similarities with invasive breast cancer (IBC), potentially indicating a poor prognosis. Understanding these characteristics, especially the immune microenvironment of DCIS, could be pivotal in identifying new therapeutic targets and preventive strategies for breast cancer.

MRNA Expression and DNA Methylation of CXCL16 in Menstrual Blood and Endometrium Tissue of Subjects with Endometriosis and Pelvic Pain

BACKGROUND: The cytokine chemokine ligand 16 (CXCL16) plays an important role in the pathophysiology of endometriosis by regulating the inflammatory response and contributing to the pain-associated endometriosis. Despite this, the impact of epigenetic modifications, such as DNA methylation, on CXCL16 has yet to be fully understood. Therefore, this research was conducted to assess both the mRNA expression and DNA methylation levels of the proinflammatory gene CXCL16 in the endometrium tissue and menstrual blood of patients with and without endometriosis.METHODS: Thirty-five women with and without endometriosis were involved in this research. Subjects' menstrual blood samples were collected using filter paper pads, meanwhile the endometrium tissue were collected by performing biopsy, from which DNA and RNA were extracted. The DNA methylation levels of the CXCL16 were measured using the pyrosequencing method following bisulfite conversion treatment. Meanwhile, the mRNA expression level was measured using the quantitative polymerase chain reaction (qPCR) method and analyzed with the Livak method.RESULTS: The mRNA expression of CXCL16 in menstrual blood of endometriosis subjects was 2.42 times higher compared to control group (p=0.030). Furthermore, the expression of CXCL16 in menstrual blood was identical to that in endometrial tissue (p=0.173). DNA methylation analysis showed that CXCL16 in the menstrual blood of endometriosis subjctes had lower methylation levels compared to controls (p=0.004), indicating hypomethylation.CONCLUSION: Increased mRNA expression and hypomethylation of CXCL16 in the menstrual blood of endometriosis patients could serve as a direct marker for diagnosing endometriosis. However, further study to validate these findings and explore the potential of CXCL16 as a diagnostic tool, and additional research involving larger patient for the cohorts study is necessary.KEYWORDS: CXCL16, DNA methylation, endometrium, menstrual blood, mRNA expression, pain

Immune-related gene methylation prognostic instrument for stratification and targeted treatment of ovarian cancer patients toward advanced 3PM approach.

DNA methylation is an important mechanism in epigenetics, which can change the transcription ability of genes and is closely related to the pathogenesis of ovarian cancer (OC). We hypothesize that DNA methylation is significantly different in OCs compared to controls. Specific DNA methylation status can be used as a biomarker of OC, and targeted drugs targeting these methylation patterns and DNA methyltransferase may have better therapeutic effects. Studying the key DNA methylation sites of immune-related genes (IRGs) in OCpatients and studying the effects of these methylation sites on the immune microenvironment may provide a new method for further exploring the pathogenesis of OC, realizing early detection and effective monitoring of OC, identifying effective biomarkers of DNA methylation subtypes and drug targets, improving the efficacy of targeted drugs or overcoming drug resistance, and better applying it to predictive diagnosis, prevention, and personalized medicine (PPPM; 3PM) of OC. Hypermethylated subtypes (cluster 1) and hypomethylated subtypes (cluster 2) were established in OCs based on the abundance of different methylation sites in IRGs. The differences in immune score, immune checkpoints, immune cells, and overall survival were analyzed between different methylation subtypes in OC samples. The significant pathways, gene ontology (GO), and protein-protein interaction (PPI) network of the identified methylation sites in IRGs were enriched. In addition, the immune-related methylation signature was constructed with multiple regression analysis. A methylation site model based on IRGs was constructed and verified. A total of 120 IRGs with 142 differentially methylated sites (DMSs) were identified. The DMSs were clustered into a high-level methylation group (cluster 1) and a low-level methylation group (cluster 2). The significant pathways and GO analysis showed many immune-related and cancer-associated enrichments. A methylation site signature based on IRGs was constructed, including RORC|cg25112191, S100A13|cg14467840, TNF|cg04425624, RLN2|cg03679581, and IL1RL2|cg22797169. The methylation sites of all five genes showed hypomethylation in OC, and there were statistically significant differences among RORC|cg25112191, S100A13|cg14467840, and TNF|cg04425624 (p < 0.05). This prognostic model based on low-level methylation and high-level methylation groups was significantly linked to the immune microenvironment as well as overall survival in OC. This study provided different methylation subtypes for OC patients according to the methylation sites of IRGs. In addition, it helps establish a relationship between methylation and the immune microenvironment, which showed specific differences in biological signaling pathways, genomic changes, and immune mechanisms within the two subgroups. These data provide ones to deeply understandthe mechanism of immune-related methylation genes on the occurrence and development of OC. The methylation-site signature is also to establish new possibilities for OC therapy. These data are a precious resource for stratification and targeted treatment of OC patients toward an advanced 3PM approach. The online version contains supplementary material available at 10.1007/s13167-024-00359-3.

