KDM4A promotes the migration and invasion of breast cancer cell line MDA-MB-231 by downregulating BMP9 / 中国癌症杂志

Background and purpose:Exogenous bone morphogenetic protein 9(BMP9)inhibits the malignant progression of human breast cancer,but its expression is often abnormally low in breast cancer.In this study,we intended to explore the expression and role of epigenetically-modified histone lysine-specific demethylase 4A(KDM4A)in breast cancer,and to investigate the relationship between KDM4A and BMP9 and its possible regulatory mechanism.Methods:The expression of KDM4A in breast cancer and its relationship with BMP9 were analyzed by bioinformatics and verified by real-time fluorescence quantitative polymerase chain reaction(RTFQ-PCR)and Western blot.Chromatin immunoprecipitation(ChIP)verified the regulatory role of KDM4A on BMP9,and RNA stability experiments and CHX protein stability experiments verified the effect of KDM4A in BMP9 expression.Exogenous recombinant MDA-MB-231 cells transfected with KDM4A small interfering RNA(siKDM4A)or infected with siBMP9 adenovirus(Ad-siBMP9)were constructed using RNA interference technology and adenoviruses knocking down BMP9,and the migratory and invasive abilities of the cells were detected by scratch healing assay and transwell assay,respectively.Results:Bioinformatics analysis showed that the expression of KDM4A was significantly higher in breast cancer than in normal tissues,and there was a negative correlation between the expression of KDM4A and that of BMP9 in breast cancer;RTFQ-PCR and Western blot showed that KDM4A was highly expressed in different breast cancer cell lines,and the knockdown of KDM4A significantly up-regulated BMP9.ChIP experiment confirmed that KDM4A could be significantly enriched in the promoter region of BMP9 gene,reducing its histone lysine 36 position instead of position 4 methyl status,thus silencing the expression of BMP9.RNA stability assay and CHX protein stability assay confirmed that KDM4A had no significant effect on the mRNA of BMP9,but could affect its protein degradation.After knocking down KDM4A,the migration and invasion abilities of breast cancer cells MDA-MB-231 were significantly inhibited,and this effect could be partially reversed by knocking down BMP9.Conclusion:KDM4A is highly expressed in breast cancer and breast cancer cell MDA-MB-231,and can silence its expression by down-regulating the level of histone methylation in the promoter region of the BMP9 gene,as well as affecting the stability of BMP9 at the protein level rather than at the level of mRNA,and promoting the migration and invasion of breast cancer.

Progress in role of m6A modification regulatory enzymes and their binding proteins in cell autophagy / 中国病理生理杂志

Autophagy is an important mechanism to maintain cellular function and metabolism,whereas ab-normal autophagy can cause the advent and worsening of various diseases.N6-Methyladenosine(m6A)RNA methylation is a reversible RNA modification,which is regulated by m6A methyltransferase,m6A demethylase and m6A-binding protein.Studies have shown that autophagy-related genes promote or attenuate autophagy level dependent on the regulation of m6A,and then participate in the process of diseases.This paper reviews the progress of m6A modification regulatory enzymes and their binding proteins in regulating cell autophagy to provide reference for future researches.

Progress of lysine-specific demethylase 1 and its inhibitors in triple-negative breast cancer / 肿瘤研究与临床

Lysine-specific demethylase 1 (LSD1) is the firstly discovered histone demethylase. In recent years, LSD1 has become a hot topic in the study of the development and progression of malignancies, and its expression is closely related to the poor prognosis of malignancies. At present, some studies have showed that LSD1 is strongly related to the proliferation, invasion and metastasis of triple-negative breast cancer (TNBC). However, the specific mechanism is not fully understood. This article summarizes the possible mechanism of the development and progression in LSD1 and TNBC, and reviews the latest progress of LSD1 in the clinical research application of TNBC, so as to provide a reference for drug combination therapy in TNBC patients.

