AIM： TO determine the DNA binding activity and protein levels of the Ku70/80 heterodimer, the functional mediator of the NHEJ activity, in human colorectal carcinogenesis. METHODS： The Ku70/80 DNA-binding activity w...AIM： TO determine the DNA binding activity and protein levels of the Ku70/80 heterodimer, the functional mediator of the NHEJ activity, in human colorectal carcinogenesis. METHODS： The Ku70/80 DNA-binding activity was determined by electrophoretic mobility shift assays in 20 colon adenoma and 15 colorectal cancer samples as well as matched normal colonic tissues. Nuclear and cytoplasmic protein expression was determined by immunohistochemistry and Western blot analysis. RESULTS： A statistical found in both adenomas y significant difference was and carcinomas as compared to matched normal colonic mucosa （P〈0.00）. However, changes in binding activity were not homogenous with approximately 50% of the tumors showing a clear increase in the binding activity, 30% displaying a modest increase and 15% showing a decrease of the activity.Tumors, with increased DNA-binding activity, also showed a statistically significant increase in Ku70 and Ku86 nuclear expression, as determined by Western blot and immunohistochemical analyses （P〈0.001）. Cytoplasmic protein expression was found in pathological samples, but not in normal tissues either from tumor patients or from healthy subjects. CONCLUSION： Overall, our DNA-binding activity and protein level are consistent with a substantial activation of the NHEJ pathway in colorectal tumors. Since the NHEJ is an error prone mechanism, its abnormal activation can result in chromosomal instability and ultimately lead to tumorigenesis.展开更多
Non-cirrhotic portal hypertension is a poorly understood condition characterized by portal hypertension in the absence of conventional hepatic cirrhosis and described in association with blood coagulation disorders, m...Non-cirrhotic portal hypertension is a poorly understood condition characterized by portal hypertension in the absence of conventional hepatic cirrhosis and described in association with blood coagulation disorders, myeloproliferative and immunological diseases and with exposure to toxic drugs. Very recently, precise classification criteria have been proposed in order to define four distinct subcategories. The present case highlights how the clinical presentation, the confounding results from imaging studies, and the difficulties in the histological evaluation often render cases of non-cirrhotic portal hypertension a real diagnostic challenge. It also underscores the classification problems which can be faced once this diagnosis is performed. Indeed, the different subcategories proposed result from the prevalent subtypes in a spectrum of hepatic regenerative responses to a variety of injuries determining microcirculatory dis-turbances. More flexibility in classification should derive from this etiopathogenic background.展开更多
基金Supported by Italian Ministero della Salute, IRCCS, RC0302TG13 by Ministero dell'Istruzíone, Università e Ricerca scientifica e tecnologica (MIUR), COFIN2002, to the Universita Campus Bio-Medico
文摘AIM： TO determine the DNA binding activity and protein levels of the Ku70/80 heterodimer, the functional mediator of the NHEJ activity, in human colorectal carcinogenesis. METHODS： The Ku70/80 DNA-binding activity was determined by electrophoretic mobility shift assays in 20 colon adenoma and 15 colorectal cancer samples as well as matched normal colonic tissues. Nuclear and cytoplasmic protein expression was determined by immunohistochemistry and Western blot analysis. RESULTS： A statistical found in both adenomas y significant difference was and carcinomas as compared to matched normal colonic mucosa （P〈0.00）. However, changes in binding activity were not homogenous with approximately 50% of the tumors showing a clear increase in the binding activity, 30% displaying a modest increase and 15% showing a decrease of the activity.Tumors, with increased DNA-binding activity, also showed a statistically significant increase in Ku70 and Ku86 nuclear expression, as determined by Western blot and immunohistochemical analyses （P〈0.001）. Cytoplasmic protein expression was found in pathological samples, but not in normal tissues either from tumor patients or from healthy subjects. CONCLUSION： Overall, our DNA-binding activity and protein level are consistent with a substantial activation of the NHEJ pathway in colorectal tumors. Since the NHEJ is an error prone mechanism, its abnormal activation can result in chromosomal instability and ultimately lead to tumorigenesis.
文摘Non-cirrhotic portal hypertension is a poorly understood condition characterized by portal hypertension in the absence of conventional hepatic cirrhosis and described in association with blood coagulation disorders, myeloproliferative and immunological diseases and with exposure to toxic drugs. Very recently, precise classification criteria have been proposed in order to define four distinct subcategories. The present case highlights how the clinical presentation, the confounding results from imaging studies, and the difficulties in the histological evaluation often render cases of non-cirrhotic portal hypertension a real diagnostic challenge. It also underscores the classification problems which can be faced once this diagnosis is performed. Indeed, the different subcategories proposed result from the prevalent subtypes in a spectrum of hepatic regenerative responses to a variety of injuries determining microcirculatory dis-turbances. More flexibility in classification should derive from this etiopathogenic background.
