根据条件基因敲除技术和基因沉默的理论,构建了可被CRE操控的条件基因沉默系统,并应用其研究分子伴侣相互作用蛋白CHIP(C-terminus of Hsc70-interacting protein)对TGF-β信号通路的调控.RT-PCR和免疫印迹结果显示,pLoxP/CHIPi与CRE相...根据条件基因敲除技术和基因沉默的理论,构建了可被CRE操控的条件基因沉默系统,并应用其研究分子伴侣相互作用蛋白CHIP(C-terminus of Hsc70-interacting protein)对TGF-β信号通路的调控.RT-PCR和免疫印迹结果显示,pLoxP/CHIPi与CRE相互作用后,可以有效地降低内源CHIP的mRNA水平,减少外源和内源CHIP的蛋白质量.荧光素酶报告系统分析表明,条件基因沉默能解除CHIP对TGF-β信号通路的抑制性调控,增强TGF-β信号通路的转录活性.结果表明,CRE依赖的条件基因沉默系统具有高效性、特异性,并通过它反向验证了CHIP对TGF-β信号通路的抑制性调控,为进一步研究与CHIP相关的TGF-β信号通路所致疾病的发生机理提供了有效工具.展开更多
Objective To explore the role and regulation of guanine nucleotide-binding protein G（i）, a-1 subunit （GNAI1） in hepatocellular carcinoma （HCC）. Methods Expression of GNAI1 in HCC samples was determined by qRT-PC...Objective To explore the role and regulation of guanine nucleotide-binding protein G（i）, a-1 subunit （GNAI1） in hepatocellular carcinoma （HCC）. Methods Expression of GNAI1 in HCC samples was determined by qRT-PCR and immunohistochemical （IHC） staining. Huh-7 and SNU-387 cells stably expressing GNAI1 were established by the infection of lentivirus transducing unit containing GNAI1. siRNA against GNAI1 was transfected into SMMC-7721 cells to knock down the GNAI1 expression in HCC cells. Mir-320a/c/d mimics were transfected into SMMC-7721 and SK-Hep-1 cells and the expression of GNAll was determined by Western blot. The migration and invasion of Huh-7, SNU-387, SK-Hep-1 and SMMC-7721 cells were investigated by Transwell assays. Results The GNAI1 protein was significantly downregulated in HCC samples without changes in its mRNA levels. GNAI1 could inhibit the migration and invasion of HCC cells in vitro. Further investigations indicated that GNAI1 was a target of miR-320a/c/d in HCC cells. Transwell assays demonstrated that these microRNAs could promote the migratory ability and invasivesess of HCC cells in vitro. Conclusions GNAII is downregulated in HCC and inhibits the migration and invasion of HCC cells. This study is the first to investigate the role of GNAI1 in cancer. Regulation of GNAI1 by miR-320a/c/d indicates new therapeutic avenues for targeting HCC metastasis.展开更多
DNA methylation is a type of epigenetic modification in the human genome,which means that gene expression is regulated without altering the DNA sequence.Methylation and the relationship between methylation and cancer ...DNA methylation is a type of epigenetic modification in the human genome,which means that gene expression is regulated without altering the DNA sequence.Methylation and the relationship between methylation and cancer have been the focus of molecular biology researches.Methylation represses gene expression and can influence embryogenesis and tumorigenesis.In different tissues and at different stages of life,the level of methylation of DNA varies,implying a fundamental but distinct role for methylation.When genes are repressed by abnormal methylation,the resulting effects can include instability of that gene and inactivation of a tumor suppressor gene.MicroRNAs have some aspects in common with this regulation of gene expression.Here we reviewed the influence of gene methylation on cancer and analyzed the methods used to profile methylation.We also assessed the correlation between methylation and other epigenetic modifications and microRNAs.About 55 845 research papers have been published about methylation,and one-fifth of these are about the appearance of methylation in cancer.We conclude that methylation does play a role in some cancer types.展开更多
The expression of phosphatase and tensin homolog (PTEN ), a tumor suppressor gene, is frequently downregulated in gastric carcinomas due to mutation, loss of heterozygosity, and promoter hypermethylation. However, it ...The expression of phosphatase and tensin homolog (PTEN ), a tumor suppressor gene, is frequently downregulated in gastric carcinomas due to mutation, loss of heterozygosity, and promoter hypermethylation. However, it is unknown if additional mechanisms may account for the down-regulation of PTEN expression. While neuronal precursor cell-expressed developmentally down-regulated 4-1 (NEDD4-1) is believed to be a potential dual regulator of PTEN, there are conflicting reports regarding their interaction. To gain further insight into the role of NEDD4-1 and its association with PTEN in gastric carcinoma development, we measured the protein expression of NEDD4-1 and PTEN in gastric mucosae with various pathological lesions and found that NEDD4-1 increased from normal gastric mucosa to intestinal metaplasia and decreased from dysplasia to gastric carcinoma. These changes did not correlate with PTEN expression changes during gastric carcinogenesis. Moreover, we found similar results in protein levels in the primary tumors and adjacent non-tumorous tissues. These results differ from a previous report showing that expression of NEDD4-1 is up-regulated in gastric carcinomas, and show a more complex pattern of NEDD4-1 gene expression during gastric carcinogenesis.展开更多
