Decrease of 5-hydroxymethylcytosine in primary cutaneous CD4+ small/medium sized pleomorphic T-cell lymphoproliferative disorder

Abstract Background: Primary cutaneous CD4+ small/medium-sized pleomorphic T-Cell lymphoproliferative disorder (PC-SMTLD) has been considered as a controversial dermatological disease that has been included in cutaneous T-cell lymphoma group, presenting most commonly as a solitary nodule and/or plaque with a specific and characteristic head and neck predilection. Due to the considerable overlap between PC-SMTLD and pseudolymphoma (PL), the differential diagnosis is often challenging. Methylation of DNA at position 5 of cytosine, and the subsequent reduction in intracellular 5-hydroxymethylcytosine (5-hmC) levels, is a key epigenetic event in several cancers, including systemic lymphomas. However, it has rarely been studied in cutaneous lymphomas. Objectives: The authors aimed to explore the role of differential 5-hmC immunostaining as a useful marker to distinguish PC-SMTLD from PL. Methods: Retrospective case series study with immunohistochemical and immunofluorescence analysis of 5-hmC was performed in PL and PC-SMTLD. Results: Significant decrease of 5-hmC nuclear staining was observed in PC-SMTLD when compared with PL (p<0.0001). By semi-quantitative grade integration, there were statistical differences in the final 5-hmC scores in the two study groups. The IF co-staining of 5-hmC with CD4 revealed a decrease of 5-hmC in CD4+ lymphocytes of PC-SMTLD. Study limitations: The small clinical sample size of the study. Conclusions: The immunorreactivity of 5-hmC in CD4+ lymphocytes was highly suggestive of a benign process as PL. Furthermore, the decrease of 5-hmC nuclear staining in PC-SMTLD indicated its lymphoproliferative status and helped to make the differential diagnosis with PL. © 2023 Sociedade Brasileira de Dermatologia. Published by Elsevier España, S.L.U. This is an open access article under the CC BY license (https://creativecommons.org/licenses/by/4.0/).

Application of vascular photobiomodulation therapy in individuals with low back pain and its relationship with global methylation / Aplicação da terapia por fotobiomodulação vascular em indivíduos com lombalgia e sua relação com a metilação global

ABSTRACT BACKGROUND AND OBJECTIVES: Low back pain is among the most disabling conditions worldwide, and among the epigenetic factors, methylation in CpG islands of gene promoter regions can modulate gene expression, potentially correlating with the development of the disease and providing insights into the choice of treatment. The objective of this study was to assess the efficacy of therapy using modified ILIB related to DNA methylation processes in low back pain. Secondary objectives of this study included investigating pain intensity, gender, sociodemographic data, and physical-functional profile. METHODS: This prospective study was conducted in a municipality in the southern region of Brazil. The sample consisted of 30 participants of both genders, with an average age of 41.77 years. The following aspects were analyzed: anthropometric characteristics, global methylation using the ELISA method, pain level, physical activity level, functional disabilities, and hesitancy level related to work and physical activity-related activities. RESULTS: A statistically significant association was observed between methylation levels before and after treatment application for the experimental and placebo groups (p < 0.005), demonstrating a mean responsiveness between methylation and treatment (d = 0.5). However, there were no other statistically significant associations correlated with the other work variables. CONCLUSION: The results obtained in this study suggest the need for further research related to the identification of specific genes in methylation, as well as the standardization of dosimetry used for transcutaneous ILIB laser application in the radial artery.

