Recent progress in DNA methyltransferase inhibitors as anticancer agents

Epigenetic Therapies in Melanoma-Targeting DNA Methylation and Histone Modification

Skin cancer prevalence has increased during the last decades, with the last years serving as a pivotal moment for comprehending its epidemiological patterns and its impact on public health. Melanoma is one of the most frequently occurring malignancies, arising from a complex interplay of genetic factors, environmental factors, lifestyle and socio-economic conditions. Epigenetic changes play a critical role in tumor development, influencing progression and aggressiveness. Epigenetic therapies could represent novel therapeutic options, while drug repositioning may serve as a viable strategy for cancer treatment. Demethylating agents, commonly used in hematological malignancies, show promising results on solid tumors, including melanoma. Methylation patterns are responsible for tumor development by modulating gene expression, while histone acetylation influences DNA processes such as transcription, replication, repair, and recombination. This review aims to identify existing potential therapeutical approaches using therapeutic agents that can modulate DNA methylation and histone modification, which can lead to tumor inhibition, cell death initiation and reactivation of tumor suppressor genes.

Recent advances on gene-related DNA methylation in cancer diagnosis, prognosis, and treatment: a clinical perspective

Recent advances in screening programs and the development of innovative therapeutic strategies have significantly improved the clinical outcomes of cancer patients. However, many patients still experience treatment failure, primarily due to inherent or acquired drug resistance mechanisms. This challenge underscores the urgent need for novel therapeutic targets for the effective treatment of malignancies, as well as cancer-specific biomarkers to enhance early diagnosis and guide interventions. Epigenetic mechanisms, including DNA methylation, have recently garnered growing interest as key regulators of gene expression under both physiological and pathological conditions. Although epigenetic dysregulations are reliable tumor hallmarks, DNA methylation is still not routinely integrated into clinical practice, highlighting the need for further research to translate preclinical findings from the bench to the bedside. On these bases, the present review aims to illustrate the state of the art regarding the role of DNA methylation in cancer, describing the technologies currently available for DNA methylation profiling. Furthermore, the latest evidence on the application of DNA methylation hotspots in cancer diagnosis and prognosis, as well as the impact of epidrugs in cancer care, is discussed to provide a comprehensive overview of the potential clinical relevance of DNA methylation in advancing personalized medicine.

DNMT1 promotes bladder cancer progression and immune escape by inhibiting MYH11 expression by methylating its promoter

BACKGROUND

Bladder cancer (BC) is a fatal malignancy of the urinary tract with limited effective biomarkers and therapeutic targets. This paper delved into the mechanism of MYH11 and DNMT1 in BC progression.

METHODS

Differential genes obtained from the GSE3167 dataset were analyzed by the R language limma package. RT-qPCR, Western blot, and immunohistochemistry were carried out to assess MYH11 and DNMT1 expression in BC cell lines and BC tissues. Cell migration, invasion, proliferation, and apoptosis were detected by Transwell assay, CCK-8, and TUNEL after different lentiviral vector treatments. MB49 cells with different infections were administered into mice to monitor tumor growth and immune escape. Flow cytometry detected the rate of CD45+CD4+-positive cells in the tumor tissues and PD-1 and TIM-3 expression in CD4+ T cells. MYH11 methylation was analyzed using the qMSP assay. ChIP and dual-luciferase assay were used for regulatory assays.

RESULTS

MYH11 was lowly expressed in BC. Overexpression of MYH11 inhibited the malignant progression of BC cells, promoted anti-tumor immune responses of CD4+ T cells, and inhibited immune escape and tumor development in mice. DNMT1 inhibited MYH11 expression by elevating MYH11 promoter methylation. DNMT1 inhibition impeded the immune escape of BC cells, which was reversed by silencing MYH11. DNMT1 silencing prevented immune escape via transcriptional activation of MYH11 and hindered tumor growth in mice.

CONCLUSION

DNMT1 promotes immune escape and malignant progression of BC by methylating the promoter of MYH11.

DNA methylation in melanoma immunotherapy: mechanisms and therapeutic opportunities

Abnormal DNA methylation is a hallmark of cancer and a nearly universal feature of melanoma. DNA methylation plays well-appreciated melanoma cell-intrinsic roles, including silencing tumor-suppressor genes, regulating genomic stability, deregulating expression of oncogenes to potentiate proliferative signaling and tumor migration. With the recent success of immunological therapies for melanoma, important roles for DNA methylation are also emerging at the interface between melanoma and immune cells with the potential to regulate the anti-tumor immune response. These newly recognized roles for DNA methylation in controlling melanoma cell immunogenicity, expression of MHC and immune checkpoint molecules as well as T cell phenotypes in the tumor microenvironment raise the possibility of using DNA methylation to develop improved therapies and methylation-based biomarkers. In addition to reviewing the "immune dimension" of DNA methylation, we summarize recent developments with potential clinical applications in melanoma, such as targeted DNA methylation editing, single-cell methylation approaches, and measurement of circulating methylated DNA. An improved understanding of the immune roles of DNA methylation presents an exciting opportunity for continued improvement of care and outcomes for patients with melanoma.

Epigenetic Control of Alveolar Macrophages: Impact on Lung Health and Disease

Alveolar macrophages (AMs) are immune cells located in the alveoli-the tiny air sacs in the lungs where gas exchange occurs. Their functions are regulated by various epigenetic mechanisms, which are essential for both healthy lung function and disease development. In the lung's microenvironment, AMs play critical roles in immune surveillance, pathogen clearance, and tissue repair. This review examines how epigenetic regulation influences AM functions and their involvement in lung diseases. Key mechanisms, such as DNA methylation, histone modifications, and non-coding RNAs, regulate gene expression in response to environmental signals. In healthy lungs, these modifications enable AMs to quickly respond to inhaled threats. However, when these processes malfunction, they could contribute to diseases such as pulmonary fibrosis, COPD, and pulmonary hypertension. By exploring how epigenetic changes affect AM polarization, plasticity, and immune responses, we can gain deeper insights into their role in lung diseases and open new avenues for treating and preventing respiratory conditions. Ultimately, understanding the epigenetic mechanisms within AMs enhances our knowledge of lung immunology and offers potential for innovative interventions to restore lung health and prevent respiratory diseases.

Advanced organoid models for targeting Kras-driven lung adenocarcinoma in drug discovery and combination therapy

BACKGROUND

Lung cancer remains one of the most challenging diseases to treat due to its heterogeneity. Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS) mutations are genetic drivers in numerous cancer types including lung adenocarcinoma (LUAD). Despite recent advances in KRAS-targeted therapies, treatment resistance and limited therapeutic options necessitate advanced preclinical models, such as organoids, to identify personalized cancer therapies by screening novel therapeutic strategies and synergistic drug combinations.