Objective： We aimed to study the effect and mechanism of low-dose radiation （LDR） on adaptive response of gastric cancer cell. Methods： SGC7901 cells were cultured in vitro, and divided into 4 groups： control gro...Objective： We aimed to study the effect and mechanism of low-dose radiation （LDR） on adaptive response of gastric cancer cell. Methods： SGC7901 cells were cultured in vitro, and divided into 4 groups： control group （DO group）, low-dose radiation group （D1 group, 75 mGy）, high-dose radiation group （D2 group, 2 Gy）, low-dose plus high-dose radiation group （D1 ＋ D2 group, 75 mGy ＋ 2 Gy, the interval of low and high-close radiation being 8 h）. Cell inhibition rate was detected by cytometry and CCK8 method; the proportion of cell cycle at different times after irradiation was determined by using a flow cytometry. The ATM mRNA levels were detected by using quantitative real-time reverse transcription polymerase chain reaction （RT-PCR）. Results： There was no significant different between groups DO and D1, groups D2 and D1 ＋ D2 cell inhibition rate （P 〉 0.05）. There was a significant increase G2/M arrest in groups D2 and D1 ＋ D2 than groups DO and D1 after 6 h of radiation and did not recover at 48 h （P 〈 0.05）. The ATM mRNA expression of group D2 and D1 ＋ D2 increased highly than that of group DO and D1 （P 〈 0.05）. However, differences between group D2 and D1 ＋ D2, group DO and D1 were not statistical significant （P 〉 0.05）. Conclusion： LDR cannot induce adaptive response in SGC7901 cells in vitro, which may be associated the regulation of cell cycle, and its ATM mRNA expression cannot be affected by 75 mGy X-ray radiation.展开更多
Although prohibitin 1(PHB) is known to be associated with tumors,there are few studies regarding the role of PHB in hepatocellular carcinoma.An earlier glycoproteomics study of ours showed that PHB is over-expressed i...Although prohibitin 1(PHB) is known to be associated with tumors,there are few studies regarding the role of PHB in hepatocellular carcinoma.An earlier glycoproteomics study of ours showed that PHB is over-expressed in MHCC97-H cells,a highly metastatic liver cancer cell line,and can be captured by wheat germ agglutinin.In the present study,western blotting and reverse transcription-PCR experiments showed an approximately 2-fold up-regulation in the expression of PHB in MHCC97-H cells.However,PHB was not significantly up-regulated in MHCC97-L cells,a low-metastatic liver cancer cell line.When PHB was over-expressed in MHCC97-L cells,cell proliferation was inhibited by 35% and migration increased about 2-fold.The results of this study show that PHB is up-regulated in MHCC97-H cells and is associated with both proliferation and migration of liver cancer cells.展开更多
MicroRNAs play important roles in the devel- opment and progression of various cancers, including tongue squamous cell carcinoma （TSCC）. miR-29b and miR-195 have been reported to be tumor suppressors in TSCC. Here, ...MicroRNAs play important roles in the devel- opment and progression of various cancers, including tongue squamous cell carcinoma （TSCC）. miR-29b and miR-195 have been reported to be tumor suppressors in TSCC. Here, we investigated the expression of miR-29b and miR- 195 and their relationship in TSCC. Our data showed that miR-29b and miR-195 were significantly downregulated in TSCC com- pared with their matched nonmalignant tissues in 60 paired samples. The level of miR-29b was positively correlated with that of miR-195 in TSCC and the matched nonmalignant tissues. Moreover, miR-29b overexpression induced the demethylation of CpG islands upstream of miR-195 via targeting DNMT3B, leading to the upregulation of miR-195 in TSCC cell lines. Following DNMT3B silencing, the expression of miR-195 was increased and the methylation of CpG islands upstream of miR-195 was reduced. Although overexpression of miR-29b alone significantly increased miR- 195 expression, co-transfection of miR-29b with DNMT3B resulted in no change in miR-195 expression. Taken together, our results demonstrated that miR-29b could upregulate miR- 195 by directly targeting DNMT3B in TSCC. The interaction between miR-29b and miR-195 might provide new insights in developing novel therapeutic approaches of TSCC.展开更多
文摘根据条件基因敲除技术和基因沉默的理论,构建了可被CRE操控的条件基因沉默系统,并应用其研究分子伴侣相互作用蛋白CHIP(C-terminus of Hsc70-interacting protein)对TGF-β信号通路的调控.RT-PCR和免疫印迹结果显示,pLoxP/CHIPi与CRE相互作用后,可以有效地降低内源CHIP的mRNA水平,减少外源和内源CHIP的蛋白质量.荧光素酶报告系统分析表明,条件基因沉默能解除CHIP对TGF-β信号通路的抑制性调控,增强TGF-β信号通路的转录活性.结果表明,CRE依赖的条件基因沉默系统具有高效性、特异性,并通过它反向验证了CHIP对TGF-β信号通路的抑制性调控,为进一步研究与CHIP相关的TGF-β信号通路所致疾病的发生机理提供了有效工具.
