BACKGROUND:Sepsis-induced liver injury is a fatal complication of sepsis.Trichostatin A(TSA)regulates inflammation and autophagy in some human diseases,and forkhead box O3a(FoxO3a)has been shown to regulate autophagy....BACKGROUND:Sepsis-induced liver injury is a fatal complication of sepsis.Trichostatin A(TSA)regulates inflammation and autophagy in some human diseases,and forkhead box O3a(FoxO3a)has been shown to regulate autophagy.The present study aims to investigate whether TSA exerts its effects on septic liver injury through the FoxO3a/autophagy signaling pathway.METHODS:A sepsis mouse model was constructed by the cecal ligation and puncture(CLP)method,and AML12 cells were pretreated with lipopolysaccharide(LPS)(1μg/mL)to establish a sepsis cell model.Forty mice were divided into four groups,namely control group,TSA group,CLP group,and CLP+TSA group,with 10 mice in each group.Cells were divided into control group,TSA group,LPS group,and LPS+TSA group.Hematoxylin-eosin(H&E)staining and biochemical methods were used to evaluate liver tissue injury.Enzyme-linked immunosorbent assay(ELISA)was applied to detect the expression of proinflammatory cytokines,and Western blotting and immunofluorescence were used to measure autophagy-related protein expression.RESULTS:Compared with the CLP group(mice),the proinflammatory cytokines(interleukin-β[IL-β]2,665.27±324.90 pg/mL to 2,080.26±373.66 pg/mL;interleukin-6[IL-6]399.01±60.98 pg/mL to 221.90±46.89 pg/mL)and the hepatocyte injury markers(aspartate transaminase[AST]from 198.18±27.07 U/L to 128.42±20.55 U/L;alanine aminotransferase[ALT]from 634.98±74.10 U/L to 478.60±32.56 U/L)were notably decreased after TSA intervention.Moreover,LC3 II and FoxO3a showed an obvious increase and P62 showed an obvious decrease in the CLP+TSA group.Cell experiment results showed the similar trend.After Fox O3a gene was knocked down in AML12 cells,the promotion of autophagy and the improvement of liver enzyme index and inflammation by TSA were weakened.CONCLUSION:TSA may improve the inflammatory response and liver injury in septic mice through Fox O3a/autophagy.展开更多
It is quite complex to evaluate the mechanism of action for antitumor drugs on cancer cells.Studies have pointed out that there is an unique advantage of Fourier transform infrared spectrum to obtain a fingerprint of ...It is quite complex to evaluate the mechanism of action for antitumor drugs on cancer cells.Studies have pointed out that there is an unique advantage of Fourier transform infrared spectrum to obtain a fingerprint of all molecules present in the cells when cancer cells were exposed to anti-cancer drugs.Trichostatin A(TSA) is a most potent reversible inhibitor of mammalian histone deacetylases.It can inhibit cancer cell growth in vitro and in vivo.In the present study,HeLa cells were exposed to 0,50,100,200,300 and 400 nmol·L-1 TSA,and FTIR spectra were applied to evaluate the effect of TSA on cancer cells.Results show that there is some significant relationship between the changes in FTIR absorption and cell cycle arresting.On the other hand,this investigation shows that the concentration of TSA had to be more than 200 nmol·L-1 in order to ensure A1 080 cm-1/A1 540 cm-1≥1 for inhibiting cell proliferation.展开更多
AIM: To explore the effect of lysine acetylation in related proteins on regulation of the proliferation of gastric cancer cells, and determine the lysine-acetylated proteins and the acetylated modified sites in AGS ga...AIM: To explore the effect of lysine acetylation in related proteins on regulation of the proliferation of gastric cancer cells, and determine the lysine-acetylated proteins and the acetylated modified sites in AGS gastric cancer cells. METHODS: The CCK-8 experiment and flow cytometry were used to observe the changes in proliferation and cycle of AGS cells treated with trichostatin A (TSA). Real time polymerase chain reaction and Western blotting were used to observe expression changes in p21, p53, Bax, Bcl-2, CDK2, and CyclinD1 in gastric cancer cells exposed to TSA. Cytoplasmic proteins in gastric cancer cells before and after TSA treatment were immunoprecipitated with anti-acetylated lysine antibodies, separated using sodium dodecyl sulfate polyacrylamide gel electrophoresis gel and silver-stained to detect the proteins by mass spectrometry after removal of the gel. The acetylated proteins in AGS cells