Methylation Markers Research Articles

Identification of DNA methylation markers for age and Bovine Respiratory Disease in dairy cattle: A pilot study based on Reduced Representation Bisulfite Sequencing

Methylation profiles of animals are known to differ by age and disease status. Bovine respiratory disease (BRD), a complex infectious disease, primarily affects calves and has significant impact on animal welfare and the cattle industry, due to production losses, increased veterinary costs as well as animal losses. BRD susceptibility is multifactorial, influenced by both environmental and genetic factors. We have performed a pilot study to investigate the epigenetic profile of BRD susceptibility in six calves (three healthy versus three diagnosed with BRD) and age-related methylation differences between healthy calves and adult dairy cows (three calves versus four adult cows) using Reduced Representation Bisulfite Sequencing (RRBS). We identified 2537 genes within differentially methylated regions between calves and adults. Functional analysis revealed enrichment of developmental pathways including cell fate commitment and tissue morphogenesis. Between healthy and BRD affected calves, 964 genes were identified within differentially methylated regions. Immune and vasculature regulatory pathways were enriched and key candidates in BRD susceptibility involved in complement cascade regulation, vasoconstriction and respiratory cilia structure and function were identified. Further studies with a greater sample size are needed to validate these findings and formulate integration into breeding programmes aiming to increase animal longevity and disease resistance.

Recognition of differently expressed genes and DNA methylation markers in patients with Lupus nephritis

Abstract Background and Objectives Systemic lupus erythematosus (SLE) is distinguished by dysregulated immune system activity, resulting in a spectrum of clinical manifestations, with lupus nephritis being particularly prominent. This study endeavors to discern novel targets as potential therapeutic markers for this condition. Methods Weighted correlation network analysis (WGCNA) was used to construct the network and select the key hub genes in the co-expression module based on the gene expression dataset GSE81622. Subsequently, functional enrichment and pathway analysis were performed for SLE and lupus nephritis. In addition, also identify genes and differences in SLE with lupus nephritis and methylation site. Finally, qRT-PCR and western blot were used to verify the up-regulated expression levels of the selected key genes. Results Within the co-expression modules constructed by WGCNA, the MElightcyan module exhibited the strongest positive correlation with lupus nephritis (0.4, P = 0.003), while showing a weaker correlation with the control group SLE (0.058) and a negative correlation with the control group (-0.41, P = 0.002). Additionally, the MEgreenyellow module displayed the highest positive correlation with SLE (0.25), but its P value was 0.06, which did not reach statistical significance(P > 0.05). Furthermore, it had a negative correlation with the control group was (-0.38, P = 0.004). The module associated with lupus nephritis was characterized by processes such as neutrophil activation (neutrophil_activation), neutrophil degranulation (neutrophil_degranulation), neutrophil activation involved in immune response (neutrophil_activation_involved_in_immune_response), neutrophils mediated immune (neutrophil_mediated_immunity) and white blood cells degranulation (leukocyte_degranulation) and so on the adjustment of the process. Secondly, in the analysis of SLE samples, the identification of differentially expressed genes revealed 125 genes, with 49 being up-regulated and 76 down-regulated. In the case of lupus nephritis samples, 156 differentially expressed genes were discerned, include in 70 up-regulated and 86 down-regulated genes. When examining differential methylation sites, we observed 12432 such sites in the SLE sample analysis, encompassing 2260 hypermethylation sites and 10172 hypomethylation sites. In the lupus nephritis samples analysis, 9613 differential methylation sites were identified, comprising 4542 hypermethylation sites and 5071 hypomethylation sites. Substantiating our findings, experimental validation of the up-regulated genes in lupus nephritis confirmed increased levels of gene expression and protein expression for CEACAM1 and SLC2A5. Conclusions We have identified several genes, notably CEACAM1 and SLC2A5, as potential markers for lupus nephritis. Their elevated expression levels and reduced DNA methylation in lupus nephritis contribute to a more comprehensive understanding of the aberrant epigenetic regulation of expression in this condition. These findings hold significant implications for the diagnosis and therapeutic strategies of lupus nephritis.

