Kanwal R, Gupta S. Epigenetic modifications in cancer.Cancer initiation and progression is controlled by both genetic and epigenetic events. The complexity of carcinogenesis cannot be accounted for by genetic alterations alone but also involves epigenetic changes. Epigenetics refers to the study of mechanisms that alter gene expression without altering the primary DNA sequence. Epigenetic mechanisms are heritable and reversible, and include changes in DNA methylation, histone modifications and small noncoding microRNAs (miRNA). Disruption of epigenetic processes can lead to altered gene function and malignant cellular transformation. Aberrant epigenetic modifications probably occur at a very early stage in neoplastic development, and they are widely described as essential players in cancer progression. Recent advances in epigenetics offer a better understanding of the underlying mechanism(s) of carcinogenesis and provide insight into the discovery of putative cancer biomarkers for early detection, disease monitoring, prognosis, and risk assessment. In this review, we summarize the current literature on epigenetic changes causing genetic alterations that are thought to contribute to cancer, and discuss the potential impact of epigenetics future research.

Little is known regarding the role of hyperglycaemia on histone H3 modifications and, in turn, altering the expression of genes during the development of diabetes-associated complications. In the present study, we have investigated the hyperinsulinaemia/hyperglycaemia-induced epigenetic changes and alteration of Fbn1 (fibrillin 1) and Col3A1 (collagen type III α1) gene expression. Insulin resistance and Type 2 diabetes in male Sprague–Dawley rats was developed by feeding rats an HFD (high-fat diet) and administering a low dose of STZ (streptozotocin). Hyperglycaemia induced deacetylation and dephosphorylation of histone H3 in the heart and kidneys of diabetic rats. Furthermore, mRNA expression of Fbn1 and Col3A1 increased in the kidneys and decreased in the heart under hyperglycaemic/hyperinsulinaemic conditions. Similar to mRNA expression, chromatin immunoprecipitation also showed an increase in the level of histone H3 acetylation of the Fbn1 gene, but not of the Col3A1 gene. Our present findings suggests that the change in expression of the Fbn1 gene is epigenetically regulated, but the expression of the Col3A1 gene may either be independent of epigenetic regulation or may involve other histone modifications. We provide the first evidence regarding the role of hyperglycaemia/hyperinsulinaemia in altering histone H3 modifications, which may result in the alteration of extracellular matrix gene expression.

Abstract Different heritable expression-states were programmed into R alleles from R/R-1st heterozygotes under different temperature conditions applied during a developmental period in which flowering is induced. At maturity, R-allele expressions in test crosses of male gametes derived from R/R-1st seedlings raised 15 days in 32 degrees and continuous light conditions differed significantly from those of sib seedlings raised for 15 days in 22 degrees and continuous light conditions and shifted to six 12-hr light-dark cycles, day 16-21. This experiment provides the first evidence in higher organisms that environmental conditions, applied at a specific stage of development cause a heritable change in a specific allele expression. My earlier evidence required a statistical analysis for demonstrating heritable change; I present photographic evidence of this environmental effect on four R alleles.

Pregnancy is an extremely stressful period in a pregnant woman’s life. Currently, women’s awareness of the proper course of pregnancy and its possible complications is constantly growing. Therefore, a significant percentage of women increasingly reach for various dietary supplements during gestation. Some of the most popular substances included in multi-ingredient supplements are folic acid and choline. Those substances are associated with positive effects on fetal intrauterine development and fewer possible pregnancy-associated complications. Recently, more and more attention has been paid to the impacts of specific environmental factors, such as diet, stress, physical activity, etc., on epigenetic modifications, understood as changes occurring in gene expression without the direct alteration of DNA sequences. Substances such as folic acid and choline may participate in epigenetic modifications by acting via a one-carbon cycle, leading to the methyl-group donor formation. Those nutrients may indirectly impact genome phenotype by influencing the process of DNA methylation. This review article presents the current state of knowledge on the use of folic acid and choline supplementation during pregnancy, taking into account their impacts on the maternal–fetal unit and possible pregnancy outcomes, and determining possible mechanisms of action, with particular emphasis on their possible impacts on epigenetic modifications.

