DNA methyltransferases

The cell wall rebuilding is one of the first stage of protoplast development that enables further mitotic divisions and differentiation. Therefore, this work focuses on the comparison of the cell wall regeneration in the parental protoplasts of Fagopyrum tataricum, F. esculentum and the F. tataricum (+) F. esculentum hybrids, which are promising materials in terms of future breeding and research programmes. It is worth emphasizing that the preparation of buckwheat hybrids using electrofusion was described for the first time. The results indicate that cell wall rebuilding exhibited a common mechanism for parent protoplasts and the heterokaryon as all analysed cell wall components recognising arabinogalactan proteins (JIM13, JIM16), extensin (JIM20), xyloglucan (LM25) and pectins (LM20, LM5, LM6) were detected during the process of wall regeneration. However, there were certainly differences in the spatio-temporal appearance or disappearance of individual epitopes during the 72 h of the cell culture, which have been discussed in the paper. Key message The hybrid protoplasts similarly restore their wall to F. tataricum and F. esculentum protoplasts despite some qualitative and quantitative differences in epitope distribution.

Background Fagopyrum tataricum (Tartary buckwheat) is a valuable crop of great nutritional importance due to its high level of bioactive compounds. Excellent opportunities to obtain plants with the high level or the desired profile of valuable metabolites may be provided by in vitro cultures. Among known in vitro techniques, protoplast technology is an exciting tool for genetic manipulation to improve crop traits. In that context, protoplast fusion may be applied to generate hybrid cells between different species of Fagopyrum. To apply protoplast cultures to the aforementioned approaches in this research, we established the protoplast-to-plant system in Tartary buckwheat. Results In this work, cellulase and pectinase activity enabled protoplast isolation from non-morphogenic and morphogenic callus (MC), reaching, on average, 2.3 × 10 6 protoplasts per g of fresh weight. However, to release protoplasts from hypocotyls, the key step was the application of driselase in the enzyme mixture. We showed that colony formation could be induced after protoplast embedding in agarose compared to the alginate matrix. Protoplasts cultured in a medium based on Kao and Michayluk supplemented with phytosulfokine (PSK) rebuilt cell walls, underwent repeated mitotic division, formed aggregates, which consequently led to callus formation. Plating efficiency, expressing the number of cell aggregate formed, in 10-day-old protoplast cultures varied from 14% for morphogenic callus to 30% for hypocotyls used as a protoplast source. However plant regeneration via somatic embryogenesis and organogenesis occurred only during the cultivation of MC-derived protoplasts. Conclusions This study demonstrated that the applied protoplast isolation approach facilitated the recovery of viable protoplasts. Moreover, the embedding of protoplasts in an agarose matrix and supplementation of a culture medium with PSK effectively stimulated cell division and further development of Tartary buckwheat protoplast cultures along with the plant regeneration. Together, these results provide the first evidence of developing a protoplast-to-plant system from the MC of Fagopyrum tataricum used as source material. These findings suggest that

This is an eLetter published in response to the research article by Carlson et al. published in Science (doi: 10.1126/science.ady3571). In this letter, I draw attention to the potential role of other DNA-targeting microbial biomolecules such as DNases, DNA restriction endonucleases, DNA methyltransferases, and even DNA-binding proteins in contributing to genotoxicity and/or carcinogenesis. This hypothesis is supported by citations from the scientific literature, and I also provide brief suggestions on how it may be tested.

The biochemical mechanism of short RNA-induced TGS (transcriptional gene silencing) in mammals is unknown. Two competing models exist; one suggesting that the short RNA interacts with a nascent transcribed RNA strand (RNA–RNA model) and the other implying that short RNA forms a heteroduplex with DNA from the unwound double helix, an R-loop structure (RNA–DNA model). Likewise, the requirement for DNA methylation to enact TGS is still controversial. In vitro assays using purified recombinant murine Dnmt (DNA methyltransferase) 1-dN (where dN indicates an N-terminal truncation), 3a and 3b enzymes and annealed oligonucleotides were designed to question whether Dnmts methylate DNA in a RNA–DNA heteroduplex context and whether a RNA–DNA heteroduplex R-loop is a good substrate for Dnmts. Specifically, model synthetic oligonucleotides were used to examine methylation of single-stranded oligonucleotides, annealed oligonucleotide duplexes, RNA–DNA heteroduplexes, DNA bubbles and R-loops. Dnmt...

c Cover image courtesy of Albert Jeltsch. 2020 by the authors. Articles in this book are Open Access and distributed under the Creative Commons Attribution (CC BY) license, which allows users to download, copy and build upon published articles, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. The book as a whole is distributed by MDPI under the terms and conditions of the Creative Commons license CC BY-NC-ND.