RESULTS

We established LUAD in genetically engineered mouse (GEM) models of KrasG12V & Trp53 Δex2-10 (KP) and KP with Ctnnb1Δex3 mutation (KPC). Tumor-derived organoids from these models recapitulated the genomic landscape and histopathological characteristics of their parental tumors. The organoids displayed tumorigenic potential when implanted in immunocompromised mice, forming tumors in contrast to unlike healthy lung-derived organoids. Drug screening identified effective kinase inhibitors and DNA methyltransferase (DNMT) inhibitors against the organoids. Notably, the combination of these drugs exhibited the highest synergy in KPC organoids.

CONCLUSION

We successfully developed LUAD organoids harboring Kras mutations and identified multiple potential therapeutic agents targeting these cells. Furthermore, we demonstrated the effectiveness of a DNMT inhibitor-based combination therapy, presenting a promising strategy for this challenging lung cancer subtype.

Exploration of the Therapeutic Potential of the Epigenetic Modulator Decitabine on 6-OHDA-Induced Experimental Models of Parkinson's Disease

Parkinson's disease (PD) poses a global menace, as the available treatment methods solely aim to mitigate symptoms. An effective strategy to address the pathogenesis of PD involves eliminating the accumulation of aggregated alpha-synuclein, emphasizing the role of epigenetics. Aberrant epigenetic changes significantly influence gene expression, which is pivotal in PD progression, impacting neuronal growth and degeneration. Epigenetic-related genes are regulated by histone modification and DNA methylation processes. Nevertheless, their significance in PD has not been confirmed. This research was carried out using both in vitro and in vivo approaches. In the in vitro investigations, N2A neuronal cell lines were utilized, and the neuroprotective effect of decitabine (DB) was observed at concentrations of 0.1 μM and 0.5 μM. In the in vivo study, PD induction led to significant motor deficits, which were notably ameliorated at the highest treatment dose. This improvement was accompanied by a marked attenuation of inflammatory mediators, including TNF-α, IL-6, IL-1β, and CRP levels. Additionally, there was a significant enhancement in antioxidative defense, evidenced by increased GSH (glutathione) levels and reduced oxidative stress marker NO (nitric oxide). Neurochemical analysis revealed a substantial rise in dopamine levels, a critical PD marker, alongside an elevation in BDNF, indicating neuroprotective effects. Furthermore, gene expression analysis indicated a notable upregulation in the mRNA expression of epigenetic genes and proteins linked to PD pathology. Histological assessments, including IHC, H&E, and CV staining of the substantia nigra, showed enhanced structural integrity following treatment. Collectively, these insights reveal DB's promise as a therapeutic solution for mitigating PD symptoms and pathology exacerbated by 6-OHDA.

The role of immunotherapy in targeting tumor microenvironment in genitourinary cancers

Genitourinary (GU) cancers, including renal cell carcinoma, prostate cancer, bladder cancer, and testicular cancer, represent a significant health burden and are among the leading causes of cancer-related mortality worldwide. Despite advancements in traditional treatment modalities such as chemotherapy, radiotherapy, and surgery, the complex interplay within the tumor microenvironment (TME) poses substantial hurdles to achieving durable remission and cure. The TME, characterized by its dynamic and multifaceted nature, comprises various cell types, signaling molecules, and the extracellular matrix, all of which are instrumental in cancer progression, metastasis, and therapy resistance. Recent breakthroughs in immunotherapy (IO) have opened a new era in the management of GU cancers, offering renewed hope by leveraging the body's immune system to combat cancer more selectively and effectively. This approach, distinct from conventional therapies, aims to disrupt cancer's ability to evade immune detection through mechanisms such as checkpoint inhibition, therapeutic vaccines, and adoptive cell transfer therapies. These strategies highlight the shift towards personalized medicine, emphasizing the importance of understanding the intricate dynamics within the TME for the development of targeted treatments. This article provides an in-depth overview of the current landscape of treatment strategies for GU cancers, with a focus on IO targeting the specific cell types of TME. By exploring the roles of various cell types within the TME and their impact on cancer progression, this review aims to underscore the transformative potential of IO strategies in TME targeting, offering more effective and personalized treatment options for patients with GU cancers, thereby improving outcomes and quality of life.

The epigenetic hallmarks of immune cells in cancer

Targeting the dysregulation of epigenetic mechanisms in cancer has emerged as a promising therapeutic strategy. Although the significant rationale progress of epigenetic therapies in blocking cancer cells, how epigenetic regulation shapes tumor microenvironment (TME) and establishes antitumor immunity remains less understood. Recent study focus has been put on the epigenetic-mediated changes in the fate of immune cells, including the differentiation, expansion, recruitment, functionalization, and exhaustion of T cells, natural killer (NK) cells, tumor-associated macrophages (TAMs), dendritic cells (DCs), myeloid-derived suppressor cells (MDSCs), and B cells within the TME. Here, we review the latest molecular and clinical insights into how DNA modifications, histone modification, and epitranscriptome-related regulations shape immune cells of various cancers. We also discuss opportunities for leveraging epigenetic therapies to improve cancer immunotherapies. This review provides the epigenetic foundations of cancer immunity and proposes the future direction of combination therapies.

Aberrant DNA methylation as a key modulator of cell death pathways: insights into cancer progression and other diseases

Cell death plays a significant role in the physiology of all living organisms, and its disruption is the underlying cause of various diseases. Previously, it was assumed that apoptosis and necrosis were the only means of cell death. Recent discoveries of alternative cell death pathways highlighted a complicated interplay between cell death regulation and its role in numerous human pathologies. DNA methylation is a universal epigenetic mechanism characterized by the covalent addition of a methyl group to cytosine in CpG dinucleotides. Alterations in DNA methylation patterns lead to the dysregulation of multiple cell death pathways. DNA methylome studies on cell death pathways have improved our understanding of the mechanism of various types of cell death, such as apoptosis, pyroptosis, necroptosis, ferroptosis, anoikis, autophagy, and cuproptosis. The irregular DNA methylation patterns of genes encoding proteins linked to multiple cell death pathways could underlie resistance to cell death. Dysregulation of cell death is linked to ailments in humans, such as cancer. However, unlike genetic alterations, DNA methylation is reversible, making it extremely interesting for therapeutics considering the potential use of DNA methyltransferase inhibitors. Furthermore, tumor microenvironment and genetic heterogeneity of cancers may influence the methylation-dependent regulation of cell death, contributing to tumor progression and therapeutic resistance. Understanding how DNA methylation influences cell death pathways may illuminate the underlying causes of cancer. This review explores the significance of the DNA methylation patterns of key genes involved in cell death pathways, emphasizing their connections and identifying potential gaps that could be exploited for developing epigenetic therapies targeting cancer.