Many crucial epigenetic changes occur during early skeletal development and throughout life due to aging, disease and are heavily influenced by an individual’s lifestyle. Epigenetics is the study of heritable changes in gene expression as the result of changes in the environment without any mutation in the underlying DNA sequence. The epigenetic profiles of cells are dynamic and mediated by different mechanisms, including histone modifications, non-coding RNA-associated gene silencing and DNA methylation. Given the underlining role of dysfunctional mesenchymal tissues in common age-related skeletal diseases such as osteoporosis and osteoarthritis, investigations into skeletal stem cells or mesenchymal stem cells (MSC) and their functional deregulation during aging has been of great interest and how this is mediated by an evolving epigenetic landscape. The present review describes the recent findings in epigenetic changes of MSCs that effect growth and cell fate determination in the context of aging, diet, exercise and bone-related diseases.

The evolutionary impact of epigenetic variation depends on its transgenerational stability and source - whether genetically determined, environmentally induced, or due to spontaneous, genotype-independent mutations. Here, we evaluate current approaches for investigating an independent role of epigenetics in evolution, pinpointing methodological challenges. We further identify opportunities arising from integrating epigenetic data with population genetic analyses in natural populations. Efforts to advance data quality, study design, and statistical treatment are encouraged to consolidate our understanding of the source of heritable epigenetic variation, quantify its autonomous potential for evolution, and enrich population genetic analyses with an additional layer of information.

gene activity during the development of complex organisms".[8] Thus epigenetic can be used to describe anything other than DNA sequence which influences the development of an organism. A stricter or narrower definition is "the study of mitotically and/or meiotically heritable changes in gene function which cannot be explained by changes in DNA sequence".[9] More simply, it is the study of cell division where there are changes in gene expression that cannot be explained by changes to the DNA of the cell. The term "epigenetics" has been used to describe processes which are not heritable. An example is histone modification. So some definitions do not require heritability. Adrian Bird defined epigenetics as "the structural adaptation of chromosomal regions so as to register, signal or perpetuate altered activity states".[4] This definition includes DNA repair or cell division phases, and stable changes across cell generations. It excludes others such as prions unless they affect chromosome function.

In eukaryotic cells, transcription occurs in the nucleus, separate from the translation that occurs in the cytoplasm along ribosomes attached to endoplasmic reticulum. As stated above, gene expression in prokaryotes is regulated at the level of transcription, whereas in eukaryotes, gene expression is regulated at multiple levels, including the epigenetic (DNA), transcriptional, pre- and post-transcriptional, and translational levels. The science of epigenetics studies heritable changes in the genome that do not affect the underlying DNA gene sequences. The content presented in this section supports the learning objectives outlined in Big Idea 3 of the AP® Biology Curriculum Framework. The AP® learning objectives merge essential knowledge content with one or more of the seven science practices. These objectives provide a transparent foundation for the AP® Biology course, along with inquiry-based laboratory experiences, instructional activities, and AP® exam questions. For a cell to function properly, necessary proteins must be synthesized at the proper time. All cells control or regulate the synthesis of proteins from information encoded in their DNA.

As research continues to hone in on different tumorigenesis mechanisms, epigenetic dysregulation continues to show promise as a major contributing factor in cancer pathology. There are a variety of mechanisms involved in epigenetic regulation, but it can occur most prominently through direct DNA methylation and demethylation by DNA methyl‐transferase (DNMT) enzymes. Dysregulation of this epigenetic modifying mechanism from exogenous stimuli can lead to alteration of DNA transcription and protein expression within cells causing mutations to develop that result in increased cell proliferation and metastasis. Dietary polyphenols are known exogenous factors that influence epigenetic change. In particular, cinnamon is a natural product that contains many of these natural polyphenols, and it has been shown to affect protein expression in MCF‐7 breast cancer cells. With our current research, we have shown that cinnamon causes changes in activity of DNMT enzymes in MCF‐7 breast cancer cells. Results from a real‐time PCR assay for DNMT have shown modified levels of expression and activity with both enzymes in vitro . It remains to be determined whether these changes promote or inhibit tumorigenesis effects within cells, but do demonstrate that natural polyphenols found within cinnamon can cause epigenetic modification in cells. Future research will determine the resultant changes in protein expression and proliferative or anti‐proliferative nature of the effects that could arise from