Prostate cancer (PCa) is a major cause of cancer-related morbidity and mortality worldwide. Although early disease is often efficiently managed therapeutically, available options for advanced disease are mostly ineffective. Aberrant DNA methylation associated with gene-silencing of cancer-related genes is a common feature of PCa. Therefore, DNA methylation inhibitors might constitute an attractive alternative therapy. Herein, we evaluated the anti-cancer properties of hydralazine, a non-nucleoside DNA methyltransferases (DNMT) inhibitor, in PCa cell lines. In vitro assays showed that hydralazine exposure led to a significant dose and time dependent growth inhibition, increased apoptotic rate and decreased invasiveness. Furthermore, it also induced cell cycle arrest and DNA damage. These phenotypic effects were particularly prominent in DU145 cells. Following hydralazine exposure, decreased levels of DNMT1, DNMT3a and DNMT3b mRNA and DNMT1 protein were depicted. Moreover, a significa...

Interest in deep space exploration underlines the needs to investigate the effects of exposure to combined sources of space radiation. The lung is a target organ for radiation, and exposure to protons and heavy ions as radiation sources may lead to the development of degenerative disease and cancer. In this study, we evaluated the pro-fibrotic and epigenetic effects of exposure to protons (150 MeV/nucleon, 0.1 Gy) and heavy iron ions ( 56 Fe, 600 MeV/nucleon, 0.5 Gy) alone or in combination (protons on Day 1 and 56 Fe on Day 2) in C57BL/6 male mice 4 weeks after irradiation). Exposure to 56 Fe, proton or in combination, did not result in histopathological changes in the murine lung. At the same time, combined exposure to protons and 56 Fe resulted in pronounced molecular alterations in comparison with either source of radiation alone. Specifically, we observed a substantial increase in the expression of cytokine Il13, loss of expression of DNA methyltransferase Dnmt1, and reactivation of LINE-1, SINE B1 retrotransposons, and major and

The DNA methylation inhibitor 5-azacytidine is widely used to stimulate the cardiac differentiation of stem cells. However, 5-azacytidine has long been employed as a tool for stimulating skeletal myogenesis. Yet, it is unclear whether the ability of 5-azacytidine to promote both cardiac and skeletal myogenesis is dependent strictly on the native potential of the starting cell population or if this drug is a transdifferentiation agent. To address this issue, we examined the effect of 5-azacytidine on cultures of adult mouse atrial tissue, which contains cardiac but not skeletal muscle progenitors. Exposure to 5-azacytidine caused atrial cells to elongate and increased the presence of fat globules within the cultures. 5-Azacytidine also induced expression of the skeletal myogenic transcription factors MyoD and myogenin. 5-Azacytidine pretreatments allowed atrial cells to undergo adipogenesis or skeletal myogenesis when subsequently cultured with either insulin and dexamethasone or low-serum media, respectively. The presence of skeletal myocytes in atrial cultures was indicated by dual staining for myogenin and sarcomeric a-actin. These data demonstrate that 5-azacytidine converts cardiac cells to noncardiac cell types and suggests that this drug has a compromised efficacy as a cardiac differentiation factor.

