OBJECTIVES: To investigate the expressions of E-eadherin and alpha-catenin in pancreatic carcinoma and their relationship with biological behaviors, and clarify the mechanism of invasion and metastasis of pancreatic c...OBJECTIVES: To investigate the expressions of E-eadherin and alpha-catenin in pancreatic carcinoma and their relationship with biological behaviors, and clarify the mechanism of invasion and metastasis of pancreatic cancer. METHODS: The expressions of E-eadherin and alpha-catenin was examined in 47 patients with infiltrative ductal adenocarcinoma of the pancreas and 12 specimens of normal pancreatic tissues by immunohistochemical technique (PicTure^(TM) two-step method). Proliferation cell nuclear antigen (PCNA) was tested as an index of the proliferation degree of pancreatic cancer cells. RESULTS: The immunoreactivity of E-cadherin and alpha-catenin was expressed by normal ductal and acinar cells with strong membranous staining at the intercellular border in 12 specimens of normal pancreatic tissues. The abnormal rate of E-cadherin expression in pancreatic cancer was 53.2% (25/47), and it was significantly related to differentiation, high proliferation degree and lymph node and liver metastases (P<0.O1, 0.05, 0.05 and O.01, respectively). 61.7% patients with pancreatic cancer (29/47) showed abnormal expression of alpha-catenin. There was a good correlation among alpha-catenin expression, histological grade, and lymph node and liver metastases (P<0.05, 0.05 and 0.01, respectively). No significant association was found among abnormal expressions of E-cadherin and alpha-catenin, tumor size, invasion, and 1-year survival rate of patients ( P>0.05, all). There was a positive relationship between the expressions of E-cadherin and alpha-catenin in the 47 patients with pancreatic cancer (P<O.O1, r=0.88). CONCLUSIONS: Pancreatic cancer likely occurs in case of the inactivation of E-cadherin and alpha-catenin genes and abnormal expression of proteins, which significantly correlate with tumorigenesis, proliferation, differentiation, and lymph node or liver metastasis of pancreatic cancer.展开更多
Although spermatozoa are formed during spermatogenesis in the testis, testicular spermatozoa are immature and cannot swim or fertilize. These critical spermatozoal functions are acquired in the epididymis where a spec...Although spermatozoa are formed during spermatogenesis in the testis, testicular spermatozoa are immature and cannot swim or fertilize. These critical spermatozoal functions are acquired in the epididymis where a specific luminal environment is created by the blood-epididymal barrier; proteins secreted by epididymal principal cells bind to maturing spermatozoa and regulate the maturational process of the spermatozoa. In the epididymis, epithelial cell-cell interactions are mediated by adhering junctions, necessary for cell adhesion, and by tight junctions, which form the blood-epididymal barrier. The regulation of these cellular junctions is thought to represent a key determinant in the process of sperm maturation within the epididymis. Tight junctions between adjacent principal cells permit the formation of a specific microenvironment in the lumen of the epididymis that is essential for sperm maturation. Although we have made significant progress in understanding epididymal function and the blood-epididymal barrier, using animal models, there is limited information on the human epididymis. If we are to understand the normal and pathological conditions attributable to human epididymal function, we must clearly establish the physiological, cellular and molecular regulation of the human epididymis, develop tools to characterize these functions and develop clinical strategies that will use epididymal functions to improve treatment of infertility. （Asian J Androl 2007 July; 9： 463- 475）展开更多
The stiffness and strength of extracellular （EC） region of cadherin are proposed to be two important mechanical properties both for cadherin as a mechanotransductor and for the formation of cell-cell adhesion. In th...The stiffness and strength of extracellular （EC） region of cadherin are proposed to be two important mechanical properties both for cadherin as a mechanotransductor and for the formation of cell-cell adhesion. In this study, we quantitatively characterized the stiffness and strength of EC structure when it binds with different types of ions by molecular dynamics simulations. Resuits show that EC structure exhibits a rod-like shape with high stiffness and strength when it binds with the bivalent ions of calcium or magnesium. However, it switches to a soft and collapsed conformation when it binds with the monova- lent ions of sodium or potassium. This study sheds light on the important role of the bivalent ions of calcium in the physiological function of EC.展开更多
