Zdá se, že doba, ve které jsme věřili, že naši osobnost, chování a nemoci předurčují naše geny, pomalu ale jistě končí. Výzkum na poli epigenetiky prokazuje, že informace obsažená v genech je pod významným regulačním vlivem aktuálního prostředí a gen tedy neobsahuje zdaleka tak konkrétní informaci, jak jsme se dlouho domnívali. I když prostředí nedovede ovlivnit strukturu genu, má přes chemické (epigenetické) modifikace zásadní vliv na to, jestli a jak se informace obsažená v genu vyjádří. Epigenetické modifikace nám umožňují učit se ze zkušeností a adaptovat naše těla, chování i metabolismus na aktuální prostředí a přežití. Současně jsou však tyto modifikace spojovány i s rozvojem nemocí a zkráceným přežitím. Jak tomuto zásadnímu konfliktu rozumět? Výzkum na poli sociální a behaviorální epigenomiky nabízí širší pohled na význam epigenetických modifikací nejen pro adaptaci a přežití jedince a sociální skupiny, ale i pro adaptaci jedince na jeho roli v sociální hierarchii a tím i na rovnováhu a přežití komplexních biologických systémů. Tento pohled může vnést do porozumění zdraví a nemoci dost odlišný význam.
The era of strong belief in gene influence on our personality, behavior and diseases seems to be getting to the end. Scientific evidence in the field of epigenetics suggests significant environmental regulatory influence on gene expression. Epigenetic research shows that genes do not carry such rigid information as it had been originally proposed. Though environmental stimuli do not change gene structure, they can influence gene expression by maens of chemical epigenetic modifications. Epigenetic modifications help us learn from our experience and adapt our bodies, behavior and metabolism for current environment and survival. Surprisingly are these modifications concurrently associated with disease development and shorter life expectancy. How should be this apperent conflict understood? Research in the fields of social and behavioral epigenomics brings more complex understanding of the role of epigenetic modifications for individual and social group adaptation and survival, for formation of individual personality and social status in complex hierarchies and perhaps even for balance and survival of complex biological systems. This view could bring quite different perspective to understanding of health and diseases.
Epigenetic mechanisms are of pivotal importance in the normal development and maintenance of cell and tissue-specific gene expression patterns, and are fundamental to the genesis of cancer. One significant category of epigenetic modifications is histone methylation. Histone methylation plays a crucial role in the regulation of gene expression, and its dysregulation has been observed in various diseases, including cancer. The maintenance of the histone methylation state is dependent on two classes of enzymes: histone methyltransferases, which add methyl groups to arginine and lysine residues, and lysine demethylases, which remove methyl groups from lysine residues of histones. To date, eight subfamilies have been identified, comprising approximately 30 lysine demethylases. These enzymes are expressed differently across cells and tissues and exert a substantial impact on the development and progression of cancer. The diverse range of lysine demethylases influence a multitude of oncogenic pathways, either by promoting or inhibiting their activity. However, comprehensive data on the full spectrum expression of lysine demethylases in distinct cancer types remain scarce. Lysine demethylases have been demonstrated to play a role in drug resistance in numerous cancers. This is achieved by modulating the metabolic profile of cancer cells, enhancing the ratio of cancer stem cells, and elevating the expression of drug-tolerant genes. Additionally, they facilitate epithelial-mesenchymal transition and metastatic potential. The objective of this review is to synthesize recent data on the relationship between lysine demethylases and cancer, with a particular focus on cancer cell drug resistance.