DNA Methylation-Derived Immune Cell Proportions and Cancer Risk in Black Participants.

This study describes associations between immune cell types and cancer risk in a Black population; elevated regulatory T-cell proportions that were associated with increased overall cancer and lung cancer risk, and elevated memory B-cell proportions that were associated with increased prostate and all cancer risk.

Plasma cell-free DNA methylome-based liquid biopsy for accurate gastric cancer detection.

Early detection plays a critical role in mitigating mortality rates linked to gastric cancer. However, current clinical screening methods exhibit suboptimal efficacy. Methylation alterations identified from cell-free DNA (cfDNA) present a promising biomarker for early cancer detection. Our study focused on identifying gastric cancer-specific markers from cfDNA methylation to facilitate early detection. We enrolled 150 gastric cancer patients and 100 healthy controls in this study, and undertook genome-wide methylation profiling of cfDNA using cell-free methylated DNA immunoprecipitation and high-throughput sequencing. We identified 21 differentially methylated regions (DMRs) between the gastric tumor and nontumor groups using multiple algorithms. Subsequently, using the 21 DMRs, we developed a gastric cancer detection model by random forest algorithm in the discovery set, and validated the model in an independent set. The model was able to accurately discriminate gastric cancer with a sensitivity and specificity of 93.90% and 95.15% in the discovery set, respectively, and 88.38% and 94.23% in the validation set, respectively. These results underscore the efficacy and accuracy of cfDNA-derived methylation markers in distinguishing early stage gastric cancer. This study highlighted the significance of cfDNA methylation alterations in early gastric cancer detection.

Loss of Malignancy of Super-Methotrexate-resistant Osteosarcoma Cells Is Associated With an Increase of Methylated Histone Marks H3K9me3 and H3K27me3.

Methotrexate (MTX) resistance in osteosarcoma results in a very poor patient prognosis. We previously reported that super MTX-resistant osteosarcoma (143B-MTXSR) cells, selected from parental 143B osteosarcoma (143B-P) cells by culturing them with increasing concentrations of MTX, exhibited reduced malignancy, despite the over-expression of oncogenes. The present study explored the mechanism of reduced malignancy in the super MTX-resistant osteosarcoma cells. Previously selected 143B-MTXSR cells which are 5,500 times more MTX resistant than parental cells, were used for this study. The status of methylated histone H3K9me3 and H3K27me3 marks was examined with western immunoblotting and compared between 143B-MTXSR and parental 143B-P cells. Histone H3K9me3 and H3K27me3 marks were over-expressed in 143B-MTXSR compared to 143B-P (p<0.05, p<0.01, respectively). Over-expression of histone H3K9me3 and H3K27me3 marks may be related to super-MTX resistance and to the loss of malignancy of super MTX-resistant osteosarcoma cells due to the fundamental relationship of methylation and cancer.

Alterations of senescence-associated markers in patients with non-syndromic cleft lip and palate

Non-syndromic cleft lip with or without cleft palate (NSCL/P) is one of the most common craniofacial anomalies. Abnormal Alu methylation in DNA of the pregnant mother may influence the abnormal development of the child. This study aimed to examine Alu methylation and cellular senescence in NSCL/P patients and their mothers as well as the correlation with the severity of NSCL/P. A total of 39 patients with NSCL/P and 33 mothers were enrolled. Of these patients, 6 were cleft lip only (CLO), 9 were cleft palate only (CPO), and 24 were cleft lip and palate (CLP). Alu methylation and senescence markers were determined in the white blood cells of NSCL/P patients, their mothers, and in the lip and palatal tissues of patients at the time of cheiloplasty and palatoplasty. Total Alu methylation was not significantly different between groups. However, a decrease in Alu hypermethylation, increased partial Alu methylation, RAGE, and p16 expression were shown in CLP, the most severe cleft type. Alu methylation in tissues did not differ between groups. In mothers, an increase in Alu methylation was observed only in the CLP. Therefore, the pathogenesis of NSCL/P may be related to Alu methylation of the mother promoting loss of Alu methylation and subsequently senescence in the children.

