Objective To investigate the mechanism of in alleviating colonic mucosal inflammation in ten-eleven translocation(TET)protein 2 gene knockout(TET2^(-/-))mice with ulcerative colitis(UC)by regulating DNA methyltransfer...Objective To investigate the mechanism of in alleviating colonic mucosal inflammation in ten-eleven translocation(TET)protein 2 gene knockout(TET2^(-/-))mice with ulcerative colitis(UC)by regulating DNA methyltransferase(DNMT)and DNA hydroxymethylase.Methods Male specific pathogen-free(SPF)grade C57BL/6J wild-type(WT)mice(n=8)and TET2^(-/-)mice(n=20)were used to establish UC models by freely drinking 3%dextran sulfate sodium solution for 7 d.After UC model validation through histopathological examination in two mice from each type,the remaining mice were divided into four groups(n=6 in each group):WT model(WT+UC),TET2^(-/-)model(TET2^(-/-)+UC),TET2^(-/-)mild moxibustion(TET2^(-/-)+MM),and TET2^(-/-)electroacupuncture(TET2^(-/-)+EA)groups.TET2^(-/-)+MM group received mild moxibustion on Tianshu(ST25)and Qihai(CV6)for 10 min daily for 7 d.The TET2^(-/-)+EA group also applied electroacupuncture(1 mA,2/100 Hz)at the same acupoints for 10 min daily for 7 d.The disease activity index(DAI)scores of each group of mice were accessed daily.The colon lengths of mice in groups were measured following intervention.The pathological changes in the colon tissues were observed with hematoxylin and eosin(HE)staining.The concentrations of interleukin(IL)-6,C-C motif chemokine 17(CCL17),and C-X-C motif chemokine ligand 10(CXCL10)in serum were detected by enzyme-linked immunosorbent assay(ELISA).The expression of DNMT proteins(DNMT1,DNMT3A,and DNMT3B)in the colon tissues was detected by immunohistochemistry.The expression of 5-methylcytosine(5-mC),5-hydroxymethylcytosine(5-hmC),histone deacetylase 2(HDAC2),and DNA hydroxymethylase family proteins(TET 1 and TET3)was detected using immunofluorescence,which also determined the co-localization of TET1 and IL-6 protein.Results Compared with WT+UC group,TET2^(-/-)+UC group exhibited significantly higher DAI scores and shorter colon lengths(P<0.01).Both mild moxibustion and electroacupuncture significantly decreased DAI scores and ameliorated colon shortening in TET2^(-/-)mice(P<0.001).Histopathological scores of TET2^(-/-)+UC mice were significantly higher than those of WT+UC group(P<0.001)and were significantly reduced after both mild moxibustion and electroacupuncture interventions(P<0.001).Serum levels of IL-6,CCL17,and CXCL10 were significantly elevated in TET2^(-/-)+UC group compared with WT+UC group(P<0.001).Mild moxibustion significantly reduced IL-6,CCL17,and CXCL10 levels(P<0.001,P<0.001,and P<0.01,respectively),while electroacupuncture also significantly reduced IL-6,CCL17,and CXCL10 levels(P<0.05,P<0.01,and P<0.01,respectively).TET2^(-/-)+UC mice showed increased expression levels of DNMT1,DNMT3A,DNMT3B,and 5-mC(P<0.05,P<0.01 and P<0.001,respectively),with decreased expression levels of TET1,TET3,5-hmC,and HDAC2(P<0.001).Mild moxibustion significantly reduced DNMT1,DNMT3B,and 5-mC levels(P<0.05,P<0.01,and P<0.001,respectively),while increasing expression levels of TET1,TET3,5-hmC,and HDAC2(P<0.001,P<0.001,P<0.05,and P<0.001,respectively).Electroacupuncture significantly decreased 5-mC and DNMT3B levels(P<0.001 and P<0.01,respectively)and increased 5-hmC and HDAC2 levels(P<0.05 and P<0.001,respectively),but did not significantly affect TET1 and TET3 expression(P>0.05).Compared with TET2^(-/-)+MM group,TET2^(-/-)+EA group showed significantly higher 5-mC expression(P<0.001).TET2^(-/-)+UC group exhibited markedly increased IL-6 expression and higher co-localization of TET1 and IL-6 in mucosal epithelium,whereas minimal IL-6 expression was observed in the other groups.Conclusion Mild moxibustion and electroacupuncture significantly ameliorate colonic inflammation exacerbated by TET2 deficiency in UC mice via epigenetic modulation.Distinct mechanisms exist between the two interventions:mild moxibustion regulates both DNMT and hydroxymethylase,whereas electroacupuncture primarily affects DNMT.展开更多
Hypoxemia is a common pathological state characterized by low oxygen saturation in the blood.This condition compromises mucosal barrier integrity particularly in the gut and oral cavity.However,the mechanisms underlyi...Hypoxemia is a common pathological state characterized by low oxygen saturation in the blood.This condition compromises mucosal barrier integrity particularly in the gut and oral cavity.However,the mechanisms underlying this association remain unclear.This study used periodontitis as a model to investigate the role of platelet activation in oral mucosal immunopathology under hypoxic conditions.Hypoxia upregulated methyltransferase-like protein 4(METTL4)expression in platelets,resulting in N6-methyladenine modification of mitochondrial DNA(mtDNA).This modification impaired mitochondrial transcriptional factor A-dependent cytosolic mtDNA degradation,leading to cytosolic mtDNA accumulation.Excess cytosolic mt-DNA aberrantly activated the cGAS-STING pathway in platelets.This resulted in excessive platelet activation and neutrophil extracellular trap formation that ultimately exacerbated periodontitis.Targeting platelet METTL4 and its downstream pathways offers a potential strategy for managing oral mucosa immunopathology.Further research is needed to examine its broader implications for mucosal inflammation under hypoxic conditions.展开更多
BACKGROUND Centromere protein A(CENPA)exhibits an increased expression level in primary human rectal cancer tissues,but its role has not been investigated.AIM To clarify the specific role and mechanism of CENPA in rec...BACKGROUND Centromere protein A(CENPA)exhibits an increased expression level in primary human rectal cancer tissues,but its role has not been investigated.AIM To clarify the specific role and mechanism of CENPA in rectal cancer progression.METHODS CENPA protein expression in rectal cancer tissues and cell lines were detected.CENPA was overexpressed and knocked down in SW837 and SW480 cells,and proliferation,invasion,apoptosis and epithelial-mesenchymal transition(EMT)marker protein levels were examined.O6-methylguanine DNA methyltransferase(MGMT)promoter methylation was assessed with methylation-specific poly-merase chain reaction.Co-immunoprecipitation assay verified the interaction between MGMT and protein tyrosine phosphatase nonreceptor type 4(PTPN4).SW837 cells with CENPA knockdown were injected subcutaneously into mice,and tumor growth was examined.RESULTS CENPA was upregulated in rectal cancer tissues and cell lines.CENPA overex-pression promoted proliferation,invasion and EMT,and inhibited apoptosis in rectal cancer cells.Whereas CENPA knockdown showed the opposite results.Moreover,CENPA inhibited MGMT expression by promoting DNA methyltrans-ferase 1-mediated MGMT promoter methylation.MGMT knockdown abolished the CENPA knockdown-mediated inhibition of rectal cancer cell progression.MGMT increased PTPN4 protein stability by inhibiting PTPN4 ubiquitination degradation via competing with ubiquitin-conjugating enzyme E2O for interacting with PTPN4.PTPN4 knockdown abolished the inhibitory effects of MGMT overexpression on rectal cancer cell progression.Moreover,CENPA knockdown inhibited xenograft tumor growth in vivo.CONCLUSION CENPA knockdown inhibited rectal cancer cell growth and attenuated xenograft tumor growth through regulating the MGMT/PTPN4 axis.展开更多
BACKGROUND Diabetic wound injury is a significant and common complication in individuals with diabetes.N6-methyladenosine(m6A)-related epigenetic regulation is widely involved in the pathogenesis of diabetes complicat...BACKGROUND Diabetic wound injury is a significant and common complication in individuals with diabetes.N6-methyladenosine(m6A)-related epigenetic regulation is widely involved in the pathogenesis of diabetes complications.However,the function of m6A methyltransferase Wilms tumor 1-associated protein(WTAP)in diabetic wound healing remains elusive.AIM To investigate the potential epigenetic regulatory mechanism of WTAP during diabetic wound healing.METHODS Human umbilical vein endothelial cells(HUVECs)were induced with high glucose(HG)to establish in vitro cell model.Male BALB/c mice were intraperitoneally injected with streptozotocin to mimic diabetes,and full-thickness excision was made to mimic diabetic wound healing.HG-induced HUVECs and mouse models were treated with WTAP siRNAs and DNA methyltransferase 1(DNMT1)overexpression vectors.Cell viability and migration ability were detected by cell counting kit-8 and Transwell assays.In vitro angiogenesis was measured using a tube formation experiment.The images of wounds were captured,and re-epithelialization and collagen deposition of skin tissues were analyzed using hematoxylin and eosin staining and Masson’s trichrome staining.RESULTS The expression of several m6A methyltransferases,including METTL3,METTL14,METTL16,KIAA1429,WTAP,and RBM15,were measured.WTAP exhibited the most significant elevation in HG-induced HUVECs compared with the normal control.WTAP depletion notably restored cell viability and enhanced tube formation ability and migration of HUVECs suppressed by HG.The unclosed wound area of mice was smaller in WTAP knockdowntreated mice than in control mice at nine days post-wounding,along with enhanced re-epithelialization rate and collagen deposition.The m6A levels on DNMT1 mRNA in HUVECs were repressed by WTAP knockdown in HUVECs.The mRNA levels and expression of DNMT1 were inhibited by WTAP depletion in HUVECs.Overexpression of DNMT1 in HUVECs notably reversed the effects of WTAP depletion on HG-induced HUVECs.CONCLUSION WTAP expression is elevated in HG-induced HUVECs and epigenetically regulates the m6A modification of DNMT1 to impair diabetic wound healing.展开更多