RESUMO JUSTIFICATIVA E OBJETIVOS: A lombalgia está entre as condições mais incapacitantes no mundo e; dentre os fatores epigenéticos, a metilação em ilhas CpG de regiões promotoras de genes pode modular a expressão gênica permitindo uma possível correlação ao desenvolvimento da doença, como também pode trazer esclarecimentos a respeito do tratamento a ser escolhido. O objetivo deste estudo foi verificar a eficácia da terapia através do uso do ILIB modificado relacionada ao processo de metilação de DNA na lombalgia. Os objetivos secundários deste estudo foram a investigação da intensidade da dor, sexo, dados sociodemográficos e perfil físico-funcional. MÉTODOS: Este estudo, desenvolvido em um município da região sul do Brasil, caracteriza-se como prospectivo. A amostra deste estudo foi composta por 30 participantes, de ambos os sexos, com idade média de 41,77 anos. Foram analisados os seguintes aspectos: características antropométricas, metilação global através do método ELISA, nível de dor, nível de atividade física, incapacidades funcionais e nível de hesitação para realizar atividades relacionada ao trabalho e atividade física. RESULTADOS: Observou-se associação estatisticamente significativa entre os níveis de metilação antes e a após aplicação do tratamento para grupo experimental e placebo (p<0,005) demostrando uma média responsividade entre as variáveis metilação e tratamento (d=0,5). No entanto, não houve nenhuma outra associação estatística correlacionada as demais variáreis do trabalho. CONCLUSÃO: Os resultados obtidos neste estudo sugerem que há necessidade mais estudos relacionados a identificação de genes específicos na metilação, além da necessidade de padronização de dosimetria utilizadas para aplicação do laser ILIB de forma transcutânea, em artéria radial.

Efecto de la epigenética en la artritis reumatoide / Effect of epigenetics on rheumatoid arthritis

La artritis reumatoide es una enfermedad autoinmune e inflamatoria que afecta de manera predominante a las articulaciones diartrodiales. En esta patología los factores ambientales o conductuales pueden actuar en sinergia con la predisposición genética, acelerando el inicio y la gravedad de la enfermedad. Este vínculo entre el medio ambiente y el genoma está mediado por marcas epigenéticas en el ácido desoxirribonucleico, incluyendo su metilación, la modificación de histonas y la regulación mediada por ácido ribonucleico no codificante. La epigenética puede generar cambios fenotípicos hereditarios, que no están determinados por modificaciones en la secuencia del ácido desoxirribonucleico y, en consecuencia, son reversibles. Por lo tanto la dieta, los medicamentos y otros factores ambientales, tendrían la capacidad de modularlos. La identificación de una desregulación epigenética específica, puede ofrecer una mayor comprensión de la fisiopatología de la enfermedad e influenciar positivamente en la prevención, diagnóstico y desarrollo de nuevas dianas terapéuticas.

Rheumatoid arthritis is an autoimmune and inflammatory disease that predominantly affects the diarthrodial joints. In this pathology, environmental or behavioral factors can act in synergy with genetic predisposition, accelerating the onset and severity of the disease. This link between the environment and the genome is mediated by epigenetic marks on deoxyribonucleic acid, including its methylation, histone modification, and noncoding ribonucleic acid-mediated regulation. Epigenetics can generate heritable phenotypic changes, which are not determined by modifications in the deoxyribonucleic acid sequence and are therefore reversible. Therefore, diet, medications and other environmental factors would have the ability to modulate them. The identification of a specific epigenetic dysregulation can offer a better understanding of the pathophysiology of the disease and positively influence the prevention, diagnosis and development of new therapeutic targets.

The pattern of alternative splicing and DNA methylation alteration and their interaction in linseed (Linum usitatissimum L) response to repeated drought stresses

