AIM:To study the significance of p16 and p15 transcription suppression with hypermethylation of their genes′5′CpG islands during human hepatocellular carcinogenesis.METHODS:The mRNA expression levels of p16 and p15 ...AIM:To study the significance of p16 and p15 transcription suppression with hypermethylation of their genes′5′CpG islands during human hepatocellular carcinogenesis.METHODS:The mRNA expression levels of p16 and p15 genes were evaluated in cancerous,para-cancerous and non-cancerous tissues of 20 HCC,3 normal liver tissues from 3 accidentally died healthy adults using simi-quantitatively Northerm blot.The methylation status was also assessed with methylation specfic PCR.RESULTS:p16 mRNA expression level was decressed in the cancerous tissues in 60%(12/20) of HCC patients,of which 2 cases had no p16 mRNA detected,5 cases(25%) displayed variation in the order of cancerous<para-cancerous<non-cancerous liver tissues.p15 mRNA expression level was decreased in the cancerous tissues in 50%(10/20) HCC patients,of which one case had no p15 mRNA detected,4 cases (20%) displayed variation in the order of cancerous<para-cancerous<non-cancerous liver tissues.In cancerous,para-cancerous and non-cancerous tissues,p16 promoter CpG islands hypernethylation occurred 65% ,60% and 35%,while p15 promoter CpG islands hypermethylation occurred 50%,40% and 25%.of 12 HCCs with lower p16 promoter CpG islands methylation(91.6%).Hundred percent(10/10) HCCs with lower p15 mRNA expression level showed p15 promoter CpG islands methylation.Significant correlation between 5′CpG islands methylation and p16/p15 mRNA expression suppression was found.The dexreased expression of p16/p15 mRNA or metyylation of p16.p15 promoters 5′CpG island was significantly,0.01.2,0.00271,0.0218,respectively,(p<0.05).CONCLUSION:p16 and p15 genes transcriptional inactivation might play an important role in hepataocarcinogenesis.5′CpG islands methylation might bi the major mechanism of p16 and p15 genes inactivation in primary HCC in the studied population.5′CpG islands methylation of p16 and p15 genes might be an early event in hepatocarcinogenesis.展开更多
A novel construction algorithm is presented to generate a conforming Voronoi mesh for any planar straight line graph (PSLG). It is also extended to tesselate multiple-intersected PSLGs. All the algorithms are guarante...A novel construction algorithm is presented to generate a conforming Voronoi mesh for any planar straight line graph (PSLG). It is also extended to tesselate multiple-intersected PSLGs. All the algorithms are guaranteed to converge. Examples are given to illustrate its efficiency.展开更多
A new method as a post-processing step is presented to improve the shape quality of triangular meshes, which uses a topological clean up procedure and discrete smoothing interpolate (DSI) algorithm together. T...A new method as a post-processing step is presented to improve the shape quality of triangular meshes, which uses a topological clean up procedure and discrete smoothing interpolate (DSI) algorithm together. This method can improve the angle distribution of mesh element. while keeping the resulting meshes conform to the predefined constraints which are inputted as a PSLG.展开更多
基金Supported by the National Natural Science Foundation of China.No.39670702
文摘AIM:To study the significance of p16 and p15 transcription suppression with hypermethylation of their genes′5′CpG islands during human hepatocellular carcinogenesis.METHODS:The mRNA expression levels of p16 and p15 genes were evaluated in cancerous,para-cancerous and non-cancerous tissues of 20 HCC,3 normal liver tissues from 3 accidentally died healthy adults using simi-quantitatively Northerm blot.The methylation status was also assessed with methylation specfic PCR.RESULTS:p16 mRNA expression level was decressed in the cancerous tissues in 60%(12/20) of HCC patients,of which 2 cases had no p16 mRNA detected,5 cases(25%) displayed variation in the order of cancerous<para-cancerous<non-cancerous liver tissues.p15 mRNA expression level was decreased in the cancerous tissues in 50%(10/20) HCC patients,of which one case had no p15 mRNA detected,4 cases (20%) displayed variation in the order of cancerous<para-cancerous<non-cancerous liver tissues.In cancerous,para-cancerous and non-cancerous tissues,p16 promoter CpG islands hypernethylation occurred 65% ,60% and 35%,while p15 promoter CpG islands hypermethylation occurred 50%,40% and 25%.of 12 HCCs with lower p16 promoter CpG islands methylation(91.6%).Hundred percent(10/10) HCCs with lower p15 mRNA expression level showed p15 promoter CpG islands methylation.Significant correlation between 5′CpG islands methylation and p16/p15 mRNA expression suppression was found.The dexreased expression of p16/p15 mRNA or metyylation of p16.p15 promoters 5′CpG island was significantly,0.01.2,0.00271,0.0218,respectively,(p<0.05).CONCLUSION:p16 and p15 genes transcriptional inactivation might play an important role in hepataocarcinogenesis.5′CpG islands methylation might bi the major mechanism of p16 and p15 genes inactivation in primary HCC in the studied population.5′CpG islands methylation of p16 and p15 genes might be an early event in hepatocarcinogenesis.
基金Supported by the Science Technology Development Program of Beijing Municipal Education Commission (KM200510011004)
文摘A novel construction algorithm is presented to generate a conforming Voronoi mesh for any planar straight line graph (PSLG). It is also extended to tesselate multiple-intersected PSLGs. All the algorithms are guaranteed to converge. Examples are given to illustrate its efficiency.
文摘A new method as a post-processing step is presented to improve the shape quality of triangular meshes, which uses a topological clean up procedure and discrete smoothing interpolate (DSI) algorithm together. This method can improve the angle distribution of mesh element. while keeping the resulting meshes conform to the predefined constraints which are inputted as a PSLG.