Global DNA Methylation Level in Tumour and Margin Samples in Relation to Human Papilloma Virus and Epstein-Barr Virus in Patients with Oropharyngeal and Oral Squamous Cell Carcinomas.

Aberrant DNA methylation is a common epigenetic modification in cancers, including oropharyngeal squamous cell carcinoma (OPSCC) and oral squamous cell carcinoma (OSCC). Therefore, the analysis of methylation levels appears necessary to improve cancer therapy and prognosis. The enzyme-linked immunosorbent assay (ELISA) was used to analyse global DNA methylation levels in OPSCC and OSCC tumours and the margin samples after DNA isolation. HPV detection was conducted by hybridisation using GenoFlow HPV Array Test Kits (DiagCor Bioscience Inc., Hong Kong, China). EBV detection was performed using real-time PCR with an EBV PCR Kit (EBV/ISEX/100, GeneProof, Brno, Czech Republic). OPSCC tumour samples obtained from women showed lower global DNA methylation levels than those from men (1.3% vs. 3.5%, p = 0.049). The margin samples from OPSCC patients with HPV and EBV coinfection showed global DNA methylation lower than those without coinfection (p = 0.042). G3 tumours from OSCC patients had significantly lower levels of global DNA methylation than G2 tumours (0.98% ± 0.74% vs. 3.77% ± 4.97%, p = 0.010). Additionally, tumours from HPV-positive OSCC patients had significantly lower global DNA methylation levels than those from HPV-negative patients (p = 0.013). In the margin samples, we observed a significant negative correlation between global DNA methylation and the N stage of OSCC patients (rS = -0.33, p = 0.039). HPV-positive OPSCC patients had higher global DNA methylation levels than HPV-positive OSCC patients (p = 0.015). We confirmed that methylation could be changed in relation to viral factors, such as HPV and EBV, as well as clinical and demographical parameters.

Integrated analysis of the gonadal methylome and transcriptome provides new insights into the expression regulation of sex determination and differentiation genes in spotted scat (Scatophagus argus)

The spotted scat (Scatophagus argus) is an economically important mariculture fish. There have been no studies of gonadal DNA methylation at the genomic level in S. argus. Here, the gonadal methylome profiles of male and female S. argus were constructed and a link between DNA methylation and transcriptional regulation was identified. The gonads at stage IV of three male and female S. argus individuals were subjected to whole-genome bisulfite sequencing (WGBS), generating an average of 17.76 Gb of clean data for each sample. Analysis of methylation levels in different genomic regions revealed that both male and female S. argus gonads exhibited low methylation levels in the promoters and first exons, but high levels in the inner exons and introns. In general, DNA methylation levels were higher in the testes than in the ovaries. A total of 234,482 differentially methylated regions (DMRs) were identified between testes and ovaries, including 234,245, 26 and 211 DMRs in the CpG, CHG, and CHH backgrounds, respectively. Combined methylation and transcriptome analysis revealed that the relationship between methylation patterns and gene expression was generally negatively correlated. The male-specific Dmrt1Y, which is the candidate sex-determining gene of S. argus, was lowly modified by DNA methylation at its promoter region in the testis. While its allele on the X chromosome, Dmrt1ΔX, was highly modified by DNA methylation in both the testis and ovary. The expression levels of some other genes involved in sex differentiation and sex steroid synthesis were also regulated by DNA methylation. This study sheds light on the divergent methylation patterns in the gonadal genomes of male and female S. argus. These findings laid the foundation for subsequent analysis of differentially expressed sex determination and differentiation genes between male and female S. argus, providing a crucial theoretical basis for sex-control breeding efforts in S. argus.

IDNA-OpenPrompt: OpenPrompt learning model for identifying DNA methylation.

