目的:探讨SET和MYND域包含蛋白质2(SET and MYND domaincontaining protein 2,SMYD2)调控结直肠癌(colorectal cancer,CRC)细胞迁移和侵袭的机制。方法:从徐州医科大学附属医院收集2019年08月至2020年03月的24对结直肠癌及癌旁组织,进...目的:探讨SET和MYND域包含蛋白质2(SET and MYND domaincontaining protein 2,SMYD2)调控结直肠癌(colorectal cancer,CRC)细胞迁移和侵袭的机制。方法:从徐州医科大学附属医院收集2019年08月至2020年03月的24对结直肠癌及癌旁组织,进行实时荧光定量PCR(quantitative real-time PCR,qRT-PCR)分析SMYD2的表达量。构建SMYD2和腺瘤性息肉病蛋白2(adenomatous polyposis coli 2,APC2)的小干扰RNA,使用Transwell和蛋白免疫印迹实验检测转染后结直肠癌细胞的迁移和侵袭能力。结果:癌组织中SMYD2的mRNA和蛋白表达量显著高于癌旁组织(P<0.001,P<0.05),且结直肠癌细胞系SW480和HCT116中SMYD2的表达量显著高于正常结直肠细胞系FHC(P<0.001)。在SW480和HCT116细胞中敲低SMYD2后细胞的迁移和侵袭能力减弱(P<0.01),同时E-cadherin的表达量升高(P<0.001),而N-cadherin和Vimentin的表达量降低(P<0.01)。生物信息学分析显示,SMYD2与APC2的表达呈负相关(P<0.001),且APC2可以抑制WNT/β-catenin通路。在SW480和HCT116细胞中敲低SMYD2后APC2的表达量增高(P<0.001),而WNT/β-catenin通路中的β-catenin、c-MYC和CyclinD1表达降低(P<0.01)。敲低APC2可以恢复SMYD2敲低引起的SW480和HCT116细胞的迁移和侵袭降低(P<0.001),E-cadherin升高(P<0.001)和N-cadherin、Vimentin、β-catenin、c-MYC、CyclinD1降低(P<0.01)。结论:在结直肠癌细胞中,SMYD2通过抑制APC2激活WNT/β-catenin通路促进结直肠癌细胞的上皮-间质转化(epithelial-mesenchymal transition,EMT),从而影响细胞的迁移和侵袭能力。展开更多
Coronary restenosis is an important cause of poor long-term prognosis in patients with coronary heart disease.Here,we show that lysine methyltransferase SMYD2 expression in the nucleus is significantly elevated in ser...Coronary restenosis is an important cause of poor long-term prognosis in patients with coronary heart disease.Here,we show that lysine methyltransferase SMYD2 expression in the nucleus is significantly elevated in serum-and PDGF-BB-induced vascular smooth muscle cells(VSMCs),and in tissues of carotid artery injury-induced neointimal hyperplasia.Smyd2 overexpression in VSMCs(Smyd2-vTg)facilitates,but treatment with its specific inhibitor LLY-507 or SMYD2 knockdown significantly inhibits VSMC phenotypic switching and carotid artery injury-induced neointima formation in mice.Transcriptome sequencing revealed that SMYD2 knockdown represses the expression of serum response factor(SRF)target genes and that SRF overexpression largely reverses the inhibitory effect of SMYD2 knockdown on VSMC proliferation.HDAC3 directly interacts with and deacetylates SRF,which enhances SRF transcriptional activity in VSMCs.Moreover,SMYD2 promotes HDAC3 expression via tri-methylation of H3K36 at its promoter.RGFP966,a specific inhibitor of HDAC3,not only counteracts the pro-proliferation effect of SMYD2 overexpression on VSMCs,but also inhibits carotid artery injury-induced neointima formation in mice.HDAC3 partially abolishes the inhibitory effect of SMYD2 knockdown on VSMC proliferation in a deacetylase activity-dependent manner.Our results reveal that the SMYD2-HDAC3-SRF axis constitutes a novel and critical epigenetic mechanism that regulates VSMC phenotypic switching and neointimal hyperplasia.展开更多
The SET-and myeloid-Nervy-DEAF-1(MYND)-domain containing(Smyd)lysine methyltransferases 1–3 share relatively high sequence similarity but exhibit divergence in the substrate specificity.Here we report the crystal str...The SET-and myeloid-Nervy-DEAF-1(MYND)-domain containing(Smyd)lysine methyltransferases 1–3 share relatively high sequence similarity but exhibit divergence in the substrate specificity.Here we report the crystal structure of the full-length human Smyd2 in complex with S-adenosyl-L-homocysteine(AdoHcy).Although the Smyd1–3 