- MeSH
- Epigenesis, Genetic MeSH
- Epithelial-Mesenchymal Transition MeSH
- Histone Demethylases * metabolism genetics MeSH
- Humans MeSH
- Neoplasms * enzymology genetics pathology MeSH
- Gene Expression Regulation, Neoplastic MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
BACKGROUND: Cancer remains a major global health challenge, necessitating innovative prevention and treatment approaches. Certain plants, adapted to specific environments, may exhibit bioactive properties with potential anticancer applications. HYPOTHESIS: Seaberry (Hippophae rhamnoides L.) fruit peels may exert anticancer effects in breast carcinoma (BC) models through the additive or synergistic actions of their unique secondary metabolites. METHODS: H. rhamnoides fruit peel extracts were analyzed using the LC-DAD-MS and LC-DAD techniques to profile the content of carotenoids and flavonoids, respectively. The preclinical study evaluated seaberry fruit peel extracts in BC models: (1) a syngeneic 4T1 mouse breast adenocarcinoma model (triple-negative), (2) a rat model of chemically induced mammary carcinogenesis, and (3) in vitro studies with MCF-7 (hormone receptor-positive) and MDA-MB-231 (triple-negative) BC cell lines. RESULTS: LC-DAD-MS and LC-DAD analyses identified dominant metabolites, including isorhamnetin, quercetin glycosides, kaempferol glycosides, catechin, zeaxanthin, and lutein. In the 4T1 mouse model, seaberry treatment resulted in a significant, dose-dependent reduction in tumor volume (43% and 48% compared to controls) and a decrease in the mitotic activity index. Serum cytokine analysis showed dose-dependent reductions in IL-6, IL-10, and TNF-α. In the rat chemopreventive model, high-dose seaberry improved cancer prognosis by reducing the ratio of poorly differentiated tumors and increasing caspase-3 and Bax expression while decreasing Ki-67 and malondialdehyde levels. Both treatment doses elevated the Bax/Bcl-2 ratio and reduced the expression of cancer stem cell markers CD44, EpCam, and VEGF compared to controls. Epigenetic analyses revealed histone modifications (H4K16ac, H4K20me3) and altered methylation of tumor-suppressor genes (PITX2, RASSF1, PTEN, TIMP3). Microarray analysis (758 miRNAs) identified beneficial changes in nine oncogenic/tumor-suppressive miRNAs, including miR-10a-5p, miR-322-5p, miR-450a-5p, miR-142-5p, miR-148b-3p, miR-1839-3p, miR-18a-5p, miR-1949, and miR-347. In vitro, ethanolic seaberry extract conferred partial resistance to cisplatin-induced cytotoxicity in MCF-7 and MDA-MB-231 cells at IC50 concentrations. CONCLUSION: This study of H. rhamnoides in rodent BC models shows promising data but requires rigorous, long-term validation. Integrating plant-based nutraceuticals into oncology necessitates precise cancer-type profiling and patient stratification for effective personalized treatments.
- Publication type
- Journal Article MeSH
BACKGROUND: Epitranscriptomics, the study of RNA modifications such as N6-methyladenosine (m6A), provides a novel layer of gene expression regulation with implications for numerous biological processes, including cellular adaptation to hypoxia. Hypoxia-inducible factor-1 (HIF-1), a master regulator of the cellular response to low oxygen, plays a critical role in adaptive and pathological processes, including cancer, ischemic heart disease, and metabolic disorders. Recent discoveries accent the dynamic interplay between m6A modifications and HIF-1 signaling, revealing a complex bidirectional regulatory network. While the roles of other RNA modifications in HIF-1 regulation remain largely unexplored, emerging evidence suggests their potential significance. MAIN BODY: This review examines the reciprocal regulation between HIF-1 and epitranscriptomic machinery, including m6A writers, readers, and erasers. HIF-1 modulates the expression of key m6A components, while its own mRNA is regulated by m6A modifications, positioning HIF-1 as both a regulator and a target in this system. This interaction enhances our understanding of cellular hypoxic responses and opens avenues for clinical applications in treating conditions like cancer and ischemic heart disease. Promising progress has been made in developing selective inhibitors targeting the m6A-HIF-1 regulatory axis. However, challenges such as off-target effects and the complexity of RNA modification dynamics remain significant barriers to clinical translation. CONCLUSION: The intricate interplay between m6A and HIF-1 highlights the critical role of epitranscriptomics in hypoxia-driven processes. Further research into these regulatory networks could drive therapeutic innovation in cancer, ischemic heart disease, and other hypoxia-related conditions. Overcoming challenges in specificity and off-target effects will be essential for realizing the potential of these emerging therapies.