BACKGROUND Cervical cancer(CC)stem cell-like cells(CCSLCs),defined by the capacity of differentiation and self-renewal and proliferation,play a significant role in the progression of CC.However,the molecular mechanism...BACKGROUND Cervical cancer(CC)stem cell-like cells(CCSLCs),defined by the capacity of differentiation and self-renewal and proliferation,play a significant role in the progression of CC.However,the molecular mechanisms regulating their self-renewal are poorly understood.Therefore,elucidation of the epigenetic mechanisms that drive cancer stem cell self-renewal will enhance our ability to improve the effectiveness of targeted therapies for cancer stem cells.AIM To explore how DNA methyltransferase 1(DNMT1)/miR-342-3p/Forkhead box M1(FoxM1),which have been shown to have abnormal expression in CCSLCs,and their signaling pathways could stimulate self-renewal-related stemness in CCSLCs.METHODS Sphere-forming cells derived from CC cell lines HeLa,SiHa and CaSki served as CCSLCs.Self-renewal-related stemness was identified by determining sphere and colony formation efficiency,CD133 and CD49f protein level,and SRY-box transcription factor 2 and octamer-binding transcription factor 4 mRNA level.The microRNA expression profiles between HeLa cells and HeLa-derived CCSLCs or mRNA expression profiles that HeLaderived CCSLCs were transfected with or without miR-342-3p mimic were compared using quantitative PCR analysis.The expression levels of DNMT1 mRNA,miR-342-3p,and FoxM1 protein were examined by quantitative real-time PCR and western blotting.In vivo carcinogenicity was assessed using a mouse xenograft model.The functional effects of the DNMT1/miR-342-3p/FoxM1 axis were examined by in vivo and in vitro gain-of-activity and loss-of-activity assessments.Interplay among DNMT1,miR-342-3p,and FoxM1 was tested by methylationspecific PCR and a respective luciferase reporter assay.RESULTS CCSLCs derived from the established HeLa cell lines displayed higher self-renewal-related stemness,including enhanced sphere and colony formation efficiency,increased CD133 and CD49f protein level,and heightened transcriptional quantity of stemness-related factors SRY-box transcription factor 2 and octamer-binding transcription factor 4 in vitro as well as a stronger tumorigenic potential in vivo compared to their parental cells.Moreover,quantitative PCR showed that the miR-342-3p level was downregulated in HeLa-derived CCSLCs compared to HeLa cells.Its mimic significantly decreased DNMT1 and FoxM1 mRNA expression levels in CCSLCs.Knockdown of DNMT1 or miR-342-3p mimic transfection suppressed DNMT1 expression,increased miR-342-3p quantity by promoter demethylation,and inhibited CCSLC self-renewal.Inhibition of FoxM1 by shRNA transfection also resulted in the attenuation of CCSLC self-renewal but had little effect on the DNMT1 activity and miR-342-3p expression.Furthermore,the loss of CCSLC self-renewal exerted by miR-342-3p mimic was inverted by the overexpression of DNMT1 or FoxM1.Furthermore,DNMT1 and FoxM1 were recognized as straight targets by miR-342-3p in HeLa-derived CCSLCs.CONCLUSION Our findings suggested that a novel DNMT1/miR-342-3p/FoxM1 signal axis promotes CCSLC self-renewal and presented a potential target for the treatment of CC through suppression of CCSLC self-renewal.However,this pathway has been previously implicated in CC,as evidenced by prior studies showing miR-342-3p-mediated downregulation of FoxM1 in cervical cancer cells.Additionally,research on liver cancer further supports the involvement of miR-342-3p in suppressing FoxM1 expression.While our study contributed to this body of knowledge,we did not present a completely novel axis but reinforced the therapeutic potential of targeting the DNMT1/miR-342-3p/FoxM1 axis to suppress CCSLC self-renewal in CC treatment.展开更多
Colitis-associated colorectal cancer(CAC),a serious complication of ulcerative colitis(UC),is associated with a poor prognosis.The vitamin D receptor(VDR)is recognized for its protective role in UC and CAC through the...Colitis-associated colorectal cancer(CAC),a serious complication of ulcerative colitis(UC),is associated with a poor prognosis.The vitamin D receptor(VDR)is recognized for its protective role in UC and CAC through the maintenance of intestinal barrier integrity and the regulation of inflammation.This study demonstrates a significant reduction in m^(6)A-related genes,particularly methyltransferase like 14(METTL14),in UC and CAC patients and identifies an association between METTL14 and VDR.In the azoxymethane(AOM)/dextran sodium sulfate(DSS)-induced mousemodel,vitamin D treatment increases METTL14 expression and reduces tumorburden,while Vdr-knockout mice exhibit lower METTL14 levels and increased tumorigenesis.In vitro,the VDR agonist calcipotriol upregulates METTL14 in NCM460 cells,with this effect attenuated by VDR knockdown.VDRknockdown inDLD-1colon cancer cellsdecreases METTL14 expressionand promotes proliferation,which is reversed by METTL14 overexpression.Mechanistic studies reveal that VDR regulates METTL14 expression via promoter binding,modulating key target genes such as SOX4,DROSH,and PHLPP2.This study highlights the role of the VDR-METTL14 axis as a protective mechanism in CAC and suggests its potential as a therapeutic target for preventing and treating CAC.展开更多
BACKGROUND Post-translational modifications play key roles in various biological processes.Protein arginine methyltransferases(PRMTs)transfer the methyl group to specific arginine residues.Both PRMT1 and PRMT6 have em...BACKGROUND Post-translational modifications play key roles in various biological processes.Protein arginine methyltransferases(PRMTs)transfer the methyl group to specific arginine residues.Both PRMT1 and PRMT6 have emerges as crucial factors in the development and progression of multiple cancer types.We posit that PRMT1 and PRMT6 might interplay directly or in-directly in multiple ways accounting for shared disease phenotypes.AIM To investigate the mechanism of the interaction between PRMT1 and PRMT6.METHODS Gel electrophoresis autoradiography was performed to test the methyltranferase activity of PRMTs and characterize the kinetics parameters of PRMTs.Liquid chromatography-tandem mass spectrometryanalysis was performed to detect the PRMT6 methylation sites.RESULTS In this study we investigated the interaction between PRMT1 and PRMT6,and PRMT6 was shown to be a novel substrate of PRMT1.We identified specific arginine residues of PRMT6 that are methylated by PRMT1,with R106 being the major methylation site.Combined biochemical and cellular data showed that PRMT1 downregulates the enzymatic activity of PRMT6 in histone H3 methylation.CONCLUSION PRMT6 is methylated by PRMT1 and R106 is a major methylation site induced by PRMT1.PRMT1 methylation suppresses the activity of PRMT6.展开更多
[Objective] This study aimed to conduct bioinformatics analysis of histone H3-1ys-4 （H3K4） methyltransferase MLL3 in animals, thus exploring its relatively conservative evolution to reveal the role of histon H3K4 tr...[Objective] This study aimed to conduct bioinformatics analysis of histone H3-1ys-4 （H3K4） methyltransferase MLL3 in animals, thus exploring its relatively conservative evolution to reveal the role of histon H3K4 trimethyltransferase MLL3 in human cancers. [Method] By using bioinformatics method, gene structure, amino acid sequences, phylogenetic tree, chromosomal localization and synteny of mouse MLL3 were analyzed. [Result] Primary structure of the encoded mouse MLL3 protein con- tained seven zinc finger domains, an HMG-box （High mobility group-box protein）, a FYRN （F/Y-rich N-terminus） domain, a FYRC （F/Yrich C-terminus） domain, a SET domain and a postSET domain. Results of sequence comparison and homology showed that 19 animal species in this study all had these structures basically, which indicated that these structures were relatively conserved in the evolution; specifically, the SET domain was highly conserved and was necessary to maintain the activity of histone methyltransferases. Results of phylogenetic analysis showed that the loca- tions of the 19 animal species in evolutionary tree were consistent with the taxo- nomic status. Results of synteny analysis showed that there were the same gene in the upstream and downstream of the mouse and human MLL3 gene which were located on different chromosomes, indicating that the mouse and human MLL3 gene had collinearity. [Conclusion] This study had revealed the primary structure of MLL3 nucleotide sequence and amino acid sequence, which had not only laid the foundation for the future research of high-level structure and function of MLL3 protein but also provided the basis for the follow-up study of primer design, promoter analysis, gene cloning and regulation patterns of localization and expression of mouse MLL3 gene.展开更多