Research progress on histone acetylation/methylation in oral diseases / 口腔疾病防治

@#Histone acetylation and methylation can affect chromatin conformation and regulate a variety of biological activities. Abnormal histone acetylation and methylation modifications are related to the occurrence and development of a variety of oral diseases. Histone acetylation and methylation increase or decrease in an orderly manner to regulate the development of teeth. Fluoride ions can destroy the balance between histone acetylation and methylation, which may be related to the occurrence of dental fluorosis. In addition, histone acetylation and methylation are involved in the regulation of oral inflammatory diseases. In the inflammatory microenvironment, the expression of histone acetyltransferase GCN5 decreases, and the expression of Dickkopf 1 (DKK1) decreases, activating the Wnt/β-catenin pathway and ultimately inhibiting the osteogenic differentiation of periodontal ligament stem cells. Enhancer of zeste homolog 2 (EZH2) and H3K27me3 levels were decreased in inflamed dental pulp tissues and cells. EZH2 inhibition inhibited the expression of interleukin (IL)-1b, IL-6 and IL-8 in human dental pulp cells under inflammatory stimulation. Histone acetylation/methylation modifications can interact with multiple signaling pathways to promote the occurrence and development of oral tumors and are related to the high invasiveness of salivary gland tumors. Small molecule drugs targeting histone acetylation and methylation-related enzymes can regulate the level of histone methylation/acetylation and have shown potential in the treatment of oral and maxillofacial diseases. For example, the histone deacetylase inhibitor vorinostat can inhibit the secretion of inflammation-related cytokines; it also promotes the maturation of odontoblasts and the formation of dentin-related matrix, demonstrating its potential in pulp preservation. Understanding the role of histone acetylation/methylation modifications in the occurrence and development of oral diseases will help promote research on epigenetic modifications in oral diseases and provide new perspectives for disease diagnosis and treatment.

Downregulation of demethylase FTO inhibits proliferation of human liver cancer cell line HepG2 / 基础医学与临床

Objective To explore the mechanism of the demethylase fat mass and obesity associatal(FTO)gene on the proliferation of human liver cancer cell line HepG2.Methods HepG2 cells were divided into the control group,FTO group(transfected with FTO over-expression plasmid),si-FTO group(transfected with si-FTO)and si-FTO+si-FoxO1 group(simultaneously transfected with si-FTO and si-FoxO1).The expression of FTO in cells was detected by RT-qPCR.Cell proliferation,invasion and apoptosis were examined using CCK-8 assay,Transwell chamber assay and flow cytometry,respectively.Dot blot assay was performed to measure m6 A methylation,and protein expression of FoxO1 in cells was detected by Western blot.Results Analysis of overall survival in liver cancer patients using The Cancer Genome Atlas(TCGA)showed higher expression of FTO associated with shorter survival(P＜0.05).Compared with normal liver cells HL7702,FTO relative expression was significantly increased in human liver cancer cells HepG2(P＜0.05).The relative expression of FTO in si-FTO group cells was lower than that in the control group,while the relative expression of FTO in FTO group was higher than that in the control group(P＜0.05).The relative expression of FTO in the si-FTO+si-FoxO1 group was higher than that in the si-FTO group(P＜0.05).Compared with the Control group,cell viability,count of invasive cells,relative level of m6 A were significantly decreased,while apoptosis rate and protein expression of FoxO1 were significantly increased in the si-FTO group(P＜0.05).Cell viability,count of invasive cells,and relative expression level of m6 A were sig-nificantly higher,while apoptosis rate and protein expression of FoxO1 were significantly lower in the FTO group compared to the Control group(P＜0.05).Compared with the si-FTO group,cell viability,invasive cells and rela-tive level of m6 A were significantly increased,while apoptosis rate and protein expression of FoxO1 were significant-ly decreased in the si-FTO+si-FoxO1 group(P＜0.05).Conclusion High expression of FTO is associated with poor clinical prognosis.Knockdown of the demethylase FTO gene inhibits proliferation and invasion of liver cancer cells and induces their apoptosis.The mechanism is potentially related to the regulation of FoxO1.

Expression and pathological diagnostic value of extracellular matrix metalloproteinase inducer,ma-trix metalloproteinase-9 and lysine demethylase 6B in invasive breast cancer / 新乡医学院学报

