AIM:To clarify the role of activated Notch2 in the invasiveness of gastric cancer.METHODS:To investigate the invasiveness of silencing Notch2 gene expression,we established a Notch2small interfering RNA(siRNA) transfe...AIM:To clarify the role of activated Notch2 in the invasiveness of gastric cancer.METHODS:To investigate the invasiveness of silencing Notch2 gene expression,we established a Notch2small interfering RNA(siRNA) transfected cell line using the MKN-45 gastric cancer cell line.After the successful transfection confirmed by real-time reverse transcription-polymerase chain reaction(RT-PCR) and Western blotting,migration and invasion assays were employed to evaluate the aggressiveness of the gastric cancer.RT-PCR and Western blottings were employed to confirm the down-regulation of Notch2 and to evaluate the expression of epithelial mesenchymal transition-related gene matrix metallopeptidase 9(MMP9),Akt,p-Akt.To confirm the relationship between PI3KAkt and MMP9,the PI3K inhibitor LY294002 was used to treat MKN-45 cells.RESULTS:Notch2 expression was dramatically decreased after Notch2 siRNA transfection(100.00% ± 9.74% vs 11.61% ± 3.85%,P < 0.01 by qRT-PCR).There was also a marked reduction of Notch target gene Hes1(100.00% ± 4.74% vs 61.61% ± 3.58%,P < 0.05) at the mRNA,indicating an inhibition of Notch signaling.Inhibition of Notch signaling was also confirmed by the marked reduction of Notch2 intracellular domain at the protein levels(100.00% ± 9.74% vs 65.61% ± 7.58%,P < 0.05).Down-regulation of Notch2 by siRNA enhanced tumor cell invasion(100.00% ± 21.64% vs 162.22% ± 16.84%,P < 0.05) and expression of MMP9(1.56 fold,P < 0.05),and activated the pro-MMP9 protein to its active form(1.48 fold,P < 0.05).There was no significant difference in the protein levels of Akt between the two groups(100.00% ± 10.87% vs 96.61% ± 7.33%,P > 0.05),while down-regulation of Notch2 elevated p-Akt expression(100.00% ± 9.87% vs 154.61% ± 13.10%,P < 0.05).Furthermore,p-Akt and MMP9 was down-regulated in response to the inhibitor LY294002(p-Akt 100.00% ± 8.87% vs 58.27% ± 5.01%,P < 0.05;MMP9 100.00% ± 9.17% vs 50.03% ± 4.88%,P < 0.05).CONCLUSION:Notch2 may negatively regulate cell invasion by inhibiting the PI3K-Akt signaling展开更多
Objective To conduct a case-control study on the association of the nucleotide polymorphisms in the promoter region of the matrix metalloproteinase-9(MMP-9)gene with phenotype of esophageal cancer.Methods All subjects...Objective To conduct a case-control study on the association of the nucleotide polymorphisms in the promoter region of the matrix metalloproteinase-9(MMP-9)gene with phenotype of esophageal cancer.Methods All subjects were unrelated residents in northern regions of China.Polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP)analysis was used to determine the MMP-9 genotypes.Results The overall distribution of genotypes in the patients was not different from that in the controls(OR=0.77,95% CI=0.45-1.34;P=0.36).There were no significant differences between the patients and the control subjects in terms of the distributions of sex and age,smoking status,alcohol dependence,pickled diet status,or history of environmental exposure.The patients were further examined with stratifications by age,sex,grade,depth of tumor invasion,lymphatic invasion,venous invasion and TNM staging.The results showed no pronounced association among the stratifications.Conclusion There is no significant association between the MMP-9 single nucleotide polymorphism genotypes and phenotype of esophageal cancer.展开更多
基金Supported by The National Natural Science Foundation of China,No. 30870364Fund for Key Laboratory of Digestive System Tumors,Gansu Province,No. lzujbky-2011-t03
文摘AIM:To clarify the role of activated Notch2 in the invasiveness of gastric cancer.METHODS:To investigate the invasiveness of silencing Notch2 gene expression,we established a Notch2small interfering RNA(siRNA) transfected cell line using the MKN-45 gastric cancer cell line.After the successful transfection confirmed by real-time reverse transcription-polymerase chain reaction(RT-PCR) and Western blotting,migration and invasion assays were employed to evaluate the aggressiveness of the gastric cancer.RT-PCR and Western blottings were employed to confirm the down-regulation of Notch2 and to evaluate the expression of epithelial mesenchymal transition-related gene matrix metallopeptidase 9(MMP9),Akt,p-Akt.To confirm the relationship between PI3KAkt and MMP9,the PI3K inhibitor LY294002 was used to treat MKN-45 cells.RESULTS:Notch2 expression was dramatically decreased after Notch2 siRNA transfection(100.00% ± 9.74% vs 11.61% ± 3.85%,P < 0.01 by qRT-PCR).There was also a marked reduction of Notch target gene Hes1(100.00% ± 4.74% vs 61.61% ± 3.58%,P < 0.05) at the mRNA,indicating an inhibition of Notch signaling.Inhibition of Notch signaling was also confirmed by the marked reduction of Notch2 intracellular domain at the protein levels(100.00% ± 9.74% vs 65.61% ± 7.58%,P < 0.05).Down-regulation of Notch2 by siRNA enhanced tumor cell invasion(100.00% ± 21.64% vs 162.22% ± 16.84%,P < 0.05) and expression of MMP9(1.56 fold,P < 0.05),and activated the pro-MMP9 protein to its active form(1.48 fold,P < 0.05).There was no significant difference in the protein levels of Akt between the two groups(100.00% ± 10.87% vs 96.61% ± 7.33%,P > 0.05),while down-regulation of Notch2 elevated p-Akt expression(100.00% ± 9.87% vs 154.61% ± 13.10%,P < 0.05).Furthermore,p-Akt and MMP9 was down-regulated in response to the inhibitor LY294002(p-Akt 100.00% ± 8.87% vs 58.27% ± 5.01%,P < 0.05;MMP9 100.00% ± 9.17% vs 50.03% ± 4.88%,P < 0.05).CONCLUSION:Notch2 may negatively regulate cell invasion by inhibiting the PI3K-Akt signaling
基金supported by the Development Funding of Xi'an(No.YF07171/05/04/2007)
文摘Objective To conduct a case-control study on the association of the nucleotide polymorphisms in the promoter region of the matrix metalloproteinase-9(MMP-9)gene with phenotype of esophageal cancer.Methods All subjects were unrelated residents in northern regions of China.Polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP)analysis was used to determine the MMP-9 genotypes.Results The overall distribution of genotypes in the patients was not different from that in the controls(OR=0.77,95% CI=0.45-1.34;P=0.36).There were no significant differences between the patients and the control subjects in terms of the distributions of sex and age,smoking status,alcohol dependence,pickled diet status,or history of environmental exposure.The patients were further examined with stratifications by age,sex,grade,depth of tumor invasion,lymphatic invasion,venous invasion and TNM staging.The results showed no pronounced association among the stratifications.Conclusion There is no significant association between the MMP-9 single nucleotide polymorphism genotypes and phenotype of esophageal cancer.
