The lysine methyltransferase SMYD2 facilitates neointimal hyperplasia by regulating the HDAC3-SRF axis

Coronary restenosis is an important cause of poor long-term prognosis in patients with coronary heart disease. Here, we show that lysine methyltransferase SMYD2 expression in the nucleus is significantly elevated in serum- and PDGF-BB-induced vascular smooth muscle cells (VSMCs), and in tissues of carotid artery injury-induced neointimal hyperplasia. Smyd2 overexpression in VSMCs (Smyd2-vTg) facilitates, but treatment with its specific inhibitor LLY-507 or SMYD2 knockdown significantly inhibits VSMC phenotypic switching and carotid artery injury-induced neointima formation in mice. Transcriptome sequencing revealed that SMYD2 knockdown represses the expression of serum response factor (SRF) target genes and that SRF overexpression largely reverses the inhibitory effect of SMYD2 knockdown on VSMC proliferation. HDAC3 directly interacts with and deacetylates SRF, which enhances SRF transcriptional activity in VSMCs. Moreover, SMYD2 promotes HDAC3 expression via tri-methylation of H3K36 at its promoter. RGFP966, a specific inhibitor of HDAC3, not only counteracts the pro-proliferation effect of SMYD2 overexpression on VSMCs, but also inhibits carotid artery injury-induced neointima formation in mice. HDAC3 partially abolishes the inhibitory effect of SMYD2 knockdown on VSMC proliferation in a deacetylase activity-dependent manner. Our results reveal that the SMYD2-HDAC3-SRF axis constitutes a novel and critical epigenetic mechanism that regulates VSMC phenotypic switching and neointimal hyperplasia.

Role of Histone Methyltransferase in Fibrosis and Traditional Chinese Medicine Treatment： A Review / 中国实验方剂学杂志

Fibrosis， a tumor-like lesion between benign tissue and malignant tumor， mostly occurs in the liver， kidney， heart， lung， bone marrow and other organs and tissues. It can affect almost every organ and eventually induce multiple organ failure and cancers， seriously endangering human life. It will be of great importance to prevent cancer if the disease can be opportunely blocked in the fibrotic stage. The pathogenesis of fibrosis is still not completely clear. It is of great clinical significance to study the occurrence， development， and mechanism of fibrosis as well as to screen new therapeutic targets. Enhancer of zeste homolog 2 （EZH2） is mainly located in the nucleus and involved in the formation of the polycomb repressive complex 2. EZH2 is a methyltransferase which makes the lysine on position 27 of histone H3 （H3K27me3） undergo trimethyl modification induces gene silencing through classical or nonclassical actions， so as to inhibit or activate transcription. EZH2 plays a critical role in cell growth， proliferation， differentiation， and apoptosis， which is regulated by different targets and signaling pathways. EZH2 regulates the transformation of myofibroblasts and participates in the fibrosis of multiple organs. Recent studies have shown that EZH2 plays a role in fibrosis-related pathophysiological processes such as epithelial-mesenchymal transition， oxidative stress， and inflammation. EZH2 as the target of fibrosis， EZH2 inhibitors， and EZH2-related traditional Chinese medicine （TCM） formula and active compounds have gradually become hot research directions. EZH2 may be a powerful target for organ fibrosis. Exploring the structure， function， and distribution of EZH2， the role of EZH2 in fibrosis， the EZH2 inhibitors， and TCM formulas and active components targeting EZH2 has great meanings. This paper reviews the research progress in EZH2 and fibrosis， providing new ideas for the diagnosis， treatment， and drug development of fibrosis.