Objective To investigate the expressions of extracellular matrix metalloproteinase inducer(EMMPRIN),matrix metalloproteinase-9(MMP-9),lysine demethylase 6B(KDM6B)proteins and their correlation with clinicopathologic features in invasive breast cancer,and analyze the correlation among the three proteins and their value in pathological diagnosis of invasive breast cancer.Methods The surgical biopsy specimens of 124 patients with invasive breast cancer who were admitted to the Department of Pathology,the Fifth Clinical Medical College of Henan University of Chinese Medicine/People's Hospital of Zhengzhou from January 2014 to December 2017 were selected as research subjects,and 20 low-grade intraductal carcinoma tissue specimens,27 high-grade intraductal carcinoma tissue specimens,and 22 adjacent tissue specimens＞1 cm away from the invasive breast cancer were selected as controls.The expressions of EMMPRIN,MMP-9 and KDM6B proteins in cancer-adjacent tissues,low-grade intraductal carcinoma tissues,high-grade intraductal carcinoma tissues and invasive breast cancer tissues were detected by immunohistochemistry.The relationship between the relative expressions of EMMPRIN,MMP-9 and KDM6B proteins and clinicopathologic features of invasive breast cancer was analyzed,Spearman correlation analysis was used to evaluate the correlation of EMMPRIN,MMP-9 and KDM6B proteins in breast cancer tissues,and receiver operating characteristic(ROC)curve was adopted to evaluate the diagnostic value of EMMPRIN,MMP-9 and KDM6B for invasive breast cancer.Results The relative expressions of EMMPRIN and MMP-9 proteins in high-grade intraductal carcinoma and invasive breast cancer tissues were significantly higher those in cancer-adjacent tissues and low-grade intraductal carcinoma tissues,and the relative expression of KDM6B protein was significantly lower than those in cancer-adjacent tissues and low-grade intraductal carcinoma tissues(P＜0.05);the relative expressions of EMMPRIN and MMP-9 proteins in invasive breast cancer tissues were significantly higher those in high-grade intraductal carcinoma tissues,and the relative expression of KDM6B protein was significantly lower than that in high-grade intraductal carcinoma tissues(P＜0.05);there was no statistically significant difference in the relative expressions of EMMPRIN,MMP-9 and KDM6B proteins between cancer-adjacent tissues and low-grade intraductal carcinoma tissues(P＞0.05).The relative expressions of EMMPRIN and KDM6B proteins were not related to the age,tumor location and tumor diameter of patients with invasive breast cancer(P＞0.05),and the relative expression of MMP-9 protein was not related to the age and tumor location of patients with invasive breast cancer(P＞0.05).Relative expressions of EMMPRIN,MMP-9 and KDM6B proteins were correlated with WHO grading,lymph node metastasis,and tumor,node and metastasis(TNM)staging of invasive breast cancer(P＜0.05),and the relative expression of MMP-9 protein was correlated with the tumor diameter(P＜0.05).In the WHO grades Ⅰ,Ⅱ,and Ⅲ of invasive breast cancer,the relative expressions of EMMPRIN and MMP-9 proteins increased sequentially,while the relative expression of KDM6B protein decreased sequentially(P＜0.05);the relative expressions of EMMPRIN and MMP-9 proteins in the lymph node metastasis group were significantly higher than those in the non-lymph node metastasis group,and the relative expression of KDM6B protein was significantly lower than that in the non-lymph node metastasis group(P＜0.05);the relative expressions of EMMPRIN and MMP-9 proteins in TNM stages Ⅲ-Ⅳ were significantly higher than those in stages Ⅰ-Ⅱ(P＜0.05),while the relative expression of KDM6B protein was significantly lower than that in stages Ⅰ-Ⅱ(P＜0.05).In the group of invasive breast cancer with diameter≤2 cm,2 to 5 cm,and＞5 cm,the relative expression of MMP-9 protein increased sequentially(P＜0.05).Spearman correlation analysis showed that the expression of EMMPRIN was positively correlated with MMP-9 protein in invasive breast cancer tissues(r=0.990,P=0.000),the expression of EMMPRIN was negatively correlated with KDM6B protein(r=-0.606,P=0.000),and the expression of MMP-9 was negatively correlated with KDM6B protein(r=-0.612,P=0.000).ROC curve analysis showed that the area under the curve(AUC)of EMMPRIN protein for diagnosing invasive breast cancer was 0.875[95％confidence interval(CI):0.823-0.926,P＜0.05],with an optimal threshold of 10.043,sensitivity of 79.0％,and specificity of 76.8％;the AUC of MMP-9 protein in diagnosing invasive breast cancer was 0.863(95％CI:0.808-0.917,P＜0.05),with an optimal threshold of 10.070,sensitivity of 74.2％,and specificity of 76.8％;the AUC of KDM6B protein in diagnosing invasive breast cancer was 0.267(95％CI:0.196-0.338,P＜0.05),with an optimal threshold of 11.003,sensitivity of 71.0％,and specificity of 98.6％.Conclusion EMMPRIN,MMP-9 and KDM6B are related to the occurrence and development of invasive breast cancer.Detection of the expressions of EMMPRIN,MMP-9 and KDM6B is helpful to the pathological diagnosis of invasive breast cancer and clinical judgment of invasion and metastasis of breast cancer.