- MeSH
- Adenosine analogs & derivatives metabolism MeSH
- Epigenesis, Genetic * MeSH
- Hypoxia-Inducible Factor 1 * metabolism genetics MeSH
- Humans MeSH
- RNA Processing, Post-Transcriptional MeSH
- Gene Expression Regulation MeSH
- Signal Transduction MeSH
- Transcriptome MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
Epigenetic DNA modifications are pivotal in eukaryotic gene expression, but their regulatory significance in bacteria is less understood. In Synechocystis 6803, the DNA methyltransferase M.Ssp6803II modifies the first cytosine in the GGCC motif, forming N4-methylcytosine (GGm4CC). Deletion of the sll0729 gene encoding M.Ssp6803II (∆sll0729) caused a bluish phenotype due to reduced chlorophyll levels, which was reversed by suppressor mutations. Re-sequencing of 7 suppressor clones revealed a common GGCC to GGTC mutation in the slr1790 promoter's discriminator sequence, encoding protoporphyrinogen IX oxidase, HemJ, crucial for tetrapyrrole biosynthesis. Transcriptomic and qPCR analyses indicated aberrant slr1790 expression in ∆sll0729 mutants. This aberration led to the accumulation of coproporphyrin III and protoporphyrin IX, indicative of impaired HemJ activity. To confirm the importance of DNA methylation in hemJ expression, hemJ promoter variants with varying discriminator sequences were introduced into the wild type, followed by sll0729 deletion. The sll0729 deletion segregated in strains with the GGTC discriminator motif, resulting in wild-type-like pigmentation, whereas freshly prepared ∆sll0729 mutants with the native hemJ promoter exhibited the bluish phenotype. These findings demonstrate that hemJ is tightly regulated in Synechocystis and that N4-methylcytosine is essential for proper hemJ expression. Thus, cytosine N4-methylation is a relevant epigenetic marker in Synechocystis and likely other cyanobacteria.
- MeSH
- Bacterial Proteins metabolism genetics MeSH
- Epigenesis, Genetic * MeSH
- DNA Methylation * MeSH
- Mutation MeSH
- Promoter Regions, Genetic * MeSH
- Gene Expression Regulation, Bacterial MeSH
- Synechocystis * genetics metabolism MeSH
- Tetrapyrroles * metabolism biosynthesis MeSH
- Publication type
- Journal Article MeSH
Spermatogenesis starts with the onset of puberty within the seminiferous epithelium of the testes. It is a complex process under intricate control of the endocrine system. Physiological regulations by steroid hormones in general and by estrogens in particular are due to their chemical nature prone to be disrupted by exogenous factors acting as endocrine disruptors (EDs). 17α-Ethynylestradiol (EE2) is an environmental pollutant with a confirmed ED activity and a well-known effect on spermatogenesis and chromatin remodeling in haploid germ cells. The aim of our study was to assess possible effects of two doses (2.5ng/ml; 2.5 μg/ml) of EE2 on both histone-to-protamine exchange and epigenetic profiles during spermatogenesis performing a multi/transgenerational study in mice. Our results demonstrated an impaired histone-to-protamine exchange with a significantly higher histone retention in sperm nuclei of exposed animals, when this process was accompanied by the changes of histone post-translational modifications (PTMs) abundancies with a prominent effect on H3K9Ac and partial changes in protamine 1 promoter methylation status. Furthermore, individual changes in molecular phenotypes were partially transmitted to subsequent generations, when no direct trans-generational effect was observed. Finally, the uncovered specific localization of the histone retention in sperm nuclei and their specific PTMs profile after EE2 exposure may indicate an estrogenic effect on sperm motility and early embryonic development via epigenetic mechanisms.
