Epigenetic mechanisms in breast cancer therapy and resistance

TET-mediated 5hmC in breast cancer: mechanism and clinical potential

Breast cancer is the most common cancer among women, with differences in clinical features due to its distinct molecular subtypes. Current studies have demonstrated that epigenetic modifications play a crucial role in regulating the progression of breast cancer. Among these mechanisms, DNA demethylation and its reverse process have been studied extensively for their roles in activating or silencing cancer related gene expression. Specifically, Ten-Eleven Translocation (TET) enzymes are involved in the conversion process from 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), which results in a significant difference in the global level of 5hmC in breast cancer compared with normal tissues. In this review, we summarize the functions of TET proteins and the regulated 5hmC levels in the pathogenesis of breast cancer. Discussions on the clinical values of 5hmC in early diagnosis and the prediction of prognosis are also mentioned.

Micro-RNAs targeting the estrogen receptor alpha involved in endocrine therapy resistance in breast cancer

Endocrine therapy resistance (ETR) in breast cancer (BC) is a multicausal phenomenon with diverse alterations in the tumor cell interactome. Within these alterations, non-coding RNAs (ncRNAs) such as micro-RNAs (miRNAs) modulate the expression of tumor suppressor genes and proto-oncogenes, such as the ESR1 gene encoding estrogen receptor alpha (ERα). This work aims to review the effects of miRNAs targeting ERα mRNA and their mechanisms related to ETR in BC. A thorough review of the literature and an in silico study were carried out to elucidate the involvement of each miRNA, thus contributing to the understanding of ETR in BC.

Arsenene-Vanadene nanodots co-activate Apoptosis/Ferroptosis for enhanced chemo-immunotherapy

Triple-Negative Breast Cancer (TNBC) represents a highly aggressive subtype of breast cancer with an unfavorable prognosis, characterized by minimal immune infiltration and pronounced immune suppression, resulting in a limited response to immunotherapy. In this study, a multifunctional Arsenene-Vanadene nanodot (AsV) drug delivery system is introduced, which responds to the tumor microenvironment by releasing arsenic and vanadium. Arsenic undergoes oxidation to generate highly toxic trivalent arsenic, which induces apoptosis in tumor cells while utilizing apoptotic cell debris to transiently activate the immune system. Additionally, arsenic binds to cysteine, indirectly facilitating ferroptosis. Concurrently, vanadium's redox cycling properties are harnessed to trigger a Fenton-like reaction, promoting lipid peroxidation. Furthermore, ferroptosis is enhanced through the depletion of glutathione and inactivation of glutathione peroxidase 4 (GPX4), leading to the release of damage-associated molecular patterns and thereby amplifying the anti-tumor immune response. This study represents the first instance of integrating arsenene's apoptosis-inducing properties with vanadium's ferroptosis-enhancing effects, providing a synergistic approach to improving the immunotherapeutic response and offering a potential strategy for enhancing TNBC prognosis. STATEMENT OF SIGNIFICANCE: Triple-negative breast cancer (TNBC) exhibits resistance to immunotherapy due to its highly immunosuppressive tumor microenvironment. In this study, tumour-responsive Arsenene-Vanadene nanodots (AsV) were developed to induce a synergistic effect by triggering apoptosis and ferroptosis through microenvironment-specific mechanisms. The arsenic component generates cytotoxic trivalent arsenic, promoting apoptosis while binding to cysteine, thereby reducing GSH synthesis. Simultaneously, vanadium initiates lipid peroxidation through Fenton-like reactions and disruption of the glutathione/GPX4 axis, further amplifying ferroptotic cell death. This dual-action system transforms tumor cell debris into immune-stimulating signals while circumventing conventional immunotherapy limitations. As the first strategy integrating arsenic-induced apoptosis with vanadium-enhanced ferroptosis, this approach provides a mechanistic framework to overcome TNBC immunosuppression through coordinated cell death pathways, demonstrating potential for precision nanomedicine applications.

USP30 Aggravating the Malignant Progression of Breast Cancer and Its Resistance to Tamoxifen by Inhibiting the Ubiquitination of TOMM40

Breast cancer (BC) is the most common malignancy among women, with high incidence and mortality rates globally. Translocase of outer mitochondrial membrane 40 (TOMM40) has also been identified as an important prognostic biomarker for BC. Meanwhile, the ubiquitin-specific protease 30 (USP30) has also been shown to promote BC progression. However, the specific mechanisms underlying the role of USP30/TOMM40 in BC development remain unclear. Therefore, this study aims to delve into the potential mechanisms of USP30/TOMM40 in the progression of BC. The expression of TOMM40 and USP30 in BC tumors and cells was verified by bioinformatics analysis and western blot (WB). The effects of USP30/TOMM40 on BC cell proliferation, angiogenesis, glycolysis, and ferroptosis were determined by colony formation, tube formation assays and commercial kits. The co-immunoprecipitation (Co-IP) experiment was applied to verify the interaction between USP30 and TOMM40. The ubiquitination level of TOMM40 was detected by ubiquitinated antibodies. The effect of tamoxifen (TAM) on BC cell viability was measured by MTT assay. TOMM40 and USP30 were highly expressed in BC tumors and cells. Silencing TOMM40 blocked the proliferation, angiogenesis, glycolytic, and induced ferroptosis of BC cells. USP30 bound to TOMM40 and reduced its ubiquitination level. TOMM40 overexpressed abolished the tumor suppressive effect of USP30 knockdown and enhanced the resistance of BC to TAM. In conclusion, USP30 deubiquitinating TOMM40 promoted BC development and TAM resistance.

Role, mechanisms and effects of Radix Bupleuri in anti‑breast cancer (Review)

The prevalence of breast cancer among women has led to a growing need for innovative anti-breast cancer medications and an in-depth investigation into their molecular mechanisms of action, both of which are essential tactics in clinical intervention. In the clinical practice of Traditional Chinese Medicine, Radix Bupleuri and its active components have shown promise as potential anti-breast cancer agents due to their ability to target multiple pathways, exhibit synergistic effects and reduce toxicity. These compounds are considered to enhance the prognosis of patients with cancer, prolong survival and combat chemotherapy resistance. The present review aimed to delve into the anti-breast cancer properties of Radix Bupleuri and its active ingredients, highlighting their mechanisms, such as inhibition of cell proliferation, promotion of apoptosis, metastasis prevention, microenvironment improvement and synergy with certain chemotherapeutic agents. These findings may provide a scientific rationale for combining Radix Bupleuri and its active components with traditional chemotherapy agents for the management of breast cancer.

Nuclear to Cytoplasmic Transport Is a Druggable Dependency in HDAC7-driven Small Cell Lung Cancer

Immunotherapy has gained approval for use in small cell lung cancer (SCLC), yet only a subset of patients (10-20%) experience meaningful benefits, underscoring the urgent need for more effective therapeutic approaches. This work discovers a distinct HDAC7-high SCLC phenotype characterized by enhanced proliferative potential, which recurs across various subtypes and serves as a predictor of poorer survival outcomes. By analyzing public datasets, this work finds a strong correlation between c-Myc and HDAC7. RNA sequencing and cellular experiments show that XPO1 is a key regulator in the HDAC7/c-Myc axis. HDAC7 promotes β-catenin deacetylation, phosphorylation modulation, nuclear translocation, and formation of the β-catenin/TCF/LEF1 complex, which binds to c-Myc and XPO1 promoters. Activation of the HDAC7/β-catenin pathway upregulates c-Myc and XPO1 expression, while c-Myc also boosts XPO1 expression. Given the difficulty in targeting c-Myc directly, this work tests selinexor and vorinostat in SCLC xenograft models, with selinexor showing superior results. High HDAC7 expression is linked to increased SCLC proliferation, poorer prognosis, and enhanced sensitivity to selinexor in SCLC cell lines and organoid models. Collectively, this work uncovers a novel HDAC7/c-Myc/XPO1 signaling axis that promotes SCLC progression, suggesting that HDAC7 may warrant further investigation as a potential biomarker for assessing selinexor sensitivity in SCLC patients.

Functions and mechanisms of non-histone post-translational modifications in cancer progression

Protein post-translational modifications (PTMs) refer to covalent and enzymatic alterations to folded or nascent proteins during or after protein biosynthesis to alter the properties and functions of proteins. PTMs are modified in a variety of types and affect almost all aspects of cell biology. PTMs have been reported to be involved in cancer progression by influencing multiple signaling pathways. The mechanism of action of histone PTMs in cancer has been extensively studied. Notably, evidence is mounting that PTMs of non-histone proteins also play a vital role in cancer progression. In this review, we provide a systematic description of main non-histone PTMs associated with cancer progression, including acetylation, lactylation, methylation, ubiquitination, phosphorylation, and SUMOylation, based on recent studies.