Changes in m6A demethylase ALKBH5 expression in form-deprivation myopic guinea pigs and its significance / 中华实验眼科杂志

Objective:To investigate the alteration of m6A demethylase AlkB homolog 5 (ALKBH5) expression and its impact on form-deprivation myopia (FDM) retina in guinea pigs.Methods:Thirty normal SPF grade 3-week-old tricolor guinea pigs were randomly divided into normal control group and experimental group, with 15 in each group.In the experimental group, the right eyes were covered as FDM group and the left eyes uncovered were set as self-control group.Ocular biometry was performed at one-week intervals from baseline to week 4 of the experiment.Spherical equivalent was detected by streak retinoscopy and axial length was measured by A-scan ultrasonography.Animals were sacrificed after 4 weeks of modeling.The distribution and expression of ALKBH5 protein in the guinea pig retina was detected by immunohistochemical and immunofluorescence staining.Expression of ALKBH5 mRNA and protein in guinea pig retina was detected by real-time fluorescence quantitative PCR and Western blot, respectively.The use of animals in ophthalmic and vision research followed the tenets of Animal Research in Vision and Ophthalmology, and the study was approved by the Ethics Committee of North Sichuan Medical College (No.2023087).Results:At weeks 2, 3, and 4 after myopia induction, diopters and axial lengths were significantly higher in the FDM group than in the normal control group and the self-control group (all at P<0.001). Immunohistochemistry and immunofluorescence assays showed that ALKBH5 protein was expressed in the retinal nerve fiber layer, rod/cone photoreceptor cells, and retinal pigment epithelium (RPE) layer, and was highly expressed in the retinal nerve fiber layer and RPE layer.The relative ALKBH5 immunofluorescence intensity in the normal control group, self-control group and FDM group was 1.000±0.204, 0.874±0.076 and 0.571±0.053, respectively, which was lower in the FDM group than in the normal control and self-control groups, showing statistically significant differences ( t=4.069, P=0.006; t=5.176, P=0.014). After 4 weeks of modeling, ALKBH5 mRNA and protein expressions were significantly lower in FDM group than in normal control and self-control groups (both at P<0.01). Conclusions:The expression of m6A demethylase ALKBH5 is decreased in the retina of FDM guinea pigs, suggesting that ALKBH5 and related m6A methylation modification may be involved in the development and progression of myopia.

The key role of RNA N 6-methyladenosine (m 6A) methylation in tumor radiotherapy and radiation damage repair / 中华放射医学与防护杂志

N 6-methyladenosine (m 6A) is the most abundant epigenetic modification in eukaryotic messenger RNA (mRNA), which could be catalyzed by m 6A methyltransferase (Writers), recognized by methylation recognition enzymes (Readers), and removed by demethylase (Erasers). RNA splicing, translation, and stability could be modulated by m 6A methylation modification. The m 6A methylation modification is involved in the biological regulation of a variety of important functional genes in cellular activities. Importantly, abnormal m 6A modification affects the occurrence, development, metastasis and recurrence of tumors. Ionizing radiation can affect the level of m 6A and m 6A methylation-related enzymes. Recently, m 6A methylation is reported to regulate the efficacy of tumor radiotherapy by affecting DNA damage and radiosensitivity of tumor cells. In addition, ionizing radiation can also affect the level of m 6A modification in normal cells to regulate the progress of radiation-induced injuries. This review summarizes the research progress on the roles of m 6A methylation in tumor radiosensitivity and radiation-induced injuries, with the aim of providing novel strategies for the development of clinical tumor radiosensitizers and radioprotective agents.

Effect of oral exposure to trichloroethylene on JMJD3 expression and polarization of M1 Kupffer cells / 环境与职业医学