Syntheses of 3 ketolanosterol, 3 acetolanosterol, 3 oximolanosterol, 3α and 3β aminolanosterol were described The products have been fully characterized on the basis of their chromatographic (TLC R f, GLC R...Syntheses of 3 ketolanosterol, 3 acetolanosterol, 3 oximolanosterol, 3α and 3β aminolanosterol were described The products have been fully characterized on the basis of their chromatographic (TLC R f, GLC RRTc) and spectral (IR, MS, 1 H NMR, 13 C NMR) properties展开更多
Mesenchymal stem cells （MSCs） are characterized by their self-renewing capacity and differentiation potential into multiple tissues. Thus, management of the differentiation capacities of MSCs is important for MSC-ba...Mesenchymal stem cells （MSCs） are characterized by their self-renewing capacity and differentiation potential into multiple tissues. Thus, management of the differentiation capacities of MSCs is important for MSC-based regenerative medicine, such as craniofacial bone regeneration, and in new treatments for metabolic bone diseases, such as osteoporosis. In recent years, histone modification has been a growing topic in the field of MSC lineage specification, in which the Su（var）3-9, enhancer-of-zeste, trithorax （SET） domain-containing family and the Jumonji C （JmjC） domain-containing family represent the major histone lysine methyltransferases （KMTs） and histone lysine demethylases （KDMs）, respectively. In this review, we summarize the current understanding of the epigenetic mechanisms by which SET domain-containine KMTs and JmiC domain-containinlz KDMs balance the osteogenic and adipogenic differentiation of MSCs.展开更多
AIM:To investigate the association between single nucleotide polymorphism (SNP) in promoter of the DNA methyltrans-ferase 3B(DNMT3B) gene and risk for development and lymphatic metastasis of gastric cardiac adenocarci...AIM:To investigate the association between single nucleotide polymorphism (SNP) in promoter of the DNA methyltrans-ferase 3B(DNMT3B) gene and risk for development and lymphatic metastasis of gastric cardiac adenocarcinoma (GCA). METHODS: The hospital based case-control study included 212 GCA patients and 294 control subjects without overt cancer. The DNMT3B SNP was genotyped by PCR and restriction fragment length polymorphism (RFLP) analysis. RESULTS: The C/C genotype was not detected in both GCA patients and controls. In control subjects, the frequency of T/T and C/T genotypes was 94.9% and 5.1% respectively, and that of T and C alleles was 97.4% and 2.6%, respectively. The genotype and allelotype distribution in the GCA patients was not significantly different from that in controls (P=0.34 and 0.33, respectively). When stratified by smoking status and family history of upper gastrointestinal cancer, significant difference in the genotype distribution was not observed between GCA patients and controls. The distribution of DNMT3B genotypes in GCA patents with or without lymphatic metastasis did not show significant difference (P= 0.42). CONCLUSION: The distribution of DNMT3B SNP in North China is distinct from that in Caucasians. Although this SNP has been associated with susceptibility to lung, head, neck and breast cancer, it may not be used as a stratification marker to predict susceptibility and lymphatic metastasis of GCA, at least in the population of North China.展开更多
High rate of abortion and developmental abnormalities is thought to be closely associated with inefficient epigenetic reprogramming of the transplanted nuclei during bovine cloning. It is known that one of the importa...High rate of abortion and developmental abnormalities is thought to be closely associated with inefficient epigenetic reprogramming of the transplanted nuclei during bovine cloning. It is known that one of the important mechanisms for epigenetic reprogramming is DNA methylation. DNA methylation is established and maintained by DNA methyltransferases （DNMTs）, therefore, it is postulated that the inefficient epigenetic reprogramming of transplanted nuclei may be due to abnormal expression of DNMTs. Since DNA methylation can strongly inhibit gene expression, aberrant DNA methylation of DNMT genes may disturb gene expression. But presently, it is not clear whether the methylation abnormality of DNMT genes is related to developmental failure of somatic cell nuclear transfer embryos. In our study, we analyzed methylation patterns of the 5＇ regions of four DNMT genes including Dnmt3a, Dnmt3b, Dnmtl and Dnmt2 in four aborted bovine clones. Using bisulfite sequencing method, we found that 3 out of 4 aborted bovine clones （AF1, AF2 and AF3） showed either hypermethylation or hypomethylation in the 5＇ regions of Dnmt3a and Dnmt3b, indicating that Dnmt3a and Dnmt3b genes are not properly reprogrammed. However, the individual AF4 exhibited similar methylation level and pattern to age-matched in vitro fertilized （IVF） fetuses. Besides, we found that the 5＇ regions of Dnmtl and Dnmt2 were nearly completely unmethylated in all normal adults, IVF fetuses, sperm and aborted clones. Together, our results suggest that the aberrant methylation of Dnmt3a and Dnmt3b 5＇ regions is probably associated with the high abortion of bovine clones.展开更多
AIM： To explore the relationship between DNA methyltransferase 1 （DNMT1） and hepatitis B virus （HBV）-related hepatocellular carcinoma （HCC） and its biological significance in primary HCC. METHODS： We carried o...AIM： To explore the relationship between DNA methyltransferase 1 （DNMT1） and hepatitis B virus （HBV）-related hepatocellular carcinoma （HCC） and its biological significance in primary HCC. METHODS： We carried out an immunohistochemical examination of DNMT1 in both HCC and paired nonneoplastic liver tissues from Chinese subjects. DNMT1 mRNA was further examined in HCC cell lines by real-time PCR. We inhibited DNMT1 using siRNA and detected the effect of depletion of DNMT1 on cell proliferation ability and cell apoptosis in the HCC celt line SMMC-7721. RESULTS： DNMT1 protein expression was increased in HCCs compared to histologically normal nonneoplastic liver tissues and the incidence of DNMT1 immunoreactivity in HCCs correlated significantly with poor tumor differentiation （P = 0.014）. There were more cases with DNMT1 overexpression in HCC with HBV （42.85%） than in HCC without HBV （28.57%）. However, no significant difference in DNMT1 expression was found in HBV-positive and HBV-negative cases in the Chinese HCC group. There was a trend that DNMT1 RNA expression increased more in HCC cell lines than in pericarcinoma cell lines and normal liver cell lines. In addition, we inhibited DNMT1 using siRNA in the SMMC-7721 HCC cell line and found depletion of DNMT1 suppressed cells growth independent of expression of proliferating cell nuclear antigen （PCNA）, even in HCC cell lines where DNMT1 was stably decreased. CONCLUSION： The findings implied that DNMT1 plays a key role in HBV-retated hepatocellular tumorigenesis. Depletion of DNMT1 mediates growth suppression in SMMC-7721 cells.展开更多
DNA methyltransferases(DNMTs)are an evolutionarily conserved family of DNA methylases,transferring a methyl group onto the fifth carbon of a cytosine residue.The mammalian DNMT family includes three major members that...DNA methyltransferases(DNMTs)are an evolutionarily conserved family of DNA methylases,transferring a methyl group onto the fifth carbon of a cytosine residue.The mammalian DNMT family includes three major members that have functional methylation activities,termed DNMT1,DNMT3A,and DNMT3B.DNMT3A and DNMT3B are responsible for methylation establishment,whereas DNMT1 maintains methylation during DNA replication.Accumulating evidence demonstrates that regulation of DNAmethylation by DNMTs is critical for normal hematopoiesis.Aberrant DNA methylation due to DNMT dysregulation and mutations is known as an important molecular event of hematological malignancies,such as DNMT3A mutations in acute myeloid leukemia.In this reviewwe first describe the basic methylation mechanisms of DNMTs and their functions in lymphocyte maturation and differentiation,We then discuss the current understanding of DNA methylation heterogeneity in leukemia and lymphoma to highlight the importance of studying DNA methylation targets.We also discuss DNMT mu-tations and pathogenic roles in human leukemia and lymphoma.We summarize the recent understanding of how DNMTs interact with transcription factors or cofactors to repress the expression of tumor suppressor genes.Firnally.we highlight current clinical studies using DNMT inhibitors for the treatment of these hematological malignancies.展开更多