Distribution, metabolism, and excretion of [14C] purinostat mesylate, a novel selective HDAC I/IIb inhibitor, in rats analyzed by high-performance liquid chromatography coupled with LTQ orbitrap mass spectrometry/radioactivity monitoring

Purinostat Mesylate (PM) is a novel and highly efficient selective histone deacetylase (HDAC) I/IIb inhibitor for hematologic tumor treatment that was granted Investigational New Drug (IND) approval for clinical investigation by the National Medical Products Administration and is currently in phase IIb clinical trials for relapsed/refractory diffuse large B-cell lymphoma. In this paper, the excretion, distribution, and metabolism properties of this IND were researched by High-Performance Liquid Chromatography coupled with LTQ Orbitrap Mass Spectrometry/Radioactivity Monitoring (HPLC-LTQ-Orbitrap-MS/RAM) and liquid scintillation counting. Following a single intravenous dose of [14C] PM to rats, a total of 98.49 % of the dose was recovered from intact rats within 0-168 h post-dose, with 14.16 % in urine and 83.15 % in feces, most of which was recovered within the first 24 h post-dose. For bile duct cannulated rats, a total of 95.54 % of the dose was recovered, with 62.37 % in bile, 23.37 % in urine and 8.58 % in feces within 0-72 h post-dose, suggesting that [14C] PM was excreted mainly into feces via biliary excretion. [14C] PM was distributed widely and eliminated rapidly throughout the body, with the lung, liver, kidney and intestine as the main organs. Interestingly, slow elimination was observed in the spleen, which could benefit the functional restoration of the spleen in hematological tumors. In terms of metabolism, [14C] PM underwent an extensive metabolic transformation in rats. Fourteen metabolites were tentatively identified, with major phase I metabolic pathways encompassing reduction, N-dealkylation, and oxidative deamination. Concomitantly, the primary phase II metabolic routes involved acetylation and glucuronic acid conjugation. This study was the first comprehensive PM pharmacokinetic study utilizing [14C] isotope labeling technology.

Potential role of lactylation in intrinsic immune pathways in lung cancer

Lung cancer, one of the most lethal malignancies, has seen its therapeutic strategies become a focal point of significant scientific attention. Intrinsic immune signaling pathways play crucial roles in anti-tumor immunity but face clinical application challenges despite promising preclinical outcomes. Lactylation, an emerging research focus, may influences lung cancer progression by modulating the functions of histones and non-histone proteins. Recent findings have suggested that lactylation regulates key intrinsic immune molecules, including cGAS-STING, TLR, and RIG-I, thereby impacting interferon expression. However, the precise mechanisms by which lactylation governs intrinsic immune signaling in lung cancer remain unclear. This review presents a comprehensive and systematic analysis of the relationship between lactylation and intrinsic immune signaling pathways in lung cancer and emphasizes the innovative perspective of linking lactylation-mediated epigenetic modifications with immune regulation. By thoroughly examining current research findings, this review uncovers potential regulatory mechanisms and highlights the therapeutic implications of targeting lactylation in lung cancer. Future investigations into the intricate interactions between lactylation and intrinsic immunity are anticipated to unveil novel therapeutic targets and strategies, potentially improving patient survival outcomes.

Signaling pathway dysregulation in breast cancer

This article provides a comprehensive analysis of the signaling pathways implicated in breast cancer (BC), the most prevalent malignancy among women and a leading cause of cancer-related mortality globally. Special emphasis is placed on the structural dynamics of protein complexes that are integral to the regulation of these signaling cascades. Dysregulation of cellular signaling is a fundamental aspect of BC pathophysiology, with both upstream and downstream signaling cascade activation contributing to cellular process aberrations that not only drive tumor growth, but also contribute to resistance against current treatments. The review explores alterations within these pathways across different BC subtypes and highlights potential therapeutic strategies targeting these pathways. Additionally, the influence of specific mutations on therapeutic decision-making is examined, underscoring their relevance to particular BC subtypes. The article also discusses both approved therapeutic modalities and ongoing clinical trials targeting disrupted signaling pathways. However, further investigation is necessary to fully elucidate the underlying mechanisms and optimize personalized treatment approaches.

Mammalian Species-Specific Resistance to Mammary Cancer

Tumorigenesis in mammals is driven by inherited genetic variants, environmental factors and random errors during normal DNA replication that lead to cancer-causing mutations. These factors initiate uncontrolled cellular proliferation and disrupt the regulation of critical checkpoints. A few mammalian species possess unique protective mechanisms that enable them to resist widespread cancer development and achieve longevity. Tissue-specific tumor protection adds another layer of complexity to this diversity. Breast cancer is a leading cause of human mortality, particularly among females. Driven by the need for new strategies in treatment and prevention, this opinion article explores and supports the idea that herbivores are more resistant to mammary cancer than carnivores and omnivores. This diversity has occurred despite the remarkably similar basic mammary biology. Herbivores' meatless diet cannot explain the differences in cancer resistance, which have accompanied species segregation since the Jurassic era. To investigate the causes of this diversity, the characteristics of tumorigenesis in the human breast-and to a lesser extent in other carnivores-have been compared with data from retrospective analyses of bovine mammary tumor development across various locations over the past century. Well-established genomic, cellular, and systemic triggers of breast cancer exhibit different, or less pronounced tissue-specific activity in the bovine mammary gland, accompanied by novel bovine-specific protective mechanisms. Together, these factors contribute to the near absence of breast cancer in bovines and offer a basis for developing future anticancer strategies.

Epigenetic Landscapes of Aging in Breast Cancer Survivors: Unraveling the Impact of Therapeutic Interventions-A Scoping Review

Breast cancer therapies have dramatically improved survival rates, but their long-term effects, especially on aging survivors, need careful consideration. This review delves into how breast cancer treatments and aging intersect, focusing on the epigenetic changes triggered by chemotherapy, radiation, hormonal treatments, and targeted therapies. Treatments can speed up biological aging by altering DNA methylation, histone modifications, and chromatin remodeling, affecting gene expression without changing the DNA sequence itself. The review explains the double-edged sword effect of therapy-induced epigenetic modifications, which help fight cancer but also accelerate aging. Chemotherapy and targeted therapies, in particular, impact DNA methylation and histone modifications, promoting chronic inflammation and shortening telomeres. These changes increase biological age, as seen in epigenetic clocks and biomarkers like p21, which also play roles in drug resistance and therapeutic decisions. Chronic inflammation, driven by higher levels of inflammatory cytokines such as TNF-α and IL-6 as well as telomere shortening, significantly contributes to the aging characteristics of breast cancer survivors. Non-coding RNAs, including microRNAs and long non-coding RNAs, are crucial in regulating gene expression and aging pathways altered by these treatments. This review explores new therapies targeting these epigenetic changes, like DNA methylation inhibitors, histone deacetylase inhibitors, and microRNA-based treatments, to reduce the aging effects of cancer therapy. Non-drug approaches, such as dietary changes and lifestyle modifications, also show promise in combating therapy-induced aging. It also highlights the clinical signs of aging-related side effects, such as heart and lung problems, endocrine and reproductive issues, and reduced quality of life. The development of comprehensive methods like the CHEMO-RADIAT score to predict major cardiovascular events after therapy is discussed. Understanding the epigenetic changes caused by breast cancer therapies offers valuable insights for creating interventions to enhance the health span and quality of life for survivors. Continued research is crucial to fully understand these epigenetic alterations and their long-term health impacts.

The role of cyclin dependent kinase molecules in the pathogenesis and immune cell infiltration of TNBC in silicosis: Based on core stem cell related genes TPX2 and CCNA2

Silicosis is a pulmonary fibrotic disease caused by long-term inhalation of silica dust. CDKs regulate the process of cell cycle by binding with cyclin. This study revealed the role of cyclin-dependent kinase molecules in the pathogenesis of TNBC in silicosis and analyzed its influence on immune cell infiltration. By retrospective analysis of clinical samples from silicosis patients and TNBC patients, we evaluated the expression level of CDKs molecules. Then, the effect of silica dust exposure on breast cancer cell cycle was simulated using in vitro cell culture technology, and the expression changes of TPX2 and CCNA2 genes were observed. Immunohistochemical techniques were used to detect the infiltration of immune cells in silicosis and TNBC tissue samples, and to analyze its correlation with the expression of CDKs. The findings from the conducted research indicated that there was a significant elevation in the expression levels of cyclin-dependent kinases, or CDKs, in patients diagnosed with silicosis as well as those with triple-negative breast cancer, or TNBC. Through immunohistochemical analysis, it was further revealed that there was an increased infiltration of immune cells within the tissues of both silicosis and TNBC patients. Interestingly, this infiltration of immune cells was found to be positively correlated with the expression levels of CDK molecules. The up-regulated expression of the TPX2 and CCNA2 genes is believed to be associated with abnormal regulation of the cell cycle, which in turn affects the infiltration patterns of immune cells within the affected tissues.

FOXF2 expression triggered by endocrine therapy orchestrates therapeutic resistance through reorganization of chromatin architecture in breast cancer

Patients with estrogen receptor-positive (ER+) breast cancer require long-term endocrine therapy. However, endocrine resistance remains a critical issue to be addressed. Herein, we show that ERα repressed FOXF2 transcription in ER+ breast cancer through facilitating H3K27me3 deposition around its genomic locus, therefore endocrine therapy triggered FOXF2 transcription via loss of H3K27me3. FOXF2 transactivation orchestrated endocrine resistance and bone metastasis. Mechanistically, FOXF2 acted as a pioneer factor to globally activate enhancers of genes involved in epithelial-mesenchymal transition/epithelial-osteogenic transition, as well as super-enhancers of NCOA3 (a coactivator of FOXF2) and SP1 (an upstream transactivator of FOXF2) by recruitingSMARCC1 that mediates the reorganization of chromatin architecture. Additionally, FOXF2 expression levels in the tumors of ER+ breast cancer predicted response to endocrine therapeutic drugs and the outcome of patients. Targeting BRD4, an essential transcriptional coactivator of FOXF2, significantly inhibited FOXF2-orchestrated endocrine resistance and bone metastasis. Our findings uncover a crucial mechanism underlying endocrine resistance and provide a promising strategy for managing endocrine-resistant breast cancer.