Alterações epigenéticas associadas a agenesia dentária não sindrômica: uma revisão sistemática / Epigenetic alterations associated with non-syndromic tooth agenesis: a systematic review

Objetivo: Avaliar se alterações epigenéticas estão associadas à ocorrência da agenesia dentária não sindrômica. Métodos: Buscas computadorizadas foram conduzidas no PubMed, Web of Science, Ovid, Embase e Scopus. Consultas na literatura cinzenta (Open Grey), no Google Scholar e pesquisas manuais nas listas de referências dos artigos incluídos também foram realizadas. Apenas estudos caso-controle avaliando indivíduos com e sem agenesia dentária não sindrômica eram elegíveis. A seleção dos estudos, a extração de dados e a avaliação do risco de viés (ferramenta da Universidade da Adelaide) foram realizadas por dois autores de forma independente. Devido à diferença metodológica dos artigos incluídos, uma meta-análise não foi possível. Resultados: 206 artigos foram identificados nas bases de dados. Após a remoção de 128 duplicatas e a análise de 78 referências, oito artigos preencheram os critérios de elegibilidade e foram incluídos. Os estudos incluídos foram realizados na China, Turquia, Tunísia, Romênia e República Tcheca. As datas de publicação ocorreram entre 2015 e 2023. Os estudos com as menores amostras avaliaram cinco indivíduos com agenesia e cinco sem agenesia e o estudo com a maior amostra avaliou 625 indivíduos com agenesia e 1144 indivíduos sem agenesia. No total, essa revisão analisou 1325 indivíduos com agenesia e 1867 sem agenesia. Dos 33 polimorfismos de nucleotídeo único avaliados, 19 deles estavam potencialmente associados a uma maior suscetibilidade à agenesia dentária não sindrômica, sendo eles identificados nos genes PAX9, AXIN2, WNT10A, MDM2, MSX1 e BMP2. Foram identificadas 29 novas mutações. No geral, os artigos incluídos apresentaram baixo risco de viés. Conclusão: Existe a associação de algumas alterações epigenéticas com a ocorrência de agenesia dentária não sindrômica.

Aim: To assess whether epigenetic alterations are associated with the occurrence of non-syndromic tooth agenesis. Methods: Computerized searches were conducted in PubMed, Web of Science, Ovid, Embase, and Scopus databases. Grey literature searches (Open Grey), Google Scholar, and manual searches in the reference lists of included articles were also performed. Only case-control studies evaluating individuals with and without non-syndromic tooth agenesis were eligible. Study selection, data extraction, and bias assessment (University of Adelaide tool) were independently conducted by two authors. Due to methodological differences in the included articles, a meta-analysis was not feasible. Results: This study identified 206 articles in the databases. After removing 128 duplicates and reviewing 78 references, eight articles met the eligibility criteria and were included. The included studies were conducted in China, Turkey, Tunisia, Romania, and the Czech Republic. Publication dates ranged from 2015 to 2023. Studies with the smallest sample assessed five individuals with agenesis and five without agenesis, and the study with the largest sample assessed 625 individuals with agenesis and 1,144 without agenesis. In total, this review analyzed 1,325 individuals with agenesis and 1,867 without agenesis. Of the 33 single nucleotide polymorphisms evaluated, 19 were potentially associated with an increased susceptibility to non-syndromic tooth agenesis, and these were identified in the PAX9, AXIN2, WNT10A, MDM2, MSX1, and BMP2 genes. Twenty-nine new mutations were identified. Overall, the included articles demonstrated a low risk of bias. Conclusion: There is an association between certain epigenetic alterations and the occurrence of non-syndromic tooth agenesis.

HDAC3-a key target for preventing organ ischemia-reperfusion injury / 中国药理学通报

Histone deacetylase 3 (HDAC3) plays an important role in chromatin remodeling, which in turn regulates gene transcription, so HDAC3 is involved in the pathophysiology of various diseases through epigenetic regulation. Organ ischemia-reperfusion injury (I R I) is a pathophysiological process that leads to the development of a variety of diseases such as delayed neuronal necrosis, irreversible shock, myocardial infarction, acute organ failure and organ transplant rejection. In this paper we review the pathophysiological function of HDAC3 and its role in the development of IRI in human parenchymal organs, and also explore the therapeutic value of HDAC3 in IRI.