Brassinosteroids （BRs） are an important class of plant steroidal hormones that are essential in a wide variety of physiological processes. Two kinds of intermediates, sitosterol and campesterol, play a crucial role ...Brassinosteroids （BRs） are an important class of plant steroidal hormones that are essential in a wide variety of physiological processes. Two kinds of intermediates, sitosterol and campesterol, play a crucial role in cell elongation, cellulose biosynthesis, and accumulation. To illuminate the effects of sitosterol and campesterol on the development of cotton （Gossypiurn hirsuturm L.） fibers through screening cotton fiber EST database and contigging the candidate ESTs, two key genes GhSMT2-1 and GhSMT2-2 controlling the sitosterol biosynthesis were cloned from developing fibers of upland cotton cv. Xuzhou 142. The full length of GhSMT2-1 was 1,151 bp, including an 8 bp 5＇-untranslated region （UTR）, a 1,086 bp open reading frame （ORF）, and a 57 bp 3＇-UTR. GhSMT2-1 gene encoded a polypeptide of 361 amino acid residues with a predicted molecular mass of 40 kDa. The full length of GhSMT2-2 was 1,166 bp, including an 18 bp 5＇-UTR, a 1,086 bp ORF, and a 62 bp 3＇-UTR. GhSMT2-2 gene encoded a polypeptide of 361 amino acid residues with a predicted molecular mass of 40 kDa. The two deduced amino acid sequences had high homology with the SMT2 from Arabidopsis thaliana and Nicotiana tabacurn. Furthermore, the typical conserved structures characterized by the sterol C-24 methyltransferase, such as region I （LDVGCGVGGPMRAI）, region II （IEATCHAP）, and region III （YEWGWGQSFHF）, were present in both deduced proteins. Southern blotting analysis indicated that GhSMT2-1 or GhSMT2-2 was a single copy in upland cotton genome. Quantitative real-time RT-PCR analysis revealed that the highest expression levels of both genes were detected in 10 DPA （day post anthesis） fibers, while the lowest levels were observed in cotyledon and leaves. The expression level of GhSMT2-1 was 10 times higher than that of GhSMT2-2 in all the organs and tissues detected. These results indicate that the homologue of sterol C-24 methyltransferase gene was cloned from upland cotton and both GhSMT2 genes play a crucial role in fiber elongation. The role of GhSMT2-1 may be more important than that of GhSMT2-2.展开更多
AIM: To evaluate the relationship between thiopu- rine S-methyltransferase (TPMT) polymorphisms and thiopurine-induced adverse drug reactions (ADRs) in inflammatory bowel disease (IBD). METHODS: Eligible articles that...AIM: To evaluate the relationship between thiopu- rine S-methyltransferase (TPMT) polymorphisms and thiopurine-induced adverse drug reactions (ADRs) in inflammatory bowel disease (IBD). METHODS: Eligible articles that compared the frequency of TPMT polymorphisms among thiopurine-tolerant and-intolerant adult IBD patients were included. Statistical analysis was performed with Review Manager 5.0. Sub-analysis/sensitivity analysis was also performed. RESULTS: Nine studies that investigated a total of 1309 participants met our inclusion criteria. The inci- dence of TPMT gene mutation was increased 2.93-fold (95% CI: 1.68-5.09, P = 0.0001) and 5.93-fold (95% CI: 2.96-11.88, P < 0.00001), respectively, in IBD patients with thiopurine-induced overall ADRs and bone marrow toxicity (BMT), compared with controls. The OR for TPMT gene mutation in IBD patients withthiopurine-induced hepatotoxicity and pancreatitis was 1.51 (95% CI: 0.54-4.19, P = 0.43) and 1.02 (95% CI: 0.26-3.99, P = 0.98) vs controls, respectively. CONCLUSION: This meta-analysis suggests that the TPMT polymorphisms are associated with thiopurine-induced overall ADRs and BMT, but not with hepatotoxicity and pancreatitis.展开更多
Melatonin is a pleiotropic signaling molecule that regulates plant growth and responses to various abiotic stresses.The last step of melatonin synthesis in plants can be catalyzed by caffeic acid O-methyltransferase(C...Melatonin is a pleiotropic signaling molecule that regulates plant growth and responses to various abiotic stresses.The last step of melatonin synthesis in plants can be catalyzed by caffeic acid O-methyltransferase(COMT),a multifunctional enzyme reported to have N-acetylserotonin O-methyltransferase(ASMT)activity;however,the ASMT activity of COMT has not yet been characterized in nonmodel plants such as watermelon(Citrullus lanatus).Here,a total of 16 putative O-methyltransferase(ClOMT)genes were identified in watermelon.Among them,ClOMT03(Cla97C07G144540)was considered a potential COMT gene(renamed ClCOMT1)based on its high identities(60.00–74.93%)to known COMT genes involved in melatonin biosynthesis,expression in almost all tissues,and upregulation under abiotic stresses.The ClCOMT1 protein was localized in the cytoplasm.Overexpression of ClCOMT1 significantly increased melatonin contents,while ClCOMT1 knockout using the CRISPR/Cas-9 system decreased melatonin contents in watermelon calli.These results suggest that ClCOMT1 plays an essential role in melatonin biosynthesis in watermelon.In addition,ClCOMT1 expression in watermelon was upregulated by cold,drought,and salt stress,accompanied by increases in melatonin contents.Overexpression of ClCOMT1 enhanced transgenic Arabidopsis tolerance against such abiotic stresses,indicating that ClCOMT1 is a positive regulator of plant tolerance to abiotic stresses.展开更多
DNA methyltransferase 1(DNMT1)is a useful biomarker for lung cancer in early clinical diagnosis.A rapid magnetic chemiluminescence immunoassay(MCLIA)for DNMT1 in human serum has been developed.Horseradish peroxidase(H...DNA methyltransferase 1(DNMT1)is a useful biomarker for lung cancer in early clinical diagnosis.A rapid magnetic chemiluminescence immunoassay(MCLIA)for DNMT1 in human serum has been developed.Horseradish peroxidase(HRP)-second-Ab was used to labeled polyclonal antibodies of anti-DNMT1.DNMT1 in sample integrates with specific immunomagnetic beads and can constitute a supersandwiched immunoreaction.In magnetic field,nonspecific materials can be separated.After luminescent substrate luminol-H2O2-BIP was added,the relative light unit(RLU)of HRP was detected and was discovered to be directly proportional to the content of DNMT1 in sample.The correlative variables involved in the MCLIA value were optimized and the methodological evaluation was carried out.After optimization,in the range of0.5–128 ng/mL,the linear regression equation was y=0.5014 x+1.769(x was logCDNMT1,y was relative luminescence units(RLU)/RLU0),and the limit of detection was 0.01 ng/mL.The RSD of intra-and interassays were 15.8%–16.9%and 14.3%–18.1%,respectively.The recovery was from 70.0%to 106.2%.Furthermore,paralleled with purchasable enzyme-linked immunosorbent assay(ELISA)kits,MCLEIA had lower detection limit,wider linear range and shorter detection time.Therefore,the MCLEIA established in this study could be used for the sensitive detection of DNMT1 in serum sample.展开更多
SETDB1 has been established as an oncogene in a number of human carcinomas. The present study was to evaluate the expression of SETDB1 in prostate cancer （PCa） tissues and cells and to preliminarily investigate the ...SETDB1 has been established as an oncogene in a number of human carcinomas. The present study was to evaluate the expression of SETDB1 in prostate cancer （PCa） tissues and cells and to preliminarily investigate the role of SETDB1 in prostate tumorigenesis in vitro. Quantitative reverse transcription polymerase chain reaction （qRT-PCR） and immunohistochemistry （IHC） were used to detect the expression of SETDB1 in PCa tissues, adjacent normal tissues, benign prostatic hyperplasia （BPH） tissues, PCa cell lines and normal prostate epithelial cells. The results suggested that SETDB1 was upregulated in human PCa tissues compared with normal tissues at the mRNA and protein levels. The role of SETDB1 in proliferation was analyzed with cell counting kit-8, colony-forming efficiency and flow cytometry assays. The results indicated that downregulation of SETDB1 by siRNA inhibited PCa cell growth, and induced GO/G1 cell cycle arrest. The PCa cell migration and invasion decreased by silcencing SETDBt which were assessed by using in vitro scratch and transwell invasion assay respectively. Our data suggested that SETDB1 is overexpressed in human PCa. Silencing SETDB1 inhibited PCa cell proliferation, migration and invasion.展开更多
基金National Natural Science Foundation of China(82274641,81873372,and 82105012).