gene. DNA methylation is a widespread mechanism for epigenetic influence on gene expression and is seen in bacteria and eukaryotes and has roles in heritable Gene expression is the process by which the information contained within a gene is used to produce a functional gene product, such as a protein or a functional RNA molecule. This process involves multiple steps, including the transcription of the gene's sequence into RNA. For protein-coding genes, this RNA is further translated into a chain of amino acids that folds into a protein, while for non-c Regulation of transcription can be broken down into three main routes of influence; genetic (direct interaction of a control factor with the gene), modulation interaction of a control factor with the transcription machinery and epigenetic (non-sequence changes in DNA structure that influence transcription). Direct interaction with DNA is the simplest and the most direct method by which a protein changes transcription levels. Genes often have several protein binding sites around the coding region with the specific function of regulating transcription. There are many classes of regulatory DNA binding sites known as enhancers, insulators and silencers. The mechanisms for regulating transcription are varied, from blocking key binding sites on the DNA for RNA polymerase to acting as an activator and promoting transcription by assisting RNA polymerase binding. The activity of transcription factors is further modulated by intracellular signals causing protein post-translational modification including phosphorylation, acetylation, or glycosylation. These changes influence a transcription factor's ability to bind, directly or indirectly, to promoter DNA, to recruit RNA polymerase, or to favor elongation of a newly synthesized RNA molecule. The nuclear membrane in eukaryotes allows further regulation of transcription factors by the duration of their presence in the nucleus, which is regulated by reversible changes in their structure and by binding of other proteins. Environmental stimuli or endocrine signals may cause modification of regulatory proteins eliciting cascades of intracellular signals, which result in regulation of gene expression. It has become apparent that there is a significant influence of non-DNA-sequence specific effects on transcription. These effects are referred to as epigenetic and involve the higher order structure of DNA, non-sequence specific DNA binding proteins and chemical modification of DNA. In general epigenetic effects alter the accessibility of DNA to proteins and so modulate transcription.

Cumulative evidence shows that modifications in lifestyle factors constitute an effective strategy to modulate molecular events related to neurodegenerative diseases, confirming the relevant role of epigenetics. Accordingly, Environmental Enrichment (EE) represents an approach to ameliorate cognitive decline and neuroprotection in Alzheimer’s disease (AD). AD is characterized by specific neuropathological hallmarks, such as β-amyloid plaques and Neurofibrillary Tangles, which severely affect the areas of the brain responsible for learning and memory. We evaluated EE neuroprotective influence on 5xFAD mice. We found a better cognitive performance on EE vs. Control (Ct) 5xFAD mice, until being similar to Wild-Type (Wt) mice group. Neurodegenerative markers as β-CTF and tau hyperphosphorylation, reduced protein levels whiles APPα, postsynaptic density 95 (PSD95) and synaptophysin (SYN) protein levels increased protein levels in the hippocampus of 5xFAD-EE mice group. Furthermore, a reduction in gene expression of Il-6, Gfap, Hmox1 and Aox1 was determined. However, no changes were found in the gene expression of neurotrophins, such as Brain-derived neurotrophic factor (Bdnf), Nerve growth factor (Ngf), Tumor growth factor (Tgf) and Nerve growth factor inducible (Vgf) in mice with EE. Specifically, we found a reduced DNA-methylation level (5-mC) and an increased hydroxymethylation level (5-hmC), as well as an increased histone H3 and H4 acetylation level. Likewise, we found change

Single molecule, real-time (SMRT) sequencing was used to characterize mitochondrial (mt) genome of Ophiocordyceps sinensis and to analyze the mt genome-wide pattern of epigenetic DNA modification. The complete mt genome of O. sinensis, with a size of 157,539 bp, is the fourth largest Ascomycota mt genome sequenced to date. It contained 14 conserved protein-coding genes (PCGs), 1 intronic protein rps3, 27 tRNAs and 2 rRNA subunits, which are common characteristics of the known mt genomes in Hypocreales. A phylogenetic tree inferred from 14 PCGs in Pezizomycotina fungi supports O. sinensis as most closely related to Hirsutella rhossiliensis in Ophiocordycipitaceae. A total of 36 sequence sites in rps3 were under positive selection, with dN/dS >1 in the 20 compared fungi. Among them, 16 sites were statistically significant. In addition, the mt genome-wide base modification pattern of O. sinensis was determined in this study, especially DNA methylation. The methylations were located in coding and uncoding regions of mt PCGs in O. sinensis, and might be closely related to the expression of PCGs or the binding affinity of transcription factor A to mtDNA. Consequently, these methylations may affect the enzymatic activity of oxidative phosphorylation and then the mt respiratory rate; or they may influence mt biogenesis. Therefore, methylations in the mitogenome of O. sinensis might be a genetic feature to adapt to the cold and low PO2 environment at high altitude, where O. sinensis i