Role of epigenetic regulation of biological clock genes in tumors / 中国药理学通报

The circadian clock is regulated at the molecular level by transcriptional-translational feedback loop of clock genes, which ensures that a variety of physiological processes have a-round 24 h circadian rhythms, including cell metabolism, cell proliferation, cell apoptosis and tumorigenesis, to maintain the homeostasis. Thus, the disturbance of circadian clock will disrupt homeostasis, causing various diseases, including neoplasm, metabolic syndrome, Parkinson's disease, COPD and cardiovascular diseases. Disturbance of circadian clock is closely related with tumorigenesis, and acts on various molecules and pathways leading to tumorigenesis, including oncogene and tumor suppressor gene, cell cycle, metabolic reprogramming, immune escape, endocrine disruption, alteration of gastrointestinal microbiome. This review focuses on changes in clock genes expression which disrupt cell cycle and may play a role in tumorigenesis, and epi-geneties, an important way to regulate gene expression, which can alter clock gene expression, thus playing an important role in the process of " the alternation of clock gene expression-disruption of cell cycle-tumorigenesis".

Mechanism of Buyang Huanwu Decoction alleviating inflammatory response after cerebral ischemia/reperfusion injury by activating SIRT1 in hippocampus of rats / 中国药理学通报

Aim To explore the inhibitory effect of Buyang Huanwu Decoction on the inflammatory response in the hippocampus of brain tissues of CIRI rats by regulating SIRT1 and the underlying mechanism. Methods The middle cerebral artery embolization (MCAO) model was prepared in rats and divided into sham operation group (Sham), model group (MCAO/R), Buyang Huanwu Decoction group (BYHWT),and BYHWT + SIRT1 inhibitor group (BYHWT + EX527). Zea Longa was used to detect the neurological function score of rats in each group; TTC staining was used to determine the volume of cerebral infarction; HE staining was used to observe the pathological damage of the hippocampus; Western blot was used to detect the expression levels of SIRT1 and IL-6; immunohistochemistry was used to detect TNF-α, IL-1β expression level. Results Compared with the sham group,the neurological function score of the MCAO/R group increased (P < 0.05); the volume of cerebral infarction increased (P < 0.05); the nerve cells in hippocampus were severely damaged, arranged disorderly, and the nucleus was broken; Western blot showed that the expression of SIRT1 decreased, IL-6 expression increased (P <0.05); immunohistochemistry showed that TNF-α,IL-1β expression increased (P < 0.05). Compared with the MCAO/R group, the neurological function score of the BYHWT group decreased (P <0.05); the volume of cerebral infarction decreased (P < 0.05); the damage of nerve cells in hippocampus was reduced; Western blot showed that the expression of SIRT1 increased and IL-6 expression decreased (P < 0.05); immunohistochemistry showed that TNF-α, IL-1β expression decreased (P < 0.05). Compared with the BYHWT group, the neurological function score of the BYHWT + EX527 group increased (P < 0.05); the volume of cerebral infarction was raised (P <0.05); the damage of nerve cells in hippocampus was aggravated; Western blot showed that the expression of SIRT1 decreased and IL-6 expression increased (P < 0.05); immunohistochemistry showed that TNF-α, IL-1β expression increased (P < 0.05). Conclusions Preliminary discussion of Buyang Huanwu Decoction can activate SIRT1 in hippocampus of rat brain tissues to reduce the inflammatory response after CIRI and play a role in brain protection.

Research progress of HDACs and associated inhibitors on regulation of acute lung injury / 中国药理学通报

Acute lung injury ( ALI) and its most extreme form a-cute respiratory distress syndrome ( ARDS) are lung diseases with high morbidity and mortality. There is no effective therapeutic intervention until now for its complicated pathophysiologi-cal processes and sophisticated regulatory mechanism. Histone deacetylases (HDACs) are a family of proteins with deacetylase activity. Studies have shown that HDACs are involved in the pathophysiological processes of ALI/ARDS, including inflammatory responses,endothelial permeability,oxidative stresses,alveolar fluid clearance and lung tissue repairment. Simultaneously, the use of HDACs inhibitors (HDACIs) can interfere with ALI/ ARDS progression. In this review we describe and summarize the pathophysiological processes and the underlying mechanisms in ALI/ARDS regulated by HDACs and HDACIs in detail, in order to provide the basis for the clinical application of HDACs-targe- ted agents and indicate directions for future study.