BACKGROUND: Drought stress has significantly hampered agricultural productivity worldwide and can also result in modifications to DNA methylation levels. However, the dynamics of DNA methylation and its association with the changes in gene transcription and alternative splicing (AS) under drought stress are unknown in linseed, which is frequently cultivated in arid and semiarid regions. RESULTS: We analysed AS events and DNA methylation patterns in drought-tolerant (Z141) and drought-sensitive (NY-17) linseed under drought stress (DS) and repeated drought stress (RD) treatments. We found that the number of intron-retention (IR) and alternative 3' splice site (Alt3'SS) events were significantly higher in Z141 and NY-17 under drought stress. We found that the linseed response to the DS treatment was mainly regulated by transcription, while the response to the RD treatment was coregulated by transcription and AS. Whole genome-wide DNA methylation analysis revealed that drought stress caused an increase in the overall methylation level of linseed. Although we did not observe any correlation between differentially methylated genes (DMGs) and differentially spliced genes (DSGs) in this study, we found that the DSGs whose gene body region was hypermethylated in Z141 and hypomethylated in NY-17 were enriched in abiotic stress response Gene Ontology (GO) terms. This finding implies that gene body methylation plays an important role in AS regulation in some specific genes. CONCLUSION: Our study is the first comprehensive genome-wide analysis of the relationship between linseed methylation changes and AS under drought and repeated drought stress. Our study revealed different interaction patterns between differentially expressed genes (DEGs) and DSGs under DS and RD treatments and differences between methylation and AS regulation in drought-tolerant and drought-sensitive linseed varieties. The findings will probably be of interest in the future. Our results provide interesting insights into the association between gene expression, AS, and DNA methylation in linseed under drought stress. Differences in these associations may account for the differences in linseed drought tolerance.

Efectos de un programa de entrenamiento aeróbico en el tiempo de reacción y la metilación de ADN del gen SHANK3 en niños con trastorno de espectro autista: un estudio piloto / Effects of an Aerobic Training Program on Reaction Time and DNA Methylation of SHANK3 Gene in Children with Autism Spectrum Disorder: a Pilot Study

Introducción. El trastorno del espectro autista (TEA) es un trastorno del neurodesarrollo que provoca déficits en áreas cognitivas y motoras y es causado por varios mecanismos, entre ellos la regulación epigenética. Los procesos epigenéticos pueden verse influenciados por factores ambientales como el ejercicio físico. Objetivo. Analizar el efecto de un programa de ejercicio físico aeróbico (EFA) en el tiempo de reacción simple (TRS) y la metilación del ADN de la isla 2 del gen SHANK3 en niños con TEA. Materiales y métodos. Estudio cuasiexperimental realizado con un grupo de 9 niños (7-11 años) con TEA, que participaron en un programa de EFA de 10 semanas. Las diferencias en el TRS y la metilación de ADN fueron analizadas mediante la prueba de Kruskall-Wallis, considerando un nivel de significancia de p<0.05.Resultados. La mediana del TRS disminuyó después del programa de entrenamiento. Sin embargo, no se encontró una diferencia estadísticamente significativa (p=0.53). Se observó un patrón de hipermetilación en 11 de los dinucleótidos, tanto antes como después del entrenamiento, y se encontró una diferencia estadísticamente significativa en la posición CpG108 (p=0.032). Conclusión. Un programa de entrenamiento basado en EFA de intensidad moderada a vigorosa tiene el potencial de modificar el TRS y la metilación del ADN en niños con TEA. No obstante, es necesario realizar nuevos estudios con muestras más grandes y en los que se analicen más genes, para corroborar los resultados aquí descritos y fortalecer el conocimiento sobre el efecto del ejercicio en los procesos epigenéticos de esta población

Introduction. Autism spectrum disorder (ASD) is a neurodevelopmental disorder that produces cognitive and motor deficits and it is caused by several mechanisms, including epigenetic regulation. Epigenetic processes can be influenced by environ-mental factors such as physical exercise.Objective. To analyze the effect of an aerobic physical exercise (APE) program on simple reaction time (SRT) and DNA methylation of island 2 of the SHANK3 gene in children with ASD.Materials and methods. A quasi-experimental study was carried out on a group of 9 children (7-11 years old) with ASD, who participated in a 10-week APE program. Differences in SRT and DNA methylation were analyzed using the Kruskall-Wallis test by considering a significance level p<0.05.Results. The median SRT decreased after the training program. However, no sta-tistically significant difference was found (p = 0.53). A pattern of hypermethylation was observed in 11 dinucleotides, both before and after training, and a statistically significant difference was found in the CpG108 position (p = 0.032).Conclusion. A moderate to vigorous intensity of APE program has the potential to modify SRT and DNA methylation in children with ASD. However, it requires further studies with larger samples in which more genes are analyzed, to corroborate the results described here and strengthen knowledge about the effect of exercise on the epigenetic processes of this population

Epigenetics, hypersensibility and asthma: what do we know so far?