Objective: For years, it has been acknowledged that cancer cells contribute to aberrant DNA methylation, an epigenetic alteration. DNA methyltransferase 1 (DNMT1) is a large multidomain protein critical DNMT in cells. Due to its significant function in epigenetic control, DNMT1 is a viable candidate gene for cancer susceptibility. The relationships between DNMT1 polymorphisms and cancer risk have been investigated; however, the outcomes are inconsistent. This metaanalysis aims to clarify the relationships between DNMT1 polymorphisms and cancer susceptibility. Materials and Methods: PubMed, Web of Science, and Scopus databases were systematically searched using specific search terms to identify potentially eligible papers published before January 2025. Fixed-effects or randomeffects models were employed to calculate odds ratios (OR) and 95% confidence intervals (CI). The I² statistic and Egger's test were utilised to evaluate inter-study heterogeneity and assess the presence of publication bias among the included studies. All statistical analyses were conducted using MetaGenyo software. Results: A total of 776 articles were retrieved from PubMed, Scopus, and Web of Science databases. After full-text evaluation and applying the literature selection criteria, 23 articles were included as case-control studies that assessed the relationship between 23 polymorphisms in DNMT1 and cancer risk were included. The rs2228612, rs2228611, rs16999593, and rs10420321 single nucleotide polymorphisms (SNPs) were most frequently investigated. The rs2228612 co-dominant model [P=0.037, OR=0.89, 95% CI (0.80-0.99)] and rs2228611 dominant model [P<0.001, OR=1.32, 95% CI (1.14-0.53)] revealed a substantial association with cancer risk. Subgroup analysis showed an association between the rs2228612 co-dominant [P=0.022, OR=0.58, 95% CI (0.74-0.98)] and recessive [P=0.046, OR=1.15, 95% CI (1.00-1.32)] models with gastrointestinal cancer and the rs2228611 co-dominant model with breast cancer [P=0.024, OR=1.15, 95% CI (1.02-1.29)]. Conclusion: Although the current study found a role for DNMT1 polymorphisms in cancer risk, further high-quality studies are needed to validate these findings.

Multiple sclerosis (MS) is a chronic inflammatory and neurodegenerative disease accompanied by demyelination of neurons in the central nervous system that mostly affects young adults, especially women. This disease has two phases including relapsing-remitting form (RR-MS) by episodes of relapse and periods of clinical remission and secondary-progressive form (SP-MS), which causes more disability. The inheritance pattern of MS is not exactly identified and there is an agreement that it has a complex pattern with an interplay among environmental, genetic and epigenetic alternations. Epigenetic mechanisms that are identified for MS pathogenesis are DNA methylation, histone modification and some microRNAs' alternations. Several cellular processes including apoptosis, differentiation and evolution can be modified along with epigenetic changes. Some alternations are associated with epigenetic mechanisms in MS patients and these changes can become key points for MS therapy. Therefore, the aim of this review was to discuss epigenetic mechanisms that are associated with MS pathogenesis and future therapeutic approaches.

Background: Temporal lobe epilepsy (TLE) with hippocampal sclerosis (HS) is a common pharmaco-resistant epilepsy referred for adult epilepsy surgery. Though associated with prolonged febrile seizures (FS) in childhood, the neurobiological basis for this relationship is not fully understood and currently no preventive or curative therapies are available. DNA methylation, an epigenetic mechanism catalyzed by DNA methyltransferases (DNMTs), potentially plays a pivotal role in epileptogenesis associated with FS. In an attempt to start exploring this notion, the present cross-sectional pilot study investigated whether global DNA methylation levels (5-mC and 5-hmC markers) and DNMT isoforms (DNMT1, DNMT3a1, and DNMT3a2) expression would be different in hippocampal and neocortical tissues between controls and TLE patients with or without a history of FS. Results: We found that global DNA methylation levels and DNMT3a2 isoform expression were lower in the hippocampus for all TLE groups when compared to control patients, with a more significant decrease amongst the TLE groups with a history of FS. Interestingly, we showed that DNMT3a1 expression was severely diminished in the hippocampus of TLE patients with a history of FS in comparison with control and other TLE groups. In the neocortex, we found a higher expression of DNMT1 and DNMT3a1 as well as increased levels of global DNA methylation for all TLE patients compared to controls. Conclusion: Together, the findings of this descriptive cross-sectional pilot study demonstrated brain region-specific changes in DNMT1 and DNMT3a isoform expression as well as global DNA methylation levels in human TLE with or without a history of FS. They highlighted a specific implication of DNMT3a isoforms in TLE after FS. Therefore, longitudinal studies that aim at targeting DNMT3a isoforms to evaluate the potential causal relationship between FS and TLE or treatment of FS-induced epileptogenesis seem warranted.

Foxp3 + regulatory T (Treg) cells restrict immune pathology in inflamed tissues; however, an inflammatory environment presents a threat to Treg cell identity and function. Here, we establish a transcriptional signature of central nervous system (CNS) Treg cells that accumulate during experimental autoimmune encephalitis (EAE) and identify a pathway that maintains Treg cell function and identity during severe inflammation. This pathway is dependent on the transcriptional regulator Blimp1, which prevents downregulation of Foxp3 expression and ''toxic'' gain-of-function of Treg cells in the inflamed CNS. Blimp1 negatively regulates IL-6-and STAT3-dependent Dnmt3a expression and function restraining methylation of Treg cell-specific conserved non-coding sequence 2 (CNS2) in the Foxp3 locus. Consequently, CNS2 is heavily methylated when Blimp1 is ablated, leading to a loss of Foxp3 expression and severe disease. These findings identify a Blimp1-dependent pathway that preserves Treg cell stability in inflamed non-lymphoid tissues.