Epigenetic drugs in cancer therapy

Genetic and epigenetic modifications of DNA are involved in cancer initiation and progression. Epigenetic modifications change chromatin structure and DNA accessibility and thus affect DNA replication, DNA repair and transcription. Epigenetic modifications are reversible and include DNA methylation, histone acetylation and histone methylation. DNA methylation is catalysed by DNA methyltransferases, histone acetylation and deacetylation are catalysed by histone acetylases and deacetylases, while histone methylation is catalysed by histone methyltransferases. Epigenetic modifications are dysregulated in several cancers, making them cancer therapeutic targets. Epigenetic drugs (epi-drugs) which are inhibitors of epigenetic modifications and include DNA methyltransferase inhibitors (DNMTi), histone deacetylase inhibitors (HDACi), histone methyltransferase inhibitors (HMTi) and bromodomain and extra-terminal motif protein inhibitors (BETi), have demonstrated clinical success as anti-cancer agents. Furthermore, the combination of epi-drugs with standard chemotherapeutic agents has demonstrated promising anti-cancer effects in pre-clinical and clinical settings. In this review, we discuss the role of epi-drugs in cancer therapy and explore their current and future use in combination with other anti-cancer agents used in the clinic. We further highlight the side effects and limitations of epi-drugs. We additionally discuss novel delivery methods and novel tumour epigenetic biomarkers for the screening, diagnosis and development of personalised cancer treatments, in order to reduce off-target toxicity and improve the specificity and anti-tumour efficacy of epi-drugs.

Integrating alternative therapies in overcoming chemotherapy resistance in tumors

Chemotherapy-resistant tumors present a significant challenge in oncology, often leading to treatment failures owing to mechanisms such as genetic mutations, drug efflux, altered metabolism, and adaptations within the tumor microenvironment. These factors limit the effectiveness of treatment and contribute to tumor resistance. This review highlights the role of alternative therapies aimed at overcoming resistance mechanisms. Several alternative strategies with high efficacy rate against tumor resistance are being explored, including targeted therapies (58-64%), immunotherapy (80%), hormone therapy (22-61%), and emerging approaches such as herbal therapies (90%), probiotics (34-90%), metabolic therapies (> 50%), epigenetic therapies (51-89%), microbiome-based therapies (50%), gene therapy (67-80%), photodynamic therapy/hypothermia (86-99%), and nanotechnology (50-67%). Integrating these alternative strategies with conventional treatments has the potent-al to augment the therapeutic efficacy and patient outcomes. Despite this progress, limitations in cancer therapeutics include the lack of predictive biomarkers, resistance mechanisms, and tumor heterogeneity, all of which contribute to treatment failure and relapse. To address these limitations, advancements in molecular diagnostics, as well as early detection through liquid biopsies, and the use of biomarkers to monitor resistance and guide treatment are crucial. Additionally, expanding clinical trials is essential to validate new therapies and improve patient outcomes.

Novel Epigenetics Control (EpC) Nanocarrier for Cancer Therapy Through Dual-Targeting Approach to DNA Methyltransferase and Ten-Eleven Translocation Enzymes

BACKGROUND/OBJECTIVES

Aberrant hypermethylation in the promoter regions of tumor suppressor genes facilitates the pathogenesis and progression of cancer. Therefore, inhibitors targeting DNA methyltransferase (DNMT) have been tested in clinical studies. However, the current monotherapy of DNMT inhibitors shows limited efficacy. Furthermore, the mechanism of action of DNMT inhibitors is DNA replication-dependent. To address these limitations, we developed a novel core-shell-type "epigenetics control (EpC) nanocarrier" that encapsulated decitabine (5-aza-dC) in the PLGA core nanoparticle and hybridized TET1 gene-encoding pDNA on the lipid shell surface. This study aimed to evaluate whether the dual delivery of DNMT inhibitors and pDNA of TET1 could synergistically enhance tumor suppressor gene expression and induce cell cycle arrest and/or apoptosis in cancer cells. Herein, we demonstrate the potential of the EpC carrier in HCT116 human colon cancer cells to upregulate tumor suppressor gene expression and rapidly achieve cell cycle arrest.

METHODS

PLGA core nanoparticles were prepared by the W/O/W double emulsion method. The formation of core-shell nanoparticles and complexation with pDNA were investigated and optimized by dynamic light scattering, zeta potential measurement, and agarose gel electrophoresis. The cellular uptake and transfection efficiency were measured by confocal laser scanning microscopy and a luciferase assay, respectively. The expression of p53 protein was detected by Western blotting. The anti-tumor effects of the EpC nanocarrier were evaluated by cell cycle analysis and an apoptosis assay.

RESULTS

The EpC nanocarrier delivered the DNMT inhibitor and TET gene-encoding pDNA into HCT116 cells. It promoted the expression of the tumor suppressor protein p53 and induced rapid cell cycle arrest in the G2/M phase in HCT116 cells.

CONCLUSIONS

Our findings suggest that the dual-targeting of DNMT and TET enzymes effectively repairs aberrant DNA methylation and induces growth arrest in cancer cells, and the dual-targeting strategy may contribute to the advancement of epigenetic cancer therapy.

The Role of the DNA Methyltransferase Family and the Therapeutic Potential of DNMT Inhibitors in Tumor Treatment

Members of the DNA methyltransferase (DNMT) family have been recognized as major epigenetic regulators of altered gene expression during tumor development. They establish and maintain DNA methylation of the CpG island of promoter and non-CpG region of the genome. The abnormal methylation status of tumor suppressor genes (TSGs) has been associated with tumorigenesis, leading to genomic instability, improper gene silence, and immune evasion. DNMT1 helps preserve methylation patterns during DNA replication, whereas the DNMT3 family is responsible for de novo methylation, creating new methylation patterns. Altered DNA methylation significantly supports tumor growth by changing gene expression patterns. FDA-approved DNMT inhibitors reverse hypermethylation-induced gene repression and improve therapeutic outcomes for cancer. Recent studies indicate that combining DNMT inhibitors with chemotherapies and immunotherapies can have synergistic effects, especially in aggressive metastatic tumors. Improving the treatment schedules, increasing isoform specificity, reducing toxicity, and utilizing genome-wide analyses of CRISPR-based editing to create personalized epigenetic therapies tailored to individual patient needs are promising strategies for enhancing therapeutic outcomes. This review discusses the interaction between DNMT regulators and DNMT1, its binding partners, the connection between DNA methylation and tumors, how these processes contribute to tumor development, and DNMT inhibitors' advancements and pharmacological properties.

Harnessing the tumor microenvironment: targeted cancer therapies through modulation of epithelial-mesenchymal transition

The tumor microenvironment (TME) is integral to cancer progression, impacting metastasis and treatment response. It consists of diverse cell types, extracellular matrix components, and signaling molecules that interact to promote tumor growth and therapeutic resistance. Elucidating the intricate interactions between cancer cells and the TME is crucial in understanding cancer progression and therapeutic challenges. A critical process induced by TME signaling is the epithelial-mesenchymal transition (EMT), wherein epithelial cells acquire mesenchymal traits, which enhance their motility and invasiveness and promote metastasis and cancer progression. By targeting various components of the TME, novel investigational strategies aim to disrupt the TME's contribution to the EMT, thereby improving treatment efficacy, addressing therapeutic resistance, and offering a nuanced approach to cancer therapy. This review scrutinizes the key players in the TME and the TME's contribution to the EMT, emphasizing avenues to therapeutically disrupt the interactions between the various TME components. Moreover, the article discusses the TME's implications for resistance mechanisms and highlights the current therapeutic strategies toward TME modulation along with potential caveats.

