AIM: To verify the effectiveness of denaturing highperformance liquid chromatography (DHPLC) in detecting somatic mutation of p53 gene in gastric carcinoma tissues.The superiority of this method has been proved in the...AIM: To verify the effectiveness of denaturing highperformance liquid chromatography (DHPLC) in detecting somatic mutation of p53 gene in gastric carcinoma tissues.The superiority of this method has been proved in the detection of germline mutations, but it was not very affirmative with respect to somatic mutations in tumor specimens. ST7 gene, a candidate tumor suppressor gene identified recently at human chromosome 7q31.1, was also detected because LOH at this site has also been widely reported in stomach cancer.METHODS: DNA was extracted from 39 cases of surgical gastric carcinoma specimen and their correspondent normal mucosa. Seven fragments spanning the 11 exons were used to detect the mutation of p53 gene and the four exons reported to have mutations in ST7 gene were amplified by PCR and directly analyzed by DHPLC without mixing with wild-type allele.RESULTS: In the analysis of p53 gene mutation, 9 aberrant DHPLC chromatographies were found in tumor tissues, while their normal-adjacent counterparts running in parallel showed a normal shape. Subsequent sequencing revealed nine sequence variations, 1 polymorphism and 8 mutations including 3 mutations not reported before. The mutation rate of p53 gene (21%) was consistent with that previously reported. Furthermore, no additional aberrant chromatography was found when wild-type DNA was added into the DNA of other 30 tumor samples that showed normal shapes previously. The positivity of p53 mutations was significantly higher in intestinal-type carcinomas (40 %) than that in diffuse-type (8.33 %) carcinomas of the stomach. No mutation of ST7 gene was found.CONCLUSION: DHPLC is a very convenient method for the detection of somatic mutations in gastric carcinoma. The amount of wild type alleles supplied by the non-tumorous cells in gastric tumor specimens is enough to form heteroduplex with mutant alleles for DHPLC detection. ST7 gene may not be the target gene of inactivation at 7q31 site in gastric carcinoma.展开更多
AIM: To study the effect of cyclin G2 on proliferation of gastric adenocarcinoma cell line-SGC-7901 cell in vitro.METHODS: By use of cation lipofectamine transfection reagent,the pIRES-G2 and pIRESneo plasmids were tr...AIM: To study the effect of cyclin G2 on proliferation of gastric adenocarcinoma cell line-SGC-7901 cell in vitro.METHODS: By use of cation lipofectamine transfection reagent,the pIRES-G2 and pIRESneo plasmids were transferred into SGC-7901cell line. Anticlones were selected by G418. Positive clones were observed and counted using Giemsa staining.Cell proliferative ability was assayed by Ml-r.RESULTS: (1) The done number of pIRES-G2 group decreased,clone volume reduced. The number of cell clones in pIRESneo group was 87+3, that of pIRES-G2 group was 53+4,occupying 60.1% of pIRESneo group, there was significant difference obviously (P<0.01, t=15.45). (2) The average absorbance of clone cell obtained by stable transfection of pIRES-G2 at 570 nm was 1.6966+0.2125, the average absorbance of clone cell obtained by stable transfection of pIRESneo at 570 nm was 2.1182+0.3675, there was significant difference between them (P<0.01, t=3.412).CONCLUSION: Cyclin G2 can inhibit SGC-7901cell proliferative ability obviously, it may be a negative regulator in cell cycle regulation.展开更多
Traffic information processing is very complicated because of dynamic, cooperative and distributed features. This paper describes the prototype system version 2.0 of Urban Traffic Information Service Application Grid ...Traffic information processing is very complicated because of dynamic, cooperative and distributed features. This paper describes the prototype system version 2.0 of Urban Traffic Information Service Application Grid (UTISAG), which is based on the previous version. In this version, a new architecture and more enhanced services are introduced, The. remarkable characteristic of the new system is providing dynamic information services for travelers by grid technology. Therefore, the key research includes integrating large multi-source traffic data, forecasting route status, simulating regional traffic flow parallelly, and implementing optimum dynamic travel scheme based on massive GPS data.展开更多