A promising future for breast cancer therapy with hydroxamic acid-based histone deacetylase inhibitors

Histone deacetylases (HDACs) play a critical role in chromatin remodelling and modulating the activity of various histone proteins. Aberrant HDAC functions has been related to the progression of breast cancer (BC), making HDAC inhibitors (HDACi) promising small-molecule therapeutics for its treatment. Hydroxamic acid (HA) is a significant pharmacophore due to its strong metal-chelating ability, HDAC inhibition properties, MMP inhibition abilities, and more. They were found to increase the efficacy of the approved drugs when used in combination. In this review we presented bioinformatic analysis using available data from the Cancer Genome Atlas and Genotype-Tissue Expression databases, outlined the recent advancements in the application of HA-based HDACi for BC during preclinical investigation and clinical trials, tried to offer the rationale for targeting HDAC in BC with HA-based HDACi, summarised the challenges faced in the successful clinical application of HDACi, and proposed potential strategies to address these challenges, aiming to enhance treatment outcomes in BC. Abbreviations: ABCG2, ATP-binding cassette super-family G member 2; ABC, ATP-binding cassette; ADP, Adenosine diphosphate; APC, Antigen presenting cell; AML, Acute myeloid leukemia; ARH1, Aplysia ras homolog 1; BCRP, Breast cancer resistance protein; BRCA, Breast invasive carcinoma; Bax, B-cell lymphoma associated X; CK5, Cytokeratin 5; CK14, Cytokeratin 14; CK17, Cytokeratin 17; CoRESTMiDAC, Co-repressor for element-1-silencing transcription factor; CRM1, Chromosomal maintenance 1; CTCL, Cutaneous T-cell lymphoma; DNMT, DNA methyltransferase; DFS, Disease-free survival; ER, Oestrogen receptor; EMT, Epithelial-mesenchymal transition; FGFR1, Fibroblast growth factor receptor 1; GEPIA, Gene Expression Profiling Interactive Analysis; GTEx, Genotype tissue expression; HAT, Histone acetylase; HDAC, Histone deacetylase; HDF, Human dermal fibroblast; HER2, Human epidermal growth factor receptor 2; HDLP, Histone deacetylase-like protein; Hsp90, Heat shock protein 90; HSF1, Heat shock factor 1; HeLa, Henrietta Lacks; HER1, Human epidermal growth factor receptor 1; IARC, International Agency for Research on Cancer; IL-10, Interleukin-10; KAP1, KRAB associated protein 1; MDM2, Mouse double minute 2 homolog; MDR, Multidrug resistance; MCF-7, Michigan cancer foundation-7; MEF-2, Myocyte enhancer factor-2MMP- Matrix metalloproteinase; NAD, Nicotinamide adenine dinucleotide; NuRD, Nucleosome remodelling and deacetylation; NF- κ B, Nuclear factor kappa light chain enhancer of activated B cell; NES, Nuclear export signal; NLS, Nuclear localization signal; NCoR, Nuclear receptor corepressor; NCT, National clinical trial; OS, Overall survival; PR, Progesterone receptor; PI3K, Phosphoinositide 3-kinase; PAX3, Paired box gene 3; P-gp, P-glycoprotein; ROS, Reactive oxygen species; SIRT, Sirtuin; SMRT, Silencing mediator for retinoid and thyroid receptor; STAT3, Signal transducer and activator of transcription-3; SAR, Structure-activity relationship; SHP1, Src homology region 2 domain-containing phosphatase 1; SAHA, Suberoylanilide hydroxamic acid; SMEDDS, Self micro emulsifying drug delivery system; TNBC, Triple-negative breast cancer; TSA, Trichostatin A; ZBG, Zinc binding group.

Expression and clinical significance of CCN5 and the oestrogen receptor in advanced breast cancer

PURPOSE

The aim of this study was to investigate the expression and clinical implications of CCN family member 5 (CCN5) and the oestrogen receptor (ER) in advanced breast cancer (BC).

METHODS

A total of 130 patients with advanced BC were selected for the study. Samples of normal breast tissue, ductal carcinoma in situ (DCIS), and invasive carcinoma were collected. The expression levels of CCN5 and ER in these tissues were examined using immunohistochemical methods. The correlation between expression of CCN5 and ER in different tissues and also differences in expression in invasive carcinoma were analysed. In addition, the relationship between CCN5 expression in advanced BC tissues and clinical pathological features was examined.

RESULTS

CCN5 and ER had low expression in normal breast tissues and invasive carcinoma tissues, but high expression in DCIS, with this difference being statistically significant (X2 = 119.899, P < 0.001; X2 = 113.524, P < 0.001, respectively). The expression of CCN5 and ER in different tissues of patients with advanced BC showed a positive correlation. Significant differences were also observed in the positive and negative expression of CCN5 and ER (X2 = 56.358, P < 0.001). Moreover, the expression of CCN5 protein in advanced BC showed a statistically significant associations (P < 0.05) with the expression of the progesterone receptor (PR), human epidermal growth factor receptor 2 (HER-2), Ki-67, and P53, tumor diameter, histological grade, lymph node metastasis, pathological molecular subtype, and clinical staging.

CONCLUSION

High expression of CCN5 and ER was observed in DCIS tissues of patients with advanced BC, with their expression being positively correlated. These findings suggest that CCN5 and ER may have a potential synergistic role in the progression of BC that influences the progression of advanced BC and can also be used to predict the effectiveness of endocrine therapy.

SMYD4 promotes MYH9 ubiquitination through lysine monomethylation modification to inhibit breast cancer progression

BACKGROUND

Breast cancer is the leading cause of female mortality worldwide. (SET And MYND Domain Containing 4) SMYD4 has been reported to be a tumour suppressor. However, the molecular mechanism of SMYD4 remains unclear.

METHODS

The expression level of SMYD4 in breast cancer cells was detected by qRT-PCR and western blot. The effect of SMYD4 was verified in vitro and in vivo. The interaction between SMYD4 and MYH9 was investigated by co‑IP assay. The regulation of SMYD4 on WNT signaling pathway was detected by luciferase reporter assay and ChIP analysis.

RESULTS

This study found that SMYD4 downregulation was associated with poor prognosis. SMYD4 was performed as a tumor suppressor both in vitro and in vivo. SMYD4 was found to interact with the downstream protein MYH9 and impede WNT signaling pathway. Further studies revealed that SMYD4 impeded the binding of MYH9 to the CTNNB1 promoter region by promoting lysine monomethylation and ubiquitination degradation of MYH9.

CONCLUSIONS

These findings reveal the emerging character of SMYD4 in Wnt/β‑catenin signaling and bring new sights of gene interaction. The discovery of this SMYD4/MYH9/CTNNB1/WNT/β-Catenin signalling pathway axis suggests that SMYD4 is a potential therapeutic target for breast cancer.

The Role of the Fox Gene in Breast Cancer Progression

Forkhead box (FOX) genes are a family of transcription factors that participate in many biological activities, from early embryogenesis to the formation of organs, and from regulation of glucose metabolism to regulation of longevity. Given the extensive influence in the multicellular process, FOX family proteins are responsible for the progression of many types of cancers, especially lung cancer, breast cancer, prostate cancer, and other cancers. Breast cancer is the most common cancer among women, and 2.3 million women were diagnosed in 2020. So, various drugs targeting the FOX signaling pathway have been developed to inhibit breast cancer progression. While the role of the FOX family gene in cancer development has not received enough attention, discovering more potential drugs targeting the FOX signaling pathway is urgently demanded. Here, we review the main members in the FOX gene family and summarize their signaling pathway, including the regulation of the FOX genes and their effects on breast cancer progression. We hope this review will emphasize the understanding of the role of the FOX gene in breast cancer and inspire the discovery of effective anti-breast cancer medicines targeting the FOX gene in the future.

Quantitative Analysis of Nonhistone Lysine Methylation Sites and Lysine Demethylases in Breast Cancer Cell Lines

Growing evidence shows that lysine methylation is a widespread protein post-translational modification (PTM) that regulates protein function on histone and nonhistone proteins. Numerous studies have demonstrated that the dysregulation of lysine methylation mediators contributes to cancer growth and chemotherapeutic resistance. While changes in histone methylation are well-documented with extensive analytical techniques available, there is a lack of high-throughput methods to reproducibly quantify changes in the abundances of the mediators of lysine methylation and nonhistone lysine methylation (Kme) simultaneously across multiple samples. Recent studies by our group and others have demonstrated that antibody enrichment is not required to detect lysine methylation, prompting us to investigate the use of tandem mass tag (TMT) labeling for global Kme quantification without antibody enrichment in four different breast cancer cell lines (MCF-7, MDA-MB-231, HCC1806, and MCF10A). To improve the quantification of KDMs, we incorporated a lysine demethylase (KDM) isobaric trigger channel, which enabled 96% of all KDMs to be quantified while simultaneously quantifying 326 Kme sites. Overall, 142 differentially abundant Kme sites and eight differentially abundant KDMs were identified among the four cell lines, revealing cell line-specific patterning.