Histone marks identify novel transcription factors that parse CAR-T subset-of-origin, clinical potential and expansion.

Chimeric antigen receptor-modified T cell (CAR-T) immunotherapy has revolutionised blood cancer treatment. Parsing the genetic underpinnings of T cell quality and CAR-T efficacy is challenging. Transcriptomics inform CAR-T state, but the nature of dynamic transcription during activation hinders identification of transiently or minimally expressed genes, such as transcription factors, and over-emphasises effector and metabolism genes. Here we explore whether analyses of transcriptionally repressive and permissive histone methylation marks describe CAR-T cell functional states and therapeutic potential beyond transcriptomic analyses. Histone mark analyses improve identification of differences between naïve, central memory, and effector memory CD8 + T cell subsets of human origin, and CAR-T derived from these subsets. We find important differences between CAR-T manufactured from central memory cells of healthy donors and of patients. By examining CAR-T products from a clinical trial in lymphoma (NCT01865617), we find a novel association between the activity of the transcription factor KLF7 with in vivo CAR-T accumulation in patients and demonstrate that over-expression of KLF7 increases in vitro CAR-T proliferation and IL-2 production. In conclusion, histone marks provide a rich dataset for identification of functionally relevant genes not apparent by transcriptomics.

Abstract A031: Methylomic Biomarkers Associated with Prostate Cancer in Black Men

Abstract Introduction: The prostate cancer (PCa) disparity remains the highest cancer disparity in the US, with Black men facing an estimated 78% higher incidence and 230% higher mortality than White men. However, current understanding of risk factors for PCa such as socioeconomic status (SES), diet, and genetics cannot fully explain these disparities. Our objective is to examine DNA methylation (DNAm) markers in a cohort of Black men and assess their associations with PCa status. Methods: We randomly selected 100 Black men for DNAm profiling (50 cases diagnosed with clinically significant (Gleason Grade 3+) prostate cancer and 50 age-matched controls) from two larger cohorts. The cohorts recruited 400 Black men who were newly diagnosed with sporadic PCa as well as 400 controls matched on age and race. All men were 40-79 at recruitment and were enrolled from urology clinics at five Chicago-area medical institutions. All PCa cases underwent a transrectal prostate biopsy for abnormal prostate-specific antigen (PSA) or digital rectal exam and had a histologically confirmed prostate cancer and were not previously diagnosed with PCa. All men in the control group had been recruited from community prostate cancer screening events or were referred to participating urology clinics and had a negative prostate biopsy for a PSA &amp;lt;10ng/ml and were not diagnosed with PCa for 2 years of follow-up. Men with prior PCa diagnosis or conditions known to affect PSA levels were excluded. After enrollment and informed consent, all men provided demographic and lifestyle data via three questionnaires, followed by venipuncture for DNA collection. These specimens were obtained using buffy coat extraction after red blood cell lysis, centrifugation, and pipetting off the overlying plasma and buffy coat for freezing followed by Illumina EPIC arrays for DNAm assays. We examined DNAm markers in gene promoter regions associated with PCa using logistic regression and adjusted for multiple testing using Bonferroni correction. All models controlled for age, BMI, smoking status, first degree family history of PCa, blood cell types, and technical control variables. Results: We found 2,180 CpG sites in gene promoter regions associated with any PCa in this population. The top ten strongest associations identified in our models include loci on genes that have already been associated with prostate cancer progression (MAFG, FAM65B, OSM, PRKAG2), risk (SLC11A1, LAT), and metastasis (S1PR4) as well as immune system functioning (RAP1GAP2). Conclusions: Our initial findings suggest that DNAm markers may be useful predictors of clinically significant PCa status among Black men. Additional research is currently ongoing to expand the sample size of the DNAm profiling and to explore links between these loci and social determinants of health, as well as associations with more advanced (i.e., higher Gleason Grade) PCa. Citation Format: Brian T. Joyce, Yishu Qu, Jun Wang, Kai Zhang, Zequn Sun, Lifang Hou, Adam B. Murphy. Methylomic Biomarkers Associated with Prostate Cancer in Black Men [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr A031.