were enriched with lysine-acetylated antibodies, and a high-resolution mass spectrometer was used to detect the acetylated proteins and modified sites. RESULTS: TSA significantly inhibited AGS cell proliferation, and promoted cell apoptosis, leading to AGS cell cycle arrest in G0/G1 and G2/M phases, especially G0/G1 phase. p21, p53 and Bax gene expression levels in AGS cells were increased with TSA treatment duration; Bcl-2, CDK2, and CyclinD1 gene expression levels were decreased with TSA treatment duration. Two unknown protein bands, 72 kDa (before exposure to TSA) and 28 kDa (after exposure to TSA), were identified by silver-staining after immunoprecipitation of AGS cells with the lysine-acetylated monoclonal antibodies. Mass spectrometry showed that the 72 kDa protein band may be PKM2 and the 28 kDa protein band may be ATP5O. The acetylated proteins and modified sites in AGS cells were determined. CONCLUSION: TSA can inhibit gastric cancer cell proliferation, which possibly activated signaling pathways in a variety of tumor-associated factors. ATP5O was obviously acetylated in AGS cells following TSA treatment.展开更多
Histone deacetylase (HDAC) inhibitors are considered as promising therapeutic agents against several malignant diseases because they inhibit cancer cell proliferation. The stress sensor genes of the growth arrest and ...Histone deacetylase (HDAC) inhibitors are considered as promising therapeutic agents against several malignant diseases because they inhibit cancer cell proliferation. The stress sensor genes of the growth arrest and DNA damage-inducible protein (gadd45) family exhibit disordered expression in several types of malignant diseases and are thus a novel target for cancer therapy. However, there have been only few investigations of whether HDAC inhibitors affect the expression of gadd45 genes. We examined the effects of a HDAC inhibitor, trichostatin A (TSA), on the time-dependent expression of gadd45 genes in the human colon cancer cell line LS174T. Addition of TSA to LS174T cells induced inhibition of cell proliferation by arresting the cell cycle. We found that TSA treatment of LS174T cells induced rapid upregulation of gadd45β mRNA expression within 15 min, reaching a peak level at 3 h. Although the time-dependent expression pattern of gadd45β mRNA was similar to that of gadd45β mRNA, the peak level of gadd45β was lower than that of gadd45β. TSA treatment also upregulated the mRNA level of p21Waf1/Cip1, a prolif- eration inhibitor, after 3 h, but downregulated the mRNA levels of cyclin D1, a proliferation inducer, after 3 h, and of c-Myc after 1 h. TSA treatment induced a certain level of apoptosis, but the mRNA level of p53, a potent apoptosis inducer, was down-regulated after 3 h. These results suggest that the up-regulation of p21Waf1/Cip1 and apoptosis was independent of p53 and that the early upregulation of gadd45β gene, which precedes the upregulation of p21Waf1/Cip1 and the downregulation of cyclin D1, are important in TSA-treated LS174T cells.展开更多
Background and Aims:DNA methylation and histone mod-ification are epigenetic modifications essential for normal function of mammalian cells.The processes are mediated by biochemical interactions between DNA methyltran...Background and Aims:DNA methylation and histone mod-ification are epigenetic modifications essential for normal function of mammalian cells.The processes are mediated by biochemical interactions between DNA methyltransferases(DNMTs)and histone deacetylases.Promoter hypermethyla-tion and deacetylation of tumor suppressor genes play major roles in cancer induction,through transcriptional silencing of these genes.DNA hypermethylation is carried out by a family of DNMTs including DNMT1,DNMT3a and DNMT3b.In hepatocellular carcinoma,a significant positive correlation bet-ween over-expression of these genes and cancer induction has been reported.The DNA demethylating agent genistein(GE)has been demonstrated to reduce different cancers.Pre-viously,we reported that GE can induce apoptosis and inhibit proliferation in hepatocellular carcinoma PLC/PRF5 and HepG2 cell lines.Besides,histone deacetylase inhibitors,such as trichostatin A(TSA),were successfully used to inhibit cancer cell growth.The present study was designed to assess the effect of GE in comparison with TSA on DNMT1,DNMT3a and DNMT3b gene expression,cell growth inhibition and