Abstract In this review, we describe recent advances in understanding the relationship between epigenetic changes, especially DNA methylation (DNAm), with hypersensitivity and respiratory disorders such as asthma in childhood. It is clearly described that epigenetic mechanisms can induce short to long-term changes in cells, tissues, and organs. Through the growing number of studies on the Origins of Health Development and Diseases, more and more data exist on how environmental and genomic aspects in early life can induce allergies and asthma. The lack of biomarkers, standardized assays, and access to more accessible tools for data collection and analysis are still a challenge for future studies. Through this review, the authors draw a panorama with the available information that can assist in the establishment of an epigenetic approach for the risk analysis of these pathologies.

Role of FoxO1/p38MAPK signaling pathway in acute lung injury induced by LPS / 中国药理学通报

Aim To investigate the effect of forkhead transcription factors of O classl (FoxO1) on lipopolysaccharide (LPS) -induced acute lung injury and its regulatory mechanism. Methods The model of acute lung injury (ALI) was simulated by LPS. HE staining was used to observe the pathological changes of lung tissues. The contents of tumor necrosis factor a (TNF-a) and interleukin-6 (IL-6) in lung tissues were determined by ELISA. The expression of FoxOl in mouse lung tissues was observed by immunohistochemical staining. The phosphorylation levels of FoxOl, DNA methyltransferase and p38 MAPK were detected by Western blot. The mRNA levels of FoxOl, IL-6, TNF-a and DNA methyltransferase were detected by qRT-PCR. DNA methylation in FoxOl promoter region in lung tissues was detected by nested methylation specific PCR (nMS-PCR). Pulmonary vascular endothelial cells (PVECs) were cultured and transfected with FoxOl siRNA, and the phosphorylation of p38 MAPK was detected by Western blot. The correlation between FoxOl methylation level and inflammatory factors was analyzed by Pearson method. Results Compared with control group, alveolar inflammatory cells increased significantly in LPS group, and pulmonary edema and hyperemia were obvious. TNF-α and IL-6 levels increased by 52. 2% and 150. 4% (P < 0. 05), respectively. The phosphorylation level of p38 MAPK and FoxOl expression increased by 134. 1% and 61. 8% (P < 0. 05), respectively, while the DNA methylation level of Fox0l promoter region decreased by 17. 2% (P < 0. 05). After transfection of FoxOl siRNA in vitro, the phosphorylation level of p38 decreased. Pearson analysis showed that FoxOl methylation level was negatively correlated with inflammatory factors. Conclusion The regulation of FoxOl/p3 8 MAPK signaling pathway by hypomethylation of FoxOl promoter is an important mechanism of LPS-induced acute lung injury.

Role of epigenetic regulation of biological clock genes in tumors / 中国药理学通报

The circadian clock is regulated at the molecular level by transcriptional-translational feedback loop of clock genes, which ensures that a variety of physiological processes have a-round 24 h circadian rhythms, including cell metabolism, cell proliferation, cell apoptosis and tumorigenesis, to maintain the homeostasis. Thus, the disturbance of circadian clock will disrupt homeostasis, causing various diseases, including neoplasm, metabolic syndrome, Parkinson's disease, COPD and cardiovascular diseases. Disturbance of circadian clock is closely related with tumorigenesis, and acts on various molecules and pathways leading to tumorigenesis, including oncogene and tumor suppressor gene, cell cycle, metabolic reprogramming, immune escape, endocrine disruption, alteration of gastrointestinal microbiome. This review focuses on changes in clock genes expression which disrupt cell cycle and may play a role in tumorigenesis, and epi-geneties, an important way to regulate gene expression, which can alter clock gene expression, thus playing an important role in the process of " the alternation of clock gene expression-disruption of cell cycle-tumorigenesis".