Epigenetics refers to heritable changes in gene expression and chromatin structure without change in a DNA sequence. Several epigenetic modifications and respective regulators have been reported. These include DNA methylation, chromatin remodeling, histone post-translational modifications, and non-coding RNAs. Emerging evidence has revealed that epigenetic dysregulations are involved in a wide range of diseases including cancers. Therefore, the reversible nature of epigenetic modifications concerning activation or inhibition of enzymes involved could be promising targets and useful tools for the elucidation of cellular and biological phenomena. In this review, emphasis is laid on natural products that inhibit DNA methyltransferases (DNMTs) and histone deacetylases (HDACs) making them promising candidates for the development of lead structures for anticancerdrugs targeting epigenetic modifications. However, most of the natural products targeting HDAC and/or DNMT lack isoform selectivity, which is important for determining their potential use as therapeutic agents. Nevertheless, the structures presented in this review offer the well-founded basis that screening and chemical modifications of natural products will in future provide not only leads to the identification of more specific inhibitors with fewer side effects, but also important features for the elucidation of HDAC and DNMT function with respect to cancer treatment.

Background: This study aims to investigate the effects of carob (Ceratonia siliqua L.) pod extract (CPE) on the viability of human endometrial mesenchymal stromal/stem cells (EnMSCs) and its impact on mRNA and protein expressions of DNA methyltransferases (DNMT1, DNMT3A, and DNMT3B), histone deacetylase 1 (HDAC1), matrix metalloproteinase-2 (MMP2), and cyclooxygenase-2 (COX-2) in endometriotic patients. Materials and Methods: In this experimental study, EnMSCs were derived from endometrium of patients with ovarian endometrioma (OMA-EnMSCs group) and deep infiltrative endometriosis (DIE) samples of 10 endometriosisassociated infertility (EAI) women (E-EnMSCs group) and compared to EnMSCs derived from the endometrium of an endometriosis-free, normal woman as the control group (C-EnMSCs). The metabolic activity of the control and case groups were evaluated by treating them with different concentrations of CPE. Cell viability was analysed by MTT. Real-time reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to evaluate the expression of specific genes at the mRNA and protein levels, respectively. Results: Treatment with 0.8 and 2 μg/mL of CPE downregulated COX-2 and HDAC1 in the E-EnMSC group compared to the C-EnMSCs group. Treatment with 0.8 μg/mL of CPE also decreased MMP2 and DNMT3B gene expressions. The COX-2 and DNMT3A genes were significantly upregulated after treatment with 2 μg/mL of CPE. Expressions of the COX-2, HDAC1, DNMT1, DNMT3A, and DNMT3B peptides decreased in the all three groups

For most organisms, crossovers forming during meiosis exhibit crossover interference – nearby crossovers are rare. This phenomenon was studied in great detail in Arabidopsis thaliana using a large backcross population for male and female meiosis. We used the gamma two-pathway model by superposing proportion (1- p) of interfering crossovers with p of non-interfering crossovers. It was observed that female meiosis shows higher interference but lower proportion of non-interfering crossovers than male meiosis. Further intra-chromosomal interference comparisons conclude that there are variations between (a) left and right arms, and (b) the central versus distal regions of a chromosome. Then statistical tests revealed heterogeneities in the non-interfering crossover proportion along chromosomes. Thereafter various statistical tools developed to examine a very novel wild-type tomato data annotating crossover positions from both pathways provided evidence for ‘cross-talk’ between the two pa...