The value of SDC2 and Septin9 combined with serum tumor markers in early diagnosis of colorectal cancer

ObjectiveThe aim of this study is to evaluate the significance of combined detection of Septin9 and syndecan-2 (SDC2) methylation markers and serum tumor markers for the early diagnosis of colorectal cancer.MethodsA total of 116 patients diagnosed with colorectal cancer between December 2022 and February 2024 were designated as the colorectal cancer group. Additionally, 31 patients with colorectal adenoma were assigned to the adenoma group, while 44 individuals undergoing routine physical examinations were included in the control group. Concentrations of Septin9, SDC2, fecal occult blood (FOB), and four tumor markers—carcinoembryonic antigen (CEA), carbohydrate antigen 199 (CA199), carbohydrate antigen 125 (CA125), and carbohydrate antigen 724 (CA724)—were measured. Diagnostic performance was assessed using receiver operating characteristic (ROC) curves for Septin9, SDC2, the four tumor markers, FOB, the combination of Septin9 and SDC2, and the combined use of all seven indicators (CEA, CA19-9, CA125, CA72-4, FOB, Septin9, and SDC2).ResultsThe colorectal cancer group exhibited the highest positive rates for Septin9, SDC2, the four tumor markers, the combined detection of Septin9 and SDC2, and the combined detection of all seven indicators, compared to both the adenoma and control groups (P < 0.05). The adenoma group also showed higher positive rates than the control group (P < 0.05). For patients with stage I–III colorectal cancer, the positive rates for the combined detection of Septin9 and SDC2 were 81.3%, 78.9%, and 90.2%, respectively, surpassing those for the combined detection of the four tumor markers (43.8%, 55.3%, and 61.0%). Additionally, the positive rates for the two-gene combination in stage III colorectal cancer were higher than those for FOB (P < 0.05). The sensitivity and area under the curve (AUC) for SDC2 were 73.3% and 0.855, respectively, exceeding the sensitivity and AUC for the combined four tumor markers, which were 60.3% and 0.734 (P < 0.05). The combined detection of the two methylated genes demonstrated a sensitivity of 86.2% and an AUC of 0.908, outperforming both FOB and the combined detection of the four tumor markers (P < 0.05).ConclusionThe detection of SDC2 exhibits high sensitivity for colorectal cancer, and when combined with Septin9, it significantly enhances the diagnostic accuracy for early-stage colorectal cancer, offering substantial clinical value.

DNA Methylation signatures underpinning blood neutrophil to lymphocyte ratio during first week of human life

Understanding of newborn immune ontogeny in the first week of life will enable age-appropriate strategies for safeguarding vulnerable newborns against infectious diseases. Here we conducted an observational study exploring the immunological profile of infants longitudinally throughout their first week of life. Our Expanded Program on Immunization - Human Immunology Project Consortium (EPIC-HIPC) studies the epigenetic regulation of systemic immunity using small volumes of peripheral blood samples collected from West African neonates on days of life (DOL) 0, 1, 3, and 7. Genome-wide DNA methylation and single nucleotide polymorphism markers are examined alongside matched transcriptomic and flow cytometric data. Integrative analysis reveals that a core network of transcription factors mediates dynamic shifts in neutrophil-to-lymphocyte ratios (NLR), which are underpinned by cell-type specific methylation patterns in the two cell types. Genetic variants are associated with lower NLRs at birth, and healthy newborns with lower NLRs at birth are more likely to subsequently develop sepsis. These findings provide valuable insights into the early-life determinants of immune system development.