S-Adenosylmethionine: A Multifaceted Regulator in Cancer Pathogenesis and Therapy

S-adenosylmethionine (SAMe) is a key methyl donor that plays a critical role in a variety of cellular processes, such as DNA, RNA and protein methylation, essential for maintaining genomic stability, regulating gene expression and maintaining cellular homeostasis. The involvement of SAMe in cancer pathogenesis is multifaceted, as through its multiple cellular functions, it can influence tumor initiation, progression and therapeutic resistance. In addition, the connection of SAMe with polyamine synthesis and oxidative stress management further underscores its importance in cancer biology. Recent studies have highlighted the potential of SAMe as a biomarker for cancer diagnosis and prognosis. Furthermore, the therapeutic implications of SAMe are promising, with evidence suggesting that SAMe supplementation or modulation could improve the efficacy of existing cancer treatments by restoring proper methylation patterns and mitigating oxidative damage and protect against damage induced by chemotherapeutic drugs. Moreover, targeting methionine cycle enzymes to both regulate SAMe availability and SAMe-independent regulatory effects, particularly in methionine-dependent cancers such as colorectal and lung cancer, presents a promising therapeutic approach. Additionally, exploring epitranscriptomic regulations, such as m6A modifications, and their interaction with non-coding RNAs could enhance our understanding of tumor progression and resistance mechanisms. Precision medicine approaches integrating patient subtyping and combination therapies with chemotherapeutics, such as decitabine or doxorubicin, together with SAMe, can enhance chemosensitivity and modulate epigenomics, showing promising results that may improve treatment outcomes. This review comprehensively examines the various roles of SAMe in cancer pathogenesis, its potential as a diagnostic and prognostic marker, and its emerging therapeutic applications. While SAMe modulation holds significant promise, challenges such as bioavailability, patient stratification and context-dependent effects must be addressed before clinical implementation. In addition, better validation of the obtained results into specific cancer animal models would also help to bridge the gap between research and clinical practice.

Hematological toxicity of cyclin-dependent kinase 4/6 inhibitors in patients with breast cancer: a network meta-analysis and pharmacovigilance study

OBJECTIVES

We aimed to evaluate and compare the risk of hematological adverse events (AEs) associated with CDK4/6 inhibitors using data from randomized controlled trials (RCTs) and Food and Drug Adverse Event Reporting System (FAERS) database.

METHODS

The PubMed, Embase, and Cochrane Library databases were searched for RCTs related to abemaciclib, palbociclib, and ribociclib. A network meta-analysis (NMA) was conducted to compare the risks of hematological AEs, and a disproportionality analysis was performed to detect signals of hematological AEs.

RESULTS

16 RCTs comprising 16,350 breast cancer patients were included. Palbociclib and ribociclib had similar risks for hematological AEs, except a higher risk of grade 3-4 leukopenia observed with palbociclib (risk ratio [RR]: 7.84, 95% confidence interval [95%CI]: 1.33-41.28). Abemaciclib had a higher risk of anemia than both ribociclib (grade 1-4: RR: 2.23, 95% CI: 1.25 - 3.96; grade 3-4: RR: 3.52, 95% CI: 1.59 - 8.11) and palbociclib (grade 1-4: RR: 1.65, 95%CI: 1.03 - 2.59), but a lower risk of grade 3-4 of both leukopenia (RR: 0.12, 95%CI: 0.02 - 0.49) and neutropenia (RR: 0.15, 95%CI: 0.04 - 0.52) compared with palbociclib. Signals indicating occurrence of leukopenia, neutropenia, anemia, and thrombocytopenia were identified for three CDK4/6 inhibitors.

CONCLUSION

Abemaciclib, palbociclib, and ribociclib showed significant but inconsistent hematological toxicity risks.

Patients with Irritable Bowel Syndrome Exhibit Aberrant Expression of Endogenous Retroviruses and SETDB1

Irritable bowel syndrome (IBS) is a common disease, whose etiopathogenesis is poorly understood. Human endogenous retroviruses (HERVs) originate from ancient infections of germinal cells and represent 8% of our DNA. Most HERVs have become defective due to the accumulated mutations; some can, however, still be activated, and their altered expressions have been associated with a number of chronic inflammatory and immune-mediated disorders, including gastrointestinal diseases. Retroviral transcription is modulated by TRIM28 and SETDB1, which also participate in the regulation of epigenetic mechanisms and in shaping the immune system. Expressions of HERVs and TRIM28/SETDB1 have not been investigated in patients affected by IBS. Using a PCR real-time Taqman amplification assay, we explored the RNA levels of HERV-H-pol, HERV-K-pol, and HERV-W-pol; syncytin 1 (SYN1), SYN2, and HERV-W-env; and TRIM28 and SETDB1 in the peripheral blood of 37 IBS patients and healthy controls (HCs) of similar age. The transcript levels were higher in IBS patients than in HCs for all HERVs except for HERV-W-pol, with significant p-values for HERV-H-pol, HERV-K-pol, and SYN1 and borderline p-values for SYN2 and HERV-W-env. The RNA levels of SETDB1 were significantly enhanced in IBS patients, while those of TRIM28 were in the normal range. Patients with severe disease had significant upregulation of SETDB1 compared to those with mild or moderate symptoms. These findings suggest that overexpression of HERVs and SETDB1 may contribute to the development of IBS and open the way to innovative therapeutic strategies.

Immunohistochemical Profiling of Histone Modification Biomarkers Identifies Subtype-Specific Epigenetic Signatures and Potential Drug Targets in Breast Cancer

Breast cancer (BC) subtypes exhibit distinct epigenetic landscapes, with triple-negative breast cancer (TNBC) lacking effective targeted therapies. This study investigates histone biomarkers and therapeutic vulnerabilities across BC subtypes. The immunohistochemical profiling of >20 histone biomarkers, including histone modifications, modifiers, and oncohistone mutations, was conducted on a discovery cohort and a validation cohort of BC tissues, healthy controls, and cell line models. Transcriptomic and cell growth analyses were conducted to evaluate the effects of the small-molecule G9a inhibitor in diverse BC models. Key histone biomarkers, including H3K9me2, H3K36me2, and H3K79me, were differentially expressed across BC subtypes. H3K9me2 emerged as an independent predictor for distinguishing TNBC from other less-aggressive BC subtypes, with elevated expression correlating with higher tumor grade and stage. G9a inhibition impaired cell proliferation and modulated epithelial-mesenchymal transition pathways, with the strongest impact in basal-like TNBC. The disruption of the oncogene and tumor suppressor regulation (e.g., TP53, SATB1) was observed in TNBC. This study highlights G9a's context-dependent roles in BC, supporting its potential as a therapeutic target. The findings provide a foundation for subtype-specific epigenetic therapies to improve outcomes in aggressive BC subtypes.

Molecular Insights on Signaling Cascades in Breast Cancer: A Comprehensive Review

The complex signaling network within the breast tumor microenvironment is crucial for its growth, metastasis, angiogenesis, therapy escape, stem cell maintenance, and immunomodulation. An array of secretory factors and their receptors activate downstream signaling cascades regulating breast cancer progression and metastasis. Among various signaling pathways, the EGFR, ER, Notch, and Hedgehog signaling pathways have recently been identified as crucial in terms of breast cancer proliferation, survival, differentiation, maintenance of CSCs, and therapy failure. These receptors mediate various downstream signaling pathways such as MAPK, including MEK/ERK signaling pathways that promote common pro-oncogenic signaling, whereas dysregulation of PI3K/Akt, Wnt/β-catenin, and JAK/STAT activates key oncogenic events such as drug resistance, CSC enrichment, and metabolic reprogramming. Additionally, these cascades orchestrate an intricate interplay between stromal cells, immune cells, and tumor cells. Metabolic reprogramming and adaptations contribute to aggressive breast cancer and are unresponsive to therapy. Herein, recent insights into the novel signaling pathways operating within the breast TME that aid in their advancement are emphasized and current developments in practices targeting the breast TME to enhance treatment efficacy are reviewed.

Targeting histone acetylation to overcome drug resistance in the parasite Trichomonas vaginalis

Trichomoniasis, caused by the parasite Trichomonas vaginalis, is the most common non-viral sexually transmitted infection. Current treatment relies exclusively on 5-nitroimidazole drugs, with metronidazole (MTZ) as the primary option. However, the increasing prevalence of MTZ-resistant strains poses a significant challenge, particularly in the current absence of alternative therapies. Several studies have revealed that the development of metronidazole resistance in T. vaginalis is linked to genomic and transcriptional alterations. Given the role of epigenetic regulation in controlling gene expression, we investigated whether targeting histone deacetylase (HDAC) enzymes could influence drug resistance. Treatment of an MTZ-resistant strain (B7268) with the HDAC inhibitor, trichostatin A (TSA), in combination with MTZ enhanced drug sensitivity and induced significant genome-wide transcriptional changes, as revealed by RNA-seq analysis. To identify drug-related genes epigenetically silenced in the resistant strain but highly active in a sensitive strain, we compared the expression levels of the genes affected by TSA and MTZ treatment with their baseline expression profiles in both resistant and sensitive strains. This analysis identified 130 candidate genes differentially expressed in the sensitive strain NYH209, less expressed in the resistant B7268 strain, that exhibited significant expression changes upon TSA and MTZ treatment. Functional validation involved transfecting the B7268 strain with plasmids encoding four individual candidate genes: a thioredoxin reductase (TrxR), a cysteine synthase (CS), and two genes containing Myb domains (Myb5 and Myb6). Overexpression of three of these genes resulted in a marked reduction in MTZ resistance, demonstrating their role in modulating drug sensitivity. Our findings identified three novel genes that modulate drug resistance in T. vaginalis. This study reveals a previously unknown epigenetic mechanism underlying drug resistance and highlights the therapeutic potential of targeting epigenetic factors, such as HDACs, to overcome resistance and improve treatment efficacy.

