AIM: To study methylation, frequencies of homozygous deletion and mutation of p16 gene in gastric carcinoma.METHODS: The methylation pattern in exon 1 and exon 2of p16 gene was studied with polymerase chain reaction (...AIM: To study methylation, frequencies of homozygous deletion and mutation of p16 gene in gastric carcinoma.METHODS: The methylation pattern in exon 1 and exon 2of p16 gene was studied with polymerase chain reaction (PCR), using methylation sensitive restriction endonuclease HpaⅡ and methylation insensitive restriction endonudease MspⅠ. PCR technique was used to detect homozygous deletions of exon 1 and exon 2 of p16 gene and single strand conformation polymorphism (SSCP) technique was used to detect the mutation of the gene.RESULTS: Hypermethylation changes in exon 1 and exon 2 of p16 gene were observed in 25 % and 45 % of 20gastric cancer tissues, respectively, while no methylation abnormality was found in normal tissues. The homozygous deletion frequency of exon 1 and exon 2 of p16 gene in 20gastric cancer tissues was 20 % and 10 %, respectively. No mutation was found in exon 1 of p16 gene, while abnormal single strands were found in 2 (10 %) cases in exon 2 as detected by SSCP.CONCLUSION: The results suggest that hypermethylation and abnormality of p16 gene may play a key role in the progress of gastric cancer. Hypermethylation of exon 2 of p16 gene may have effects on the carcinogenesis of gastric mucosa and may be a later event.展开更多
AIM: To detect the loss of heterozygosity (LOH) frequency of microsatellite sites D9s171, D9s1604 of p16 gene and expression of hMSH2 mRNA in various differentiated types of gastric cancer, adjacent cancer tissues and...AIM: To detect the loss of heterozygosity (LOH) frequency of microsatellite sites D9s171, D9s1604 of p16 gene and expression of hMSH2 mRNA in various differentiated types of gastric cancer, adjacent cancer tissues and normal gastric mucosa.METHODS: LOH was detected by polymerase chain reaction (PCR)-denaturing polyacrylamide gel electrophoresis-silver staining. The expression of hMSH2 mRNA was examined with in situ hybridization.RESULTS: The frequency rate of LOH was significantly higher in gastric cancers than that in adjacent cancer tissues (P=0.032). No significant difference was noted among various differentiated types and various clinical stages of gastric cancers. The significantly reduced expression of hMSH2mRNA positive signal cells exhibited in gastric cancers, in comparison with that in the adjacent cancer tissues and normal gastric mucosa, respectively (P=0.001). No significant difference was noted among various clinical stages of gastric cancers (P＞0.05). The difference of positive signal cells in poorly differentiated cancers and those in well and moderately differentiated cancers were significant (P＜0.001).CONCLUSION: The frequencies of LOH in two microsatellite sites, D9s171 and D9s1604, in p16 genome were associated with development of gastric cancer and no significant correlation was demonstrated between the LOH frequency and the cell differentiated types of tumor cells or clinical stages. There was a positive relationship between the expression of hMSH2 mRNA and the differentiated types of gastric cancer.展开更多
Redox mechanism of ferrocene, acetylferrocene, ferrocenyl cinnamenyl ketone at a platinum electrode was studied with cyclic voltammetry (CV) and in-situ Fourier transform infrared (FTIR) spectroelectrochemistry. The ...Redox mechanism of ferrocene, acetylferrocene, ferrocenyl cinnamenyl ketone at a platinum electrode was studied with cyclic voltammetry (CV) and in-situ Fourier transform infrared (FTIR) spectroelectrochemistry. The IR bands in the range of 2000-1000 cm-1 attributed to the stretching and ring vibrations of these materials show the main spectral changes in the processes.展开更多
基金the National Natural Science Foundation of China,No.39170440
文摘AIM: To study methylation, frequencies of homozygous deletion and mutation of p16 gene in gastric carcinoma.METHODS: The methylation pattern in exon 1 and exon 2of p16 gene was studied with polymerase chain reaction (PCR), using methylation sensitive restriction endonuclease HpaⅡ and methylation insensitive restriction endonudease MspⅠ. PCR technique was used to detect homozygous deletions of exon 1 and exon 2 of p16 gene and single strand conformation polymorphism (SSCP) technique was used to detect the mutation of the gene.RESULTS: Hypermethylation changes in exon 1 and exon 2 of p16 gene were observed in 25 % and 45 % of 20gastric cancer tissues, respectively, while no methylation abnormality was found in normal tissues. The homozygous deletion frequency of exon 1 and exon 2 of p16 gene in 20gastric cancer tissues was 20 % and 10 %, respectively. No mutation was found in exon 1 of p16 gene, while abnormal single strands were found in 2 (10 %) cases in exon 2 as detected by SSCP.CONCLUSION: The results suggest that hypermethylation and abnormality of p16 gene may play a key role in the progress of gastric cancer. Hypermethylation of exon 2 of p16 gene may have effects on the carcinogenesis of gastric mucosa and may be a later event.
基金the National Natural Science Foundation of China,No.39170440
文摘AIM: To detect the loss of heterozygosity (LOH) frequency of microsatellite sites D9s171, D9s1604 of p16 gene and expression of hMSH2 mRNA in various differentiated types of gastric cancer, adjacent cancer tissues and normal gastric mucosa.METHODS: LOH was detected by polymerase chain reaction (PCR)-denaturing polyacrylamide gel electrophoresis-silver staining. The expression of hMSH2 mRNA was examined with in situ hybridization.RESULTS: The frequency rate of LOH was significantly higher in gastric cancers than that in adjacent cancer tissues (P=0.032). No significant difference was noted among various differentiated types and various clinical stages of gastric cancers. The significantly reduced expression of hMSH2mRNA positive signal cells exhibited in gastric cancers, in comparison with that in the adjacent cancer tissues and normal gastric mucosa, respectively (P=0.001). No significant difference was noted among various clinical stages of gastric cancers (P＞0.05). The difference of positive signal cells in poorly differentiated cancers and those in well and moderately differentiated cancers were significant (P＜0.001).CONCLUSION: The frequencies of LOH in two microsatellite sites, D9s171 and D9s1604, in p16 genome were associated with development of gastric cancer and no significant correlation was demonstrated between the LOH frequency and the cell differentiated types of tumor cells or clinical stages. There was a positive relationship between the expression of hMSH2 mRNA and the differentiated types of gastric cancer.
文摘Redox mechanism of ferrocene, acetylferrocene, ferrocenyl cinnamenyl ketone at a platinum electrode was studied with cyclic voltammetry (CV) and in-situ Fourier transform infrared (FTIR) spectroelectrochemistry. The IR bands in the range of 2000-1000 cm-1 attributed to the stretching and ring vibrations of these materials show the main spectral changes in the processes.