Changes of biomarkers in plasma of patients with occupational silicosis and their diagnostic value / 中国职业医学

{L-End}Objective To analyze the changes of seven potential biomarkers in plasma of patients with occupational silicosis (hereinafter referred to as "silicosis"), and explore their clinical value in determining the stage of silicosis. {L-End}Methods A total of 100 male silicosis patients were selected as the silicosis group (63 cases in stage Ⅰ and 37 cases in stage Ⅱ subgroups), and 100 male healthy individuals were selected as the control group using the 1∶1 matched case-control study. Enzyme-linked immunosorbent assay was used to analyze the level of interleukin-17 (IL-17), monocyte chemoattractant protein-1 (MCP-1), matrix metalloproteinase-9 (MMP-9), Krebs von den Lungen-6 (KL-6), connective tissue growth factor (CTGF), platelet-derived growth factor (PDGF), and histone H4 in plasma. Their clinical value for diagnosing silicosis was evaluated using receiver operating characteristic (ROC) curve, discriminant analysis stepwise method, and Fisher discriminant function analysis. {L-End}Results The levels of IL-17, MCP-1, MMP-9, KL-6, CTGF, PDGF, and histone H4 in the plasma of the silicosis group, silicosis stage Ⅰ subgroups, and stage Ⅱ subgroups were higher than those in the control group (all P<0.05). The levels of IL-17, MCP-1, and MMP-9 in the plasma of the stage Ⅱ subgroup decreased (all P<0.05), while the levels of KL-6, CTGF and histone H4 increased (all P<0.05) compared with the stage Ⅰ subgroup. The area under the ROC curve for diagnosing silicosis using these seven potential biomarkers ranged from 0.761 to 1.000 (all P<0.01), with the sensitivity of 0.640-1.000, the specificity of 0.840-0.990, and the Youden index of 0.540-0.990. The Fisher discriminant function was formed by stepwise discriminant analysis, and the results showed that the coincidence rate was 99.5%, and the misdiagnosis rate was 0.5% for diagnosing and staging silicosis with these seven potential biomarkers. The coincidence rate of diagnosing control group, silicosis stageⅠsubgroup and the silicosis stage Ⅱ subgroup was 100.0%, 98.4% and 100.0%, respectively. {L-End}Conclusion IL-17, MCP-1, MMP-9, KL-6, CTGF, PDGF and histone H4 in plasma can be used as biomarkers for the diagnosis of silicosis, and the Fisher discriminant function based on the combination of these seven biomarkers can assist in staging silicosis.

Neuronal Histone Methyltransferase EZH2 Regulates Neuronal Morphogenesis, Synaptic Plasticity, and Cognitive Behavior in Mice / 神经科学通报·英文版

The histone methyltransferase enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2)-mediated trimethylation of histone H3 lysine 27 (H3K27me3) regulates neural stem cell proliferation and fate specificity through silencing different gene sets in the central nervous system. Here, we explored the function of EZH2 in early post-mitotic neurons by generating a neuron-specific Ezh2 conditional knockout mouse line. The results showed that a lack of neuronal EZH2 led to delayed neuronal migration, more complex dendritic arborization, and increased dendritic spine density. Transcriptome analysis revealed that neuronal EZH2-regulated genes are related to neuronal morphogenesis. In particular, the gene encoding p21-activated kinase 3 (Pak3) was identified as a target gene suppressed by EZH2 and H3K27me3, and expression of the dominant negative Pak3 reversed Ezh2 knockout-induced higher dendritic spine density. Finally, the lack of neuronal EZH2 resulted in impaired memory behaviors in adult mice. Our results demonstrated that neuronal EZH2 acts to control multiple steps of neuronal morphogenesis during development, and has long-lasting effects on cognitive function in adult mice.