enzymes are similar in the overall structure,detailed comparisons demonstrate that they differ substantially in the potential substrate-binding site.The binding site of Smyd3 consists mainly of a deep and narrow pocket,while those of Smyd1 and Smyd2 consist of a comparable pocket and a long groove.In addition,Smyd2,which has lysine methyltransferase activity on histone H3-lysine 36,exhibits substantial differences in the wall of the substrate-binding pocket compared with those of Smyd1 and Smyd3 which have activity specifically on histone H3-lysine 4.The differences in the substrate-binding site might account for the observed divergence in the specificity and methylation state of the substrates.Further modeling study of Smyd2 in complex with a p53 peptide indicates that mono-methylation of p53-Lys372 might result in steric conflict of the methyl group with the surrounding residues of Smyd2,providing a structural explanation for the inhibitory effect of the SET7/9-mediated mono-methylation of p53-Lys372 on the Smyd2-mediated methylation of p53-Lys370.展开更多
CCAAT/enhancer binding protein α （C/EBPα） is a transcriptional regulatory factor that inhibits cell proliferation, and alternative translational initiation produces two polypeptides, C/EBPαp30 and C/EBPαp42. By ...CCAAT/enhancer binding protein α （C/EBPα） is a transcriptional regulatory factor that inhibits cell proliferation, and alternative translational initiation produces two polypeptides, C/EBPαp30 and C/EBPαp42. By expression profiling, it was revealed that C/EBPap30 specifically inhibited a unique set of genes, including MPP 11, p84N5 and SMYD2, which were not affected by C/EBPαp42 in both QSG-7701 hepatocyte cell line and QGY-7703 hepatoma cells. Semiquantitative RT-PCR analysis independently confirmed these results. Chromatin immunoprecipitation assay showed that C/EBPαp30 bound to the promoters of these genes more strongly than C/EBPαp42. In clinical hepatoma samples in which C/EBPα was downregulated, all three genes specifically inhibited by C/EBPαp30 were upregulated. However, repression of MPP 11, p84N5 and SMYD2 genes might not be directly involved in C/EBPαp30-mediated growth inhibition. Our data suggest that C/EBPαp30 regulates a unique set of target genes and is more than a dominant-negative regulator of C/EBPαp42.展开更多
文摘目的:探讨SET和MYND域包含蛋白质2(SET and MYND domaincontaining protein 2,SMYD2)调控结直肠癌(colorectal cancer,CRC)细胞迁移和侵袭的机制。方法:从徐州医科大学附属医院收集2019年08月至2020年03月的24对结直肠癌及癌旁组织,进行实时荧光定量PCR(quantitative real-time PCR,qRT-PCR)分析SMYD2的表达量。构建SMYD2和腺瘤性息肉病蛋白2(adenomatous polyposis coli 2,APC2)的小干扰RNA,使用Transwell和蛋白免疫印迹实验检测转染后结直肠癌细胞的迁移和侵袭能力。结果:癌组织中SMYD2的mRNA和蛋白表达量显著高于癌旁组织(P<0.001,P<0.05),且结直肠癌细胞系SW480和HCT116中SMYD2的表达量显著高于正常结直肠细胞系FHC(P<0.001)。在SW480和HCT116细胞中敲低SMYD2后细胞的迁移和侵袭能力减弱(P<0.01),同时E-cadherin的表达量升高(P<0.001),而N-cadherin和Vimentin的表达量降低(P<0.01)。生物信息学分析显示,SMYD2与APC2的表达呈负相关(P<0.001),且APC2可以抑制WNT/β-catenin通路。在SW480和HCT116细胞中敲低SMYD2后APC2的表达量增高(P<0.001),而WNT/β-catenin通路中的β-catenin、c-MYC和CyclinD1表达降低(P<0.01)。敲低APC2可以恢复SMYD2敲低引起的SW480和HCT116细胞的迁移和侵袭降低(P<0.001),E-cadherin升高(P<0.001)和N-cadherin、Vimentin、β-catenin、c-MYC、CyclinD1降低(P<0.01)。结论:在结直肠癌细胞中,SMYD2通过抑制APC2激活WNT/β-catenin通路促进结直肠癌细胞的上皮-间质转化(epithelial-mesenchymal transition,EMT),从而影响细胞的迁移和侵袭能力。
基金supported by grants from the National Natural Science Foundation of China(Nos.81974013 and 82270512).