Clinical significance of lipid pathway-targeted therapy in breast cancer

Globally, breast cancer represents the most common cancer and the primary cause of death by cancer in women. Lipids are crucial in human physiology, serving as vital energy reserves, structural elements of biological membranes, and essential signaling molecules. The metabolic reprogramming of lipid pathways has emerged as a critical factor in breast cancer progression, drug resistance, and patient prognosis. In this study, we delve into the clinical implications of lipid pathway-targeted therapy in breast cancer. We highlight key enzymes and potential therapeutic targets involved in lipid metabolism reprogramming, and their associations with cancer progression and treatment outcomes. Furthermore, we detail the clinical trials exploring the anticancer and cancer chemopreventive activity of therapies targeting these molecules. However, the clinical efficacy of these therapies remains controversial, highlighting the urgent need for predictive biomarkers to identify patient subpopulations likely to benefit from such treatment. We propose the Selective Lipid Metabolism Therapy Benefit Hypothesis, emphasizing the importance of personalized medicine in optimizing lipid pathway-targeted therapy for breast cancer patients.

Drug response-based precision therapeutic selection for tamoxifen-resistant triple-positive breast cancer

Breast cancer adaptability to the drug environment reduces the chemotherapeutic response and facilitates acquired drug resistance. Cancer-specific therapeutics can be more effective against advanced-stage cancer than standard chemotherapeutics. To extend the paradigm of cancer-specific therapeutics, clinically relevant acquired tamoxifen-resistant MCF-7 proteome was deconstructed to identify possible druggable targets (N = 150). Twenty-eight drug inhibitors were used against identified druggable targets to suppress non-resistant (NC) and resistant cells (RC). First, selected drugs were screened using growth-inhibitory response against NC and RC. Seven drugs were shortlisted for their time-dependent (10-12 days) cytotoxic effect and further narrowed to three effective drugs (e.g., cisplatin, doxorubicin, and hydroxychloroquine). The growth-suppressive effectiveness of selected drugs was validated in the complex spheroid model (progressive and regressive). In the progressive model, doxorubicin (RC: 83.64 %, NC: 54.81 %), followed by cisplatin (RC: 76.66 %, NC: 68.94 %) and hydroxychloroquine (RC: 68.70 %, NC: 61.78 %) showed a significant growth-suppressive effect. However, in fully grown regressive spheroid, after 4th drug treatment, cisplatin significantly suppressed RC (84.79 %) and NC (40.21 %), while doxorubicin and hydroxychloroquine significantly suppressed only RC (76.09 and 76.34 %). Our in-depth investigation effectively integrated the expression data with the cancer-specific therapeutic investigation. Furthermore, our three-step sequential drug-screening approach unbiasedly identified cisplatin, doxorubicin, and hydroxychloroquine as an efficacious drug to target heterogeneous cancer cell populations. SIGNIFICANCE STATEMENT: Hormonal-positive BC grows slowly, and hormonal-inhibitors effectively suppress the oncogenesis. However, development of drug-resistance not only reduces the drug-response but also increases the chance of BC aggressiveness. Further, alternative chemotherapeutics are widely used to control advanced-stage BC. In contrast, we hypothesized that, compared to standard chemotherapeutics, cancer-specific drugs can be more effective against resistant-cancer. Although cancer-specific treatment identification is an uphill battle, our work shows proteome data can be used for drug selection. We identified multiple druggable targets and, using ex-vivo methods narrowed multiple drugs to disease-condition-specific therapeutics. We consider that our investigation successfully interconnected the expression data with the functional disease-specific therapeutic investigation and selected drugs can be used for effective resistant treatment with higher therapeutic response.

hsa-mir-483-3p modulates delayed breast cancer recurrence

Patients with estrogen receptor-positive breast cancer undergoing continuous adjuvant hormone therapy often experience delayed recurrence with tamoxifen use, potentially causing adverse effects. However, the lack of biomarkers hampers patient selection for extended endocrine therapy. This study aimed to elucidate the molecular mechanisms underlying delayed recurrence and identify biomarkers. When miRNA expression was assessed in luminal breast cancer tissues with and without delayed recurrence using NanoString, a significant increase in the expression of miR483-3p was observed in samples from patients with delayed recurrence compared with those without. miR483-3p expression was elevated in tamoxifen resistant (TAMR) EFM19 cells than in non-resistant EFM19 cells. Notably, genes associated with cancer metastasis (AMOTL2, ANKRD1, CTGF, and VEGF) were upregulated in TAMR EFM19 cells, although cell motility and proliferation were reduced. Transfection of miR483-3p mimics into both non-resistant EFM19 and MCF7 cells resulted in increased expression of cancer metastasis-related genes, but decreased proliferation and migration. Given that miR483-3p can bind to the 3'UTR region of O-GlcNAc transferase (OGT) and potentially affect its protein expression, we examined OGT protein levels and found that transfection with miR483-3p mimics selectively reduced OGT expression. Overall, breast cancer cells subjected to long-term hormone therapy displayed elevated miR483-3p expression, reducing motility and dormancy induction via decreased OGT expression. These findings suggest that miR483-3p is a potential biomarker for long-term endocrine therapy.

TBOPP, a DOCK1 Inhibitor, Potentiates Cisplatin Efficacy in Breast Cancer by Regulating Twist-mediated EMT

BACKGROUND

DOCK1 has been reported to be involved in tumor progression and re-sistance.1-(2-(30-(trifluoromethyl)-[1,10-biphenyl]-4-yl)-2-oxoethyl)-5-pyrrolidinylsulfonyl2(1H)- pyridone (TBOPP) is a selective DOCK1 inhibitor; however, the role and molecular mechanisms of DOCK1 and its inhibition in breast cancer (BC) resistance remain poorly understood.

OBJECTIVE

This study aims toinvestigate the underlying mechanisms of DOCK1 in BC resistance.

OBJECTIVE

This study aims toinvestigate the underlying mechanisms of DOCK1 in BC resistance.

METHODS

DOCK1 or Twist siRNA and Twist plasmid were used to explore the function of DOCK1 in vitro experiments. A mouse xenograft model was used for in vivo experiments.

RESULTS

In the present study, we demonstrated that DOCK1 siRNA promoted cisplatin sensitivity in BC cells. Moreover, TBOPP also enhances the therapeutic effect of cisplatin both in vitro and in vivo. Mechanistically, DOCK1 siRNA inhibited EMT. Twist 1 is one of the EMT-inducing transcription factors and is known to induce EMT. To further reveal the effect of DOCK in BC cells, we co-transfected with DOCK1 and Twist1 siRNA to BC cells and found that co-transfection with DOCK1 and Twist siRNA could not further enhance the cisplatin sensitivity of BC cells. Moreover, DOCK1 siRNA failed to reverse the effect of Twist 1 up-regulation.

CONCLUSION

Taken together, these results demonstrate that DOCK1 may function as a potential therapeutic target in BC and that combining cisplatin with TBOPP may provide a promising therapeutic strategy for cisplatin-resistant BC patients.

Histone-acetyl epigenome regulates TGF-β pathway-associated chemoresistance in colorectal cancer

TGF-β signaling pathway has been demonstrated to be closely related to chemoresistance, which is the major cause of recurrence and poor outcome in colorectal cancer (CRC), however, the comprehensive epigenetic landscape that functionally implicates in the regulation of TGF-β pathway-associated chemoresistance has not yet well established in CRC. In our study, chromatin immunoprecipitation sequencing (ChIP-seq) and Western blot were employed to investigate epigenetic modifications for histones in response to TGF-β1 intervene. We found that the activation of the TGF-β pathway was characterized by genome-wide high levels of H3K9ac and H3K18ac. Mechanistically, the activation of the TGF-β signaling pathway leads to the downregulation of the deacetylase HDAC4, resulting in the upregulation of H3K9ac and H3K18ac. Consequently, this cascade induces oxaliplatin chemoresistance in CRC by triggering the anti-apoptotic PI3K/AKT signaling pathway. Our in vivo experiment results confirmed that overexpression of HDAC4 significantly enhances the sensitivity of CRC to oxaliplatin chemotherapy. Moreover, the expression level of HDAC4 was positively correlated with patients' prognosis in CRC. Our data suggest that histone-acetyl modification demonstrates a crucial role in modulating TGF-β pathway-associated chemoresistance in CRC, and HDAC4 would be a biomarker for prognostic prediction and potential therapeutic target for treatment in CRC.