AimTo evaluate the association between spontaneous preterm birth (SPTB) and DNA methyltransferase (DNMT)1, 3A, 3B, and 3L gene polymorphisms, and their contribution to the clinical characteristics of women with SPTB and their newborns.MethodsThis case-control study, conducted in 2018, enrolled 162 women with SPTB and 162 women with term delivery. DNMT1 rs2228611, DNMT3A rs1550117, DNMT3B rs1569686, DNMT3B rs2424913, and DNMT3L rs2070565 single nucleotide polymorphisms were genotyped using polymerase chain reaction and restriction fragment length polymorphism methods. The clinical characteristics included in the analysis were family history of preterm birth, maternal smoking, maternal age, gestational week at delivery, and fetal birth weight.ResultsDNMT gene polymorphisms were not significantly associated with SPTB. DNMT3B rs1569686 and rs2424913 minor alleles (T) were significantly more frequent in women with familial PTB than in women with non-familial PTB, increasing the odds for familial PTB 3.30 and 3.54 times under dominant genetic models. They were also significantly more frequent in women with SPTB who smoked before pregnancy, reaching the most significant association under additive genetic models (odds ratio 6.86, 95% confidence interval 2.25-20.86, P < 0.001; odds ratio 3.77, 95% confidence interval 1.36-10.52, P = 0.011, respectively).ConclusionsDNMT3B rs1569686 and rs2424913 gene polymorphisms might be associated with positive family history of PTB and smoking status.

Specialized cell types of trophoblast cells form the placenta in which each cell type has particular properties of proliferation and invasion. The placenta sustains the growth of the fetus throughout pregnancy and any aberrant trophoblast differentiation or invasion potentially affects the future health of the child and adult. Recently, the field of epigenetics has been applied to understand differentiation of trophoblast lineages and embryonic stem cells (ESC), from fertilization of the oocyte onward. Each trophoblast cell-type has a distinctive epigenetic profile and we will concentrate on the epigenetic mechanism of DNA methyltransferases and TETs that regulate DNA methylation. Environmental factors affecting the mother potentially regulate the DNA methyltransferases in trophoblasts, and so do steroid hormones, cell cycle regulators, such as p53, and cytokines, especially interlukin-1β. There are interesting questions of why trophoblast genomes are globally hypomethylated yet specific genes can be suppressed by hypermethylation (in general, tumor suppressor genes, such as E-cadherin) and how invasive cell-types are liable to have condensed chromatin, as in metastatic cancer cells. Future work will attempt to understand the interactive nature of all epigenetic mechanisms together and their effect on the complex biological system of trophoblast differentiation and invasion in normal as well as pathological conditions.

Progesterone, estrogen and cyclic adenosine monophosphate (cAMP) together regulate the decidualization of human endometrial stromal cells in a time-dependent manner. The role of DNA methylation and the three active DNA methyltransferases (DNMTs) in the regulation of decidualization is gaining interest but the exact role of this epigenetic mechanism during decidualization is largely unknown. We aimed to understand the effect of the main regulators of decidualization on the expression of the DNMTs and in turn on the expression of steroid hormone receptors during the decidualization. We conducted a time-course analysis from 6 h to 10 days to examine the change in gene expression of the DNMTs and the steroid hormone receptors over time in response to estradiol, medroxy-progesterone acetate (MPA) and dibutyryl-cAMP (db-cAMP) in a human endometrial stromal cells (HESC) cell line. Only the combination treatment with MPA-mix (estradiol + MPA + db-cAMP) up-regulated ERa, PGR, progesterone receptor B (PRB) and androgen receptor at 24 h. Both decidualization pathways of db-cAMP and estradiol/MPA, independently and combined, consistently down-regulated DNMT3B mRNA expression from 6 h till 10 days, whereas DNMT1 and DNMT3A mRNA expression were down-regulated transiently. Forced expression of DNMT3B in HESC for 10 days attenuated IGFBP1 mRNA and protein expression; and forced expression of DNMT3B combined with MPA-mix treatment synergistically increased the expression of PRB at 24 h. The HESC morphology and proliferation remained unchanged in response to forced expression of DNMT3B. In conclusion, mRNA expression of the DNMTs during decidualization is dynamic, so that expression varies according to the cAMP or estradiol/MPA pathway treatments that regulate them in a time-dependent manner. Although forced expression of DNMT3B by itself is insufficient to inhibit decidualization, forced expression of DNMT3B in combination with MPA-mix synergistically upregulated PRB, as well as attenuated the expression of IGFBP1, the decidualization marker.