文摘Objective To investigate the mechanism of in alleviating colonic mucosal inflammation in ten-eleven translocation(TET)protein 2 gene knockout(TET2^(-/-))mice with ulcerative colitis(UC)by regulating DNA methyltransferase(DNMT)and DNA hydroxymethylase.Methods Male specific pathogen-free(SPF)grade C57BL/6J wild-type(WT)mice(n=8)and TET2^(-/-)mice(n=20)were used to establish UC models by freely drinking 3%dextran sulfate sodium solution for 7 d.After UC model validation through histopathological examination in two mice from each type,the remaining mice were divided into four groups(n=6 in each group):WT model(WT+UC),TET2^(-/-)model(TET2^(-/-)+UC),TET2^(-/-)mild moxibustion(TET2^(-/-)+MM),and TET2^(-/-)electroacupuncture(TET2^(-/-)+EA)groups.TET2^(-/-)+MM group received mild moxibustion on Tianshu(ST25)and Qihai(CV6)for 10 min daily for 7 d.The TET2^(-/-)+EA group also applied electroacupuncture(1 mA,2/100 Hz)at the same acupoints for 10 min daily for 7 d.The disease activity index(DAI)scores of each group of mice were accessed daily.The colon lengths of mice in groups were measured following intervention.The pathological changes in the colon tissues were observed with hematoxylin and eosin(HE)staining.The concentrations of interleukin(IL)-6,C-C motif chemokine 17(CCL17),and C-X-C motif chemokine ligand 10(CXCL10)in serum were detected by enzyme-linked immunosorbent assay(ELISA).The expression of DNMT proteins(DNMT1,DNMT3A,and DNMT3B)in the colon tissues was detected by immunohistochemistry.The expression of 5-methylcytosine(5-mC),5-hydroxymethylcytosine(5-hmC),histone deacetylase 2(HDAC2),and DNA hydroxymethylase family proteins(TET 1 and TET3)was detected using immunofluorescence,which also determined the co-localization of TET1 and IL-6 protein.Results Compared with WT+UC group,TET2^(-/-)+UC group exhibited significantly higher DAI scores and shorter colon lengths(P<0.01).Both mild moxibustion and electroacupuncture significantly decreased DAI scores and ameliorated colon shortening in TET2^(-/-)mice(P<0.001).Histopathological scores of TET2^(-/-)+UC mice were significantly higher than those of WT+UC group(P<0.001)and were significantly reduced after both mild moxibustion and electroacupuncture interventions(P<0.001).Serum levels of IL-6,CCL17,and CXCL10 were significantly elevated in TET2^(-/-)+UC group compared with WT+UC group(P<0.001).Mild moxibustion significantly reduced IL-6,CCL17,and CXCL10 levels(P<0.001,P<0.001,and P<0.01,respectively),while electroacupuncture also significantly reduced IL-6,CCL17,and CXCL10 levels(P<0.05,P<0.01,and P<0.01,respectively).TET2^(-/-)+UC mice showed increased expression levels of DNMT1,DNMT3A,DNMT3B,and 5-mC(P<0.05,P<0.01 and P<0.001,respectively),with decreased expression levels of TET1,TET3,5-hmC,and HDAC2(P<0.001).Mild moxibustion significantly reduced DNMT1,DNMT3B,and 5-mC levels(P<0.05,P<0.01,and P<0.001,respectively),while increasing expression levels of TET1,TET3,5-hmC,and HDAC2(P<0.001,P<0.001,P<0.05,and P<0.001,respectively).Electroacupuncture significantly decreased 5-mC and DNMT3B levels(P<0.001 and P<0.01,respectively)and increased 5-hmC and HDAC2 levels(P<0.05 and P<0.001,respectively),but did not significantly affect TET1 and TET3 expression(P>0.05).Compared with TET2^(-/-)+MM group,TET2^(-/-)+EA group showed significantly higher 5-mC expression(P<0.001).TET2^(-/-)+UC group exhibited markedly increased IL-6 expression and higher co-localization of TET1 and IL-6 in mucosal epithelium,whereas minimal IL-6 expression was observed in the other groups.Conclusion Mild moxibustion and electroacupuncture significantly ameliorate colonic inflammation exacerbated by TET2 deficiency in UC mice via epigenetic modulation.Distinct mechanisms exist between the two interventions:mild moxibustion regulates both DNMT and hydroxymethylase,whereas electroacupuncture primarily affects DNMT.
基金supported by the National Natural Science Foundation of China(82325012)the Youth Fund of the National Natural Science Foundation of China(82301043)+1 种基金the Natural Science Basic Research Program of Shaanxi (Program No.2024JC-YBQN-0980)the Shaanxi Key Scientific and Technological Innovation Team(2020TD-033).
文摘Hypoxemia is a common pathological state characterized by low oxygen saturation in the blood.This condition compromises mucosal barrier integrity particularly in the gut and oral cavity.However,the mechanisms underlying this association remain unclear.This study used periodontitis as a model to investigate the role of platelet activation in oral mucosal immunopathology under hypoxic conditions.Hypoxia upregulated methyltransferase-like protein 4(METTL4)expression in platelets,resulting in N6-methyladenine modification of mitochondrial DNA(mtDNA).This modification impaired mitochondrial transcriptional factor A-dependent cytosolic mtDNA degradation,leading to cytosolic mtDNA accumulation.Excess cytosolic mt-DNA aberrantly activated the cGAS-STING pathway in platelets.This resulted in excessive platelet activation and neutrophil extracellular trap formation that ultimately exacerbated periodontitis.Targeting platelet METTL4 and its downstream pathways offers a potential strategy for managing oral mucosa immunopathology.Further research is needed to examine its broader implications for mucosal inflammation under hypoxic conditions.
基金This study was reviewed and approved by the Ethic Committee of Medical College of Henan Vocational University of Science and Technology(Approval No.HVUYL414101416920231017001)all participants signed a written informed consent.
文摘BACKGROUND Centromere protein A(CENPA)exhibits an increased expression level in primary human rectal cancer tissues,but its role has not been investigated.AIM To clarify the specific role and mechanism of CENPA in rectal cancer progression.METHODS CENPA protein expression in rectal cancer tissues and cell lines were detected.CENPA was overexpressed and knocked down in SW837 and SW480 cells,and proliferation,invasion,apoptosis and epithelial-mesenchymal transition(EMT)marker protein levels were examined.O6-methylguanine DNA methyltransferase(MGMT)promoter methylation was assessed with methylation-specific poly-merase chain reaction.Co-immunoprecipitation assay verified the interaction between MGMT and protein tyrosine phosphatase nonreceptor type 4(PTPN4).SW837 cells with CENPA knockdown were injected subcutaneously into mice,and tumor growth was examined.RESULTS CENPA was upregulated in rectal cancer tissues and cell lines.CENPA overex-pression promoted proliferation,invasion and EMT,and inhibited apoptosis in rectal cancer cells.Whereas CENPA knockdown showed the opposite results.Moreover,CENPA inhibited MGMT expression by promoting DNA methyltrans-ferase 1-mediated MGMT promoter methylation.MGMT knockdown abolished the CENPA knockdown-mediated inhibition of rectal cancer cell progression.MGMT increased PTPN4 protein stability by inhibiting PTPN4 ubiquitination degradation via competing with ubiquitin-conjugating enzyme E2O for interacting with PTPN4.PTPN4 knockdown abolished the inhibitory effects of MGMT overexpression on rectal cancer cell progression.Moreover,CENPA knockdown inhibited xenograft tumor growth in vivo.CONCLUSION CENPA knockdown inhibited rectal cancer cell growth and attenuated xenograft tumor growth through regulating the MGMT/PTPN4 axis.