基金supported by grants from the National 973 Key Basic Research Program(No.2011CB933100)National Natural Science Foundation of China(No.81125016 and 81101481)+1 种基金Science and Technology Commission of Shanghai Municipality(No.11XD1404500 and 10JC1414200)Shanghai Health Bureau(No.XYQ2011047 and XBR2011039)
文摘Objective To explore the role and regulation of guanine nucleotide-binding protein G（i）, a-1 subunit （GNAI1） in hepatocellular carcinoma （HCC）. Methods Expression of GNAI1 in HCC samples was determined by qRT-PCR and immunohistochemical （IHC） staining. Huh-7 and SNU-387 cells stably expressing GNAI1 were established by the infection of lentivirus transducing unit containing GNAI1. siRNA against GNAI1 was transfected into SMMC-7721 cells to knock down the GNAI1 expression in HCC cells. Mir-320a/c/d mimics were transfected into SMMC-7721 and SK-Hep-1 cells and the expression of GNAll was determined by Western blot. The migration and invasion of Huh-7, SNU-387, SK-Hep-1 and SMMC-7721 cells were investigated by Transwell assays. Results The GNAI1 protein was significantly downregulated in HCC samples without changes in its mRNA levels. GNAI1 could inhibit the migration and invasion of HCC cells in vitro. Further investigations indicated that GNAI1 was a target of miR-320a/c/d in HCC cells. Transwell assays demonstrated that these microRNAs could promote the migratory ability and invasivesess of HCC cells in vitro. Conclusions GNAII is downregulated in HCC and inhibits the migration and invasion of HCC cells. This study is the first to investigate the role of GNAI1 in cancer. Regulation of GNAI1 by miR-320a/c/d indicates new therapeutic avenues for targeting HCC metastasis.
文摘DNA methylation is a type of epigenetic modification in the human genome,which means that gene expression is regulated without altering the DNA sequence.Methylation and the relationship between methylation and cancer have been the focus of molecular biology researches.Methylation represses gene expression and can influence embryogenesis and tumorigenesis.In different tissues and at different stages of life,the level of methylation of DNA varies,implying a fundamental but distinct role for methylation.When genes are repressed by abnormal methylation,the resulting effects can include instability of that gene and inactivation of a tumor suppressor gene.MicroRNAs have some aspects in common with this regulation of gene expression.Here we reviewed the influence of gene methylation on cancer and analyzed the methods used to profile methylation.We also assessed the correlation between methylation and other epigenetic modifications and microRNAs.About 55 845 research papers have been published about methylation,and one-fifth of these are about the appearance of methylation in cancer.We conclude that methylation does play a role in some cancer types.
基金Supported by Grants from the National Natural Science Foundation of China, No. 81060038the Graduate Innovative Fund of Jiangxi Province, No. YC10A020
文摘The expression of phosphatase and tensin homolog (PTEN ), a tumor suppressor gene, is frequently downregulated in gastric carcinomas due to mutation, loss of heterozygosity, and promoter hypermethylation. However, it is unknown if additional mechanisms may account for the down-regulation of PTEN expression. While neuronal precursor cell-expressed developmentally down-regulated 4-1 (NEDD4-1) is believed to be a potential dual regulator of PTEN, there are conflicting reports regarding their interaction. To gain further insight into the role of NEDD4-1 and its association with PTEN in gastric carcinoma development, we measured the protein expression of NEDD4-1 and PTEN in gastric mucosae with various pathological lesions and found that NEDD4-1 increased from normal gastric mucosa to intestinal metaplasia and decreased from dysplasia to gastric carcinoma. These changes did not correlate with PTEN expression changes during gastric carcinogenesis. Moreover, we found similar results in protein levels in the primary tumors and adjacent non-tumorous tissues. These results differ from a previous report showing that expression of NEDD4-1 is up-regulated in gastric carcinomas, and show a more complex pattern of NEDD4-1 gene expression during gastric carcinogenesis.