apoptosis induction in the HepG2 cell line.Methods:Cells were seeded and treated with various doses of GE and TSA.The MTT assay,flow cytometry assay,and real-time RT-PCR were used to determine viability,apoptosis,and DNMT1,DNMT3a and DNMT3b gene expression respectively.Results:Both agents inhibited cell growth,induced apoptosis and re-activated DNMT1,DNMT3a and DNMT3b gene expression.Furthermore,TSA demonstrated a significantly greater apop-totic effect than the other agent,whereas GE improved gene expression more significantly than TSA.Conclusions:Our findings suggest that GE and TSA can significantly inhibit cell growth,induce apoptosis and restore DNMT1,DNMT3a and DNMT3b gene reactivation.展开更多
The secondary laticifer, a specific tissue in the secondary phloem of rubber tree, is differentiated from the vascular cambia. The number of the secondary laticifer in the trunk bark of rubber tree is positively corre...The secondary laticifer, a specific tissue in the secondary phloem of rubber tree, is differentiated from the vascular cambia. The number of the secondary laticifer in the trunk bark of rubber tree is positively correlated with rubber yield. Although jasmonates have been demonstrated to be crucial in the regulation of secondary laticifer differentiation, the mechanism for the jasmonate-induced secondary laticifer differentiation remains to be elucidated.By using an experimental morphological technique, the present study revealed that trichostatin A(TSA), an inhibitor of histone deacetylation, could induce the secondary laticifer differentiation in a concentrationdependent manner. The results suggest that histone acetylation is essential for the secondary laticifer differentiation in rubber tree.展开更多
Differentiation of bone marrow mesenchymal stem cells (MSCs) into endothelial cells (EC) is characterized by the expression of specific endothelial marker genes. Mechanical stimulations play potential effects in EC or...Differentiation of bone marrow mesenchymal stem cells (MSCs) into endothelial cells (EC) is characterized by the expression of specific endothelial marker genes. Mechanical stimulations play potential effects in EC oriented differentiation of MSCs. However, molecular mechanisms of endothelial differentiation from MSCs have not been defined.Histone acetylations play important roles in regulating gene expression. Histone acetylation status is maintained by histone acetyltransferase (HAT) and histone deacetylases (HDACs). Our previous work described that VEGF and laminar shear stress (SS) work together in determining EC oriented differentiation of MSC. Trichostatin A (TSA) is one of the lustone deacetylase inhibitor. In this study, we found that both TSA and SS could induce EC oriented differentiation of MSCs. And TSA combined with SS showed more powerful influence on the EC oriented differentiation of MSCs.展开更多
背景与目的:腺病毒感染依赖于靶细胞表面柯萨奇-腺病毒受体(Coxsackie and adenovirus receptor,CAR)的表达,肿瘤细胞CAR表达的缺失和下调是造成腺病毒为载体基因治疗效果不佳的根本原因。本研究通过观察组氨酸去乙酰化酶(histone deace...背景与目的:腺病毒感染依赖于靶细胞表面柯萨奇-腺病毒受体(Coxsackie and adenovirus receptor,CAR)的表达,肿瘤细胞CAR表达的缺失和下调是造成腺病毒为载体基因治疗效果不佳的根本原因。本研究通过观察组氨酸去乙酰化酶(histone deacetylase,HDAC)抑制剂TrichostatinA(TSA)对卵巢癌细胞株A2780CAR表达水平的影响,探讨HDAC抑制剂在腺病毒载体基因治疗中应用的可能性。方法:分别在TSA作用A2780细胞前后检测CARmRNA和蛋白水平的表达,同时采用流式细胞术测定病毒转染效率,MTT实验评价腺病毒携带的胸苷激酶(ADV/TK)的体外抗瘤效应。结果:TSA处理后,A2780细胞内CARmRNA和蛋白表达明显增高。通过流式细胞仪分析GFP/ADV转染后GFP的表达发现,未处理组细胞转染率为(1.24±0.14)%;5nmol/L和100nmol/LTSA处理48h后,细胞的转染效率分别为(7.58±0.32)%和(7.94±0.28)%。MTT结果表明,ADV/TK介导的体外杀伤作用在5nmol/L和100nmol/LTSA处理组较未处理组增强了4～10倍。结论:TSA可以增强针对卵巢癌细胞的腺病毒基因转染效率,为增强卵巢癌基因治疗效果提供可能的方法。展开更多
Background: Telomere length dysregulation plays a major role in cancer development and aging. Telomeres are maintained by a group of specialized genes known as shelterin and shelterin-associated proteins. In breast ca...Background: Telomere length dysregulation plays a major role in cancer development and aging. Telomeres are maintained by a group of specialized genes known as shelterin and shelterin-associated proteins. In breast cancer lines it has been shown that shelterin proteins are dysregulated thereby affecting the telomere stability and contributing to the neoplastic conversion of the mammary epithelial cells. Interestingly, the regulation of some of the shelterin genes is thought to be controlled epigenetically. Methods and Results: In this study, we set out to measure the effect of increased