基金National Science Fund for Distinguished Young Scholars,No.30125017the Major State Basic Research Development Program of China(973 Program),No.G1998051203
文摘AIM: To verify the effectiveness of denaturing highperformance liquid chromatography (DHPLC) in detecting somatic mutation of p53 gene in gastric carcinoma tissues.The superiority of this method has been proved in the detection of germline mutations, but it was not very affirmative with respect to somatic mutations in tumor specimens. ST7 gene, a candidate tumor suppressor gene identified recently at human chromosome 7q31.1, was also detected because LOH at this site has also been widely reported in stomach cancer.METHODS: DNA was extracted from 39 cases of surgical gastric carcinoma specimen and their correspondent normal mucosa. Seven fragments spanning the 11 exons were used to detect the mutation of p53 gene and the four exons reported to have mutations in ST7 gene were amplified by PCR and directly analyzed by DHPLC without mixing with wild-type allele.RESULTS: In the analysis of p53 gene mutation, 9 aberrant DHPLC chromatographies were found in tumor tissues, while their normal-adjacent counterparts running in parallel showed a normal shape. Subsequent sequencing revealed nine sequence variations, 1 polymorphism and 8 mutations including 3 mutations not reported before. The mutation rate of p53 gene (21%) was consistent with that previously reported. Furthermore, no additional aberrant chromatography was found when wild-type DNA was added into the DNA of other 30 tumor samples that showed normal shapes previously. The positivity of p53 mutations was significantly higher in intestinal-type carcinomas (40 %) than that in diffuse-type (8.33 %) carcinomas of the stomach. No mutation of ST7 gene was found.CONCLUSION: DHPLC is a very convenient method for the detection of somatic mutations in gastric carcinoma. The amount of wild type alleles supplied by the non-tumorous cells in gastric tumor specimens is enough to form heteroduplex with mutant alleles for DHPLC detection. ST7 gene may not be the target gene of inactivation at 7q31 site in gastric carcinoma.
基金Supported by a grant for Distinguished Young Teachers of HigherEducation of the Ministry of Education of the Teaching and ResearchEncouragement Plan
文摘AIM: To study the effect of cyclin G2 on proliferation of gastric adenocarcinoma cell line-SGC-7901 cell in vitro.METHODS: By use of cation lipofectamine transfection reagent,the pIRES-G2 and pIRESneo plasmids were transferred into SGC-7901cell line. Anticlones were selected by G418. Positive clones were observed and counted using Giemsa staining.Cell proliferative ability was assayed by Ml-r.RESULTS: (1) The done number of pIRES-G2 group decreased,clone volume reduced. The number of cell clones in pIRESneo group was 87+3, that of pIRES-G2 group was 53+4,occupying 60.1% of pIRESneo group, there was significant difference obviously (P<0.01, t=15.45). (2) The average absorbance of clone cell obtained by stable transfection of pIRES-G2 at 570 nm was 1.6966+0.2125, the average absorbance of clone cell obtained by stable transfection of pIRESneo at 570 nm was 2.1182+0.3675, there was significant difference between them (P<0.01, t=3.412).CONCLUSION: Cyclin G2 can inhibit SGC-7901cell proliferative ability obviously, it may be a negative regulator in cell cycle regulation.
文摘Traffic information processing is very complicated because of dynamic, cooperative and distributed features. This paper describes the prototype system version 2.0 of Urban Traffic Information Service Application Grid (UTISAG), which is based on the previous version. In this version, a new architecture and more enhanced services are introduced, The. remarkable characteristic of the new system is providing dynamic information services for travelers by grid technology. Therefore, the key research includes integrating large multi-source traffic data, forecasting route status, simulating regional traffic flow parallelly, and implementing optimum dynamic travel scheme based on massive GPS data.