Specialized cell types of trophoblast cells form the placenta in which each cell type has particular properties of proliferation and invasion. The placenta sustains the growth of the fetus throughout pregnancy and any aberrant trophoblast differentiation or invasion potentially affects the future health of the child and adult. Recently, the field of epigenetics has been applied to understand differentiation of trophoblast lineages and embryonic stem cells (ESC), from fertilization of the oocyte onward. Each trophoblast cell-type has a distinctive epigenetic profile and we will concentrate on the epigenetic mechanism of DNA methyltransferases and TETs that regulate DNA methylation. Environmental factors affecting the mother potentially regulate the DNA methyltransferases in trophoblasts, and so do steroid hormones, cell cycle regulators, such as p53, and cytokines, especially interlukin-1β. There are interesting questions of why trophoblast genomes are globally hypomethylated yet specific genes can be suppressed by hypermethylation (in general, tumor suppressor genes, such as E-cadherin) and how invasive cell-types are liable to have condensed chromatin, as in metastatic cancer cells. Future work will attempt to understand the interactive nature of all epigenetic mechanisms together and their effect on the complex biological system of trophoblast differentiation and invasion in normal as well as pathological conditions.

Progesterone, estrogen and cyclic adenosine monophosphate (cAMP) together regulate the decidualization of human endometrial stromal cells in a time-dependent manner. The role of DNA methylation and the three active DNA methyltransferases (DNMTs) in the regulation of decidualization is gaining interest but the exact role of this epigenetic mechanism during decidualization is largely unknown. We aimed to understand the effect of the main regulators of decidualization on the expression of the DNMTs and in turn on the expression of steroid hormone receptors during the decidualization. We conducted a time-course analysis from 6 h to 10 days to examine the change in gene expression of the DNMTs and the steroid hormone receptors over time in response to estradiol, medroxy-progesterone acetate (MPA) and dibutyryl-cAMP (db-cAMP) in a human endometrial stromal cells (HESC) cell line. Only the combination treatment with MPA-mix (estradiol + MPA + db-cAMP) up-regulated ERa, PGR, progesterone receptor B (PRB) and androgen receptor at 24 h. Both decidualization pathways of db-cAMP and estradiol/MPA, independently and combined, consistently down-regulated DNMT3B mRNA expression from 6 h till 10 days, whereas DNMT1 and DNMT3A mRNA expression were down-regulated transiently. Forced expression of DNMT3B in HESC for 10 days attenuated IGFBP1 mRNA and protein expression; and forced expression of DNMT3B combined with MPA-mix treatment synergistically increased the expression of PRB at 24 h. The HESC morphology and proliferation remained unchanged in response to forced expression of DNMT3B. In conclusion, mRNA expression of the DNMTs during decidualization is dynamic, so that expression varies according to the cAMP or estradiol/MPA pathway treatments that regulate them in a time-dependent manner. Although forced expression of DNMT3B by itself is insufficient to inhibit decidualization, forced expression of DNMT3B in combination with MPA-mix synergistically upregulated PRB, as well as attenuated the expression of IGFBP1, the decidualization marker.

During meiosis, chromatin undergoes extensive changes to facilitate recombination, homolog pairing, and chromosome segregation. To investigate the relationship between chromatin organization and meiotic processes, we used formaldehydeassisted isolation of regulatory elements (FAIRE) to map open chromatin during the transition from mitosis to meiosis in the budding yeast Saccharomyces cerevisiae. We found that meiosis-induced opening of chromatin is associated with meiotic DSB hotpots. The positive association between open chromatin and DSB hotspots is most prominent 3 h into meiosis, when the early meiotic genes DMC1 and HOP1 exhibit maximum transcription and the early recombination genes SPO11 and RAD51 are strongly up-regulated. While the degree of chromatin openness is positively associated with the occurrence of recombination hotspots, many hotspots occur outside of open chromatin. Of particular interest, many DSB hotspots that fell outside of meiotic open chromatin nonetheless occurred in chromatin that had recently been open during mitotic growth. Finally, we find evidence for meiosis-specific opening of chromatin at the regions adjacent to boundaries of subtelomeric sequences, which exhibit specific crossover control patterns hypothesized to be regulated by chromatin.

There is increasing evidence that abnormalities in epigenetic mechanisms of gene expression contribute to the development of multiple sclerosis (MS). Advances in epigenetics have given rise to a new class of drugs, epigenetic drugs. Although many classes of epigenetic drugs are being investigated, at present most attention is being paid to two classes of epigenetic drugs: drugs that inhibit DNA methyltransferase (DNMTi) and drugs that inhibit histone deacetylase (HDACi). This paper discusses the potential use of epigenetic drugs in the treatment of MS, focusing on DNMTi and HDACi. Preclinical drug trials of DNMTi and HDACi for the treatment of MS are showing promising results. Epigenetic drugs could improve the clinical management of patients with MS.