PHF8/KDM7B: A Versatile Histone Demethylase and Epigenetic Modifier in Nervous System Disease and Cancers.

Many human diseases, such as malignant tumors and neurological diseases, have a complex pathophysiological etiology, often accompanied by aberrant epigenetic changes including various histone modifications. Plant homologous domain finger protein 8 (PHF8), also known as lysine-specific demethylase 7B (KDM7B), is a critical histone lysine demethylase (KDM) playing an important role in epigenetic modification. Characterized by the zinc finger plant homology domain (PHD) and the Jumonji C (JmjC) domain, PHF8 preferentially binds to H3K4me3 and erases repressive methyl marks, including H3K9me1/2, H3K27me1, and H4K20me1. PHF8 is indispensable for developmental processes and the loss of PHF8 enzyme activity is linked to neurodevelopmental disorders. Moreover, increasing evidence shows that PHF8 is highly expressed in multiple tumors as an oncogenic factor. These findings indicate that studying the role of PHF8 will facilitate the development of novel therapeutic agents by the manipulation of PHF8 demethylation activity. Herein, we summarize the current knowledge of PHF8 about its structure and demethylation activity and its involvement in development and human diseases, with an emphasis on nervous system disorders and cancer. This review will update our understanding of PHF8 and promote the clinical transformation of its predictive and therapeutic value.

A - 20 Association between Smoking-Related DNA Methylation Marker and Brain MRI Volumes in Older Adults

Abstract Objective Smoking is a well-established risk factor for dementia. Studies have shown that a history of smoking is linked to higher rates of cortical volume loss in older adults. However, biological mechanisms of smoking, particularly through epigenetic changes, remain poorly understood. This study investigates the association between DNA methylation markers of smoking and patterns of brain atrophy. Methods In this cross-sectional analysis, 78 participants aged 47 years and older (68% female) from the ongoing Health Brain Initiative Study were included. DNA methylation markers of smoking were quantified using a validated algorithm applied to blood samples analyzed via the 850 k EPIC array (i.e., EpiSmoking). Brain MRI variables assessed included total cortical, hippocampal, entorhinal cortex, white matter hyperintensity volumes, and machine learning-derived atrophy scores for various cortical regions. Partial correlation analysis controlled for age, sex, education, and cognitive status (normal or mild cognitive impairment). Results Higher EpiSmoking scores significantly correlated with increased atrophy in the total cerebral cortex (r = 0.27, p &amp;lt; 0.05), frontal (r = 0.25, p &amp;lt; 0.05), parietal (r = 0.20, p &amp;lt; 0.05), and temporal lobes (r = 0.28, p &amp;lt; 0.01). No significant associations were found with other brain regions. Conclusions Our findings indicate that smoking-related DNA methylation changes are linked to specific patterns of brain atrophy. These results support the theory that environmental factors, such as smoking, may negatively impact the epigenome and potentially increase the risk of dementia. However, further research with larger cohorts is necessary to validate these associations and explore the underlying mechanisms.

A Chemoselective Enrichment Strategy for In-Depth Coverage of the Methyllysine Proteome.

Proteomics is a powerful method to comprehensively understand cellular posttranslational modifications (PTMs). Owing to low abundance, tryptic peptides with PTMs are usually enriched for enhanced coverage by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). Affinity chromatography for phosphoproteomes by metal-oxide and pan-specific antibodies for lysine acetylome allow identification of tens of thousands of modification sites. Lysine methylation is a significant PTM; however, only hundreds of methylation sites were identified by available approaches. Herein we report an aryl diazonium based chemoselective strategy that enables enrichment of monomethyllysine (Kme1) peptides through covalent bonds with extraordinary sensitivity. We identified more than 10000 Kme1 peptides from diverse cell lines and mouse tissues, which implied a wide lysine methylation impact on cellular processes. Furthermore, we found a significant amount of methyl marks that were not S-adenosyl methionine (SAM)-dependent by isotope labeling experiments.