shelterin gene expression on telomere length in breast cancer cell line 21NT treated with 5-aza-2-deoxycytidine (5-aza-CdR) using known telomere length assays. We measured telomere lengths using: Telomere Restriction Fragment length (TRF), absolute quantitative-PCR and cytogenetic Interphase Quantitative Fluorescent in situ Hybridization (iQ-FISH). We found that non-cytotoxic levels of 5-aza-CdR affect telomere lengths by causing a significant and stable increase in telomere lengths of the breast cancer cell line. The increase in telomere lengths was consistently observed when various telomere length methods were used. Conclusions: Further investigation is required to understand the underlying mechanism involved, and the significance of telomere length elongation in relation to clinical outcome when epigenetic modifying drugs are utilized.展开更多
In our previous studies, significant hypermethylation of the sirtuin 1(SIRT1) gene and demethylation of the b-amyloid precursor protein(APP) gene were found in patients with Alzheimer's disease(AD) compared with t...In our previous studies, significant hypermethylation of the sirtuin 1(SIRT1) gene and demethylation of the b-amyloid precursor protein(APP) gene were found in patients with Alzheimer's disease(AD) compared with the normal population. Moreover, the expression of SIRT1 was significantly decreased while that of APP was increased in AD patients. These results indicated a correlation of DNA methylation with gene expression levels in AD patients. To further investigate the epigenetic mechanism of gene modulation in AD, we used two epigenetic drugs, the DNA methylation inhibitor 5-aza-20-deoxycytidine(DAC) and the histone deacetylase inhibitor trichostatin A(TSA), to treat human neuroblastoma SK-N-SH cells in the presence of amyloid b-peptide Ab25–35(Ab25–35). We found that DAC and TSA had different effects on the expression trends of SIRT1 and APP in the cell model of amyloid toxicity. Although other genes, such as microtubule-associated protein s, presenilin 1, presenilin 2, and apolipoprotein E, were up-regulated after Ab25–35treatment, no significant differences were found after DAC and/or TSA treatment. These results support the evidence in AD patients and reveal a strong correlation of SIRT1/APP expression with DNA methylation and/or histone modification, which may help understand the pathogenesis of AD.展开更多
基金This study was supported by a grant from National Natural Science Foundation of China (81871600)
文摘BACKGROUND:Sepsis-induced liver injury is a fatal complication of sepsis.Trichostatin A(TSA)regulates inflammation and autophagy in some human diseases,and forkhead box O3a(FoxO3a)has been shown to regulate autophagy.The present study aims to investigate whether TSA exerts its effects on septic liver injury through the FoxO3a/autophagy signaling pathway.METHODS:A sepsis mouse model was constructed by the cecal ligation and puncture(CLP)method,and AML12 cells were pretreated with lipopolysaccharide(LPS)(1μg/mL)to establish a sepsis cell model.Forty mice were divided into four groups,namely control group,TSA group,CLP group,and CLP+TSA group,with 10 mice in each group.Cells were divided into control group,TSA group,LPS group,and LPS+TSA group.Hematoxylin-eosin(H&E)staining and biochemical methods were used to evaluate liver tissue injury.Enzyme-linked immunosorbent assay(ELISA)was applied to detect the expression of proinflammatory cytokines,and Western blotting and immunofluorescence were used to measure autophagy-related protein expression.RESULTS:Compared with the CLP group(mice),the proinflammatory cytokines(interleukin-β[IL-β]2,665.27±324.90 pg/mL to 2,080.26±373.66 pg/mL;interleukin-6[IL-6]399.01±60.98 pg/mL to 221.90±46.89 pg/mL)and the hepatocyte injury markers(aspartate transaminase[AST]from 198.18±27.07 U/L to 128.42±20.55 U/L;alanine aminotransferase[ALT]from 634.98±74.10 U/L to 478.60±32.56 U/L)were notably decreased after TSA intervention.Moreover,LC3 II and FoxO3a showed an obvious increase and P62 showed an obvious decrease in the CLP+TSA group.Cell experiment results showed the similar trend.After Fox O3a gene was knocked down in AML12 cells,the promotion of autophagy and the improvement of liver enzyme index and inflammation by TSA were weakened.CONCLUSION:TSA may improve the inflammatory response and liver injury in septic mice through Fox O3a/autophagy.