文摘BACKGROUND Diabetic wound injury is a significant and common complication in individuals with diabetes.N6-methyladenosine(m6A)-related epigenetic regulation is widely involved in the pathogenesis of diabetes complications.However,the function of m6A methyltransferase Wilms tumor 1-associated protein(WTAP)in diabetic wound healing remains elusive.AIM To investigate the potential epigenetic regulatory mechanism of WTAP during diabetic wound healing.METHODS Human umbilical vein endothelial cells(HUVECs)were induced with high glucose(HG)to establish in vitro cell model.Male BALB/c mice were intraperitoneally injected with streptozotocin to mimic diabetes,and full-thickness excision was made to mimic diabetic wound healing.HG-induced HUVECs and mouse models were treated with WTAP siRNAs and DNA methyltransferase 1(DNMT1)overexpression vectors.Cell viability and migration ability were detected by cell counting kit-8 and Transwell assays.In vitro angiogenesis was measured using a tube formation experiment.The images of wounds were captured,and re-epithelialization and collagen deposition of skin tissues were analyzed using hematoxylin and eosin staining and Masson’s trichrome staining.RESULTS The expression of several m6A methyltransferases,including METTL3,METTL14,METTL16,KIAA1429,WTAP,and RBM15,were measured.WTAP exhibited the most significant elevation in HG-induced HUVECs compared with the normal control.WTAP depletion notably restored cell viability and enhanced tube formation ability and migration of HUVECs suppressed by HG.The unclosed wound area of mice was smaller in WTAP knockdowntreated mice than in control mice at nine days post-wounding,along with enhanced re-epithelialization rate and collagen deposition.The m6A levels on DNMT1 mRNA in HUVECs were repressed by WTAP knockdown in HUVECs.The mRNA levels and expression of DNMT1 were inhibited by WTAP depletion in HUVECs.Overexpression of DNMT1 in HUVECs notably reversed the effects of WTAP depletion on HG-induced HUVECs.CONCLUSION WTAP expression is elevated in HG-induced HUVECs and epigenetically regulates the m6A modification of DNMT1 to impair diabetic wound healing.
基金Supported by Guangzhou Basic and Applied Basic Research Foundation,No.202201010121Medical Joint Fund of Jinan University,No.YXZY2024014 and No.YXJC2022001+2 种基金Hospital Achievement Transformation and Cultivation Project,No.ZH201911the Key Discipline Project of Guangdong Province,No.2019-GDXK-0016and the Medical Science and Technology Research Foundation of Guangdong Province,No.B2021145.
文摘BACKGROUND Cervical cancer(CC)stem cell-like cells(CCSLCs),defined by the capacity of differentiation and self-renewal and proliferation,play a significant role in the progression of CC.However,the molecular mechanisms regulating their self-renewal are poorly understood.Therefore,elucidation of the epigenetic mechanisms that drive cancer stem cell self-renewal will enhance our ability to improve the effectiveness of targeted therapies for cancer stem cells.AIM To explore how DNA methyltransferase 1(DNMT1)/miR-342-3p/Forkhead box M1(FoxM1),which have been shown to have abnormal expression in CCSLCs,and their signaling pathways could stimulate self-renewal-related stemness in CCSLCs.METHODS Sphere-forming cells derived from CC cell lines HeLa,SiHa and CaSki served as CCSLCs.Self-renewal-related stemness was identified by determining sphere and colony formation efficiency,CD133 and CD49f protein level,and SRY-box transcription factor 2 and octamer-binding transcription factor 4 mRNA level.The microRNA expression profiles between HeLa cells and HeLa-derived CCSLCs or mRNA expression profiles that HeLaderived CCSLCs were transfected with or without miR-342-3p mimic were compared using quantitative PCR analysis.The expression levels of DNMT1 mRNA,miR-342-3p,and FoxM1 protein were examined by quantitative real-time PCR and western blotting.In vivo carcinogenicity was assessed using a mouse xenograft model.The functional effects of the DNMT1/miR-342-3p/FoxM1 axis were examined by in vivo and in vitro gain-of-activity and loss-of-activity assessments.Interplay among DNMT1,miR-342-3p,and FoxM1 was tested by methylationspecific PCR and a respective luciferase reporter assay.RESULTS CCSLCs derived from the established HeLa cell lines displayed higher self-renewal-related stemness,including enhanced sphere and colony formation efficiency,increased CD133 and CD49f protein level,and heightened transcriptional quantity of stemness-related factors SRY-box transcription factor 2 and octamer-binding transcription factor 4 in vitro as well as a stronger tumorigenic potential in vivo compared to their parental cells.Moreover,quantitative PCR showed that the miR-342-3p level was downregulated in HeLa-derived CCSLCs compared to HeLa cells.Its mimic significantly decreased DNMT1 and FoxM1 mRNA expression levels in CCSLCs.Knockdown of DNMT1 or miR-342-3p mimic transfection suppressed DNMT1 expression,increased miR-342-3p quantity by promoter demethylation,and inhibited CCSLC self-renewal.Inhibition of FoxM1 by shRNA transfection also resulted in the attenuation of CCSLC self-renewal but had little effect on the DNMT1 activity and miR-342-3p expression.Furthermore,the loss of CCSLC self-renewal exerted by miR-342-3p mimic was inverted by the overexpression of DNMT1 or FoxM1.Furthermore,DNMT1 and FoxM1 were recognized as straight targets by miR-342-3p in HeLa-derived CCSLCs.CONCLUSION Our findings suggested that a novel DNMT1/miR-342-3p/FoxM1 signal axis promotes CCSLC self-renewal and presented a potential target for the treatment of CC through suppression of CCSLC self-renewal.However,this pathway has been previously implicated in CC,as evidenced by prior studies showing miR-342-3p-mediated downregulation of FoxM1 in cervical cancer cells.Additionally,research on liver cancer further supports the involvement of miR-342-3p in suppressing FoxM1 expression.While our study contributed to this body of knowledge,we did not present a completely novel axis but reinforced the therapeutic potential of targeting the DNMT1/miR-342-3p/FoxM1 axis to suppress CCSLC self-renewal in CC treatment.
基金funded by National High-Level Hospital Clinical Research Funding (2022-PUMCH-A-203)CAMS Innovation Fund for Medical Sciences (2021-I2M-1-001)+4 种基金Health Research & Special Projects Grant of China (201002020 and 201502005)The Integrated Entrusted Project of Research Funding at Peking Union Medical College Hospital (ZC201903347)the National Natural Science Foundation of China (81970495)Capital Health Development Scientific Research Fund (2022-2-4014)Peking Union Medical College Hospital Research Funding for Postdoc (kyfyjj202315)
文摘Colitis-associated colorectal cancer(CAC),a serious complication of ulcerative colitis(UC),is associated with a poor prognosis.The vitamin D receptor(VDR)is recognized for its protective role in UC and CAC through the maintenance of intestinal barrier integrity and the regulation of inflammation.This study demonstrates a significant reduction in m^(6)A-related genes,particularly methyltransferase like 14(METTL14),in UC and CAC patients and identifies an association between METTL14 and VDR.In the azoxymethane(AOM)/dextran sodium sulfate(DSS)-induced mousemodel,vitamin D treatment increases METTL14 expression and reduces tumorburden,while Vdr-knockout mice exhibit lower METTL14 levels and increased tumorigenesis.In vitro,the VDR agonist calcipotriol upregulates METTL14 in NCM460 cells,with this effect attenuated by VDR knockdown.VDRknockdown inDLD-1colon cancer cellsdecreases METTL14 expressionand promotes proliferation,which is reversed by METTL14 overexpression.Mechanistic studies reveal that VDR regulates METTL14 expression via promoter binding,modulating key target genes such as SOX4,DROSH,and PHLPP2.This study highlights the role of the VDR-METTL14 axis as a protective mechanism in CAC and suggests its potential as a therapeutic target for preventing and treating CAC.
基金Supported by National Institutes of Health,No.5R01GM126154 and No.1R35GM149230。
文摘BACKGROUND Post-translational modifications play key roles in various biological processes.Protein arginine methyltransferases(PRMTs)transfer the methyl group to specific arginine residues.Both PRMT1 and PRMT6 have emerges as crucial factors in the development and progression of multiple cancer types.We posit that PRMT1 and PRMT6 might interplay directly or in-directly in multiple ways accounting for shared disease phenotypes.AIM To investigate the mechanism of the interaction between PRMT1 and PRMT6.METHODS Gel electrophoresis autoradiography was performed to test the methyltranferase activity of PRMTs and characterize the kinetics parameters of PRMTs.Liquid chromatography-tandem mass spectrometryanalysis was performed to detect the PRMT6 methylation sites.RESULTS In this study we investigated the interaction between PRMT1 and PRMT6,and PRMT6 was shown to be a novel substrate of PRMT1.We identified specific arginine residues of PRMT6 that are methylated by PRMT1,with R106 being the major methylation site.Combined biochemical and cellular data showed that PRMT1 downregulates the enzymatic activity of PRMT6 in histone H3 methylation.CONCLUSION PRMT6 is methylated by PRMT1 and R106 is a major methylation site induced by PRMT1.PRMT1 methylation suppresses the activity of PRMT6.