Background Trichloroethylene (TCE) can enter human body through biological accumulation of polluted water or air, resulting in health hazards. The most commonly involved organs are the liver. Objective To observe potential polarization of M1 Kupffer cells (KCs) in mice liver exposed to TCE orally, and to investigate the relationship between histones lysin demethylase JMJD3 and M1 KCs polarization. Methods A total of 72 SPF BALB/c mice aged 6 to 8 weeks were randomly divided into a blank control group (n=18), a vehicle control group (n=18), a 2.5 mg·mL−1 TCE group (n=18), and a 5.0 mg·mL−1 TCE group (n=18) after adaptive feed for one week. A TCE transoral exposure model was established after eight weeks of administration according to previous research of the research group. In the 2nd, 4th, and 8th weeks, the mice were sacrificed and liver tissue samples were collected. Western blotting was used to detect the expression level of JMJD3 in the liver tissue samples. Immunofluorescence was used to co-locate the macrophage marker F4/80 and the surface marker CD11c of M1 macrophages. Immunohistochemistry was used to detect the expressions of CD16/32, a marker of M1 macrophages, and TNF-α, an inflammatory factor of M1 macrophages in mouse liver. Results In the 2nd, 4th, and 8th weeks, the mice in each group were generally in good condition, and no individual died due to TCE. There was no statistically significant difference in the amount of water consumed by each group, nor in the body weight gain and the liver coefficient of mice at each time point (P>0.05). The results of Western blotting analysis showed that there was no statistically significant difference in JMJD3 protein expression level between the blank control group and the vehicle control group at each time point, the expression levels of JMJD3 protein in the 2.5 mg·mL−1 TCE group and the 5.0 mg·mL−1 TCE group were higher than that in the control group , and the expression level of JMJD3 protein in the 5.0 mg·mL−1 TCE group was higher than that in the 2.5 mg·mL−1 TCE group (P<0.05). The results of immunofluorescence co-localization showed that the expressions of F4/80 and CD11c were low in the blank control group and the vehicle control group, while the expressions of F4/80 and CD11c were increased in the 2.5 mg·mL−1 and the 5.0 mg·mL−1 TCE groups. The results of immunohistochemistry showed that the expressions of CD16/32 and TNF-α in the blank control group and the vehicle control group were low, and there were large deposits in the 2.5 mg·mL−1 TCE group and the 5.0 mg·mL−1 TCE group. Conclusion The polarization of M1 KCs and the expression of proinflammatory factors may be related to an increased expression level of JMJD3 induced by oral TCE exposure.

Expressions of m6A methyltransferases and their associations with microR-21 and transforming growth factor-β1 in kidney of rats exposed to cadmium / 环境与职业医学

Background Environmental pollutants can affect N6-methyladenosine (m6A) level in the body, but the change of m6A level in kidney after being exposed to cadmium (Cd) and the molecular mechanism of renal injury need to be further studied. Objective To analyze the associations of m6A modification and methyltransferases/demethylases with microRNA-21 (miR-21) and transforming growth factor- β1 (TGF - β1) in kidney of rats exposed to Cd. Methods Twenty-four SPF male SD rats were divided into 4 groups, with 6 rats in each group, and were exposed to Cd by subcutaneous injection of 2.0, 1.0, and 0.5 mg·kg−1 cadmium chloride (CdCl2) and equal volume of normal saline for 2 weeks, 7 d a week, respectively. The levels of N-acetyl-β-D-glucosidase (UNAG) and albumin (UALB) in urine, and the levels of m6A methylation and TGF-β1 in kidney were detected by enzyme-linked immunosorbent assay (ELISA). The level of blood urea nitrogen (BUN) was measured by urease method. The levels of renal oxidative stress indicators such as malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) were detected by total bile acid method, water-soluble tetrazolium asssay, and colorimetric method respectively. The relative levels of TGF-β1, methyltransferases, and demethylases in kidney were measured by reverse transcription-polymerase chain reaction. The expression of miR-21 in kidney was detected by fluorescent quantitative polymerase chain reaction. Results After 2 weeks of exposure to Cd, the body weights of rats in the 2.0 and 1.0 mg·kg−1 cadmium chloride groups decreased, and the ratio of kidney/body weight and the levels of BUN, UNAG, and TGF-β1 mRNA and protein increased in the 2.0 mg·kg−1 cadmium chloride group (P<0.05). The expression levels of m6A modification, methyltransferases METTL3, METTL14, Wilms’ tumor 1-associated protein (WTAP), and miR-21 were increased both in the 2.0 and 1.0 mg·kg−1 cadmium chloride groups, with significant differences compared with the control group (P<0.05). The results of correlation analysis showed that the m6A modification level was negatively correlated with SOD (r=−0.4489, P<0.05) and GSH-Px (r=−0.4874, P<0.05), METTL3 was negatively correlated with MDA (r=−0.5158, P<0.05), while there was a positive correlation between FTO and GSH-Px (r=0.4802, P<0.05). In addition, miR-21 was positively correlated with METTL3 (r=0.7491), METTL14 (r=0.6157), and WTAP (r=0.6660) (P<0.05), TGF-β1 was positively correlated with METTL3 (r=0.5025, P<0.05) but negatively correlated with FTO (r=−0.5634, P<0.05) . Conclusion Cd can induce m6A methylation and up-regulation of METTL3, METTL14, WTAP, and miR-21 expression levels in rat kidney tissues, indicating that m6A and miR-21 may be associated with Cd-induced renal fibrosis.