DNA methylation, histone acetylation in the regulation of memory and its modulation during aging

Memory formation is associated with constant modifications of neuronal networks and synaptic plasticity gene expression in response to different environmental stimuli and experiences. Dysregulation of synaptic plasticity gene expression affects memory during aging and neurodegenerative diseases. Covalent modifications such as methylation on DNA and acetylation on histones regulate the transcription of synaptic plasticity genes. Changes in these epigenetic marks correlated with alteration of synaptic plasticity gene expression and memory formation during aging. These epigenetic modifications, in turn, are regulated by physiology and metabolism. Steroid hormone estrogen and metabolites such as S-adenosyl methionine and acetyl CoA directly impact DNA and histones' methylation and acetylation levels. Thus, the decline of estrogen levels or imbalance of these metabolites affects gene expression and underlying brain functions. In the present review, we discussed the importance of DNA methylation and histone acetylation on chromatin modifications, regulation of synaptic plasticity gene expression and memory consolidation, and modulation of these epigenetic marks by epigenetic modifiers such as phytochemicals and vitamins. Further, understanding the molecular mechanisms that modulate these epigenetic modifications will help develop recovery approaches.

Cancer epigenetic therapy: recent advances, challenges, and emerging opportunities

Epigenetic dysregulation is an important nexus in the development and maintenance of human cancers. This review provides an overview of how understanding epigenetic dysregulation in cancers has led to insights for novel cancer therapy development. Over the past two decades, significant strides have been made in drug discovery efforts targeting cancer epigenetic mechanisms, leading to successes in clinical development and approval of cancer epigenetic therapeutics. This article will discuss the current therapeutic rationale guiding the discovery and development of epigenetic therapeutics, key learnings from clinical experiences and new opportunities on the horizon.

Epigenetic Impact of Curcumin and Thymoquinone on Cancer Therapeutics

Today, one of the most prevalent reasons for death among people is carcinoma. Because it is still on the increase throughout the world, there is a critical need for in- -depth research on the pathogenic mechanisms behind the disease as well as for efficient treatment. In the field of epigenetics, gene expression alterations that are inherited but not DNA sequence changes are investigated. Three key epigenetic changes, histone modifications, DNA methylation and non-coding RNA (ncRNA) expression, are principally responsible for the initiation and progression of different tumors. These changes are interconnected and constitute many epigenetic changes. A form of polyphenolic chemical obtained from plants called curcumin has great bioactivity against several diseases, specifically cancer. A naturally occurring substance called thymoquinone is well-known for its anticancer properties. Thymoquinone affects cancer cells through a variety of methods, according to preclinical studies. We retrieved information from popular databases, including PubMed, Google Scholar, and CNKI, to summarize current advancements in the efficiency of curcumin against cancer and its epigenetic regulation in terms of DNA methylation, histone modifications, and miRNA expression. The present investigation offers thorough insights into the molecular processes, based on epigenetic control, that underlie the clinical use of curcumin and thymoquinone in cancerous cells.

Targeting mitochondrial RNAs enhances the efficacy of the DNA-demethylating agents

Hypomethylating agents (HMAs) such as azacytidine and decitabine are FDA-approved chemotherapy drugs for hematologic malignancy. By inhibiting DNA methyltransferases, HMAs reactivate tumor suppressor genes (TSGs) and endogenous double-stranded RNAs (dsRNAs) that limit tumor growth and trigger apoptosis via viral mimicry. Yet, HMAs show limited effects in many solid tumors despite the strong induction of TSGs and dsRNAs. Here we show that targeting mitochondrial RNAs (mtRNAs) can enhance the HMA-mediated cell death in lung adenocarcinoma cells. We find that HMA treatment accompanies increased mtRNA levels and subsequent enhancement of metabolic activity, resulting in higher ATP production. Compromising the mitochondrial function by downregulating mature mtRNA expression increased cell death by HMAs. We further perform a CRISPR screening on mtRNA processing factors and find that mtRNA polymerase (POLRMT) and ElaC Ribonuclease Z 2 (ELAC2) depleted cells show increased sensitivity to HMAs by suppressing decitabine-triggered enhancement of ATP production. Moreover, we show that a small molecular inhibitor of POLRMT compromises the metabolic activity and synergistically enhances the cytotoxicity of HMAs. Our study unveils the insensitivity to HMAs through the elevation of mtRNAs and suggests mtRNA regulatory factors as potential synergistic targets to improve the therapeutic benefit of HMAs.

DNMT1 prolonged absence is a tunable cellular stress that triggers cell proliferation arrest to protect from major DNA methylation loss

Methylation of cytosine in CpG dinucleotides is an epigenetic modification carried out by DNA-methyltransferases (DNMTs) that contributes to chromatin condensation and structure and, thus, to gene transcription regulation and chromosome stability. DNMT1 maintains the DNA methylation pattern of the genome at each cell cycle by copying it to the newly synthesized DNA strand during the S-phase. DNMT1 pharmacological inhibition as well as genetic knockout and knockdown, leads to passive DNA methylation loss. However, these strategies have been associated with different cell fates, even in the same cell background, suggesting that they can question the interpretation of the obtained results. Using a cell system in which endogenous DNMT1 is fused with an inducible degron and can be rapidly degraded, we found that in non-tumoral RPE-1 cells, DNMT1 loss progressively induced cell proliferation slowing-down and cell cycle arrest at the G1/S transition. The latter is due to p21 activation, which is partly mediated by p53 and leads to a global reduction in DNA methylation. DNMT1 restoration rescues cell proliferation, indicating that its deregulation is sensed as tunable cellular stress.

Potential Antimicrobial and Cytotoxic Activity of Caralluma indica Seed Extract

Background: Plant-derived phytochemicals are crucial in fighting bacterial infections and in cancer therapy. Objective: This study investigates the phytochemical composition of the ethanolic extract obtained from Caralluma indica (C. indica) seeds and assesses its antimicrobial, anticancer, and antioxidant activities. Results: GC-MS analysis found 30 phytochemicals in C. indica seeds, including 5 bioactive compounds that have been shown to have antioxidant, antimicrobial, and cytotoxicity properties, through in silico evaluation. Phytochemical screening of C. indica identified and measured the phenolic compounds, providing insight into its bioactive potential and therapeutic properties. C. indica exhibited robust antioxidant capacity (DPPH, ABTS, nitric oxide, and H2O2 radical scavenging) alongside potent antimicrobial activity against oral pathogen and cytotoxicity activity on a human oral squamous carcinoma cell line (OECM-1) (EC50 of 169.35 µg/mL) and yeast cell Saccharomyces cerevisiae (215.82 µg/mL), with a selective index of 1.27. The subminimum % MBC/MFC of C. indica significantly reduced biofilm formation against oral pathogens (p < 0.05). Molecular docking studies showed a strong correlation (r = 0.862) between antifungal and anticancer targets, suggesting that the antimicrobial agents in C. indica contribute to cancer prevention mechanisms. Conclusions: These findings propose C. indica seeds as promising candidates for combating oral pathogens, inhibiting biofilm formation, and reducing the risk of oral cancer progression.