Estimation of Hand Function Impairment in Breast Cancer Survivors with Lymphedema

Breast cancer (BC) is one of the most frequent cancers in women, and breast cancer-related lymphedema (BCRL) is a common side effect of BC treatment. When the lymphatic drainage system is damaged, lymphedema develops, which further exacerbates swelling and leads to pain, an increase in limb circumference, a reduction in joint range of motion, and a decrease in the use of the affected hand for functional tasks. Handgrip strength is essential for performing upper limb functional daily activities. Less is known about the long-term effects of lymphedema on hand function. The objective of the study was estimation of hand function impairment in BC survivors with lymphedema. This study was carried out by randomly selecting 100 out of 1,200 women with lymphedema, aged between 40 and 80 years, and who underwent sentinel lymph node biopsy along with radiotherapy, were included in this study. The handgrip strength was tested using an electronic handheld dynamometer. The functional wrist and hand scales were used to evaluate hand function. The Michigan Hand Outcome Questionnaire (MHQ) was used to evaluate the hand's overall function. A statistical analysis was done using SPSS statistical software (version 23.0). Handgrip strength of the affected hand by BCRL when compared with the unaffected hand was reduced. Functional hand and wrist scale have shown very poor results of the affected hand when compared with the unaffected hand. Majority of participants in the MHQ were unsatisfied with the overall functioning of the hand ( p  < 0.0001). This study concluded that there was significant hand function impairment in BC survivors with lymphedema. BCRL had a negative impact on daily activities of the individual and also affected the mental, emotional, and social aspects. BCRL also had an impact on overall self-reported physical function and quality of life.

Unlocking the epigenetic code: new insights into triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a highly aggressive and clinically challenging subtype of breast cancer, lacking the expression of estrogen receptor (ER), progesterone receptor (PR), and HER2/neu. The absence of these receptors limits therapeutic options necessitating the exploration of novel treatment strategies. Epigenetic modifications, which include DNA methylation, histone modifications, and microRNA (miRNA) regulation, play a pivotal role in TNBC pathogenesis and represent promising therapeutic targets. This review delves into the therapeutic potential of epigenetic interventions in TNBC, with a focus on DNA methylation, histone modifications, and miRNA therapeutics. We examine the role of DNA methylation in gene silencing within TNBC and the development of DNA methylation inhibitors designed to reactivate silenced tumor suppressor genes. Histone modifications, through histone deacetylation and acetylation in particular, are critical in regulating gene expression. We explore the efficacy of histone deacetylase inhibitors (HDACi), which have shown promise in reversing aberrant histone deacetylation patterns, thereby restoring normal gene function, and suppressing tumor growth. Furthermore, the review highlights the dual role of miRNAs in TNBC as both oncogenes and tumor suppressors and discusses the therapeutic potential of miRNA mimics and inhibitors in modulating these regulatory molecules to inhibit cancer progression. By integrating these epigenetic therapies, we propose a multifaceted approach to target the underlying epigenetic mechanisms that drive TNBC progression. The synergistic use of DNA methylation inhibitors, HDACi, and the miRNA-based therapies offers a promising avenue for personalized treatment strategies, aiming to enhance the clinical outcome for patients with TNBC.

Chidamide induces cell cycle arrest via NR4A3/P21 axis upregulation to suppress relapsed and refractory acute myeloid leukemia

(1) Currently, the survival prognosis for patients with relapsed and refractory acute myeloid leukemia (R/R AML) is extremely poor. Therefore, the exploration of novel drugs is imperative to enhance the prognosis of patients with R/R AML. The therapeutic efficacy and mechanism of Chidamide, a novel epigenetic regulatory drug, in the treatment of R/R AML remain unclear.

METHODS

The mechanism of action of Chidamide has been explored in various AML cell lines through various methods such as cell apoptosis, cell cycle analysis, high-throughput transcriptome sequencing, gene silencing, and xenograft models.

RESULTS

Here, we have discovered that chidamide potently induces apoptosis, G0/G1 phase arrest, and mitochondrial membrane potential depolarization in R/R AML cells, encompassing both primary cells and cell lines. Through RNA-seq analysis, we further revealed that chidamide epigenetically regulates the upregulation of differentiation-related pathways while suppressing those associated with cell replication and cell cycle progression. Notably, our screening identified NR4A3 as a key suppressor gene whose upregulation by chidamide leads to P21-dependent cell cycle arrest in the G0/G1 phase.

CONCLUSIONS

We have discovered a novel epigenetic regulatory mechanism of chidamide in the treatment of relapsed and refractory acute myeloid leukemia (R/R AML).

Impact of Structural Racism and Social Determinants of Health on Disparities in Breast Cancer Mortality

The striking ethnic and racial disparities in breast cancer mortality are not explained fully by pathologic or clinical features. Structural racism contributes to adverse conditions that promote cancer inequities, but the pathways by which this occurs are not fully understood. Social determinants of health, such as economic status and access to care, account for a portion of this variability, yet interventions designed to mitigate these barriers have not consistently led to improved outcomes. Based on the current evidence from multiple disciplines, we describe a conceptual model in which structural racism and racial discrimination contribute to increased mortality risk in diverse groups of patients by promoting adverse social determinants of health that elevate exposure to environmental hazards and stress; these exposures in turn contribute to epigenetic and immune dysregulation, thereby altering breast cancer outcomes. Based on this model, opportunities and challenges arise for interventions to reduce racial and ethnic disparities in breast cancer mortality.

Thiouracil and triazole conjugate induces autophagy through the downregulation of Wnt/β-catenin signaling pathway in human breast cancer cells

Autophagy is vital for maintaining cellular homeostasis by breaking down unnecessary organelles and proteins within cells. Its activity varies abnormally in several diseases, including cancer, making it a potential target for therapeutic strategies. The Wnt/β-catenin signaling pathway significantly impacts cancer by stabilizing β-catenin protein and promoting the transcription of its target genes. Therefore, we aimed to identify candidate substances targeting this signaling pathway. We designed and tested a thiouracil conjugate, discovering that TTP-8 had anti-tumor effects on human breast cancer cell lines MCF-7 and MDA-MB231. Our findings showed that TTP-8 upregulated the expression of LC3 protein, a marker of autophagy in breast cancer cells, suggesting that TTP-8 might induce autophagy. Further analysis confirmed an increase in autophagy-related proteins, with consistent results obtained from flow cytometry and confocal microscopy. Interestingly, the induction of LC3 expression by TTP-8 was even more pronounced in MCF-7 and MDA-MB231 cells transfected with β-catenin siRNA. Thus, our research supports the idea that the Wnt/β-catenin signaling pathway influences the regulation of autophagy-related proteins, thereby inducing autophagy. This suggests that TTP-8 could serve as a novel agent for treating breast cancer.

Pyrimidine-triazole-tethered tert-butyl-piperazine-carboxylate suppresses breast cancer by targeting estrogen receptor signaling and β-catenin activation

Several chemotherapeutics against breast cancer are constrained by their adverse effects and chemoresistance. The development of novel chemotherapeutics to target metastatic breast cancer can bring effective clinical outcomes. Many breast cancer patients present with tumors that are positive for estrogen receptors (ERs), highlighting the importance of targeting the ER pathway in this particular subtype. Although selective estrogen receptor modulators (SERMs) are commonly used, their side effects and resistance issues necessitate the development of new ER-targeting agents. In this study, we report that a newly synthesized compound, TTP-5, a hybrid of pyrimidine, triazole, and tert-butyl-piperazine-carboxylate, effectively binds to estrogen receptor alpha (ERα) and suppresses breast cancer cell growth. We assessed the impact of TTP-5 on cell proliferation using MTT and colony formation assays and evaluated its effect on cell motility through wound healing and invasion assays. We further explored the mechanism of action of this novel compound by detecting protein expression changes using Western blotting. Molecular docking was used to confirm the interaction of TTP-5 with ERα. The results indicated that TTP-5 significantly reduced the proliferation of MCF-7 cells by blocking the ERα signaling pathway. Conversely, although it did not influence the growth of MDA-MB-231 cells, TTP-5 hindered their motility by modulating the expression of proteins associated with epithelial-mesenchymal transition (EMT), possibly via the Wnt/β-catenin pathway.

Epigenetic modification of hepatitis B virus infection and related hepatocellular carcinoma

Hepatitis B virus (HBV) infection poses a challenge to global public health. Persistent liver infection with HBV is associated with an increased risk of developing severe liver disease. The complex interaction between the virus and the host is the reason for the persistent presence of HBV and the risk of tumor development. Chronic liver inflammation, integration of viral genome with host genome, expression of HBx protein, and viral genotype are all key participants in the pathogenesis of hepatocellular carcinoma (HCC). Epigenetic regulation in HBV-associated HCC involves complex interactions of molecular mechanisms that control gene expression and function without altering the underlying DNA sequence. These epigenetic modifications can significantly affect the onset and progression of HCC. This review summarizes recent research on the epigenetic regulation of HBV persistent infection and HBV-HCC development, including DNA methylation, histone modification, RNA modification, non-coding RNA, etc. Enhanced knowledge of these mechanisms will offer fresh perspectives and potential targets for intervention tactics in HBV-HCC.