A Chemoselective Enrichment Strategy for In‐Depth Coverage of the Methyllysine Proteome

AbstractProteomics is a powerful method to comprehensively understand cellular posttranslational modifications (PTMs). Owing to low abundance, tryptic peptides with PTMs are usually enriched for enhanced coverage by liquid chromatography‐mass spectrometry/mass spectrometry (LC–MS/MS). Affinity chromatography for phosphoproteomes by metal‐oxide and pan‐specific antibodies for lysine acetylome allow identification of tens of thousands of modification sites. Lysine methylation is a significant PTM; however, only hundreds of methylation sites were identified by available approaches. Herein we report an aryl diazonium based chemoselective strategy that enables enrichment of monomethyllysine (Kme1) peptides through covalent bonds with extraordinary sensitivity. We identified more than 10000 Kme1 peptides from diverse cell lines and mouse tissues, which implied a wide lysine methylation impact on cellular processes. Furthermore, we found a significant amount of methyl marks that were not S‐adenosyl methionine (SAM)‐dependent by isotope labeling experiments.

Discovery and validation of colorectal cancer tissue-specific methylation markers: a dual-center retrospective cohort study

Background and purposeEarly detection, diagnosis, and treatment of colorectal cancer and its precancerous lesions can significantly improve patients’ survival rates. The purpose of this research is to identify methylation markers specific to colorectal cancer tissues and validate their diagnostic capability in colorectal cancer and precancerous changes by measuring the level of DNA methylation in stool samples.MethodWe analyzed samples from six cancer tissues and adjacent normal tissues and fecal samples from 758 participants, including 62 patients with interfering diseases. Bioinformatics databases were used to screen for candidate biomarkers for CRC, and quantitative methylation-specific PCR methods were applied for identification. The methylation levels of the candidate biomarkers in fecal and tissue samples were measured. Logistic regression and random forest models were built and validated using fecal sample data from one of the centers, and the independent or combined diagnostic value of the candidate biomarkers in fecal samples for CRC and precancerous lesions was analyzed. Finally, the diagnostic capability and stability of the model were validated at another medical center.ResultsThis study identified two colorectal cancer CpG sites with tissue specificity. These two biomarkers have certain diagnostic power when used individually, but their diagnostic value for colorectal cancer and colorectal adenoma is more significant when they are used in combination.ConclusionThe results indicate that a DNA methylation biomarker combined diagnostic model based on two CpG sites, cg13096260 and cg12587766, has the potential for screening and diagnosing precancerous lesions and colorectal cancer. Additionally, compared to traditional diagnostic models, machine learning algorithms perform better but may yield more false-positive results, necessitating further investigation.

Retrotransposons and Diabetes Mellitus.

Retrotransposons are invasive genetic elements, which replicate by copying and pasting themselves throughout the genome in a process called retrotransposition. The most abundant retrotransposons by number in the human genome are Alu and LINE-1 elements, which comprise approximately 40% of the human genome. The ability of retrotransposons to expand and colonize eukaryotic genomes has rendered them evolutionarily successful and is responsible for creating genetic alterations leading to significant impacts on their hosts. Previous research suggested that hypomethylation of Alu and LINE-1 elements is associated with global hypomethylation and genomic instability in several types of cancer and diseases, such as neurodegenerative diseases, obesity, osteoporosis, and diabetes mellitus (DM). With the advancement of sequencing technologies and computational tools, the study of the retrotransposon's association with physiology and diseases is becoming a hot topic among researchers. Quantifying Alu and LINE-1 methylation is thought to serve as a surrogate measurement of global DNA methylation level. Although Alu and LINE-1 hypomethylation appears to serve as a cellular senescence biomarker promoting genomic instability, there is sparse information available regarding their potential functional and biological significance in DM. This review article summarizes the current knowledge on the involvement of the main epigenetic alterations in the methylation status of Alu and LINE-1 retrotransposons and their potential role as epigenetic markers of global DNA methylation in the pathogenesis of DM.