Introduction: DNA methylation is a critical epigenetic modification involving the addition of a methyl group to the DNA molecule, playing a key role in regulating gene expression without changing the DNA sequence. The main difficulty in identifying DNA methylation sites lies in the subtle and complex nature of methylation patterns, which may vary across different tissues, developmental stages, and environmental conditions. Traditional methods for methylation site identification, such as bisulfite sequencing, are typically labor-intensive, costly, and require large amounts of DNA, hindering high-throughput analysis. Moreover, these methods may not always provide the resolution needed to detect methylation at specific sites, especially in genomic regions that are rich in repetitive sequences or have low levels of methylation. Furthermore, current deep learning approaches generally lack sufficient accuracy. Methods: This study introduces the iDNA-OpenPrompt model, leveraging the novel OpenPrompt learning framework. The model combines a prompt template, prompt verbalizer, and Pre-trained Language Model (PLM) to construct the prompt-learning framework for DNA methylation sequences. Moreover, a DNA vocabulary library, BERT tokenizer, and specific label words are also introduced into the model to enable accurate identification of DNA methylation sites. Results and Discussion: An extensive analysis is conducted to evaluate the predictive, reliability, and consistency capabilities of the iDNA-OpenPrompt model. The experimental outcomes, covering 17 benchmark datasets that include various species and three DNA methylation modifications (4mC, 5hmC, 6mA), consistently indicate that our model surpasses outstanding performance and robustness approaches.

Tubulin alpha-1b chain was identified as a prognosis and immune biomarker in pan-cancer combing with experimental validation in breast cancer

The α-tubulin subtype, Tubulin α-1b chain (TUBA1B), has been shown to influence immune cell infiltration, cancer growth, and survival across various malignancies. However, a comprehensive study has not yet been undertaken examining the immunological and predictive effects of TUBA1B in a pan-carcinoma context. Using data from TCGA, GEO, and other databases, we analyzed TUBA1B expression across various carcinoma types using transcriptional profiling, prognostic implications, genetic and epigenetic alterations, methylation patterns, and immunological significance. To validate our findings, we conducted Western blot analysis to assess TUBA1B protein levels in matched breast cancer tissue samples and performed CCK-8 proliferation assay, flow cytometry, transwell invasion, and migration assays to comprehensively examine the functional impact of TUBA1B on breast cancer cells. Our pan-cancer analysis found TUBA1B upregulation across most tumor types, with varying expression patterns in distinct immune and molecular subtypes. High TUBA1B expression was an independent risk factor and associated with poor prognoses in several cancers, including BRCA, KICH, LGG, LUAD, and MESO. TUBA1B also demonstrates moderate to high diagnostic accuracy in most tumor types. Increased m6A methylation levels were observed in the TUBA1B gene, while its promoter region displayed low methylation levels. TUBA1B's expression impacted some cancers by elevating tumor mutation burden, microsatellite instability, neoantigen formation, immune cell infiltration, and the modulation of immune checkpoints. Functional enrichment analysis highlights TUBA1B’s involvement in important cellular processes such as the cell cycle, p53 signaling, cell senescence, programmed cell death, and the regulation of immune-related pathways. Moreover, our study reveals higher TUBA1B protein expression in breast cancer tissues compared to adjacent tissues. In vitro experiments confirm that TUBA1B deletion reduces breast cancer cell proliferation, invasion, and migration while increasing apoptosis. In conclusion, our study suggests that TUBA1B could potentially serve as a diagnostic marker for predicting cancer immunological profiles and survival outcomes and shed light on the expression and role of TUBA1B in breast cancer, providing a solid foundation for considering it as a promising therapeutic target for breast cancer patient treatment.

Methylation levels of the IL10 gene in peripheral blood are related to the intractability of Graves' disease

The prognosis of autoimmune thyroid diseases (AITDs), including Hashimoto's disease (HD) and Graves' disease (GD), is difficult to predict. DNA methylation regulates gene expression of immune mediating factors. Interleukin (IL)-10 is a Th2 cytokine that downregulates inflammatory cytokines produced by Th1 cells. To clarify the role of methylation of the IL10 gene in the prognosis of AITD, we evaluated the methylation levels of two CpG sites in the IL10 promoter using pyrosequencing. The methylation levels of the −185 CpG site of the IL10 gene were related to age and GD intractability in GD patients. Furthermore, the C carrier of the IL10–592 A/C polymorphism was related to low methylation levels of the −185 CpG site. The methylation levels of the IL10–185 CpG site of the IL10 gene were related to the intractability of GD and were lower in individuals with the C allele of the IL10–592 A/C polymorphism.