Effect of histone H4 on polarization of alveolar macrophages in mice with acute respiratory distress syndrome / 中国职业医学

Objective To investigate the role of histone H4 in the polarization of alveolar macrophages (AM) in lipopolysaccharide (LPS)-induced acute respiratory distress syndrome (ARDS) in mice. Methods i) The specific pathogen free male C57BL/6 mice were randomly divided into control group and 2, 4, 6 and 8 mg/kg LPS groups, with six mice in each group. The mice in the LPS groups were intratracheally administered LPS according to their respective doses, while the mice in the control group received an equivalent volume of 0.9% saline. After 12 hours, the arterial blood gas was analyzed, and the pulmonary edema and histopathological changes in lung tissues of mice in each group were observed. The level of histone H4 in bronchoalveolar lavage fluid (BALF) of mice was detected using enzyme-linked immunosorbent assay , and mice AMs of the five group were isolated using adherent method. ii) AMs from normal mice were isolated using adherent method and randomly divided into control group, histone H4 injury group, BALF injury group and anti-histone H4 antibody (anti-H4) intervention group. In the histone H4 injury group, AMs were treated with histone H4 at a final concentration of 20 mg/L. In the BALF injury group and anti-H4 intervention group, AMs were treated with 200 μL BALF supernatant from mice intratracheally administered 6 mg/kg body weight LPS, with the latter group treated with 25 mg/L anti-H4 antibody. The control group AMs were treated with phosphate-buffered saline. iii) After 12 hours of stimulation, the cells were collected, and the relative expression of tumor necrosis factor-α (Tnfa), interleukin-1β (Il1b), differentiation antigen 206 (Cd206) and arginase 1 (Arg1) in AMs was detected using real-time quantitative polymerase chain reaction. Results i) Compared with the control group, mice in all four LPS groups exhibited rapid breathing, inflammatory reaction and lung edema in lung tissues, which were aggravated in a dose-dependent manner. The ratio of partial pressure of arterial oxygen to fraction of inspired oxygen in mice decreased with the increase of LPS dose (P<0.05). The wet/dry weight ratio of lung, the level of histone H4 in BALF and the relative expression of Tnfa and Il1b mRNA in AMs increased with the increase of LPS dose (all P<0.05). The mice in the 6 and 8 mg/kg LPS groups developed ARDS. The level of histone H4 in BALF and the relative expression of Tnfa and Il1b mRNA in AMs of mice in 6 and 8 mg/kg LPS groups were higher than those in the other three groups (all P<0.05). ii) The relative expression of Tnfa and Il1b mRNA increased (both P<0.05), and the relative expression of Cd206 and Arg1 mRNA decreased (both P<0.05) in AMs of histone H4 injury group and BALF injury group compared with the control group. Compared with BALF injury group, the relative mRNA expression of Tnfa and Il1b in AMs of anti-H4 intervention group decreased (both P<0.05), while the relative expression of Arg1 mRNA increased (P<0.05). Conclusion LPS can induce a dose-dependent increase in histone H4 levels in BALF in mice. Histone H4 drives the development of ARDS by activating AMs to M1 polarization. Antagonizing histone H4 to interfere with AM polarization to M1 could be a target for the treatment of ARDS.

Traditional Chinese Medicine Treatment, Gua Sha, can Induce Subtle Molecular Changes in Gene Expression / 生物医学与环境科学（英文）

OBJECTIVE@#Here, we explored molecular changes that could potentially mediate healing effects of Gua Sha - a method employed by the Chinese traditional medicine with proven track records of safe and efficient applications dating back to ancient times as well as support from randomized controlled trials performed by modern medical studies - yet remaining almost entirely unexplored by the modern-day high-throughput methods of the -omics sciences.@*METHODS@#We investigated transcriptome changes occurring shortly after Gua Sha treatment in the whole blood of healthy volunteers using bulk RNA-seq analysis. We applied various analytical tools to identify genes with consistent expression changes in multiple individuals in response to Gua Sha and their networks.@*RESULTS@#We found that while the changes were very subtle and individual-specific, we could identify consistent upregulation of three histone genes. Further analysis of the potential regulatory networks of these histone genes revealed the enrichment of functions involved in the immune response and inflammation.@*CONCLUSION@#The significance of these results in the context of potential effects of Gua Sha and the next steps in exploring the molecular mechanisms of action of this technique are discussed.