基金This research work was supported by the National Natural Science Funds of China(30800204)
文摘It is quite complex to evaluate the mechanism of action for antitumor drugs on cancer cells.Studies have pointed out that there is an unique advantage of Fourier transform infrared spectrum to obtain a fingerprint of all molecules present in the cells when cancer cells were exposed to anti-cancer drugs.Trichostatin A(TSA) is a most potent reversible inhibitor of mammalian histone deacetylases.It can inhibit cancer cell growth in vitro and in vivo.In the present study,HeLa cells were exposed to 0,50,100,200,300 and 400 nmol·L-1 TSA,and FTIR spectra were applied to evaluate the effect of TSA on cancer cells.Results show that there is some significant relationship between the changes in FTIR absorption and cell cycle arresting.On the other hand,this investigation shows that the concentration of TSA had to be more than 200 nmol·L-1 in order to ensure A1 080 cm-1/A1 540 cm-1≥1 for inhibiting cell proliferation.
基金Supported by Shanghai Municipal Health Bureau Key Disciplines Grant, No. ZK2012A05National Natural Science Foundation, No. 81070344
文摘AIM: To explore the effect of lysine acetylation in related proteins on regulation of the proliferation of gastric cancer cells, and determine the lysine-acetylated proteins and the acetylated modified sites in AGS gastric cancer cells. METHODS: The CCK-8 experiment and flow cytometry were used to observe the changes in proliferation and cycle of AGS cells treated with trichostatin A (TSA). Real time polymerase chain reaction and Western blotting were used to observe expression changes in p21, p53, Bax, Bcl-2, CDK2, and CyclinD1 in gastric cancer cells exposed to TSA. Cytoplasmic proteins in gastric cancer cells before and after TSA treatment were immunoprecipitated with anti-acetylated lysine antibodies, separated using sodium dodecyl sulfate polyacrylamide gel electrophoresis gel and silver-stained to detect the proteins by mass spectrometry after removal of the gel. The acetylated proteins in AGS cells were enriched with lysine-acetylated antibodies, and a high-resolution mass spectrometer was used to detect the acetylated proteins and modified sites. RESULTS: TSA significantly inhibited AGS cell proliferation, and promoted cell apoptosis, leading to AGS cell cycle arrest in G0/G1 and G2/M phases, especially G0/G1 phase. p21, p53 and Bax gene expression levels in AGS cells were increased with TSA treatment duration; Bcl-2, CDK2, and CyclinD1 gene expression levels were decreased with TSA treatment duration. Two unknown protein bands, 72 kDa (before exposure to TSA) and 28 kDa (after exposure to TSA), were identified by silver-staining after immunoprecipitation of AGS cells with the lysine-acetylated monoclonal antibodies. Mass spectrometry showed that the 72 kDa protein band may be PKM2 and the 28 kDa protein band may be ATP5O. The acetylated proteins and modified sites in AGS cells were determined. CONCLUSION: TSA can inhibit gastric cancer cell proliferation, which possibly activated signaling pathways in a variety of tumor-associated factors. ATP5O was obviously acetylated in AGS cells following TSA treatment.
文摘Histone deacetylase (HDAC) inhibitors are considered as promising therapeutic agents against several malignant diseases because they inhibit cancer cell proliferation. The stress sensor genes of the growth arrest and DNA damage-inducible protein (gadd45) family exhibit disordered expression in several types of malignant diseases and are thus a novel target for cancer therapy. However, there have been only few investigations of whether HDAC inhibitors affect the expression of gadd45 genes. We examined the effects of a HDAC inhibitor, trichostatin A (TSA), on the time-dependent expression of gadd45 genes in the human colon cancer cell line LS174T. Addition of TSA to LS174T cells induced inhibition of cell proliferation by arresting the cell cycle. We found that TSA treatment of LS174T cells induced rapid upregulation of gadd45β mRNA expression within 15 min, reaching a peak level at 3 h. Although the time-dependent expression pattern of gadd45β mRNA was similar to that of gadd45β mRNA, the peak level of gadd45β was lower than that of gadd45β. TSA treatment also upregulated the mRNA level of p21Waf1/Cip1, a prolif- eration inhibitor, after 3 h, but downregulated the mRNA levels of cyclin D1, a proliferation inducer, after 3 h, and of c-Myc after 1 h. TSA treatment induced a certain level of apoptosis, but the mRNA level of p53, a potent apoptosis inducer, was down-regulated after 3 h. These results suggest that the up-regulation of p21Waf1/Cip1 and apoptosis was independent of p53 and that the early upregulation of gadd45β gene, which precedes the upregulation of p21Waf1/Cip1 and the downregulation of cyclin D1, are important in TSA-treated LS174T cells.