Differential expression profiles analysis of DNA methylation between “disease” and “syndrome” in coronary heart disease-induced unstable angina patientswith Qi deficiency and blood stasis syndrome / 数字中医药（英文）

Objective@#To explore the differential expression profiles of DNA methylation sites/regions and potential molecular mechanisms in the peripheral blood of coronary heart disease (CHD)-induced unstable angina pectoris patients with or without Qi deficiency and blood stasis syndrome, and to provide scientific evidence for the conbination of disease and syndrome.@*Methods@#According to the pre-determined inclusion and exclusion criteria, the study subjects were enrolled and divided into two groups namely CHD-induced unstable angina group (G group) and healthy control group (J group) to conduct “disease” analysis, while G group was further divided into Qi deficiency and blood stasis syndrome group (case group) and non-Qi deficiency blood stasis syndrome group (control group) to perform “syndrome” analysis. The general data and clinical information of the study subjects were collected. The peripheral venous blood was extracted on an empty stomach, and the Illumina Infinium MethylationEPIC BeadChip (850K methylation chip) was used to detect the differential expressionprofiles of DNA methylation in each group, ChAMP software (V 2.14.0) was used for the differential methylation data analysis, with a threshold of the adjusted P value (adj.P.val) < 0.01. Gene Ontology (GO) and Kyoto Encyclopedia of Genomes (KEGG) were employed for the functional and pathway enrichment analyses of related mapped genes.@*Results@#A total of 263 differentially methylated CpG positions (DMPs) were screened out between G and J groups, including 191 hypermethylated positions such as cg05845204 and cg08906898, and 72 hypomethylated positions such as cg26919182 and cg13149459. These positions were mainly mapped to 148 genes encompassing RNA binding motif protein 39 (RBM39), acetyl-CoA acyltransferase 2 (ACAA2), protein phosphatase 1 regulatory subunit 12B (PPP1R12B), and the dual-specificity tyrosine phosphorylation-regulated kinase 2 (DYRK2). GO functional enrichment analysis revealed that the genes of the DMPs were primarily enriched in protein localization to chromosomes, regulation of cell morphogenesis, negative regulation of calcium-mediated signals, etc. KEGG pathway analysis suggested that the genes were mainly enriched in fatty acid metabolism and endocytosis pathways. In addition, a total of 23 differential methylation regions (DMRs) were identified, with overlapping genes such as transmembrane protein 232 (TMEM232), ribosomal protein large P1 (RPLP1), peroxisomal biogenesis factor 10 (PEX10), and forkhead box N3 (FOXN3) recognized. It was found that GO functions were mainly enriched in the negative regulation of Ras protein signal transduction, small GTPase-mediated signal transduction, negative regulation, etc. A total of 1 703 differential methylation sites were screened out between case and control groups, including 444 increased methylation positions such as cg05573767 and 1 259 decreased methylationpositions such as cg19938535, and cg03893872. These positions were mapped to 1 108 genes such as ribosomal protein S6 kinase A2 (RPS6KA2), leucine rich repeat containing 16A (LRRC16A), and hedgehog acyltransferase (HHAT). According to the GO functional enrichment analysis, the genes relating to the DMPs were mainly enriched in biological functions such as transmembrane receptor protein serine/threonine kinase signaling pathway and axonogenesis. The KEGG pathway enrichment analysis suggested the involvement of Rap1 signaling pathway, adenosine 5’-monophosphate-activated protein kinase (AMPK) signaling pathway, etc. A total of 21 DMRs were identified, including 22 overlapping genes such as mucin 4 (MUC4), three prime repair exonuclease 1 (TREX1), and LIM homeobox 6 (LHX6). GO analysis demonstrated that the genes primarily participated in molecular functions such as positive regulation of transmembrane transport, regulation of fatty acid metabolism, and copper ion binding.@*Conclusion@#This study reveals the methylation patterns of DMPs and DMRs in patients with Qi deficiency and blood stasis syndrome caused by CHD-induced unstable angina pectoris. Potential epigenetic regulation of fatty acid metabolism, Rap1 signaling, and other molecular functions are involved in the development of CHD between the "disease" and "syndrome".