基金Supported by National Natural Science Foundation of China (No.31071310)Provincial Scientific Research Institution Commissioned Special Project of Fuyang Normal University (No.2011PTFY03ZD)+1 种基金Natural Science Research Project for Universities from the Education Department of Anhui Province (KJ2011B121)Natural Science Foundation of Fuyang Normal University (No.2010FSKJ13)~~
文摘[Objective] This study aimed to conduct bioinformatics analysis of histone H3-1ys-4 （H3K4） methyltransferase MLL3 in animals, thus exploring its relatively conservative evolution to reveal the role of histon H3K4 trimethyltransferase MLL3 in human cancers. [Method] By using bioinformatics method, gene structure, amino acid sequences, phylogenetic tree, chromosomal localization and synteny of mouse MLL3 were analyzed. [Result] Primary structure of the encoded mouse MLL3 protein con- tained seven zinc finger domains, an HMG-box （High mobility group-box protein）, a FYRN （F/Y-rich N-terminus） domain, a FYRC （F/Yrich C-terminus） domain, a SET domain and a postSET domain. Results of sequence comparison and homology showed that 19 animal species in this study all had these structures basically, which indicated that these structures were relatively conserved in the evolution; specifically, the SET domain was highly conserved and was necessary to maintain the activity of histone methyltransferases. Results of phylogenetic analysis showed that the loca- tions of the 19 animal species in evolutionary tree were consistent with the taxo- nomic status. Results of synteny analysis showed that there were the same gene in the upstream and downstream of the mouse and human MLL3 gene which were located on different chromosomes, indicating that the mouse and human MLL3 gene had collinearity. [Conclusion] This study had revealed the primary structure of MLL3 nucleotide sequence and amino acid sequence, which had not only laid the foundation for the future research of high-level structure and function of MLL3 protein but also provided the basis for the follow-up study of primer design, promoter analysis, gene cloning and regulation patterns of localization and expression of mouse MLL3 gene.
文摘Syntheses of 3 ketolanosterol, 3 acetolanosterol, 3 oximolanosterol, 3α and 3β aminolanosterol were described The products have been fully characterized on the basis of their chromatographic (TLC R f, GLC RRTc) and spectral (IR, MS, 1 H NMR, 13 C NMR) properties
基金supported by the National Institute of Dental and Craniofacial Research grants, K08DE024603-02, DE019412, and DE01651a grant from 111 Project of MOE, Chinasupported by Open Fund of State Key Laboratory of Oral Diseases, Sichuan University
文摘Mesenchymal stem cells （MSCs） are characterized by their self-renewing capacity and differentiation potential into multiple tissues. Thus, management of the differentiation capacities of MSCs is important for MSC-based regenerative medicine, such as craniofacial bone regeneration, and in new treatments for metabolic bone diseases, such as osteoporosis. In recent years, histone modification has been a growing topic in the field of MSC lineage specification, in which the Su（var）3-9, enhancer-of-zeste, trithorax （SET） domain-containing family and the Jumonji C （JmjC） domain-containing family represent the major histone lysine methyltransferases （KMTs） and histone lysine demethylases （KDMs）, respectively. In this review, we summarize the current understanding of the epigenetic mechanisms by which SET domain-containine KMTs and JmiC domain-containinlz KDMs balance the osteogenic and adipogenic differentiation of MSCs.
基金Supported by the National Natural Science Foundation of China,No.30371591the Natural Science Foundation of Hebei Province,No.C20040062
文摘AIM:To investigate the association between single nucleotide polymorphism (SNP) in promoter of the DNA methyltrans-ferase 3B(DNMT3B) gene and risk for development and lymphatic metastasis of gastric cardiac adenocarcinoma (GCA). METHODS: The hospital based case-control study included 212 GCA patients and 294 control subjects without overt cancer. The DNMT3B SNP was genotyped by PCR and restriction fragment length polymorphism (RFLP) analysis. RESULTS: The C/C genotype was not detected in both GCA patients and controls. In control subjects, the frequency of T/T and C/T genotypes was 94.9% and 5.1% respectively, and that of T and C alleles was 97.4% and 2.6%, respectively. The genotype and allelotype distribution in the GCA patients was not significantly different from that in controls (P=0.34 and 0.33, respectively). When stratified by smoking status and family history of upper gastrointestinal cancer, significant difference in the genotype distribution was not observed between GCA patients and controls. The distribution of DNMT3B genotypes in GCA patents with or without lymphatic metastasis did not show significant difference (P= 0.42). CONCLUSION: The distribution of DNMT3B SNP in North China is distinct from that in Caucasians. Although this SNP has been associated with susceptibility to lung, head, neck and breast cancer, it may not be used as a stratification marker to predict susceptibility and lymphatic metastasis of GCA, at least in the population of North China.
基金the National Basic Re-search Program of China (973 Program) (No. 2006CB504004 and 2006CB944004)the National Natural Science Foundation of China (No. 30430530)the Knowledge Innovation Program of the Chinese Academy of Sciences (No. KSCX2-YW-N-017).
文摘High rate of abortion and developmental abnormalities is thought to be closely associated with inefficient epigenetic reprogramming of the transplanted nuclei during bovine cloning. It is known that one of the important mechanisms for epigenetic reprogramming is DNA methylation. DNA methylation is established and maintained by DNA methyltransferases （DNMTs）, therefore, it is postulated that the inefficient epigenetic reprogramming of transplanted nuclei may be due to abnormal expression of DNMTs. Since DNA methylation can strongly inhibit gene expression, aberrant DNA methylation of DNMT genes may disturb gene expression. But presently, it is not clear whether the methylation abnormality of DNMT genes is related to developmental failure of somatic cell nuclear transfer embryos. In our study, we analyzed methylation patterns of the 5＇ regions of four DNMT genes including Dnmt3a, Dnmt3b, Dnmtl and Dnmt2 in four aborted bovine clones. Using bisulfite sequencing method, we found that 3 out of 4 aborted bovine clones （AF1, AF2 and AF3） showed either hypermethylation or hypomethylation in the 5＇ regions of Dnmt3a and Dnmt3b, indicating that Dnmt3a and Dnmt3b genes are not properly reprogrammed. However, the individual AF4 exhibited similar methylation level and pattern to age-matched in vitro fertilized （IVF） fetuses. Besides, we found that the 5＇ regions of Dnmtl and Dnmt2 were nearly completely unmethylated in all normal adults, IVF fetuses, sperm and aborted clones. Together, our results suggest that the aberrant methylation of Dnmt3a and Dnmt3b 5＇ regions is probably associated with the high abortion of bovine clones.
基金Supported by National Natural Science Foundation of China,No.30470950
文摘AIM： To explore the relationship between DNA methyltransferase 1 （DNMT1） and hepatitis B virus （HBV）-related hepatocellular carcinoma （HCC） and its biological significance in primary HCC. METHODS： We carried out an immunohistochemical examination of DNMT1 in both HCC and paired nonneoplastic liver tissues from Chinese subjects. DNMT1 mRNA was further examined in HCC cell lines by real-time PCR. We inhibited DNMT1 using siRNA and detected the effect of depletion of DNMT1 on cell proliferation ability and cell apoptosis in the HCC celt line SMMC-7721. RESULTS： DNMT1 protein expression was increased in HCCs compared to histologically normal nonneoplastic liver tissues and the incidence of DNMT1 immunoreactivity in HCCs correlated significantly with poor tumor differentiation （P = 0.014）. There were more cases with DNMT1 overexpression in HCC with HBV （42.85%） than in HCC without HBV （28.57%）. However, no significant difference in DNMT1 expression was found in HBV-positive and HBV-negative cases in the Chinese HCC group. There was a trend that DNMT1 RNA expression increased more in HCC cell lines than in pericarcinoma cell lines and normal liver cell lines. In addition, we inhibited DNMT1 using siRNA in the SMMC-7721 HCC cell line and found depletion of DNMT1 suppressed cells growth independent of expression of proliferating cell nuclear antigen （PCNA）, even in HCC cell lines where DNMT1 was stably decreased. CONCLUSION： The findings implied that DNMT1 plays a key role in HBV-retated hepatocellular tumorigenesis. Depletion of DNMT1 mediates growth suppression in SMMC-7721 cells.
基金the National lnstitutes of Health/National Cancer Institute(NlH/NCT)grant RO1 CA187299(L.R.)。
文摘DNA methyltransferases(DNMTs)are an evolutionarily conserved family of DNA methylases,transferring a methyl group onto the fifth carbon of a cytosine residue.The mammalian DNMT family includes three major members that have functional methylation activities,termed DNMT1,DNMT3A,and DNMT3B.DNMT3A and DNMT3B are responsible for methylation establishment,whereas DNMT1 maintains methylation during DNA replication.Accumulating evidence demonstrates that regulation of DNAmethylation by DNMTs is critical for normal hematopoiesis.Aberrant DNA methylation due to DNMT dysregulation and mutations is known as an important molecular event of hematological malignancies,such as DNMT3A mutations in acute myeloid leukemia.In this reviewwe first describe the basic methylation mechanisms of DNMTs and their functions in lymphocyte maturation and differentiation,We then discuss the current understanding of DNA methylation heterogeneity in leukemia and lymphoma to highlight the importance of studying DNA methylation targets.We also discuss DNMT mu-tations and pathogenic roles in human leukemia and lymphoma.We summarize the recent understanding of how DNMTs interact with transcription factors or cofactors to repress the expression of tumor suppressor genes.Firnally.we highlight current clinical studies using DNMT inhibitors for the treatment of these hematological malignancies.