文摘Objective： We aimed to study the effect and mechanism of low-dose radiation （LDR） on adaptive response of gastric cancer cell. Methods： SGC7901 cells were cultured in vitro, and divided into 4 groups： control group （DO group）, low-dose radiation group （D1 group, 75 mGy）, high-dose radiation group （D2 group, 2 Gy）, low-dose plus high-dose radiation group （D1 ＋ D2 group, 75 mGy ＋ 2 Gy, the interval of low and high-close radiation being 8 h）. Cell inhibition rate was detected by cytometry and CCK8 method; the proportion of cell cycle at different times after irradiation was determined by using a flow cytometry. The ATM mRNA levels were detected by using quantitative real-time reverse transcription polymerase chain reaction （RT-PCR）. Results： There was no significant different between groups DO and D1, groups D2 and D1 ＋ D2 cell inhibition rate （P 〉 0.05）. There was a significant increase G2/M arrest in groups D2 and D1 ＋ D2 than groups DO and D1 after 6 h of radiation and did not recover at 48 h （P 〈 0.05）. The ATM mRNA expression of group D2 and D1 ＋ D2 increased highly than that of group DO and D1 （P 〈 0.05）. However, differences between group D2 and D1 ＋ D2, group DO and D1 were not statistical significant （P 〉 0.05）. Conclusion： LDR cannot induce adaptive response in SGC7901 cells in vitro, which may be associated the regulation of cell cycle, and its ATM mRNA expression cannot be affected by 75 mGy X-ray radiation.
基金supported by the Shanghai Leading Academic Discipline Project (Grant No. B110)grants from CNHLPP (Grant No. 2005-BAC11A11)the Scientific Research Foundation for Young Talents of Shanghai Jiaotong University (Grant No. AB150200)
文摘Although prohibitin 1(PHB) is known to be associated with tumors,there are few studies regarding the role of PHB in hepatocellular carcinoma.An earlier glycoproteomics study of ours showed that PHB is over-expressed in MHCC97-H cells,a highly metastatic liver cancer cell line,and can be captured by wheat germ agglutinin.In the present study,western blotting and reverse transcription-PCR experiments showed an approximately 2-fold up-regulation in the expression of PHB in MHCC97-H cells.However,PHB was not significantly up-regulated in MHCC97-L cells,a low-metastatic liver cancer cell line.When PHB was over-expressed in MHCC97-L cells,cell proliferation was inhibited by 35% and migration increased about 2-fold.The results of this study show that PHB is up-regulated in MHCC97-H cells and is associated with both proliferation and migration of liver cancer cells.
基金the National Natural Science Foundation of China (81402235)Foundation of Peking University School and Hospital of Stomatology (PKUSS20140104)
文摘MicroRNAs play important roles in the devel- opment and progression of various cancers, including tongue squamous cell carcinoma （TSCC）. miR-29b and miR-195 have been reported to be tumor suppressors in TSCC. Here, we investigated the expression of miR-29b and miR- 195 and their relationship in TSCC. Our data showed that miR-29b and miR-195 were significantly downregulated in TSCC com- pared with their matched nonmalignant tissues in 60 paired samples. The level of miR-29b was positively correlated with that of miR-195 in TSCC and the matched nonmalignant tissues. Moreover, miR-29b overexpression induced the demethylation of CpG islands upstream of miR-195 via targeting DNMT3B, leading to the upregulation of miR-195 in TSCC cell lines. Following DNMT3B silencing, the expression of miR-195 was increased and the methylation of CpG islands upstream of miR-195 was reduced. Although overexpression of miR-29b alone significantly increased miR- 195 expression, co-transfection of miR-29b with DNMT3B resulted in no change in miR-195 expression. Taken together, our results demonstrated that miR-29b could upregulate miR- 195 by directly targeting DNMT3B in TSCC. The interaction between miR-29b and miR-195 might provide new insights in developing novel therapeutic approaches of TSCC.
