Objective To evaluate the relationship of E cadherin (E CD) expression to cellular DNA content and biological behavior of gastric cancer. Methods E CD expression and cellular DNA content were quantitatively measure...Objective To evaluate the relationship of E cadherin (E CD) expression to cellular DNA content and biological behavior of gastric cancer. Methods E CD expression and cellular DNA content were quantitatively measured by flow cytometry and immunofluorescence methods in 80 cases of formalinfixed, paraffin embedded gastric cancer. Systematic pathological examinations and follow up were performed for all cases. Results E CD expression was significantly reduced in all cases of gastric cancer. Fluorescence Index (FI) of E CD expression was 0.67±0.11 in gastric cancer, 1.0±0.07 in normal gastric mucosa ( P <0.001). The reduction of E CD expression was also found in 2 cases of early gastric cancer. Tumors with a decrease in E CD expression occurred significantly more frequently in undifferentiated, diffuse growth pattern Borrmann 4 type, positive lymph node (LN) metastasis and infiltrated serosa type gastric cancer, of which survival time was within 5 years ( P <0.001). E CD expression was also reduced in gastric cancer with the number of LN metastasis above 5, metastasis to more than group 2. E CD expression was lower in uneuploid cancer than that in diploid cancer ( P <0.01). The value of DI and PI with negative E CD expression was significantly higher than that of positive E CD expression ( P <0.01). Conclusion Down regulation of E CD expression correlates with bad biological behavior and poor prognosis of gastric cancer. The reduction of E CD expression may take place during early time of gastric cancer. Quantitative analysis of E CD expression may have some value in evaluating the intensity of LN metastasis of gastric cancer.展开更多
Gene expression is a critical process in biological system that is influenced and modulated by many factors including genetic variation. Expression Quantitative Trait Loci（e QTL） analysis provides a powerful way to ...Gene expression is a critical process in biological system that is influenced and modulated by many factors including genetic variation. Expression Quantitative Trait Loci（e QTL） analysis provides a powerful way to understand how genetic variants affect gene expression. For genome wide e QTL analysis, the number of genetic variants and that of genes are large and thus the search space is tremendous. Therefore, e QTL analysis brings about computational and statistical challenges. In this paper, we provide a comprehensive review of recent advances in methods for e QTL analysis in population-based studies. We first present traditional pairwise association methods, which are widely used in human genetics. To account for expression heterogeneity, we investigate the methods for correcting confounding factors. Next, we discuss newly developed statistical learning methods including Lasso-based models. In the conclusion, we provide an overview of future method development in analyzing e QTL associations. Although we focus on human genetics in this review, the methods are applicable to many other organisms.展开更多
文摘Objective To evaluate the relationship of E cadherin (E CD) expression to cellular DNA content and biological behavior of gastric cancer. Methods E CD expression and cellular DNA content were quantitatively measured by flow cytometry and immunofluorescence methods in 80 cases of formalinfixed, paraffin embedded gastric cancer. Systematic pathological examinations and follow up were performed for all cases. Results E CD expression was significantly reduced in all cases of gastric cancer. Fluorescence Index (FI) of E CD expression was 0.67±0.11 in gastric cancer, 1.0±0.07 in normal gastric mucosa ( P <0.001). The reduction of E CD expression was also found in 2 cases of early gastric cancer. Tumors with a decrease in E CD expression occurred significantly more frequently in undifferentiated, diffuse growth pattern Borrmann 4 type, positive lymph node (LN) metastasis and infiltrated serosa type gastric cancer, of which survival time was within 5 years ( P <0.001). E CD expression was also reduced in gastric cancer with the number of LN metastasis above 5, metastasis to more than group 2. E CD expression was lower in uneuploid cancer than that in diploid cancer ( P <0.01). The value of DI and PI with negative E CD expression was significantly higher than that of positive E CD expression ( P <0.01). Conclusion Down regulation of E CD expression correlates with bad biological behavior and poor prognosis of gastric cancer. The reduction of E CD expression may take place during early time of gastric cancer. Quantitative analysis of E CD expression may have some value in evaluating the intensity of LN metastasis of gastric cancer.
基金supported in part by a Faculty Research Grant from the University of North Carolina at Charlotte
文摘Gene expression is a critical process in biological system that is influenced and modulated by many factors including genetic variation. Expression Quantitative Trait Loci（e QTL） analysis provides a powerful way to understand how genetic variants affect gene expression. For genome wide e QTL analysis, the number of genetic variants and that of genes are large and thus the search space is tremendous. Therefore, e QTL analysis brings about computational and statistical challenges. In this paper, we provide a comprehensive review of recent advances in methods for e QTL analysis in population-based studies. We first present traditional pairwise association methods, which are widely used in human genetics. To account for expression heterogeneity, we investigate the methods for correcting confounding factors. Next, we discuss newly developed statistical learning methods including Lasso-based models. In the conclusion, we provide an overview of future method development in analyzing e QTL associations. Although we focus on human genetics in this review, the methods are applicable to many other organisms.