文摘OBJECTIVES: To investigate the expressions of E-eadherin and alpha-catenin in pancreatic carcinoma and their relationship with biological behaviors, and clarify the mechanism of invasion and metastasis of pancreatic cancer. METHODS: The expressions of E-eadherin and alpha-catenin was examined in 47 patients with infiltrative ductal adenocarcinoma of the pancreas and 12 specimens of normal pancreatic tissues by immunohistochemical technique (PicTure^(TM) two-step method). Proliferation cell nuclear antigen (PCNA) was tested as an index of the proliferation degree of pancreatic cancer cells. RESULTS: The immunoreactivity of E-cadherin and alpha-catenin was expressed by normal ductal and acinar cells with strong membranous staining at the intercellular border in 12 specimens of normal pancreatic tissues. The abnormal rate of E-cadherin expression in pancreatic cancer was 53.2% (25/47), and it was significantly related to differentiation, high proliferation degree and lymph node and liver metastases (P<0.O1, 0.05, 0.05 and O.01, respectively). 61.7% patients with pancreatic cancer (29/47) showed abnormal expression of alpha-catenin. There was a good correlation among alpha-catenin expression, histological grade, and lymph node and liver metastases (P<0.05, 0.05 and 0.01, respectively). No significant association was found among abnormal expressions of E-cadherin and alpha-catenin, tumor size, invasion, and 1-year survival rate of patients ( P>0.05, all). There was a positive relationship between the expressions of E-cadherin and alpha-catenin in the 47 patients with pancreatic cancer (P<O.O1, r=0.88). CONCLUSIONS: Pancreatic cancer likely occurs in case of the inactivation of E-cadherin and alpha-catenin genes and abnormal expression of proteins, which significantly correlate with tumorigenesis, proliferation, differentiation, and lymph node or liver metastasis of pancreatic cancer.
文摘Although spermatozoa are formed during spermatogenesis in the testis, testicular spermatozoa are immature and cannot swim or fertilize. These critical spermatozoal functions are acquired in the epididymis where a specific luminal environment is created by the blood-epididymal barrier; proteins secreted by epididymal principal cells bind to maturing spermatozoa and regulate the maturational process of the spermatozoa. In the epididymis, epithelial cell-cell interactions are mediated by adhering junctions, necessary for cell adhesion, and by tight junctions, which form the blood-epididymal barrier. The regulation of these cellular junctions is thought to represent a key determinant in the process of sperm maturation within the epididymis. Tight junctions between adjacent principal cells permit the formation of a specific microenvironment in the lumen of the epididymis that is essential for sperm maturation. Although we have made significant progress in understanding epididymal function and the blood-epididymal barrier, using animal models, there is limited information on the human epididymis. If we are to understand the normal and pathological conditions attributable to human epididymal function, we must clearly establish the physiological, cellular and molecular regulation of the human epididymis, develop tools to characterize these functions and develop clinical strategies that will use epididymal functions to improve treatment of infertility. （Asian J Androl 2007 July; 9： 463- 475）
基金supported by the National Natural Science Foundation of China(11025208,11221202,11372042,and 11202026)the Excellent Young Scholars Research Fund of Beijing Institute of Technology
文摘The stiffness and strength of extracellular （EC） region of cadherin are proposed to be two important mechanical properties both for cadherin as a mechanotransductor and for the formation of cell-cell adhesion. In this study, we quantitatively characterized the stiffness and strength of EC structure when it binds with different types of ions by molecular dynamics simulations. Resuits show that EC structure exhibits a rod-like shape with high stiffness and strength when it binds with the bivalent ions of calcium or magnesium. However, it switches to a soft and collapsed conformation when it binds with the monova- lent ions of sodium or potassium. This study sheds light on the important role of the bivalent ions of calcium in the physiological function of EC.