Supercomputer-Based Virtual Screening for Deoxyribonucleic Acid Methyltransferase 1 Inhibitors as Novel Anticancer Agents

Targeting epigenetics is a new strategy to treat cancer and develop novel epigenetic drugs with anti-tumor activity. DNA methyltransferases transfer the methyl group from S-adenosyl-L-methionine (SAM) to the cytosine residue in a CpG island, leading to the transcription silencing of the gene. Hypermethylation can frequently be observed in several tumor types. Hence, the inhibition of DNMT1 has become a novel approach to cure cancer. In this study, virtual screening and molecular docking were performed for more than 11,000 ligands from the ZINC15 database to discover new hypomethylation agents. Four candidate compounds were further tested for their effects on DNMT1 in silico and in vitro. Compounds 2 and 4 showed the best DNMT1 inhibitory activity, but only compound 4 was able to inhibit the growth of several cancer cell lines. The hypomethylation of the luciferase gene by compound 4 was verified by a CMV- luciferase assay using KG-1 cells. Additionally, compound 4 suppressed cell migration in a dose- and time-dependent manner in the wound healing assay. Moreover, cell cycle analyses demonstrated that compound 4 arrested CCRF-CEM cells and MDA-MB-468 cells in the G0/G1 phase. Also, compound 4 significantly induced early and late apoptosis in a dose-dependent manner. In conclusion, we introduce compound 4 as a novel DNMT1 inhibitor with anticancer activity.

Determination of global DNA methylation level by methylation-sensitive comet assay in patients with urinary bladder cancer

DNA methylation is an important mechanism in the regulation of gene expression and maintenance of genomic integrity. Aberrant DNA methylation is an early event in carcinogenesis. DNA methyltransferase inhibitors are used to restore aberrant DNA methylation and inhibit tumor growth. Evaluation of DNA methylation level is important for an effective anti-cancer therapy. In the present study, the determination of global DNA methylation levels in patients with urinary bladder cancer was proposed. The methylation-sensitive comet assay determined the global DNA methylation level at the level of single cells. McrBC enzyme, a methylation-sensitive restriction endonuclease, was used for enzymatic digestion to generate additional breaks at methylated sites. % DNA methylation level was significantly higher in patients with bladder cancer compared to the control group. The clinical performance of % DNA methylation analysis by methylation-sensitive comet assay was evaluated by ROC curve. Using the cutoff value of 6.5% DNA methylation, 92% sensitivity, and 42% specificity were obtained. In conclusion, global DNA methylation measured by methylation-sensitive comet assay may be a promising noninvasive biomarker that reduces interventional tests required in the diagnosis and follow-up of urinary bladder cancer.

Epigenetics and aging: relevance for sleep medicine

PURPOSE OF REVIEW

Sleep disorders encompass a wide range of conditions with substantial individual variability. Epigenetics, the study of heritable changes beyond DNA sequence, offers a promising avenue for personalized medicine in this field.

RECENT FINDINGS

There is great potential of epigenetic markers for sleep disorder diagnosis and the development of epigenetic drugs for targeted treatment. Epigenetic age acceleration, a marker of biological aging, is linked to sleep disorders and comorbidities. Very importantly, this acceleration may be reversible with effective treatment.

SUMMARY

While the underlying mechanisms and assessment of clinical utility require further investigation, the potential of epigenetics in sleep medicine is recognized. Future research focused on closing knowledge gaps and clinical validation is crucial to translate these findings into practical applications, paving the way for more effective and personalized management of sleep disorders.

Closing in on human methylation-the versatile family of seven-β-strand (METTL) methyltransferases

Methylation is a common biochemical reaction, and a number of methyltransferase (MTase) enzymes mediate the various methylation events occurring in living cells. Almost all MTases use the methyl donor S-adenosylmethionine (AdoMet), and, in humans, the largest group of AdoMet-dependent MTases are the so-called seven-β-strand (7BS) MTases. Collectively, the 7BS MTases target a wide range of biomolecules, i.e. nucleic acids and proteins, as well as several small metabolites and signaling molecules. They play essential roles in key processes such as gene regulation, protein synthesis and metabolism, as well as neurotransmitter synthesis and clearance. A decade ago, roughly half of the human 7BS MTases had been characterized experimentally, whereas the remaining ones merely represented hypothetical enzymes predicted from bioinformatics analysis, many of which were denoted METTLs (METhylTransferase-Like). Since then, considerable progress has been made, and the function of > 80% of the human 7BS MTases has been uncovered. In this review, I provide an overview of the (estimated) 120 human 7BS MTases, grouping them according to substrate specificities and sequence similarity. I also elaborate on the challenges faced when studying these enzymes and describe recent major advances in the field.

Adipose-Derived Stromal Cells and Cancer-Associated Fibroblasts: Interactions and Implications in Tumor Progression

Adipose-derived stromal cells (ASCs) and cancer-associated fibroblasts (CAFs) play pivotal roles in the tumor microenvironment (TME), significantly influencing cancer progression and metastasis. This review explores the plasticity of ASCs, which can transdifferentiate into CAFs under the influence of tumor-derived signals, thus enhancing their secretion of extracellular matrix components and pro-inflammatory cytokines that promote tumorigenesis. We discuss the critical process of the epithelial-to-mesenchymal transition (EMT) facilitated by ASCs and CAFs, highlighting its implications for increased invasiveness and therapeutic resistance in cancer cells. Key signaling pathways, including the transforming growth factor-β (TGF-β), Wnt/β-catenin, and Notch, are examined for their roles in regulating EMT and CAF activation. Furthermore, we address the impact of epigenetic modifications on ASC and CAF functionality, emphasizing recent advances in targeting these modifications to inhibit their pro-tumorigenic effects. This review also considers the metabolic reprogramming of ASCs and CAFs, which supports their tumor-promoting activities through enhanced glycolytic activity and lactate production. Finally, we outline potential therapeutic strategies aimed at disrupting the interactions between ASCs, CAFs, and tumor cells, including targeted inhibitors of key signaling pathways and innovative immunotherapy approaches. By understanding the complex roles of ASCs and CAFs within the TME, this review aims to identify new therapeutic opportunities that could improve patient outcomes in cancer treatment.