Research progress on the mechanism of valproic acid against glioma / 中国药房

Gliomas are commonly central nervous system tumors. The conventional treatment is surgical resection combined with chemoradiotherapy， but glioma patients often have a poor prognosis. Therefore， there is an urgent need to identify new potential targets in gliomas and develop more effective treatments. Valproic acid has the properties of histone deacetylase inhibitor， which has been proven to have inhibitory effects on various tumors. It is confirmed that valproic acid could promote apoptosis and cell arrest of glioma cells， inhibit cell invasion and glioma stem cells， increase the sensitivity of glioma cells to radiotherapy and chemotherapy by regulating ERK/Akt signaling pathway， Akt/mTOR signaling pathway， and regulating expression levels of RECK， MGMT， Nrf2， PON2， Smad4， GSK3β and other proteins. In addition， valproic acid can also enhance the effectiveness of anticancer drugs by inhibiting the growth of glioma stem cells and inducing their differentiation. In conclusion， valproic acid can inhibit glioma through multiple targeted actions， and may become a new targeted drug for the treatment of glioma.

Role of Histone Modifications and 12/15-lipoxygenase Metabolic Pathway in the Development of Diabetic Kidney Disease / 中山大学学报(医学科学版)

Diabetic kidney disease （DKD） is one of the most common microvascular complications in patients with diabetes. DKD is also the main cause of end-stage renal failure， with very complex pathogenesis. A large number of experiments have confirmed that epigenetic mechanisms， including histone chemical modifications and lipid metabolites 12/15-lipoxygenase （12/15-LO）， are involved in regulating the characteristic pathophysiological process of DKD， based on which， this review further explores the pathogenesis of DKD and provides the new research direction for DKD treatment.

Progress of enhancer of zeste homolog 2 in hematological tumors / 白血病·淋巴瘤

The enhancer of zeste homolog 2 (EZH2) is a histone methyltransferase, which is widely studied in histone methylation modification. It can promote epigenetic gene silencing and mediate the occurrence of tumors through a variety of regulatory mechanisms. The gain-of-function and loss-of-function mutations of EZH2 have been confirmed in many cancers. At present, with the extensive attention paid to the regulatory role of EZH2 in epigenetic mechanism, the exact way in which EZH2 imbalance affects the pathogenesis of hematologic malignancies remains to be clarified. This article reviews the pathogenetic role of EZH2 in hematological tumors, and hope to find new targets for the prevention and treatment of hematological tumors.

Protective effects of histone deacetylase 6 specific inhibitor tubastatin A on subarachnoid hemorrhage in rats and the underlying mechanisms / 中南大学学报(医学版)