Epigenetic modifications involving ncRNAs in digestive system cancers: focus on histone modification

In recent years, epigenetic modifications have been strongly linked to tumor development, with histone modifications representing a key epigenetic mechanism. In addition, non-coding RNAs (ncRNAs) play a critical role in regulating cancer-related pathways. The abnormal interaction between histone modifications and ncRNAs, both pivotal epigenetic regulators, has been widely observed across various cancer types. Here, we systematically explore the molecular mechanisms through which histone modifications and ncRNAs contribute in the pathogenesis of digestive system cancers, and aberrant ncRNA-mediated histone modifications manipulate various biological behaviors of tumor cells including proliferation, migration, angiogenesis, etc. In addition, we provide new insights into diagnostic, prognostic markers, therapeutic targets and chemoradiation resistance for digestive system cancers from the epigenetic perspective.

A bidirectional Mendelian randomization analysis of the causal relationship between inflammatory bowel disease and breast cancer based on estrogen receptor status

The incidence of patients diagnosed with either breast cancer (BC) or inflammatory bowel disease (IBD) is increasing each year. IBD has been shown to be strongly associated with the development of a variety of solid tumors, but the relationship with breast cancer is not yet definitive. We explored the causative relationship between IBD and BC using a Mendelian randomization (MR) strategy. MR-Egger regression, weighted median (WM), simple median (SM), maximum likelihood (ML), and inverse variance weighting (IVW) methods were among the analytical techniques used in this work. The examination of heterogeneity was conducted by the use of Cochran's Q test and Rucker's Q test. The sensitivity analysis in this study used the IVW and MR-Egger methodologies. The results of our investigation suggested that IBD had a beneficial impact on estrogen receptor-negative (ER-) breast cancer (odds ratio (OR) = 0.92, P = 0.02). The study did not find a significant association between IBD and the risk of developing overall breast cancer (OR = 0.99, P = 0.60), as well as estrogen receptor-positive (ER+) breast cancer (OR = 1.02, P = 0.60) specifically. In addition, our study findings indicated that there was a detrimental association between ER+ breast cancer and IBD as determined using reverse MR analysis (OR = 1.07, P = 0.04). Furthermore, this analysis failed to observe any significant association between overall breast cancer (OR = 1.07, P = 0.07) or ER- breast cancer (OR = 0.99, P = 0.89) and IBD. Our bidirectional MR study yielded a correlation between IBD and some specific hormone receptor status of BC.

Abemaciclib increases the risk of venous thromboembolism in breast cancer: Integrate meta-analysis, pharmacovigilance database analysis, and in vitro validation

BACKGROUND

Recently, cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) have emerged as a novel treatment strategy for breast cancer. However, increasing reports of CDK4/6i-associated venous thromboembolism (VTE) have garnered attention. This study assessed CDK4/6i-associated VTE in breast cancer, and examined the effect of CDK4/6i on platelet/coagulation function for the first time in vitro.

METHODS

PubMed and Embase databases were searched for studies published from the establishment of the database to December 31, 2022 for randomized controlled trials (RCTs) and real-world studies of CDK4/6i in patients with breast cancer, and the data obtained from the included studies were used for meta-analysis. A disproportionality analysis by extracting adverse drug reaction signals of CDK4/6i-associated VTE from the FDA Adverse Event Reporting System (FAERS) database was also conducted. Additionally, the in vitro effect of CDK4/6i on platelet function was assessed based on platelet aggregation tests and flow cytometry, and coagulation function was assessed based on the blood clotting function test.

FINDINGS

A total of 16,903 patients in 13 RCTs and 6,490 patients in 9 real-world studies were included in the meta-analysis. In RCTs, VTE occurred in 193 (2.1 %) and 55 (0.7 %) patients in the CDK4/6i and control groups, respectively. In real-world studies, the aggregate incidence rate of VTE was 4.2 % (95 % CI: 2.1, 6.3). The meta-analysis of RCTs revealed that abemaciclib (Odds ratio [OR]: 4.40 [95 % CI: 2.74,7.05], p < 0.001) and palbociclib (OR: 2.35 [95 % CI: 1.34, 4.12], p < 0.01) significantly increased the risk of VTE in patients with breast cancer compared to placebo. FAERS database analysis revealed that abemaciclib (reporting odds ratio [ROR]: 1.63 [95 % CI: 1.36, 1.97]; IC025: 0.67) and ribociclib (ROR: 1.17 [95 % CI: 1.0, 1.39]; IC025: 0.18) demonstrated a significantly increased signal of VTE. Similarly, findings from in vitro experiments demonstrated that abemaciclib enhanced agonist-induced platelet activation, especially when collagen was used as the inducer, and this effect became more prominent with increasing its concentration.

INTERPRETATION

Use of abemaciclib may increase the risk of VTE in patients with breast cancer, which may be partially attributed to the effect of abemaciclib on platelet function. Close monitoring of VTE occurrence is highly recommended while using abemaciclib, especially in patients at a high risk of VTE.

The Biological Roles of ZKSCAN3 (ZNF306) in the Hallmarks of Cancer: From Mechanisms to Therapeutics

ZKSCAN3 (also known as ZNF306) plays a pivotal role in the regulation of various cellular processes that are fundamental to the development of cancer. It has been widely acknowledged as a key contributor to cancer progression, with its overexpression consistently reported in a broad spectrum of malignancies. Importantly, clinical studies have demonstrated a significant association between elevated ZKSCAN3 levels and adverse prognosis, as well as resistance to therapeutic drugs. Specifically, ZKSCAN3 promotes tumor progression by enhancing multiple hallmark features of cancer and promoting the acquisition of cancer-specific phenotypes. These effects manifest as increased tumor cell proliferation, invasion, and metastasis, accompanied by inhibiting tumor cell apoptosis and modulating autophagy. Consequently, ZKSCAN3 emerges as a promising prognostic marker, and targeting its inhibition represents a potential strategy for anti-tumor therapy. In this review, we provide an updated perspective on the role of ZKSCAN3 in governing tumor characteristics and the underlying molecular mechanisms. Furthermore, we underscore the clinical relevance of ZKSCAN3 and its potential implications for tumor prognosis and therapeutic strategies.

FANCI Inhibition Induces PARP1 Redistribution to Enhance the Efficacy of PARP Inhibitors in Breast Cancer

Breast cancer is a global public health concern with high mortality rates, necessitating the development of innovative treatment strategies. PARP inhibitors have shown efficacy in certain patient populations, but their application is largely limited to cancers with homologous recombination deficiency. Here, we identified the suppression of FANCI as a therapeutic strategy to enhance the efficacy of PARP inhibitors in breast cancer. Elevated FANCI expression in breast cancer was associated with poor prognosis and increased cell proliferation and migration. FANCI interacted with PARP1, and suppressing FANCI limited the nuclear localization and functionality of PARP1. Importantly, FANCI inhibition sensitized breast cancer cells to the PARP inhibitor talazoparib in the absence of BRCA mutations. Additionally, the CDK4/6 inhibitor palbociclib enhanced the sensitivity of breast cancer cells to talazoparib through FANCI inhibition. These findings highlight the potential of targeting FANCI to enhance the efficacy of PARP inhibitors in treating breast cancer. Significance: Targeting FANCI is a promising therapeutic strategy for enhancing PARP inhibitor sensitivity in breast cancer that holds potential for broader therapeutic applications beyond cancers harboring BRCA mutations.

Recent advancements in small interfering RNA based therapeutic approach on breast cancer

Breast cancer (BC) is the most common and malignant tumor diagnosed in women, with 2.9 million cases in 2023 and the fifth highest cancer-causing mortality worldwide. Recent developments in targeted therapy options for BC have demonstrated the promising potential of small interfering RNA (siRNA)-based cancer therapeutic approaches. As BC continues to be a global burden, siRNA therapy emerges as a potential treatment strategy to regulate disease-related genes in other types of cancers, including BC. siRNAs are tiny RNA molecules that, by preventing their expression, can specifically silence genes linked to the development of cancer. In order to increase the stability and effectiveness of siRNA delivery to BC cells, minimize off-target effects, and improve treatment efficacy, advanced delivery technologies such as lipid nanoparticles and nanocarriers have been created. Additionally, combination therapies, such as siRNAs that target multiple pathways are used in conjunction with conventional chemotherapy agents, have shown synergistic effects in various preclinical studies, opening up new treatment options for breast cancer that are personalized and precision medicine-oriented. Targeting important genes linked to BC growth, metastasis, and chemo-resistance has been reported in BC research using siRNA-based therapies. This study reviews recent reports on therapeutic approaches to siRNA for advanced treatment of BC. Furthermore, this review evaluates the role and mechanisms of siRNA in BC and demonstrates the potential of exploiting siRNA as a novel target for BC therapy.

Design, Synthesis, and Biological Evaluation of HDAC Inhibitors Containing Natural Product-Inspired N-Linked 2-Acetylpyrrole Cap

Drawing inspiration from the structural resemblance between a natural product N-(3-carboxypropyl)-2-acetylpyrrole and phenylbutyric acid, a pioneer HDAC inhibitor evaluated in clinical trials, we embarked on the design and synthesis of a novel array of HDAC inhibitors containing an N-linked 2-acetylpyrrole cap by utilizing the pharmacophore fusion strategy. Among them, compound 20 exhibited potential inhibitory activity on HDAC1, and demonstrated notable potency against RPMI-8226 cells with an IC50 value of 2.89 ± 0.43 μM, which was better than chidamide (IC50 = 10.23 ± 1.02 μM). Western blot analysis and Annexin V-FTIC/propidium iodide (PI) staining showed that 20 could enhance the acetylation of histone H3, as well as remarkably induce apoptosis of RPMI-8226 cancer cells. The docking study highlighted the presence of a hydrogen bond between the carbonyl oxygen of the 2-acetylpyrrole cap group and Phe198 of the HDAC1 enzyme in 20, emphasizing the crucial role of introducing this natural product-inspired cap group. Molecular dynamics simulations showed that the docked complex had good conformational stability. The ADME parameters calculation showed that 20 possesses remarkable theoretical drug-likeness properties. Taken together, these results suggested that 20 is worthy of further exploration as a potential HDAC-targeted anticancer drug candidate.