基金supported by the National Natural Science Foundation of China(No.30370904 and 30671258)the National High Technology Research and Development Program(863 Project)of China(No.2006AA10Z121)the Program for New Century Excellent Talents in University(No.NCET-07-0712).
文摘Brassinosteroids （BRs） are an important class of plant steroidal hormones that are essential in a wide variety of physiological processes. Two kinds of intermediates, sitosterol and campesterol, play a crucial role in cell elongation, cellulose biosynthesis, and accumulation. To illuminate the effects of sitosterol and campesterol on the development of cotton （Gossypiurn hirsuturm L.） fibers through screening cotton fiber EST database and contigging the candidate ESTs, two key genes GhSMT2-1 and GhSMT2-2 controlling the sitosterol biosynthesis were cloned from developing fibers of upland cotton cv. Xuzhou 142. The full length of GhSMT2-1 was 1,151 bp, including an 8 bp 5＇-untranslated region （UTR）, a 1,086 bp open reading frame （ORF）, and a 57 bp 3＇-UTR. GhSMT2-1 gene encoded a polypeptide of 361 amino acid residues with a predicted molecular mass of 40 kDa. The full length of GhSMT2-2 was 1,166 bp, including an 18 bp 5＇-UTR, a 1,086 bp ORF, and a 62 bp 3＇-UTR. GhSMT2-2 gene encoded a polypeptide of 361 amino acid residues with a predicted molecular mass of 40 kDa. The two deduced amino acid sequences had high homology with the SMT2 from Arabidopsis thaliana and Nicotiana tabacurn. Furthermore, the typical conserved structures characterized by the sterol C-24 methyltransferase, such as region I （LDVGCGVGGPMRAI）, region II （IEATCHAP）, and region III （YEWGWGQSFHF）, were present in both deduced proteins. Southern blotting analysis indicated that GhSMT2-1 or GhSMT2-2 was a single copy in upland cotton genome. Quantitative real-time RT-PCR analysis revealed that the highest expression levels of both genes were detected in 10 DPA （day post anthesis） fibers, while the lowest levels were observed in cotyledon and leaves. The expression level of GhSMT2-1 was 10 times higher than that of GhSMT2-2 in all the organs and tissues detected. These results indicate that the homologue of sterol C-24 methyltransferase gene was cloned from upland cotton and both GhSMT2 genes play a crucial role in fiber elongation. The role of GhSMT2-1 may be more important than that of GhSMT2-2.
文摘AIM: To evaluate the relationship between thiopu- rine S-methyltransferase (TPMT) polymorphisms and thiopurine-induced adverse drug reactions (ADRs) in inflammatory bowel disease (IBD). METHODS: Eligible articles that compared the frequency of TPMT polymorphisms among thiopurine-tolerant and-intolerant adult IBD patients were included. Statistical analysis was performed with Review Manager 5.0. Sub-analysis/sensitivity analysis was also performed. RESULTS: Nine studies that investigated a total of 1309 participants met our inclusion criteria. The inci- dence of TPMT gene mutation was increased 2.93-fold (95% CI: 1.68-5.09, P = 0.0001) and 5.93-fold (95% CI: 2.96-11.88, P < 0.00001), respectively, in IBD patients with thiopurine-induced overall ADRs and bone marrow toxicity (BMT), compared with controls. The OR for TPMT gene mutation in IBD patients withthiopurine-induced hepatotoxicity and pancreatitis was 1.51 (95% CI: 0.54-4.19, P = 0.43) and 1.02 (95% CI: 0.26-3.99, P = 0.98) vs controls, respectively. CONCLUSION: This meta-analysis suggests that the TPMT polymorphisms are associated with thiopurine-induced overall ADRs and BMT, but not with hepatotoxicity and pancreatitis.
基金This study was supported by the National Key Research and Development Program of China(2018YFD1000800)the National Natural Science Foundation of China(31972479,31801884)+1 种基金the Earmarked Fund for Modern Agroindustry Technology Research System of China(CARS-25)the funding for Tang Scholar of Northwest A&F University.
文摘Melatonin is a pleiotropic signaling molecule that regulates plant growth and responses to various abiotic stresses.The last step of melatonin synthesis in plants can be catalyzed by caffeic acid O-methyltransferase(COMT),a multifunctional enzyme reported to have N-acetylserotonin O-methyltransferase(ASMT)activity;however,the ASMT activity of COMT has not yet been characterized in nonmodel plants such as watermelon(Citrullus lanatus).Here,a total of 16 putative O-methyltransferase(ClOMT)genes were identified in watermelon.Among them,ClOMT03(Cla97C07G144540)was considered a potential COMT gene(renamed ClCOMT1)based on its high identities(60.00–74.93%)to known COMT genes involved in melatonin biosynthesis,expression in almost all tissues,and upregulation under abiotic stresses.The ClCOMT1 protein was localized in the cytoplasm.Overexpression of ClCOMT1 significantly increased melatonin contents,while ClCOMT1 knockout using the CRISPR/Cas-9 system decreased melatonin contents in watermelon calli.These results suggest that ClCOMT1 plays an essential role in melatonin biosynthesis in watermelon.In addition,ClCOMT1 expression in watermelon was upregulated by cold,drought,and salt stress,accompanied by increases in melatonin contents.Overexpression of ClCOMT1 enhanced transgenic Arabidopsis tolerance against such abiotic stresses,indicating that ClCOMT1 is a positive regulator of plant tolerance to abiotic stresses.
基金supported by the National Natural Science Foundation of China(Nos.81402721,81573203,21605131)Science and Technology Department of Henan Province(No.22170004)
文摘DNA methyltransferase 1(DNMT1)is a useful biomarker for lung cancer in early clinical diagnosis.A rapid magnetic chemiluminescence immunoassay(MCLIA)for DNMT1 in human serum has been developed.Horseradish peroxidase(HRP)-second-Ab was used to labeled polyclonal antibodies of anti-DNMT1.DNMT1 in sample integrates with specific immunomagnetic beads and can constitute a supersandwiched immunoreaction.In magnetic field,nonspecific materials can be separated.After luminescent substrate luminol-H2O2-BIP was added,the relative light unit(RLU)of HRP was detected and was discovered to be directly proportional to the content of DNMT1 in sample.The correlative variables involved in the MCLIA value were optimized and the methodological evaluation was carried out.After optimization,in the range of0.5–128 ng/mL,the linear regression equation was y=0.5014 x+1.769(x was logCDNMT1,y was relative luminescence units(RLU)/RLU0),and the limit of detection was 0.01 ng/mL.The RSD of intra-and interassays were 15.8%–16.9%and 14.3%–18.1%,respectively.The recovery was from 70.0%to 106.2%.Furthermore,paralleled with purchasable enzyme-linked immunosorbent assay(ELISA)kits,MCLEIA had lower detection limit,wider linear range and shorter detection time.Therefore,the MCLEIA established in this study could be used for the sensitive detection of DNMT1 in serum sample.
基金This study was supported by the National Basic Research Program of China （No. 2012CB518306）, the National Natural Science Foundation of China （No. 81101946）, the Prostate Cancer Foundation Young Investigator Award and the Shanghai Pujiang Program （No. 12PID008）.
文摘SETDB1 has been established as an oncogene in a number of human carcinomas. The present study was to evaluate the expression of SETDB1 in prostate cancer （PCa） tissues and cells and to preliminarily investigate the role of SETDB1 in prostate tumorigenesis in vitro. Quantitative reverse transcription polymerase chain reaction （qRT-PCR） and immunohistochemistry （IHC） were used to detect the expression of SETDB1 in PCa tissues, adjacent normal tissues, benign prostatic hyperplasia （BPH） tissues, PCa cell lines and normal prostate epithelial cells. The results suggested that SETDB1 was upregulated in human PCa tissues compared with normal tissues at the mRNA and protein levels. The role of SETDB1 in proliferation was analyzed with cell counting kit-8, colony-forming efficiency and flow cytometry assays. The results indicated that downregulation of SETDB1 by siRNA inhibited PCa cell growth, and induced GO/G1 cell cycle arrest. The PCa cell migration and invasion decreased by silcencing SETDBt which were assessed by using in vitro scratch and transwell invasion assay respectively. Our data suggested that SETDB1 is overexpressed in human PCa. Silencing SETDB1 inhibited PCa cell proliferation, migration and invasion.