OBJECTIVES@#Subarachnoid hemorrhage (SAH) is a serious cerebrovascular disease. Early brain injury (EBI) and cerebral vasospasm are the main reasons for poor prognosis of SAH patients. The specific inhibitor of histone deacetylase 6 (HDAC6), tubastatin A (TubA), has been proved to have a definite neuroprotective effect on a variety of animal models of acute and chronic central nervous system diseases. However, the neuroprotective effect of TubA on SAH remains unclear. This study aims to investigate the expression and localization of HDAC6 in the early stage of SAH, and to evaluate the protective effects of TubA on EBI and cerebral vasospasm after SAH and the underlying mechanisms.@*METHODS@#Adult male SD rats were treated with modified internal carotid artery puncture to establish SAH model. In the first part of the experiment, rats were randomly divided into 6 groups: a sham group, a SAH-3 h group, a SAH-6 h group, a SAH-12 h group, a SAH-24 h group, and a SAH-48 h group. At 3, 6, 12, and 24 h after SAH modeling, the injured cerebral cortex of rats in each group was taken for Western blotting to detect the expression of HDAC6. In addition, the distribution of HDAC6 in the cerebral cortex of the injured side was measured by immunofluorescence double staining in SAH-24 h group rats. In the second part, rats were randomly divided into 4 groups: a sham group, a SAH group, a SAH+TubAL group (giving 25 mg/kg TubA), and a SAH+TubAH group (giving 40 mg/kg TubA). At 24 h after modeling, the injured cerebral cortex tissue was taken for Western blotting to detect the expression levels of HDAC6, endothelial nitric oxide synthase (eNOS), and inducible nitric oxide synthase (iNOS), terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) staining to detect apoptosis, and hematoxylin and eosin (HE) staining to detect the diameter of middle cerebral artery.@*RESULTS@#The protein expression of HDAC6 began to increase at 6 h after SAH (P<0.05), peaked at 24 h (P<0.001), and decreased at 48 h, but there was still a difference compared with the sham group (P<0.05). HDAC6 is mainly expressed in the cytoplasm of the neurons. Compared with the sham group, the neurological score was decreased significantly and brain water content was increased significantly in the SAH group (both P<0.01). Compared with the SAH group, the neurological score was increased significantly and brain water content was decreased significantly in the SAH+TubAH group (both P<0.05), while the improvement of the above indexes was not significant in the SAH+TubAL group (both P>0.05). Compared with the sham group, the expression of eNOS was significantly decreased (P<0.01) and the expressions of iNOS and HDAC6 were significantly increased (P<0.05 and P<0.01, respectively) in the SAH group. Compared with the SAH group, the expression of eNOS was significantly increased, and iNOS and HDAC6 were significantly decreased in the SAH+TubA group (all P<0.05). Compared with the SAH group, the number of TUNEL positive cells was significantly decreased and the diameter of middle cerebral artery was significantly increased in the SAH+TubA group (both P<0.05) .@*CONCLUSIONS@#HDAC6 is mainly expressed in neurons and is up-regulated in the cerebral cortex at the early stage of SAH. TubA has protective effects on EBI and cerebral vasospasm in SAH rats by reducing brain edema and cell apoptosis in the early stage of SAH. In addition, its effect of reducing cerebral vasospasm may be related to regulating the expression of eNOS and iNOS.

Research Progress of Role and Mechanism of SETD7 in Tumor Occurrence and Progression / 中国肺癌杂志

The occurence and development of tumors is a complicated process, which not only depends on the mutation or deletion of genes, but also is affected by epigenetic regulation. Accumulating evidences have shown that epigenetic modifications play fundamental roles in transcriptional regulation, heterochromatin formation, X chromosome inactivation, DNA damage response and tumor development. SET domain containing lysine methyltransferase 7 (SETD7) was initially identified as an important lysine methyltransferase, which methylated histone and non-histone proteins. These modifications play fundamental roles. Once this modification disorders, it can directly lead to cell abnormalities and cause many diseases. Studies have shown that SETD7 is related to the occurence and development of various tumors, but the methylation sites of SETD7 and its regulatory mechanism have not been fully elucidated. This article summarizes the research progress of the role of SETD7 on histone and non-histone methylation modification in tumors and the molecular mechanism, in order to provide new therapeutic targets for tumor pathogenesis and diagnosis.
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Recent advances in prostate cancer: WNT signaling, chromatin regulation, and transcriptional coregulators / 亚洲男科学杂志(英文版)

Prostate cancer is one of the most common diseases in men worldwide. Surgery, radiation therapy, and hormonal therapy are effective treatments for early-stage prostate cancer. However, the development of castration-resistant prostate cancer has increased the mortality rate of prostate cancer. To develop novel drugs for castration-resistant prostate cancer, the molecular mechanisms of prostate cancer progression must be elucidated. Among the signaling pathways regulating prostate cancer development, recent studies have revealed the importance of noncanonical wingless-type MMTV integration site family (WNT) signaling pathways, mainly that involving WNT5A, in prostate cancer progression and metastasis; however, its role remains controversial. Moreover, chromatin remodelers such as the switch/sucrose nonfermentable (SWI/SNF) complex and chromodomain helicase DNA-binding proteins 1 also play important roles in prostate cancer progression through genome-wide gene expression changes. Here, we review the roles of noncanonical WNT signaling pathways, chromatin remodelers, and epigenetic enzymes in the development and progression of prostate cancer.