Effects of aluminum on expressions of fat mass and obesity-associated protein and brain-derived neurotrophic factor in rat brain and PC12 cells / 环境与职业医学

Background Chemical modification of RNA is a recent hotspot in the field of epigenetics, but the specific mechanism of chemical modification of RNA in aluminum neurotoxicity has not been fully reported. Objective To investigate the alterations of fat mass and obesity-associated protein (FTO), that demethylates N6-methyladenosine (m6A), and brain-derived neurotrophic factor (BDNF) in different brain regions of rats and rat adrenal pheochromocytoma differentiated cells (PC12 cells) following aluminum exposure. Methods Animal experiment: Twenty-four healthy male SD rats were randomly divided into a control group (normal saline) and 10, 20, and 40 μmol·kg−1 exposure groups according to body weight, with 6 rats in each group. Maltol aluminum [Al(mal)3] was injected intraperitoneally every other day for 3 months. Cell experiment: PC12 cells were divided into a control group and 100, 200, and 400 μmol·L−1 exposure groups exposed to Al(mal)3 for 24 h. After exposure, the learning and memory ability of rats was measured by water maze experiment, and the protein expression levels of FTO and BDNF in rat cortex (n=6) and hippocampus (n=6) samples as well as in PC12 cells (n=5) were determined by Western blotting. Results The results of water maze test showed that the escape latency of the 40 μmol·kg−1Al(mal)3 group was higher than those of the control group, the 10 μmol·kg−1Al(mal)3 group, and the 20 μmol·kg−1Al(mal)3 group on day 3, 4, and 5 of training (P<0.05). The retention time of the target quadrant of the 40 μmol·kg−1Al(mal)3 group was also reduced compared with that of the control group (P<0.05), indicating that aluminum exposure damaged the learning and memory ability of the rats. The Western blotting results showed that in the cortex, compared with the control group, the protein expression levels of FTO and BDNF in the aluminum treated groups were decreased (P<0.05). In the hippocampus, compared with the control group, the protein expression levels of FTO and BDNF in the 20 μmol·kg−1 and the 40 μmol·kg−1Al(mal)3 groups were decreased (P<0.05). In PC12 cells, compared with the control group, the protein expression levels of FTO and BDNF in the aluminum treated groups were decreased (P<0.05). Conclusion Aluminum-induced learning and memory impairment is related to a simultaneous reduction of FTO and BDNF protein expressions, suggesting that m6A methylation may be involved.

Research progress of N6-methyladenine demethylase inhibitors / 中国药科大学学报

@#N6-methyladenine (m6A) modification, the most abundant and dynamic chemical modification on messenger RNA, plays an essential role in physiological and pathological progress.Recent studies have found that tumor progression can be affected by altering the m6A modification level of target genes. Therefore, small molecule targeted m6A demethylase can be used as a new anti-tumor strategy.This review focuses on the regulatory mechanism of m6A demethylases, including fat mass and obesity-associated protein (FTO) and AlkB homlog 5 (ALKBH5), as well as their biological functions in tumors, and summarizes the research progress of their small molecule inhibitors.

Promising natural lysine specific demethylase 1 inhibitors for cancer treatment: advances and outlooks / 中国天然药物

Lysine specific demethylase 1 (LSD1), a transcriptional corepressor or coactivator that serves as a demethylase of histone 3 lysine 4 and 9, has become a potential therapeutic target for cancer therapy. LSD1 mediates many cellular signaling pathways and regulates cancer cell proliferation, invasion, migration, and differentiation. Recent research has focused on the exploration of its pharmacological inhibitors. Natural products are a major source of compounds with abundant scaffold diversity and structural complexity, which have made a major contribution to drug discovery, particularly anticancer agents. In this review, we briefly highlight recent advances in natural LSD1 inhibitors over the past decade. We present a comprehensive review on their discovery and identification process, natural plant sources, chemical structures, anticancer effects, and structure-activity relationships, and finally provide our perspective on the development of novel natural LSD1 inhibitors for cancer therapy.