Epigenetic therapies targeting histone lysine methylation: complex mechanisms and clinical challenges

As epigenetic therapies continue to gain ground as potential treatment strategies for cancer and other diseases, compounds that target histone lysine methylation and the enzyme complexes represent a major frontier for therapeutic development. Clinically viable therapies targeting the activities of histone lysine methyltransferases (HKMT) and demethylases (HKDMs) have only recently begun to emerge following FDA approval of the EZH2 inhibitor tazemetostat in 2020 and remain limited to compounds targeting the well-studied SET domain-containing HKMTs and their opposing HKDMs. These include the H3K27 methyltransferases EZH2/EZH1, the singular H3K79 methyltransferase DOT1L, and the H3K4 methyltransferase MLL1/COMPASS as well as H3K9 and H3K36 methyltransferases. They additionally include the H3K4/9-preferential demethylase LSD1 and the H3K4-, H3K27-, and H3K36-preferential KDM5, KDM6, and KDM2 demethylase subfamilies, respectively. This Review discusses the results of recent clinical and preclinical studies relevant to all of these existing and potential therapies. It provides an update on advancements in therapeutic development, as well as more basic molecular understanding, within the past 5 years approximately. It also offers a perspective on histone lysine methylation that departs from the long-predominant "histone code" metaphor, emphasizing complex-disrupting inhibitors and proximity-based approaches rather than catalytic domain inhibitors in the outlook for future therapeutic development.

Targeting DNA methyltransferases for cancer therapy

DNA methyltransferases (DNMTs) play a crucial role in genomic DNA methylation. In mammals, DNMTs regulate the dynamic patterns of DNA methylation in embryonic and adult cells. Abnormal functions of DNMTs are often indicative of cancers, including overall hypomethylation and partial hypermethylation of tumor suppressor genes (TSG), which accelerate the malignancy of tumors, worsen the condition of patients, and significantly exacerbate the difficulty of cancer treatment. Currently, nucleoside DNMT inhibitors such as Azacytidine and Decitabine have been approved by the FDA and EMA for the treatment of acute myeloid leukemia (AML), chronic myelomonocytic leukemia (CMML), and myelodysplastic syndrome (MDS). Therefore, targeting DNMTs is a very promising anti-tumor strategy. This review mainly summarizes the therapeutic effects of DNMT inhibitors on cancers. It aims to provide more possibilities for the treatment of cancers by discovering more DNMT inhibitors with high activity, high selectivity, and good drug-like properties in the future.

Methylation synthetic lethality: Exploiting selective drug targets for cancer therapy

In cancer, synthetic lethality refers to the drug-induced inactivation of one gene and the inhibition of another in cancer cells by a drug, resulting in the death of only cancer cells; however, this effect is not present in normal cells, leading to targeted killing of cancer cells. Recent intensive epigenetic research has revealed that aberrant epigenetic changes are more frequently observed than gene mutations in certain cancers. Recently, numerous studies have reported various methylation synthetic lethal combinations involving DNA damage repair genes, metabolic pathway genes, and paralogs with significant results in cellular models, some of which have already entered clinical trials with promising results. This review systematically introduces the advantages of methylation synthetic lethality and describes the lethal mechanisms of methylation synthetic lethal combinations that have recently demonstrated success in cellular models. Furthermore, we discuss the future opportunities and challenges of methylation synthetic lethality in targeted anticancer therapies.

Identification of 3-(9H-carbazol-9-yl)-2-(1,3-dioxoisoindolin-2-yl)propanoic acids as promising DNMT1 inhibitors

DNA methyltransferase 1 (DNMT1) is the primary enzyme responsible for maintaining DNA methylation patterns during cellular division, crucial for cancer development by suppressing tumor suppressor genes. In this study, we retained the phthalimide structure of N-phthaloyl-l-tryptophan (RG108) and substituted its indole ring with nitrogen-containing aromatic rings of varying sizes. We synthesized 3-(9H-carbazol-9-yl)-2-(1,3-dioxoisoindolin-2-yl)propanoic acids and confirmed them as DNMT1 inhibitors through protein affinity testing, radiometric method using tritium labeled SAM, and MTT assay. Preliminary structure-activity relationship analysis revealed that introducing substituents on the carbazole ring could enhance inhibitory activity, with S-configuration isomers showing greater activity than R-configuration ones. Notably, S-3-(3,6-di-tert-butyl-9H-carbazol-9-yl)-2-(1,3-dioxoisoindolin-2-yl)propanoic acid (7r-S) and S-3-(1,3,6-trichloro-9H-carbazol-9-yl)-2-(1,3-dioxoisoindolin-2-yl)propanoic acid (7t-S) exhibited significant DNMT1 enzyme inhibition activity, with IC50 values of 8.147 μM and 0.777 μM, respectively (compared to RG108 with an IC50 above 250 μM). Moreover, they demonstrated potential anti-proliferative activity on various tumor cell lines including A2780, HeLa, K562, and SiHa. Transcriptome analysis and KEGG pathway enrichment of K562 cells treated with 7r-S and 7t-S identified differentially expressed genes (DEGs) related to apoptosis and cell cycle pathways. Flow cytometry assays further indicated that 7r-S and 7t-S induce apoptosis in K562 cells and arrest them in the G0/G1 phase in a concentration-dependent manner. Molecular docking revealed that 7t-S may bind to the methyl donor S-adenosyl-l-methionine (SAM) site in DNMT1 with an orientation opposite to RG108, suggesting potential for deeper penetration into the DNMT1 pocket and laying the groundwork for further modifications.

Evaluating the Cellular Roles of the Lysine Acetyltransferase Tip60 in Cancer: A Multi-Action Molecular Target for Precision Oncology

Precision (individualized) medicine relies on the molecular profiling of tumors' dysregulated characteristics (genomic, epigenetic, transcriptomic) to identify the reliance on key pathways (including genome stability and epigenetic gene regulation) for viability or growth, and then utilises targeted therapeutics to disrupt these survival-dependent pathways. Non-mutational epigenetic changes alter cells' transcriptional profile and are a key feature found in many tumors. In contrast to genetic mutations, epigenetic changes are reversable, and restoring a normal epigenetic profile can inhibit tumor growth and progression. Lysine acetyltransferases (KATs or HATs) protect genome stability and integrity, and Tip60 is an essential acetyltransferase due to its roles as an epigenetic and transcriptional regulator, and as master regulator of the DNA double-strand break response. Tip60 is commonly downregulated and mislocalized in many cancers, and the roles that mislocalized Tip60 plays in cancer are not well understood. Here we categorize and discuss Tip60-regulated genes, evaluate Tip60-interacting proteins based on cellular localization, and explore the therapeutic potential of Tip60-targeting compounds as epigenetic inhibitors. Understanding the multiple roles Tip60 plays in tumorigenesis will improve our understanding of tumor progression and will inform therapeutic options, including informing potential combinatorial regimes with current chemotherapeutics, leading to improvements in patient outcomes.

Epigenetic modulators provide a path to understanding disease and therapeutic opportunity

The discovery of epigenetic modulators (writers, erasers, readers, and remodelers) has shed light on previously underappreciated biological mechanisms that promote diseases. With these insights, novel biomarkers and innovative combination therapies can be used to address challenging and difficult to treat disease states. This review highlights key mechanisms that epigenetic writers, erasers, readers, and remodelers control, as well as their connection with disease states and recent advances in associated epigenetic therapies.