- MeSH
- Endocrine Disruptors pharmacology toxicity MeSH
- Epigenesis, Genetic * drug effects MeSH
- Ethinyl Estradiol * pharmacology MeSH
- Histones * metabolism MeSH
- Mice MeSH
- Protein Processing, Post-Translational drug effects MeSH
- Protamines * metabolism genetics MeSH
- Spermatogenesis * drug effects genetics MeSH
- Spermatozoa drug effects metabolism MeSH
- Testis * drug effects metabolism MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Myelodysplastic syndromes (MDS) are myeloid malignancies with heterogeneous genotypes and phenotypes, characterized by ineffective haematopoiesis and a high risk of progression towards acute myeloid leukaemia (AML). Prognosis for patients treated with hypomethylating agents (HMAs), as is azacytidine, the main drug used as frontline therapy for MDS is mostly based on cytogenetics and next generation sequencing (NGS) of the initial myeloid clone. Although the critical influence of the epigenetic landscape upon cancer cells survival and development as well on tumour environment establishment is currently recognized and approached within current clinical practice in MDS, the heterogenous response of the patients to epigenetic therapy is suggesting a more complex mechanism of action, as is the case of RNA methylation. In this sense, the newly emerging field of epitranscriptomics could provide a more comprehensive perspective upon the modulation of gene expression in malignancies, as is the proof-of-concept of MDS. We initially did RNA methylation sequencing on MDS patients (n = 6) treated with azacytidine and compared responders with non-responders. Afterwards, the genes identified were assessed in vitro and afterwards validated on a larger cohort of MDS patients treated with azacytidine (n = 58). Our data show that a more accurate prognosis could be based on analysing the methylome and thus we used methylation sequencing to differentially split high-grade MDS patients with identical demographical and cytogenetic features, between azacytidine responders and non-responders.
- MeSH
- Azacitidine * pharmacology therapeutic use MeSH
- Epigenesis, Genetic drug effects MeSH
- Middle Aged MeSH
- Humans MeSH
- RNA Methylation MeSH
- DNA Methylation * drug effects MeSH
- Myelodysplastic Syndromes * genetics drug therapy pathology MeSH
- Prognosis MeSH
- Antimetabolites, Antineoplastic therapeutic use pharmacology MeSH
- Sequence Analysis, RNA MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Gene Expression Profiling MeSH
- Transcriptome genetics drug effects MeSH
- High-Throughput Nucleotide Sequencing MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
INTRODUCTION: Within oncology research, there is a high effort for new approaches to prevent and treat cancer as a life-threatening disease. Specific plant species that adapt to harsh conditions may possess unique properties that may be utilized in the management of cancer. HYPOTHESIS: Chokeberry fruit is rich in secondary metabolites with anti-cancer activities potentially useful in cancer prevention and treatment. AIMS OF THE STUDY AND METHODS: Based on mentioned hypothesis, the main goal of our study was to evaluate the antitumor effects of dietary administered Aronia melanocarpa L. fruit peels (in two concentrations of 0.3 and 3% [w/w]) in the therapeutic syngeneic 4T1 mouse adenocarcinoma model, the chemopreventive model of chemically induced mammary carcinogenesis in rats, a cell antioxidant assay, and robust in vitro analyses using MCF-7 and MDA-MB-231 cancer cells. RESULTS: The dominant metabolites in the A. melanocarpa fruit peel extract tested were phenolic derivatives classified as anthocyanins and procyanidins. In a therapeutic model, aronia significantly reduced the volume of 4T1 tumors at both higher and lower doses. In the same tumors, we noted a significant dose-dependent decrease in the mitotic activity index compared to the control. In the chemopreventive model, the expression of Bax was significantly increased by aronia at both doses. Additionally, aronia decreased Bcl-2 and VEGF levels, increasing the Bax/Bcl-2 ratio compared to the control group. The cytoplasmic expression of caspase-3 was significantly enhanced when aronia was administered at a higher dosage, in contrast to both the control group and the aronia group treated with a lower dosage. Furthermore, the higher dosage of aronia exhibited a significant reduction in the expression of the tumor stem cell marker CD133 compared to the control group. In addition, the examination of aronia`s epigenetic impact on tumor tissue through in vivo analyses revealed significant alterations in histone chemical modifications, specifically H3K4m3 and H3K9m3, miRNAs expression (miR155, miR210, and miR34a) and methylation status of tumor suppressor genes (PTEN and TIMP3). In vitro studies utilizing a methanolic extract of A.melanocarpa demonstrated significant anti-cancer properties in the MCF-7 and MDA-MB-231 cell lines. Various analyses, including Resazurin, cell cycle, annexin V/PI, caspase-3/7, Bcl-2, PARP, and mitochondrial membrane potential, were conducted in this regard. Additionally, the aronia extract enhanced the responsiveness to epirubicin in both cancer cell lines. CONCLUSION: This study is the first to analyze the antitumor effect of A. melanocarpa in selected models of experimental breast carcinoma in vivo and in vitro. The utilization of the antitumor effects of aronia in clinical practice is still minimal and requires precise and long-term clinical evaluations. Individualized cancer-type profiling and patient stratification are crucial for effectively implementing plant nutraceuticals within targeted anti-cancer strategies in clinical oncology.