Recent advance in N6-methyladenine methylation regulating neurodevelopment and neurological diseases / 中华神经医学杂志

Among the abundant known modifications that occur within messenger RNA (mRNA), N6-methyladenine (m6A) is the most common post-transcriptional modification in eukaryotes, accounting for almost 80% of all RNA methylation modification. At molecule level, m6A, a reversible modification, participates in regulation of the shearing, nucleation, translation, and degradation of mRNA. Existing studies have also revealed that m6A modification is involved in multiple physiological and pathological processes such as DNA damage repair, stem cell self-renew and differentiation, growth and development, learning and memory, and immune regulation; this kind of modification has also become an important research direction in the field of neuroscience recently. This article mainly summarizes recent processes in the molecular mechanisms of m6A methylation and its relevance to the neurodevelopment and neurological diseases, with aim to provide a comprehensive understanding of m6A regulation in this research area.

Role of N6-methyladenosine in the development and progression of hepatocellular carcinoma / 临床肝胆病杂志

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and has relatively high incidence and mortality rates. Abnormal modification of N6-methyladenosine (m6A) may promote the development and progression of HCC. This article describes the structure and function of m6A and summarizes the mechanism of action of methylase complexes which decide the function of m6A in HCC, including methyltransferases (writers), demethylases (erasers), and m6A-binding proteins (readers). It is pointed out that more in-depth studies are needed to clarify the diverse and specific role of methylase complexes in HCC, so as to help them become the new targets for the prevention and treatment of HCC in the future.

Effect of histone methylation and its inhibitors on the progression of colorectal cancer / 国际生物医学工程杂志

Colorectal cancer is a malignant tumor occurring in the colon or rectum, which has a high incidence rate. In order to improve the prognosis of colorectal cancer, the pathogenesis of colorectal cancer still needs to be further clarified. Epigenetics can directly affect the progression and metastasis of colorectal cancer, and histone methylation is an important means of histone modification, which can regulate the transcriptional activation and inhibition of downstream genes. A large number of studies have confirmed the effects of histone methylation on the progression of colorectal cancer, and inhibitors of related methylation and demethylation may play a role as potential therapeutic drugs for colorectal cancer. In this article, the colorectal cancer and its related methylation regulation were introduced, the types of histone methylation modifications and their regulation were summarized, and the regulation of histone methyltransferases and demethylases involved in the progression of colorectal cancer was demonstrated. In addition, the potential significance of histone methylation inhibitors for the treatment of colorectal cancer was summarized, and the possibility of related inhibitors as treatment drugs for colorectal cancer was explored.

HistonedemethylaseJMJD3promotesthestemnessofdiffuselargeBcelllymphoma cells / 中国肿瘤生物治疗杂志

@#[Abstract] Objective: To investigate the effect of histone demethylase JMJD3 (jumonji domain-containing protein 3) on the stemness of diffuse large B-cell lymphoma (DLBCL) cells. Methods: The relationship between the expression of JMJD3 and the overall survival of DLBCL patients was analyzed using the clinical data of DLBCL patients in TCGA database. The control plasmid (pCMV) and JMJD3 expression plasmid(pCMV-JMJD3)weretransfectedintoDLBCLcellsofABCandGCBsubtype via lipofectamine transfection. Then, the mRNAlevels of JMJD3,ALDH1, OCT4 and SOX2 were detected by RT-PCR and qPCR; the activity ofALDH1 enzyme was detected by Flow cytometry; the protein expressions of OCT4 and SOX2 were detected by Western blotting. Gene enrichment in DLBCL patients with high JMJD3 expression was analyzed by gene set enrichment analysis (GSEA). Results: The result of prognosis analysis showed that high expression of JMJD3 was related with poor prognosis in DLBCL patients (P<0.05); however, multivariate analysis showed that the expression of JMJD3 was not the independent factor affecting the prognosis of DLBCL patients (all P>0.05). The expression of JMJD3 was remarkably increased in DLBCL cells transfected with pCMV-JMJD3, which led to significantly increased mRNA level and enzyme activity of ALDH1 as well as up-regulated mRNA and protein expressions of OCT4 and SOX2 (P<0.05 or P<0.01). GSEA analysis showed that enrichment of Wnt/β-catenin signaling pathway related gene set was observed in DLBCL patients with high JMJD3 expression (P<0.05). Conclusion: JMJD3 promotes the stemness of DLBCL cells, which may be a potential therapeutic target for DLBCL patients.

Effect of RNA N6-methyladenosine on immunoregulation / 上海交通大学学报（医学版）

N6-methyladenosine (m6A) is the most prevalent and abundant post-transcriptional RNA modification in eukaryotes. m6A is a dy-namic and reversible process catalyzed by m6A methyltransferase complex and demethylase. m6A is involved in the regulations of gene expres-sion and biological processes. Recently, researches have discovered that m6A plays a vital role in the differentiation and regulation of immune cells, which could provide a new idea for the research and therapy of immune-related diseases. The present article reviews the recent progresses of m6A in immunoregulation.