Vascular Cognitive Impairment with Kidney Yang Deficiency Syndrome and DNA Methylation Essence / 中国实验方剂学杂志

ObjectiveTo investigate the distribution of vascular cognitive impairment （VCI） with kidney Yang deficiency syndrome and explore the biological nature of VCI with kidney Yang deficiency syndrome from the perspective of DNA methylation under the combination of disease and syndrome， so as to provide an epigenetic target for traditional Chinese medicine （TCM） treatment of this disease with this syndrome in the future. MethodCommunity residents in Beijing were screened out for cognitive impairment from September 2020 to November 2022 through the scale， and VCI patients were analyzed for the syndrome. VCI patients with kidney Yang deficiency syndrome and healthy people were enrolled in this study. Peripheral venous blood was collected and subjected to genome-wide DNA methylation detection by Illumina Human Methylation 850K BeadChip. Then， differentially methylated genes （DMGs） were screened out for bioinformatics analysis. ResultA total of 1 902 people were investigated in this study， and 201 of them had VCI， accounting for 10.57%， including 72.14% with kidney Yang deficiency syndrome. The methylation results showed that compared with the normal group， the VCI group had 386 differential methylation sites， and 136 DMGs were annotated. The Kyoto Encyclopedia of Gene and Genomes（KEGG） signaling pathway enrichment analysis showed that the DMGs between the two groups were mainly involved in mammalian target of rapamycin（mTOR） signaling pathway， Estrogen signaling pathway， cyclic adenosine monophosphate（cAMP） signaling pathway， etc. Protein-protein interaction （PPI） analysis showed that DMGs， such as epidermal growth factor receptor（EGFR）， epidermal growth factor （EGF）， and signal transducer and activator of transcription 3（STAT3）， played important roles in the network. ConclusionKidney Yang deficiency is the main syndrome in VCI patients. DMGs including EGFR， EGF， and STAT3 and the related pathways such as mTOR signaling pathway， Estrogen signaling pathway， and cAMP signaling pathway may play a vital role in the occurrence and development of VCI with kidney Yang deficiency syndrome.

Research progress in epigenetic toxicity of diesel exhausts / 环境与职业医学

Diesel exhaust (DE) can enter the organism body and cause multiple organ damage. DE contains particles that can be suspended in the air for a long time. Epigenetic regulation is a post transcriptional regulation change that does not involve DNA sequence changes. Many evidences showed that DE can affect the normal physiological functions of multiple organs and systems through epigenetic changes, thus regulating the occurrence and development of multiple diseases. This paper reviewed the research progress of DNA methylation and non-coding RNA in the biological harmful effects of DE. This will provide a basis for the safety evaluation, health risk assessment, and management of DE.

Research progress on the role of environmentally induced DNA methylation in congenital cleft lip and/or palate / 口腔疾病防治

@#Congenital cleft lip and/or palate (CL/P) is a common malformation of maxillofacial development. At present, it is believed that the etiology of congenital cleft lip and palate mainly results from genetic factors and environmental factors. Epigenetic changes induced by environmental factors may be the key factor in the occurrence of fetal congenital malformations. As one of the important epigenetic modifications, DNA methylation has been widely and deeply studied in many fields, but as a link between the individual and the environment, its application in CL/P is limited. Existing studies have shown that DNA methylation is closely related to the occurrence of cleft lip and palate. Stimulation of folate deficiency, smoking, pollutant exposure and other environmental factors can induce changes in the state of DNA methylation, thus affecting gene expression in the development of lip and palate and leading to the occurrence of deformities.