基金supported by adjutancy of research of Jahrom Medical University-Iran
文摘Background and Aims:DNA methylation and histone mod-ification are epigenetic modifications essential for normal function of mammalian cells.The processes are mediated by biochemical interactions between DNA methyltransferases(DNMTs)and histone deacetylases.Promoter hypermethyla-tion and deacetylation of tumor suppressor genes play major roles in cancer induction,through transcriptional silencing of these genes.DNA hypermethylation is carried out by a family of DNMTs including DNMT1,DNMT3a and DNMT3b.In hepatocellular carcinoma,a significant positive correlation bet-ween over-expression of these genes and cancer induction has been reported.The DNA demethylating agent genistein(GE)has been demonstrated to reduce different cancers.Pre-viously,we reported that GE can induce apoptosis and inhibit proliferation in hepatocellular carcinoma PLC/PRF5 and HepG2 cell lines.Besides,histone deacetylase inhibitors,such as trichostatin A(TSA),were successfully used to inhibit cancer cell growth.The present study was designed to assess the effect of GE in comparison with TSA on DNMT1,DNMT3a and DNMT3b gene expression,cell growth inhibition and apoptosis induction in the HepG2 cell line.Methods:Cells were seeded and treated with various doses of GE and TSA.The MTT assay,flow cytometry assay,and real-time RT-PCR were used to determine viability,apoptosis,and DNMT1,DNMT3a and DNMT3b gene expression respectively.Results:Both agents inhibited cell growth,induced apoptosis and re-activated DNMT1,DNMT3a and DNMT3b gene expression.Furthermore,TSA demonstrated a significantly greater apop-totic effect than the other agent,whereas GE improved gene expression more significantly than TSA.Conclusions:Our findings suggest that GE and TSA can significantly inhibit cell growth,induce apoptosis and restore DNMT1,DNMT3a and DNMT3b gene reactivation.
基金supported by the National Natural Science Foundation of China (31300504)Fundamental Research Funds for Rubber Research Institute,Chinese Academy of Tropical Agricultural Sciences (1630022016006)the Earmarked Fund for China Agriculture Research System (CARS-34-GW1)
文摘The secondary laticifer, a specific tissue in the secondary phloem of rubber tree, is differentiated from the vascular cambia. The number of the secondary laticifer in the trunk bark of rubber tree is positively correlated with rubber yield. Although jasmonates have been demonstrated to be crucial in the regulation of secondary laticifer differentiation, the mechanism for the jasmonate-induced secondary laticifer differentiation remains to be elucidated.By using an experimental morphological technique, the present study revealed that trichostatin A(TSA), an inhibitor of histone deacetylation, could induce the secondary laticifer differentiation in a concentrationdependent manner. The results suggest that histone acetylation is essential for the secondary laticifer differentiation in rubber tree.
基金National Natural Science Foundation of Chinagrant number:10925208,11120101001,10802006 and 10972024+1 种基金NFundamental Research Funds for the Central Universitiesgrant number:YWF-10-02-065
文摘Differentiation of bone marrow mesenchymal stem cells (MSCs) into endothelial cells (EC) is characterized by the expression of specific endothelial marker genes. Mechanical stimulations play potential effects in EC oriented differentiation of MSCs. However, molecular mechanisms of endothelial differentiation from MSCs have not been defined.Histone acetylations play important roles in regulating gene expression. Histone acetylation status is maintained by histone acetyltransferase (HAT) and histone deacetylases (HDACs). Our previous work described that VEGF and laminar shear stress (SS) work together in determining EC oriented differentiation of MSC. Trichostatin A (TSA) is one of the lustone deacetylase inhibitor. In this study, we found that both TSA and SS could induce EC oriented differentiation of MSCs. And TSA combined with SS showed more powerful influence on the EC oriented differentiation of MSCs.