- Publication type
- Journal Article MeSH
V posledných desaťročiach sme zaznamenali výrazný nárast počtu cisárskych rezov. Hoci je pôrod cisárskym rezom život zachraňujúci, je spojený so zvýšeným rizikom nepriaznivých zdravotných následkov u novorodencov, vrátane respiračných a atopických ochorení, obezity, cukrovky a závažných autoimunitných ochorení. Presné mechanizmy, ktoré sú základom týchto spojitostí zostávajú nepochopené; epigenetické modifikácie sa však ukázali ako pravdepodobný molekulárny základ spájajúci perinatálne faktory s budúcou náchylnosťou na ochorenie. Tento prehľad spája súčasnú literatúru a odhaľuje, že spôsob pôrodu môže ovplyvniť epigenetické markery u novorodencov, predovšetkým prostredníctvom zmien globálnej metylácie DNA a génovo špecifických metylačných vzorcov.
Recent decades have seen a notable increase in cesarean section rates. Although lifesaving, cesarean delivery is associated with an elevated risk of adverse health outcomes in newborns, including respiratory diseases, atopic disorders, obesity, diabetes, and severe autoimmune conditions. The exact mechanisms underlying these associations remain elusive; however, epigenetic modifications have emerged as a plausible molecular basis linking perinatal factors with future disease susceptibility. This review summarizes current literature, revealing that the delivery method may influence epigenetic markers in neonates, primarily through alterations in global DNA methylation and gene-specific methylation patterns.
BACKGROUND: Obesity is a major health burden. Preadipocytes proliferate and differentiate in mature adipocytes in the adipogenic process, which could be a potential therapeutic approach for obesity. Deficiency of SIRT6, a stress-responsive protein deacetylase and mono-ADP ribosyltransferase enzyme, blocks adipogenesis. Mutants of SIRT6 (N308K/A313S) were recently linked to the in the long lifespan Ashkenazi Jews. In this study, we aimed to clarify how these new centenarian-associated SIRT6 genetic variants affect adipogenesis at the transcriptional and epigenetic level. METHODS: We analyzed the role of SIRT6 wild-type (WT) or SIRT6 centenarian-associated mutant (N308K/A313S) overexpression in adipogenesis, by creating stably transduced preadipocyte cell lines using lentivirus on the 3T3-L1 model. Histone post-translational modifications (PTM: acetylation, methylation) and transcriptomic changes were analyzed by mass spectrometry (LC-MS/MS) and RNA-Seq, respectively, in 3T3-L1 adipocytes. In addition, the adipogenic process and related signaling pathways were investigated by bioinformatics and biochemical approaches. RESULTS: Overexpression of centenarian-associated SIRT6 mutant increased adipogenic differentiation to a similar extent compared to the WT form. However, it triggered distinct histone PTM profiles in mature adipocytes, with significantly higher acetylation levels, and activated divergent transcriptional programs, including those dependent on signaling related to the sympathetic innervation and to PI3K pathway. 3T3-L1 mature adipocytes overexpressing SIRT6 N308K/A313S displayed increased insulin sensitivity in a neuropeptide Y (NPY)-dependent manner. CONCLUSIONS: SIRT6 N308K/A313S overexpression in mature adipocytes ameliorated glucose sensitivity and impacted sympathetic innervation signaling. These findings highlight the importance of targeting SIRT6 enzymatic activities to regulate the co-morbidities associated with obesity.
- MeSH
- Adipogenesis * genetics MeSH
- 3T3-L1 Cells * MeSH
- Epigenesis, Genetic * genetics MeSH
- Histones metabolism genetics MeSH
- Humans MeSH
- Mutation MeSH
- Mice MeSH
- Obesity genetics metabolism MeSH
- Protein Processing, Post-Translational genetics MeSH
- Sirtuins * genetics metabolism MeSH
- Adipocytes * metabolism MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