Personality vulnerability to depression, resilience, and depressive symptoms: epigenetic markers among perinatal women.

We examined differences in DNA methylation patterns in the NR3C1 and FKBP5 genes in relation to personality vulnerability to depression, resilience, and perinatal depressive symptoms, whilst also considering possible moderating effects of childhood traumatic events. N = 160 perinatal women were assessed at late pregnancy and 1 year postpartum for personality vulnerability to depression, resilience, depressive symptoms, and childhood traumatic events with self-reported questionnaires. NR3C1 and FKBP5 methylation markers were analyzed via sodium bisulfite sequencing. Associations of methylation markers with the above mentioned variables were tested using multivariable regressions. NR3C1 methylation at CpGs 1, 4 and average methylation sites were negatively associated with resilience; NR3C1 methylation at CpG 2 was positively associated with postpartum depressive symptoms; methylation at CpG 4 was positively associated with prenatal depressive symptoms. The interaction between current distress due to interpersonal traumatic events and NR3C1 CpG sites in relation to personality vulnerability was significant on CpG sites 3 and 4, whereas the interaction between current distress due to total traumatic events and NR3C1 in relation to personality vulnerability was significant on CpG site 2. FKBP5 showed no significant associations with the outcomes. This study identified associations between NR3C1 methylation and resilience as well as perinatal depressive symptoms. Interestingly, an interaction between early trauma and personality vulnerability was noted. Our findings on these specific DNA methylation markers may, if replicated and integrated into risk prediction models, contribute to early diagnosis of mothers at risk, targeted health promotion, and early interventions.

Histone Arginine Methylation as a Regulator of Gene Expression in the Dehydrating African Clawed Frog (Xenopus laevis).

The African clawed frog (Xenopus laevis) endures prolonged periods of dehydration while estivating underground during the dry season. Epigenetic modifications play crucial roles in regulating gene expression in response to environmental changes. The elucidation of epigenetic changes relevant to survival could serve as a basis for further studies on organ preservation under extreme stress. The current study examined the relative protein levels of key enzymes involved in the arginine methylation of histones in the liver and kidney tissues of control versus dehydrated (35 ± 1%) X. laevis through immunoblotting. Protein arginine methyltransferases (PRMT) 4, 5, and 6 showed significant protein level decreases of 35 ± 3%, 71 ± 7%, and 25 ± 5%, respectively, in the liver tissues of the dehydrated frogs relative to controls. In contrast, PRMT7 exhibited an increase of 36 ± 4%. Similarly, the methylated histone markers H3R2m2a, H3R8m2a, and H3R8m2s were downregulated by 34 ± 11%, 15 ± 4%, and 42 ± 12%, respectively, in the livers of dehydrated frogs compared to controls. By contrast, the kidneys of dehydrated frogs showed an upregulation of histone markers. H3R2m2a, H3R8m2a, H3R8m2s, and H4R3m2a were significantly increased by 126 ± 12%, 112 ± 7%, 47 ± 13%, and 13 ± 3%, respectively. These changes can play vital roles in the metabolic reorganization of X. laevis during dehydration, and are likely to increase the chances of survival. In turn, the tissue-specific regulation of the histone arginine methylation mechanism suggests the importance of epigenetic regulation in the adaptation of X. laevis for whole-body dehydration.

97P GENIE-seq: A novel methylation sequencing method for effective and accurate identification of methylation markers from cfDNA

97P GENIE-seq: A novel methylation sequencing method for effective and accurate identification of methylation markers from cfDNA

1445P Novel DNA methylation markers for early detection of cardia gastric adenocarcinoma and esophageal squamous cell carcinoma

1445P Novel DNA methylation markers for early detection of cardia gastric adenocarcinoma and esophageal squamous cell carcinoma