文摘背景与目的:腺病毒感染依赖于靶细胞表面柯萨奇-腺病毒受体(Coxsackie and adenovirus receptor,CAR)的表达,肿瘤细胞CAR表达的缺失和下调是造成腺病毒为载体基因治疗效果不佳的根本原因。本研究通过观察组氨酸去乙酰化酶(histone deacetylase,HDAC)抑制剂TrichostatinA(TSA)对卵巢癌细胞株A2780CAR表达水平的影响,探讨HDAC抑制剂在腺病毒载体基因治疗中应用的可能性。方法:分别在TSA作用A2780细胞前后检测CARmRNA和蛋白水平的表达,同时采用流式细胞术测定病毒转染效率,MTT实验评价腺病毒携带的胸苷激酶(ADV/TK)的体外抗瘤效应。结果:TSA处理后,A2780细胞内CARmRNA和蛋白表达明显增高。通过流式细胞仪分析GFP/ADV转染后GFP的表达发现,未处理组细胞转染率为(1.24±0.14)%;5nmol/L和100nmol/LTSA处理48h后,细胞的转染效率分别为(7.58±0.32)%和(7.94±0.28)%。MTT结果表明,ADV/TK介导的体外杀伤作用在5nmol/L和100nmol/LTSA处理组较未处理组增强了4～10倍。结论:TSA可以增强针对卵巢癌细胞的腺病毒基因转染效率,为增强卵巢癌基因治疗效果提供可能的方法。
文摘Background: Telomere length dysregulation plays a major role in cancer development and aging. Telomeres are maintained by a group of specialized genes known as shelterin and shelterin-associated proteins. In breast cancer lines it has been shown that shelterin proteins are dysregulated thereby affecting the telomere stability and contributing to the neoplastic conversion of the mammary epithelial cells. Interestingly, the regulation of some of the shelterin genes is thought to be controlled epigenetically. Methods and Results: In this study, we set out to measure the effect of increased shelterin gene expression on telomere length in breast cancer cell line 21NT treated with 5-aza-2-deoxycytidine (5-aza-CdR) using known telomere length assays. We measured telomere lengths using: Telomere Restriction Fragment length (TRF), absolute quantitative-PCR and cytogenetic Interphase Quantitative Fluorescent in situ Hybridization (iQ-FISH). We found that non-cytotoxic levels of 5-aza-CdR affect telomere lengths by causing a significant and stable increase in telomere lengths of the breast cancer cell line. The increase in telomere lengths was consistently observed when various telomere length methods were used. Conclusions: Further investigation is required to understand the underlying mechanism involved, and the significance of telomere length elongation in relation to clinical outcome when epigenetic modifying drugs are utilized.
基金supported by the National Basic Research Development Program of China (2006cb500700)the National Natural Science Foundation of China (30470904 and 31401627)+3 种基金Guangdong Provincial Natural Science Foundation of China (2010B031600070 and 2015A030313066)Science and Technology Social Development Project of Guangdong Province (2008B030301320 and 2012B031800053)a Guangdong Provincial Science and Technology Project (2013B051000009)a Guangzhou Science and Technology Plan Application Basic Research Project (2012J410076)
文摘In our previous studies, significant hypermethylation of the sirtuin 1(SIRT1) gene and demethylation of the b-amyloid precursor protein(APP) gene were found in patients with Alzheimer's disease(AD) compared with the normal population. Moreover, the expression of SIRT1 was significantly decreased while that of APP was increased in AD patients. These results indicated a correlation of DNA methylation with gene expression levels in AD patients. To further investigate the epigenetic mechanism of gene modulation in AD, we used two epigenetic drugs, the DNA methylation inhibitor 5-aza-20-deoxycytidine(DAC) and the histone deacetylase inhibitor trichostatin A(TSA), to treat human neuroblastoma SK-N-SH cells in the presence of amyloid b-peptide Ab25–35(Ab25–35). We found that DAC and TSA had different effects on the expression trends of SIRT1 and APP in the cell model of amyloid toxicity. Although other genes, such as microtubule-associated protein s, presenilin 1, presenilin 2, and apolipoprotein E, were up-regulated after Ab25–35treatment, no significant differences were found after DAC and/or TSA treatment. These results support the evidence in AD patients and reveal a strong correlation of SIRT1/APP expression with DNA methylation and/or histone modification, which may help understand the pathogenesis of AD.