Hedgehog pathway orchestrates the interplay of histone modifications and tailors combination epigenetic therapies in breast cancer

Epigenetic therapies that cause genome-wide epigenetic alterations, could trigger local interplay between different histone marks, leading to a switch of transcriptional outcome and therapeutic responses of epigenetic treatment. However, in human cancers with diverse oncogenic activation, how oncogenic pathways cooperate with epigenetic modifiers to regulate the histone mark interplay is poorly understood. We herein discover that the hedgehog (Hh) pathway reprograms the histone methylation landscape in breast cancer, especially in triple-negative breast cancer (TNBC). This facilitates the histone acetylation caused by histone deacetylase (HDAC) inhibitors and gives rise to new therapeutic vulnerability of combination therapies. Specifically, overexpression of zinc finger protein of the cerebellum 1 (ZIC1) in breast cancer promotes Hh activation, facilitating the switch of H3K27 methylation (H3K27me) to acetylation (H3K27ac). The mutually exclusive relationship of H3K27me and H3K27ac allows their functional interplay at oncogenic gene locus and switches therapeutic outcomes. Using multiple in vivo breast cancer models including patient-derived TNBC xenograft, we show that Hh signaling-orchestrated H3K27me and H3K27ac interplay tailors combination epigenetic drugs in treating breast cancer. Together, this study reveals the new role of Hh signaling-regulated histone modifications interplay in responding to HDAC inhibitors and suggests new epigenetically-targeted therapeutic solutions for treating TNBC.

Entinostat, a class I selective histone deacetylase inhibitor, plus exemestane for Chinese patients with hormone receptor-positive advanced breast cancer: A multicenter, randomized, double-blind, placebo-controlled, phase 3 trial

Entinostat plus exemestane in hormone receptor-positive (HR+) advanced breast cancer (ABC) previously showed encouraging outcomes. This multicenter phase 3 trial evaluated the efficacy and safety of entinostat plus exemestane in Chinese patients with HR + ABC that relapsed/progressed after ≥1 endocrine therapy. Patients were randomized (2:1) to oral exemestane 25 mg/day plus entinostat (n = 235) or placebo (n = 119) 5 mg/week in 28-day cycles. The primary endpoint was the independent radiographic committee (IRC)-assessed progression-free survival (PFS). The median age was 52 (range, 28-75) years and 222 (62.7%) patients were postmenopausal. CDK4/6 inhibitors and fulvestrant were previously used in 23 (6.5%) and 92 (26.0%) patients, respectively. The baseline characteristics were comparable between the entinostat and placebo groups. The median PFS was 6.32 (95% CI, 5.30-9.11) and 3.72 (95% CI, 1.91-5.49) months in the entinostat and placebo groups (HR, 0.76; 95% CI, 0.58-0.98; P = 0.046), respectively. Grade ≥3 adverse events (AEs) occurred in 154 (65.5%) patients in the entinostat group versus 23 (19.3%) in the placebo group, and the most common grade ≥3 treatment-related AEs were neutropenia [103 (43.8%)], thrombocytopenia [20 (8.5%)], and leucopenia [15 (6.4%)]. Entinostat plus exemestane significantly improved PFS compared with exemestane, with generally manageable toxicities in HR + ABC (ClinicalTrials.gov #NCT03538171).

The engagement of histone lysine methyltransferases with nucleosomes: structural basis, regulatory mechanisms, and therapeutic implications

Histone lysine methyltransferases (HKMTs) deposit methyl groups onto lysine residues on histones and play important roles in regulating chromatin structure and gene expression. The structures and functions of HKMTs have been extensively investigated in recent decades, significantly advancing our understanding of the dynamic regulation of histone methylation. Here, we review the recent progress in structural studies of representative HKMTs in complex with nucleosomes (H3K4, H3K27, H3K36, H3K79, and H4K20 methyltransferases), with emphasis on the molecular mechanisms of nucleosome recognition and trans-histone crosstalk by these HKMTs. These structural studies inform HKMTs' roles in tumorigenesis and provide the foundations for developing new therapeutic approaches targeting HKMTs in cancers.