Radiation therapy for the treatment of thoracic malignancies has improved significantly by directing of the proton beam in higher doses on the targeted tumor while normal tissues around the tumor receive much lower doses. Nevertheless, exposure of normal tissues to protons is known to pose a substantial risk in long-term survivors, as confirmed by our work in space-relevant exposures of murine lungs to proton radiation. Thus, radioprotective strategies are being sought. We established that LGM2605 is a potent protector from radiation-induced lung toxicity and aimed in the current study to extend the initial findings of space-relevant, proton radiation-associated late lung damage in mice by looking at acute changes in human lung. We used an ex vivo model of organ culture where tissue slices of donor living human lung were kept in culture and exposed to proton radiation. We exposed donor human lung precision-cut lung sections (huPCLS), pretreated with LGM2605, to 4 Gy proton radiation...

We describe a large-scale random approach termed reduced representation bisulfite sequencing (RRBS) for analyzing and comparing genomic methylation patterns. BglII restriction fragments were sizeselected to 500-600 bp, equipped with adapters, treated with bisulfite, PCR amplified, cloned and sequenced. We constructed RRBS libraries from murine ES cells and from ES cells lacking DNA methyltransferases Dnmt3a and 3b and with knocked-down (kd) levels of Dnmt1 (Dnmt [1 kd ,3a À/À , 3b À/À ]). Sequencing of 960 RRBS clones from Dnmt[1 kd ,3a À/À ,3b À/À ] cells generated 343 kb of nonredundant bisulfite sequence covering 66 212 cytosines in the genome. All but 38 cytosines had been converted to uracil indicating a conversion rate of .99.9%. Of the remaining cytosines 35 were found in CpG and 3 in CpT dinucleotides. Non-CpG methylation was .250-fold reduced compared with wild-type ES cells, consistent with a role for Dnmt3a and/or Dnmt3b in CpA and CpT methylation. Closer inspection revealed neither a consensus sequence around the methylated sites nor evidence for clustering of residual methylation in the genome. Our findings indicate random loss rather than specific maintenance of methylation in Dnmt [1 kd ,3a À/À ,3b À/À ] cells. Near-complete bisulfite conversion and largely unbiased representation of RRBS libraries suggest that random shotgun bisulfite sequencing can be scaled to a genome-wide approach.

Prostate cancer (PCa) is a major cause of cancer-related morbidity and mortality worldwide. Although early disease is often efficiently managed therapeutically, available options for advanced disease are mostly ineffective. Aberrant DNA methylation associated with gene-silencing of cancer-related genes is a common feature of PCa. Therefore, DNA methylation inhibitors might constitute an attractive alternative therapy. Herein, we evaluated the anti-cancer properties of hydralazine, a non-nucleoside DNA methyltransferases (DNMT) inhibitor, in PCa cell lines. In vitro assays showed that hydralazine exposure led to a significant dose and time dependent growth inhibition, increased apoptotic rate and decreased invasiveness. Furthermore, it also induced cell cycle arrest and DNA damage. These phenotypic effects were particularly prominent in DU145 cells. Following hydralazine exposure, decreased levels of DNMT1, DNMT3a and DNMT3b mRNA and DNMT1 protein were depicted. Moreover, a significa...

Breast cancer is one of the most commonly diagnosed neoplasms affecting women worldwide, and it remains a leading cause of both mortality and morbidity. While genetic predisposition plays a critical role in the development of this neoplasm, significant epigenetic dysregulations accompany existing variants. The emergence of acquired drug resistance to current chemotherapeutics poses a significant challenge in managing therapy. However, progress has been made in developing novel agents that directly target epigenetic modifications. These agents, called "epi-drugs, " can be used alone in the clinic or in combination with current treatment regimens, offering the potential to create diversified effects on the disease's predictive process. Within the scope of this review, general information about the major epigenetic dysregulations in breast cancer will be provided, and their effects on the molecular mechanisms in the carcinogenesis process will be discussed. Furthermore, current treatment approaches for breast cancer will be explored, classifying these epi-drugs, such as DNA methyltransferase inhibitors (DNMTIs), histone deacetylase inhibitors (HDA-CIs), histone acetyltransferases (HATIs), and others that have been developed to target these mechanisms. Predictions regarding the future prospects of these epi-drugs are highlighted, and their contributions to the field of personalized medicine are emphasized based on the results obtained from clinical studies.