Epigenetic regulation of chromatin structure is central to the process of DNA repair. A well-characterized epigenetic feature is the dynamic phosphorylation of the histone H2AX (gammaH2AX) and mobilization of double strand break (DSB) recognition and repair factors to the site. How chromatin structure is altered in response to DNA damage and how such alterations influence DSB repair mechanisms are currently relevant issues. Despite the clear link between histone deacetylases (HDACs) and radiosensitivity, how histone hyperacetylation influence DSB repair remains poorly understood. We have determined the structure of chromatin is a major factor determining radiosensitivity and repair in human cells. Trichostatin A (TSA) enhances radiosensitivity with dose modification factors of 1.2 and 1.9 at 0.2 and 1 microM, respectively. Cells treated with TSA causing hyperacetylation and remodelling on euchromatic alleles coexist with gammaH2AX accumulation in radiosensitized cells. Formation of gammaH2AX on heterochromatin was significantly reduced even when cells were treated with TSA, suggesting that chromatin structure and histone hyperacetylation are pronounced features of radiation sensitivity and repair in euchromatic regions.

Chronological age is a poor indicator of interindividual differences in biological aging. DNA methylation-based epigenetic clocks provide a reliable measure of biological age and epigenetic age acceleration (EAA). Although modifiable behavioral, environmental, and social factors appear to influence EAA, the magnitude, consistency, and potential preventability of these associations have never been systematically quantified. We conducted a systematic review and meta-analysis following PRISMA 2020 guidelines. PubMed/MEDLINE and Scopus were searched from inception to 7 April 2026 for English-language observational and interventional studies reporting quantitative associations between modifiable determinants and EAA measured using validated clocks (Horvath, PhenoAge, GrimAge, DunedinPACE). Effect sizes were harmonized into four analytical pools. Random-effects meta-analyses were performed using the DerSimonian-Laird estimator, with pre-specified subgroup analyses by exposure category. Heterogeneity, publication bias, and robustness were thoroughly assessed. A novel Modifiable Epigenetic Aging Burden Index (MEAB-Index) was developed to quantify the cumulative preventable burden. Only studies conducted in adult populations (≥18 years) were eligible. Eighty-three studies providing 118 distinct exposure-clock associations were included. In the primary analysis (Pool A, <i>n</i> = 60), adverse modifiable exposures were associated with accelerated EAA (pooled β = +0.310 years per unit exposure, 95% CI 0.255-0.366). The strongest associations were observed for metabolic and inflammatory markers (β = +0.913) and environmental exposures (β = +0.466). The MEAB-Index yielded a Cumulative Preventable Burden of +1.566 years (bootstrap 95% CI 1.011-2.123). Findings were robust across sensitivity analyses and remained directionally consistent in secondary pools (B-D). This study provides the most comprehensive quantitative synthesis to date on the modifiability of epigenetic aging. Our findings demonstrate that EAA is meaningfully shaped by behavioral, environmental, and social determinants. The MEAB-Index introduces a novel framework for estimating the preventable burden of biological aging and for prioritizing interventions. Reducing key modifiable risk factors, particularly metabolic/inflammatory and environmental exposures, could substantially slow biological aging at the population level and support the transition toward ageing-centered preventive strategies.

Hyperhomocysteinemia, characterized by elevated levels of circulating homocysteine, has emerged as a significant risk factor for cardiovascular disease (CVD). This literature review explores the multifactorial relationship between one-carbon metabolism (OCM) and cardiovascular health, focusing on the biological mechanisms that link OCM disruptions to vascular dysfunction and disease development. Emphasis is placed on the biochemical interplay between genetic polymorphisms, nutritional deficiencies (particularly B vitamins and folate), and epigenetic processes including DNA methylation, histone modifications, and non-coding RNAs. These alterations can affect gene expression, endothelial integrity, lipid metabolism, and inflammatory pathways, thereby increasing the risk of atherosclerosis, hypertension, and other CVDs. Promising therapeutic interventions-such as targeted supplementation and epigenetic-modulating strategies-are discussed as future tools for prevention and personalized treatment of cardiovascular disorders.