De Novo Design of Inhibitors of DNA Methyltransferase 1: A Critical Comparison of Ligand- and Structure-Based Approaches

Designing and developing inhibitors against the epigenetic target DNA methyltransferase (DNMT) is an attractive strategy in epigenetic drug discovery. DNMT1 is one of the epigenetic enzymes with significant clinical relevance. Structure-based de novo design is a drug discovery strategy that was used in combination with similarity searching to identify a novel DNMT inhibitor with a novel chemical scaffold and warrants further exploration. This study aimed to continue exploring the potential of de novo design to build epigenetic-focused libraries targeted toward DNMT1. Herein, we report the results of an in-depth and critical comparison of ligand- and structure-based de novo design of screening libraries focused on DNMT1. The newly designed chemical libraries focused on DNMT1 are freely available on GitHub.

Epigenetic regulation of androgen dependent and independent prostate cancer

Prostate cancer is one of the most common malignancies among men worldwide. Besides genetic alterations, epigenetic modulations including DNA methylation, histone modifications and miRNA mediated alteration of gene expression are the key driving forces for the prostate tumor development and cancer progression. Aberrant expression and/or the activity of the epigenetic modifiers/enzymes, results in aberrant expression of genes involved in DNA repair, cell cycle regulation, cell adhesion, apoptosis, autophagy, tumor suppression and hormone response and thereby disease progression. Altered epigenome is associated with prostate cancer recurrence, progression, aggressiveness and transition from androgen-dependent to androgen-independent phenotype. These epigenetic modifications are reversible and various compounds/drugs targeting the epigenetic enzymes have been developed that are effective in cancer treatment. This chapter focuses on the epigenetic alterations in prostate cancer initiation and progression, listing different epigenetic biomarkers for diagnosis and prognosis of the disease and their potential as therapeutic targets. This chapter also summarizes different epigenetic drugs approved for prostate cancer therapy and the drugs available for clinical trials.

A Computational Approach for the Discovery of Novel DNA Methyltransferase Inhibitors

Nowadays, the explosion of knowledge in the field of epigenetics has revealed new pathways toward the treatment of multifactorial diseases, rendering the key players of the epigenetic machinery the focus of today's pharmaceutical landscape. Among epigenetic enzymes, DNA methyltransferases (DNMTs) are first studied as inhibition targets for cancer treatment. The increasing clinical interest in DNMTs has led to advanced experimental and computational strategies in the search for novel DNMT inhibitors. Considering the importance of epigenetic targets as a novel and promising pharmaceutical trend, the present study attempted to discover novel inhibitors of natural origin against DNMTs using a combination of structure and ligand-based computational approaches. Particularly, a pharmacophore-based virtual screening was performed, followed by molecular docking and molecular dynamics simulations in order to establish an accurate and robust selection methodology. Our screening protocol prioritized five natural-derived compounds, derivatives of coumarins, flavones, chalcones, benzoic acids, and phenazine, bearing completely diverse chemical scaffolds from FDA-approved "Epi-drugs". Their total DNMT inhibitory activity was evaluated, revealing promising results for the derived hits with an inhibitory activity ranging within 30-45% at 100 µM of the tested compounds.

Exploring epigenetic strategies for the treatment of osteoporosis

The worldwide trend toward an aging population has resulted in a higher incidence of chronic conditions, such as osteoporosis. Osteoporosis, a prevalent skeletal disorder characterized by decreased bone mass and increased fracture risk, encompasses primary and secondary forms, each with distinct etiologies. Mechanistically, osteoporosis involves an imbalance between bone resorption by osteoclasts and bone formation by osteoblasts. Current pharmacological interventions for osteoporosis, such as bisphosphonates, denosumab, and teriparatide, aim to modulate bone turnover and preserve bone density. Hormone replacement therapy and lifestyle modifications are also recommended to manage the condition. While current medications offer therapeutic options, they are not devoid of limitations. Recent studies have highlighted the importance of epigenetic mechanisms, including DNA methylation and histone modifications, in regulating gene expression during bone remodeling. The use of epigenetic drugs, or epidrugs, to target these mechanisms offers a promising avenue for therapeutic intervention in osteoporosis. In this review, we comprehensively examine the recent advancements in the application of epidrugs for treating osteoporosis.

Epigenetic reprogramming as a key to reverse ageing and increase longevity

The pursuit for the fountain of youth has long been a fascination amongst scientists and humanity. Ageing is broadly characterized by a cellular decline with increased susceptibility to age-related diseases, being intimately associated with epigenetic modifications. Recently, reprogramming-induced rejuvenation strategies have begun to greatly alter longevity research not only to tackle age-related defects but also to possibly reverse the cellular ageing process. Hence, in this review, we highlight the major epigenetic changes during ageing and the state-of-art of the current emerging epigenetic reprogramming strategies leveraging on transcription factors. Notably, partial reprogramming enables the resetting of the ageing clock without erasing cellular identity. Promising chemical-based rejuvenation strategies harnessing small molecules, including DNA methyltransferase and histone deacetylase inhibitors are also discussed. Moreover, in parallel to longevity interventions, the foundations of epigenetic clocks for accurate ageing assessment and evaluation of reprogramming approaches are briefly presented. Going further, with such scientific breakthroughs, we are witnessing a rise in the longevity biotech industry aiming to extend the health span and ideally achieve human rejuvenation one day. In this context, we overview the main scenarios proposed for the future of the socio-economic and ethical challenges associated with such an emerging field. Ultimately, this review aims to inspire future research on interventions that promote healthy ageing for all.

Alteration of DNA methyltransferases by eribulin elicits broad DNA methylation changes with potential therapeutic implications for triple-negative breast cancer

Background: Triple-negative breast cancer (TNBC) is an aggressive disease with limited treatment options. Eribulin, a chemotherapeutic drug, induces epigenetic changes in cancer cells, suggesting a unique mechanism of action. Materials & methods: MDA-MB 231 cells were treated with eribulin and paclitaxel, and the samples from 53 patients treated with neoadjuvant eribulin were compared with those from 14 patients who received the standard-of-care treatment using immunohistochemistry. Results: Eribulin treatment caused significant DNA methylation changes in drug-tolerant persister TNBC cells, and it also elicited changes in the expression levels of epigenetic modifiers (DNMT1, TET1, DNMT3A/B) in vitro and in primary TNBC tumors. Conclusion: These findings provide new insights into eribulin's mechanism of action and potential biomarkers for predicting TNBC treatment response.