文摘Coronary restenosis is an important cause of poor long-term prognosis in patients with coronary heart disease.Here,we show that lysine methyltransferase SMYD2 expression in the nucleus is significantly elevated in serum-and PDGF-BB-induced vascular smooth muscle cells(VSMCs),and in tissues of carotid artery injury-induced neointimal hyperplasia.Smyd2 overexpression in VSMCs(Smyd2-vTg)facilitates,but treatment with its specific inhibitor LLY-507 or SMYD2 knockdown significantly inhibits VSMC phenotypic switching and carotid artery injury-induced neointima formation in mice.Transcriptome sequencing revealed that SMYD2 knockdown represses the expression of serum response factor(SRF)target genes and that SRF overexpression largely reverses the inhibitory effect of SMYD2 knockdown on VSMC proliferation.HDAC3 directly interacts with and deacetylates SRF,which enhances SRF transcriptional activity in VSMCs.Moreover,SMYD2 promotes HDAC3 expression via tri-methylation of H3K36 at its promoter.RGFP966,a specific inhibitor of HDAC3,not only counteracts the pro-proliferation effect of SMYD2 overexpression on VSMCs,but also inhibits carotid artery injury-induced neointima formation in mice.HDAC3 partially abolishes the inhibitory effect of SMYD2 knockdown on VSMC proliferation in a deacetylase activity-dependent manner.Our results reveal that the SMYD2-HDAC3-SRF axis constitutes a novel and critical epigenetic mechanism that regulates VSMC phenotypic switching and neointimal hyperplasia.
基金supported by the grants from the Ministry of Science and Technology of China (2007CB914302 and 2011CB966301)the National Natural Science Foundation of China (30730028)+2 种基金the Chinese Academy of Sciences (SIBS2008002)the Science and Technology Commission of Shanghai Municipality (10JC1416500)support of the SA-SIBS scholarship program.
文摘The SET-and myeloid-Nervy-DEAF-1(MYND)-domain containing(Smyd)lysine methyltransferases 1–3 share relatively high sequence similarity but exhibit divergence in the substrate specificity.Here we report the crystal structure of the full-length human Smyd2 in complex with S-adenosyl-L-homocysteine(AdoHcy).Although the Smyd1–3 enzymes are similar in the overall structure,detailed comparisons demonstrate that they differ substantially in the potential substrate-binding site.The binding site of Smyd3 consists mainly of a deep and narrow pocket,while those of Smyd1 and Smyd2 consist of a comparable pocket and a long groove.In addition,Smyd2,which has lysine methyltransferase activity on histone H3-lysine 36,exhibits substantial differences in the wall of the substrate-binding pocket compared with those of Smyd1 and Smyd3 which have activity specifically on histone H3-lysine 4.The differences in the substrate-binding site might account for the observed divergence in the specificity and methylation state of the substrates.Further modeling study of Smyd2 in complex with a p53 peptide indicates that mono-methylation of p53-Lys372 might result in steric conflict of the methyl group with the surrounding residues of Smyd2,providing a structural explanation for the inhibitory effect of the SET7/9-mediated mono-methylation of p53-Lys372 on the Smyd2-mediated methylation of p53-Lys370.
文摘CCAAT/enhancer binding protein α （C/EBPα） is a transcriptional regulatory factor that inhibits cell proliferation, and alternative translational initiation produces two polypeptides, C/EBPαp30 and C/EBPαp42. By expression profiling, it was revealed that C/EBPap30 specifically inhibited a unique set of genes, including MPP 11, p84N5 and SMYD2, which were not affected by C/EBPαp42 in both QSG-7701 hepatocyte cell line and QGY-7703 hepatoma cells. Semiquantitative RT-PCR analysis independently confirmed these results. Chromatin immunoprecipitation assay showed that C/EBPαp30 bound to the promoters of these genes more strongly than C/EBPαp42. In clinical hepatoma samples in which C/EBPα was downregulated, all three genes specifically inhibited by C/EBPαp30 were upregulated. However, repression of MPP 11, p84N5 and SMYD2 genes might not be directly involved in C/EBPαp30-mediated growth inhibition. Our data suggest that C/EBPαp30 regulates a unique set of target genes and is more than a dominant-negative regulator of C/EBPαp42.