Association of folic acid with the development and progression of liver cancer / 临床肝胆病杂志

So far, liver cancer is still a highly malignant tumor with a high incidence rate in China, and it seriously affects the life and health of Chinese people. Previous studies have shown that the development of liver cancer is associated with various factors such as virus, smoking, drinking, and nonalcoholic fatty liver disease. With continuous exploration, more and more studies have pointed out that nutritional factors and living environment are associated with the development and progression of liver cancer. Folic acid is a necessary nutrient for cell growth and reproduction, and its level in human body has an impact on the growth of tumor cells and is closely associated with liver cancer. This article reviews the research advances in the association between folic acid and liver cancer in recent years, so as to provide new reference and basis for the prevention and treatment of liver cancer.

The critical importance of epigenetics in autoimmune-related skin diseases / 医学前沿

Autoimmune-related skin diseases are a group of disorders with diverse etiology and pathophysiology involved in autoimmunity. Genetics and environmental factors may contribute to the development of these autoimmune disorders. Although the etiology and pathogenesis of these disorders are poorly understood, environmental variables that induce aberrant epigenetic regulations may provide some insights. Epigenetics is the study of heritable mechanisms that regulate gene expression without changing DNA sequences. The most important epigenetic mechanisms are DNA methylation, histone modification, and noncoding RNAs. In this review, we discuss the most recent findings regarding the function of epigenetic mechanisms in autoimmune-related skin disorders, including systemic lupus erythematosus, bullous skin diseases, psoriasis, and systemic sclerosis. These findings will expand our understanding and highlight the possible clinical applications of precision epigenetics approaches.

Research Progress of DNA Methylation in Cisplatin Resistance in Lung Cancer / 中国肺癌杂志

As one of the most common malignant tumors, lung cancer poses a serious threat to human life and health. The platinum-based drug cisplatin (DDP) is used as the first-line treatment for lung cancer. The poor prognosis of lung cancer is mostly due to developed resistance to cisplatin, which poses a serious treatment challenge. The mechanism of cisplatin resistance is complex and unclear. Numerous studies have shown that DNA methylation plays a crucial role in the emergence of lung cancer cisplatin resistance. DNA hypermethylation results in the deactivation of numerous drug resistance genes and tumor suppressor genes through a change in chromatin conformation. Finding new therapeutic targets and indicators to predict the therapeutic effect can be aided by elucidating the complex mechanism. In order to discover novel strategies to overcome cisplatin resistance in lung cancer, this paper discusses DNA methylation-mediated cisplatin resistance and offers an overview of current demethylation procedures.
.

Association Analysis Between Methylation of SCARB1 Gene Promoter and Coronary Heart Disease / 中国医学科学院学报

Objective To explore the relationship between scavenger receptor class B member 1 (SCARB1) gene promoter methylation and the pathogenesis of coronary artery disease. Methods A total of 120 patients with coronary heart disease treated in Renji Hospital affiliated to Shanghai Jiao Tong University School of Medicine from December 2018 to May 2020 were selected as the case group,while 140 gender and age matched healthy participants were randomly selected as the control group for a case-control study.The methylation status was detected by high-throughput target sequencing after bisulfite converting,and the methylation of CpG sites in the promoter region of SCARB1 gene was compared between the two groups. Results The case group showed higher methylation level of SCARB1+67 and lower methylation level of SCARB1+134 than the control group (both P<0.001),and the differences remained statistically significant in men (both P<0.001) and women (both P<0.001).The overall methylation level in the case group was lower than that in the control group [(80.27±2.14)% vs.(81.11±1.27)%;P=0.006],while this trend was statistically significant only in men (P=0.002). Conclusion The methylation of SCARB1 gene promotor is associated with the pathogenesis and may participate in the occurrence and development of coronary heart disease.