Knocking down LSD1 inhibits the stemness features of colorectal cancer stem cells

As a top leading cause of cancer death in many countries, colorectal cancer (CRC) has drawn increasing attention to the study of the pathological mechanism. According to the "cancer stem cell hypothesis", malignancies originate from a small fraction of cancer cells that show self-renewal properties to initiate and sustain tumor growth and tumor metastasis. Therefore, these cancer stem cells (CSC) probably play important roles in tumor recurrence, metastasis, and drug resistance. Previous research reported that lysine-specific histone demethylase 1 (LSD1) maintains cancer stemness through up-regulating stemness markers SOX2 and OCT4. CD133 is believed to be the most robust surface marker for CRC stem cells, however the regulatory effect of LSD1 on stemness of CD133+ CRC has never been reported. In this study, our objectives included: 1) to isolate pure CD133+ and CD133− cells from SW620 cell line; 2) to investigate the effect of LSD1 on the characteristics of CD133+ stem cancer cells by knocking down the target gene. Results suggested that the SW620 cell line had both CD133+ and CD133− subsets. The CD133+ subset exhibited more CSC-like characteristics compared with the CD133− subset with higher viability, colony formation rate, migration and invasion rate, resistance to anti-cancer drugs, and apoptosis in vitro. The CD133+ also induced faster tumor formation and larger tumors in vivo. In the LSD1-knockdown CD133+ cells, the CSC-like characteristics had been all weakened. We conclude that LSD1 was important for CSCs to maintain their "stemness" features, which could be a potential therapeutic target of CRC.

Expressions of LSD1, MGMT and Ki-67 in high-grade glioma and their influences on prognosis / 国际肿瘤学杂志

Objective To investigate the expressions of histone lysine-specific demethylase 1 (LSD1),O6-methylguanine DNA methyltransferase (MGMT) and cell proliferation-associated antigen Ki-67 in high-grade glioma and their influences on prognosis.Methods Sixty-five cases of grade Ⅲ and Ⅳ glioma confirmed by pathology from January 2011 to June 2017 in the First Affiliated Hospital of Xinjiang Medical University were selected.Immunohistochemistry (SP method) was used to detect the expressions of LSD1,MGMT and Ki-67 in pathological specimens.The therapeutic effect was evaluated by long-term follow-up.The relationships between the three markers and pathological grade,progression-free survival (PFS) and overall survival (OS) were analyzed.Results The overall positive rates of LSD1,MGMT and Ki-67 in the 65 high-grade glioma specimens were 70.8％ (46/65),60.0％ (39/65) and 100.0％ (65/65),respectively.There were no significant differences in the expressions of LSD1 and MGMT in grade Ⅲ and Ⅳ glioma (x2 =1.588,P =0.208,x2 =0.013,P=0.908).Ki-67 expression (+),(++),(+++) in grade Ⅳ glioma were observed in 18,19 and 11 cases,respectively.Ki-67 expression (+),(++) in grade Ⅲ glioma were observed in 11,5 cases,and 1 case was (+++),and the difference in expression intensity between the two groups was statistically significant (Z =-2.083,P =0.037).Log-rank test showed that the positive expressions of LSD1,MGMT and Ki-67 were negatively correlated with the PFS of patients with high-grade glioma (x2 =12.217,P =0.007;x2=4.446,P =0.035;x2=12.536,P =0.002),also were negatively correlated with OS (x2 =11.708,P =O.008;x2 =6.637,P =0.010;x2 =11.807,P =0.003).Grade Ⅳ patients were more likely to have relapse progression than grade Ⅲ patients (x2 =6.573,P =0.010),and OS was shorter (x2 =3.974,P=0.046).Cox proportional hazards model analysis showed that the expressions of LSD1 (HR =1.361,95％CI:1.094-1.694,P=0.006;HR=1.406,95％CI:1.117-1.771,P =0.004) and Ki-67 (HR=1.703,95％ CI:1.175-2.468,P =0.005;HR =1.778,95％ CI:1.209-2.616,P =0.003) were the independent prognostic risk factors for PFS and OS of patients with high-grade glioma.Correlation analysis results showed that the expression of MGMT was positively correlated with the expression of LSD1 (r =0.406,P =0.001).Conclusion LSD1,MGMT and Ki-67 have higher positive expression rates in high-grade glioma.MGMT is a prognostic factor for high-grade glioma,and LSD1 and Ki-67 can be used as independent predictors of prognosis for high-grade gliomas.