Integrative Epigenetic and Molecular Analysis Reveals a Novel Promoter for a New Isoform of the Transcription Factor TEAD4

TEAD4 is a transcription factor that plays a crucial role in the Hippo pathway by regulating the expression of genes related to proliferation and apoptosis. It is also involved in the maintenance and differentiation of the trophectoderm during pre- and post-implantation embryonic development. An alternative promoter for the TEAD4 gene was identified through epigenetic profile analysis, and a new transcript from the intronic region of TEAD4 was discovered using the 5'RACE method. The transcript of the novel promoter encodes a TEAD4 isoform (TEAD4-ΔN) that lacks the DNA-binding domain but retains the C-terminal protein-protein interaction domain. Gene expression studies, including end-point PCR and Western blotting, showed that full-length TEAD4 was present in all investigated tissues. However, TEAD4-ΔN was only detectable in certain cell types. The TEAD4-ΔN promoter is conserved throughout evolution and demonstrates transcriptional activity in transient-expression experiments. Our study reveals that TEAD4 interacts with the alternative promoter and increases the expression of the truncated isoform. DNA methylation plays a crucial function in the restricted expression of the TEAD4-ΔN isoform in specific tissues, including the umbilical cord and the placenta. The data presented indicate that the DNA-methylation status of the TEAD4-ΔN promoter plays a critical role in regulating organ size, cancer development, and placenta differentiation.

Discovery of potent DNMT1 inhibitors against sickle cell disease using structural-based virtual screening, MM-GBSA and molecular dynamics simulation-based approaches

Sickle cell disease (SCD) is an autosomal recessive genetic disorder affecting millions of people worldwide. A reversible and selective DNMT1 inhibitor, GSK3482364, has been known to decrease the overall methylation activity of DNMT1, resulting in the increase of HbF levels and percentage of HbF-expressing erythrocytes in an in vitro and in vivo model. In this study, a structure-based virtual screening was done with GSK3685032, a co-crystalized ligand of DNMT1 (PDB ID: 6X9K) with an IC50 value of 0.036 μM and identified 3988 compounds from three databases (ChEMBL, PubChem and Drug Bank). Using this screening method, we identified around 15 compounds with XP docking scores greater than -8 kcal/mol. Further, prime MM-GBSA calculations have been performed and found compound SCHEMBL19716714 with the highest binding free energy of -83.31 kcal/mol. Finally, four compounds were identified based on glide energy and ΔG bind scores that have the most binding with DG7, DG19, DG20 bases and Lys1535, His1507, Trp1510, Ser1230, which were required for the target enzyme inhibition. Furthermore, molecular dynamics simulation studies of top ligands validate the stability of the docked complexes by examining root mean square deviations, root mean square fluctuations, solvent accessible surface area, and radius of gyration graphs from simulation trajectories. These findings suggest that the top four hit compounds may be capable of inhibiting DNMT1 and that additional in vitro and in vivo studies will be essential to prove the clinical effectiveness of the selected lead compounds.Communicated by Ramaswamy H. Sarma.

Synergistic combination of doxorubicin with hydralazine, and disulfiram against MCF-7 breast cancer cell line

Disulfiram and hydralazine have recently been reported to have anti-cancer action, and repositioned to be used as adjuvant in cancer therapy. Chemotherapy combined with other medications, such as those that affect the immune system or epigenetic cell profile, can overcome resistance with fewer adverse effects compared to chemotherapy alone. In the present study, a combination of doxorubicin (DOX) with hydrazine (Hyd) and disulfiram (Dis), as a triple treatment, was evaluated against wild-type and DOX-resistant MCF-7 breast cancer cell line. Both wild-type MCF-7 cell line (MCF-7_WT) and DOX-resistant MCF-7 cell line (MCF-7_DoxR) were treated with different combination ratios of DOX, Dis, and Hyd followed by measuring the cell viability using the MTT assay. Synergism was determined using a combination index, isobologram analysis, and dose-reducing index. The anti-proliferation activity and mechanism of the triple combination were investigated by apoptosis analysis. The results showed a reduction in the IC50 values of DOX in MCF-7_WT cells (from 0.24 μM to 0.012 μM) and MCF-7_DoxR cells (from 1.13 μM to 0.44 μM) when treated with Dis (0.03μM), and Hyd (20μM) combination. Moreover, The triple combination DOX/Hyd/Dis induced significant apoptosis in both MCF-7_WT and MCF-7_DoxR cells compared to DOX alone. The triple combination of DOX, Dis, and Hyd showed a synergistic drugs combination to decrease the DOX dose needed to kill both MCF-7_WT and MCF-7_DoxR cancer cells and enhanced chemosensitivity to DOX.

DNA methylation meningioma biomarkers: attributes and limitations

Meningioma, one of the most common primary central nervous system tumors, are classified into three grades by the World Health Organization (WHO) based on histopathology. The gold-standard treatment, surgical resection, is hampered by issues such as incomplete resection in some cases and a high recurrence rate. Alongside genetic alterations, DNA methylation, plays a crucial role in progression of meningiomas in the occurrence and development of meningiomas. The epigenetic landscape of meningioma is instrumental in refining tumor classification, identifying robust molecular markers, determining prognosis, guiding treatment selection, and innovating new therapeutic strategies. Existing classifications lack comprehensive accuracy, and effective therapies are limited. Methylated DNA markers, exhibiting differential characteristics across varying meningioma grades, serve as invaluable diagnostic tools. Particularly, combinatorial methylated markers offer insights into meningioma pathogenesis, tissue origin, subtype classification, and clinical outcomes. This review integrates current research to highlight some of the most promising DNA and promoter methylation markers employed in meningioma diagnostics. Despite their promise, the development and application of DNA methylation biomarkers for meningioma diagnosis and treatment are still in their infancy, with only a handful of DNA methylation inhibitors currently clinically employed for meningioma treatment. Future studies are essential to validate these markers and ascertain their clinical utility. Combinatorial methylated DNA markers for meningiomas have broad implications for understanding tumor development and progression, signaling a paradigm shift in therapeutic strategies for meningiomas.

Insights on the Role of Polyphenols in Combating Cancer Drug Resistance

Chemotherapy resistance is still a serious problem in the treatment of most cancers. Many cellular and molecular mechanisms contribute to both inherent and acquired drug resistance. They include the use of unaffected growth-signaling pathways, changes in the tumor microenvironment, and the active transport of medicines out of the cell. The antioxidant capacity of polyphenols and their potential to inhibit the activation of procarcinogens, cancer cell proliferation, metastasis, and angiogenesis, as well as to promote the inhibition or downregulation of active drug efflux transporters, have been linked to a reduced risk of cancer in epidemiological studies. Polyphenols also have the ability to alter immunological responses and inflammatory cascades, as well as trigger apoptosis in cancer cells. The discovery of the relationship between abnormal growth signaling and metabolic dysfunction in cancer cells highlights the importance of further investigating the effects of dietary polyphenols, including their ability to boost the efficacy of chemotherapy and avoid multidrug resistance (MDR). Here, it is summarized what is known regarding the effectiveness of natural polyphenolic compounds in counteracting the resistance that might develop to cancer drugs as a result of a variety of different mechanisms.