Age Estimation Based on DNA Methylation and Its Application Prospects in Forensic Medicine / 法医学杂志

With the improvement of DNA methylation detection techniques, studies on age-related methylation sites have found more age-specific ones across tissues, which improves the sensitivity and accuracy of age estimation. In addition, the establishment of various statistical models also provides a new direction for the age estimation of tissues from different sources. This review summarizes the related studies of age estimation based on DNA methylation from the aspects of detection technology, age-related cytosine phosphate guanine site and model selection in recent years.

Modeling Methods and Influencing Factors for Age Estimation Based on DNA Methylation / 法医学杂志

Age estimation based on tissues or body fluids is an important task in forensic science. The changes of DNA methylation status with age have certain rules, which can be used to estimate the age of the individuals. Therefore, it is of great significance to discover specific DNA methylation sites and develop new age estimation models. At present, statistical models for age estimation have been developed based on the rule that DNA methylation status changes with age. The commonly used models include multiple linear regression model, multiple quantile regression model, support vector machine model, artificial neural network model, random forest model, etc. In addition, there are many factors that affect the level of DNA methylation, such as the tissue specificity of methylation. This paper reviews these modeling methods and influencing factors for age estimation based on DNA methylation, with a view to provide reference for the establishment of age estimation models.

Cross-Platform Application of DNA Methylation Age Estimation Model in Eastern Chinese Han Population / 法医学杂志

OBJECTIVES@#To evaluate the forensic application value of an age estimation model based on DNA methylation in eastern Chinese Han population, and to provide a theoretical basis for exploring age estimation models suitable for different detection platforms.@*METHODS@#According to the 6 age-related methylation sites in the published blood DNA methylation age estimation models of Chinese Han population, the DNA methylation level of 48 samples was detected by pyrosequencing and next-generation sequencing (NGS). After submitting DNA methylation levels to the age estimation model, the DNA methylation ages were predicted and compared with their real ages.@*RESULTS@#The 6 DNA methylation sites in both detection techniques were age-related, with an R2 of 0.85 and a median absolute deviation (MAD) of 4.81 years when using pyrosequencing；with an R2 of 0.84 and MAD of 4.41 years when using NGS.@*CONCLUSIONS@#The blood DNA methylation age estimation model can be used under pyrosequencing and multi-purpose regional methylation enrichment sequencing technology based on NGS and it can accurately estimate the age.

Construction and evaluation of in-house methylation-sensitive SNaPshot system and three classification prediction models for identifying the tissue origin of body fluid / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The identification of tissue origin of body fluid can provide clues and evidence for criminal case investigations. To establish an efficient method for identifying body fluid in forensic cases, eight novel body fluid-specific DNA methylation markers were selected in this study, and a multiplex singlebase extension reaction (SNaPshot) system for these markers was constructed for the identification of five common body fluids (venous blood, saliva, menstrual blood, vaginal fluid, and semen). The results indicated that the in-house system showed good species specificity, sensitivity, and ability to identify mixed biological samples. At the same time, an artificial body fluid prediction model and two machine learning prediction models based on the support vector machine (SVM) and random forest (RF) algorithms were constructed using previous research data, and these models were validated using the detection data obtained in this study (n=95). The accuracy of the prediction model based on experience was 95.79%; the prediction accuracy of the SVM prediction model was 100.00% for four kinds of body fluids except saliva (96.84%); and the prediction accuracy of the RF prediction model was 100.00% for all five kinds of body fluids. In conclusion, the in-house SNaPshot system and RF prediction model could achieve accurate tissue origin identification of body fluids.