Pterostilbene Induces Pyroptosis in Breast Cancer Cells through Pyruvate Kinase 2/Caspase-8/Gasdermin C Signaling Pathway

The incidence and mortality of breast cancer increase year by year, and it is urgent to find high-efficiency and low-toxicity anti-cancer drugs. Pterostilbene (PTE) is a natural product with antitumor activity, but the specific antitumor mechanism is not very clear. Aerobic glycolysis is the main energy supply for cancer cells. Pyroptosis is an inflammatory, programmed cell death. The aim of this study was to investigate the effect of PTE on glycolysis and pyroptosis in EMT6 and 4T1 cells and the specific mechanism, and to elucidate the role of pyruvate kinase 2 (PKM2), a key enzyme in glycolysis, in the antitumor role of PTE. Our study suggested that PTE induced pyroptosis by inhibiting tumor glycolysis. PKM2 played an important role in both the inhibition of glycolysis and the induction of pyroptosis by PTE.

Restoration of TFPI2 by LSD1 inhibition suppresses tumor progression and potentiates antitumor immunity in breast cancer

Histone lysine-specific demethylase 1 (LSD1) is frequently overexpressed in triple negative breast cancer (TNBC), which is associated with worse clinical outcome in TNBC patients. However, the underlying mechanisms by which LSD1 promotes TNBC progression remain to be identified. We recently established a genetically engineered murine model by crossing mammary gland conditional LSD1 knockout mice with Brca1-deficient mice to explore the role of LSD1 in TNBC pathogenesis. Cre-mediated Brca1 loss led to higher incidence of tumor formation in mouse mammary glands, which was hindered by concurrent depletion of LSD1, indicating a critical role of LSD1 in promoting Brca1-deficient tumors. We also demonstrated that the silencing of a tumor suppressor gene, Tissue Factor Pathway Inhibitor 2 (TFPI2), is functionally associated with LSD1-mediated TNBC progression. Mouse Brca1-deficient tumors exhibited elevated LSD1 expression and decreased TFPI2 level compared to normal mammary tissues. Analysis of TCGA database revealed that TFPI2 expression is significantly lower in aggressive ER-negative or basal-like BC. Restoration of TFPI2 through LSD1 inhibition increased H3K4me2 enrichment at the TFPI2 promoter, suppressed tumor progression, and enhanced antitumor efficacy of chemotherapeutic agent. Induction of TFPI2 by LSD1 ablation downregulates activity of matrix metalloproteinases (MMPs) that in turn increases the level of cytotoxic T lymphocyte attracting chemokines in tumor environment, leading to enhanced tumor infiltration of CD8+ T cells. Moreover, induction of TFPI2 potentiates antitumor effect of LSD1 inhibitor and immune checkpoint blockade in poorly immunogenic TNBC. Together, our study identifies previously unrecognized roles of TFPI2 in LSD1-mediated TNBC progression, therapeutic response, and immunogenic effects.

Integrated multi-omics profiling reveals the ZZZ3/CD70 axis is a super-enhancer-driven regulator of diffuse large B-cell lymphoma cell-natural killer cell interactions

Tumor immune microenvironment is crucial for diffuse large B-cell lymphoma (DLBCL) development. However, the mechanisms by which super-enhancers (SEs) regulate the interactions between DLBCL cells and tumor-infiltrating immune cells remains largely unknown. This study aimed to investigate the role of SE-controlled genes in regulating the interactions between DLBCL cells and tumor-infiltrating immune cells. Single-cell RNA-seq, bulk RNA-seq and H3K27ac ChIP-seq data were downloaded from the Heidelberg Open Research Data database and Gene Expression Omnibus database. HOMER algorithm and Seurat package in R were used for bioinformatics analysis. Cell proliferation and lactate dehydrogenase (LDH) release was detected by MTS and LDH release assays, respectively. Interaction between B cell cluster and CD8+ T cell and NK cell cluster was most obviously enhanced in DLBCL, with CD70-CD27, MIF-CD74/CXCR2 complex, MIF-CD74/CD44 complex and CCL3-CCR5 interactions were significantly increased. NK cell sub-cluster showed the strongest interaction with B cell cluster. ZZZ3 upregulated the transcription of CD70 by binding to its SE. Silencing CD70 in DOHH2 cells significantly promoted the proliferation of co-cultured NK92 cells and LDH release from DOHH2 cells, which was counteracted by ZZZ3 overexpression in DOHH2 cells. CD70 silencing combined with PD-L1 blockade promoted LDH release from DOHH2 cells co-cultured with NK92 cells. In conclusion, DLBCL cells inhibited the proliferation and killing of infiltrating NK cells by regulating ZZZ3/CD70 axis. Targeting ZZZ3/CD70 axis combined with PD-L1 blockade is expected to be a promising strategy for DLBCL treatment.

Quantitative analysis of non-histone lysine methylation sites and lysine demethylases in breast cancer cell lines

Growing evidence shows that lysine methylation is a widespread protein post-translational modification that regulates protein function on histone and non-histone proteins. Numerous studies have demonstrated that dysregulation of lysine methylation mediators contributes to cancer growth and chemotherapeutic resistance. While changes in histone methylation are well documented with extensive analytical techniques available, there is a lack of high-throughput methods to reproducibly quantify changes in the abundances of the mediators of lysine methylation and non-histone lysine methylation (Kme) simultaneously across multiple samples. Recent studies by our group and others have demonstrated that antibody enrichment is not required to detect lysine methylation, prompting us to investigate the use of Tandem Mass Tag (TMT) labeling for global Kme quantification sans antibody enrichment in four different breast cancer cell lines (MCF-7, MDA-MB-231, HCC1806, and MCF10A). To improve the quantification of KDMs, we incorporated a lysine demethylase (KDM) isobaric trigger channel, which enabled 96% of all KDMs to be quantified while simultaneously quantifying 326 Kme sites. Overall, 142 differentially abundant Kme sites and eight differentially abundant KDMs were identified between the four cell lines, revealing cell line-specific patterning.

Extracellular matrix regulation of cell spheroid invasion in a 3D bioprinted solid tumor-on-a-chip

Tumor organoids and tumors-on-chips can be built by placing patient-derived cells within an engineered extracellular matrix (ECM) for personalized medicine. The engineered ECM influences the tumor response, and understanding the ECM-tumor relationship accelerates translating tumors-on-chips into drug discovery and development. In this work, we tuned the physical and structural characteristics of ECM in a 3D bioprinted soft-tissue sarcoma microtissue. We formed cell spheroids at a controlled size and encapsulated them into our gelatin methacryloyl (GelMA)-based bioink to make perfusable hydrogel-based microfluidic chips. We then demonstrated the scalability and customization flexibility of our hydrogel-based chip via engineering tools. A multiscale physical and structural data analysis suggested a relationship between cell invasion response and bioink characteristics. Tumor cell invasive behavior and focal adhesion properties were observed in response to varying polymer network densities of the GelMA-based bioink. Immunostaining assays and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) helped assess the bioactivity of the microtissue and measure the cell invasion. The RT-qPCR data showed higher expressions of HIF-1α, CD44, and MMP2 genes in a lower polymer density, highlighting the correlation between bioink structural porosity, ECM stiffness, and tumor spheroid response. This work is the first step in modeling STS tumor invasiveness in hydrogel-based microfluidic chips. STATEMENT OF SIGNIFICANCE: We optimized an engineering protocol for making tumor spheroids at a controlled size, embedding spheroids into a gelatin-based matrix, and constructing a perfusable microfluidic device. A higher tumor invasion was observed in a low-stiffness matrix than a high-stiffness matrix. The physical characterizations revealed how the stiffness is controlled by the density of polymer chain networks and porosity. The biological assays revealed how the structural properties of the gelatin matrix and hypoxia in tumor progression impact cell invasion. This work can contribute to personalized medicine by making more effective, tailored cancer models.

Regulating ferroptosis by non-coding RNAs in hepatocellular carcinoma

Ferroptosis, a unique type of regulated cell death plays a vital role in inhibiting tumour malignancy and has presented new opportunities for treatment of therapy in hepatocellular carcinoma. Accumulating studies indicate that epigenetic modifications by non-coding RNAs, including microRNAs, long noncoding RNAs, and circular RNAs, can determine cancer cell vulnerability to ferroptosis in HCC. The present review first summarize the updated core molecular mechanisms of ferroptosis. We then provide a concised overview of epigenetic modification of ferroptosis in HCC. Finally, we review the recent progress in understanding of the ncRNA-mediated regulated mechanisms on ferroptosis in HCC. The review will promote our understanding of the ncRNA-mediated epigenetic regulatory mechanisms modulating ferroptosis in malignancy of HCC, highlighting a novel strategies for treatment of HCC through targeting ncRNA-ferroptosis axis.