Nasopharyngeal carcinoma （NPC） is a common cancer in Southern China and Southeast Asia. The disease is a poorly differentiated carcinoma without effective cure, and the mechanism underlying its development remains l...Nasopharyngeal carcinoma （NPC） is a common cancer in Southern China and Southeast Asia. The disease is a poorly differentiated carcinoma without effective cure, and the mechanism underlying its development remains largely unknown. Of several factors identified in NPC aetiology in recent years, Epstein-Barr virus （EBV） infection has emerged to be most important. In almost all NPC cells, EBV uses several intracellular mechanisms to cause oncogenic evolution of the infected cells. One such mechanism by which EBV infection induces cellular immortalization is believed to be through the activation of telomerase, an enzyme that is normally repressed but becomes activated during cancer development. Studies show that greater than 85% of primary NPC display high telomerase activity by mechanisms involving EBV infection, consistent with the notion that EBV is commonly involved in inducing cell immortalization. More recently, different EBV proteins have been shown to activate or inhibit the human telomerase reverse transcriptase gene, by modulating intracellular signalling pathways. These findings suggest a new model with a number of challenges towards our understanding, molecular targeting and therapeutic intervention in NPC.展开更多
AIM:To evaluate the multiple biomarkers of colorectal tumor and their potential usage in early diagnosis of colorectal cancers. METHODS:Multiple biomarkers (DNA contents,AgNOR, PCNA,p53,c-erbB-2) in 10 normal colorect...AIM:To evaluate the multiple biomarkers of colorectal tumor and their potential usage in early diagnosis of colorectal cancers. METHODS:Multiple biomarkers (DNA contents,AgNOR, PCNA,p53,c-erbB-2) in 10 normal colorectal mucosae,37 colorectal adenomas and 55 colorectal cancers were analyzed quantitatively in the computed processing imaging system. Discrimination patterns were employed to evaluate the significance of single and multiple indices in diagnosis of colorectal cancers. RESULTS:The mean values of the analyzed parameters increased in order of the normal mucosa,adenoma and adenocarcinoma,and this tendency reflected the progression of colorectal malignancy.The parameters including DNA index,positive rates,densities of AgNOR,c-erbB-2,and p53, shape and density of nucleus were relatively valuable for diagnoses.Then a diagnostic discrimination model was established.The samples were confirmed with the model, the sensitivity rates in cancer group and adenoma group were 96.36% and 89.19%,respectively.The value of proliferating cell nuclear antigen (PCNA) in early diagnosis of colorectal cancers was uncertain. CONCLUSION:The quantitative evaluation of some parameters for colorectal tumor can provide reproducible data for differential diagnosis.The established diagnostic discrimination model may be of clinicopathological value, and can make the early diagnosis of colorectal cancer possible.展开更多
文摘Nasopharyngeal carcinoma （NPC） is a common cancer in Southern China and Southeast Asia. The disease is a poorly differentiated carcinoma without effective cure, and the mechanism underlying its development remains largely unknown. Of several factors identified in NPC aetiology in recent years, Epstein-Barr virus （EBV） infection has emerged to be most important. In almost all NPC cells, EBV uses several intracellular mechanisms to cause oncogenic evolution of the infected cells. One such mechanism by which EBV infection induces cellular immortalization is believed to be through the activation of telomerase, an enzyme that is normally repressed but becomes activated during cancer development. Studies show that greater than 85% of primary NPC display high telomerase activity by mechanisms involving EBV infection, consistent with the notion that EBV is commonly involved in inducing cell immortalization. More recently, different EBV proteins have been shown to activate or inhibit the human telomerase reverse transcriptase gene, by modulating intracellular signalling pathways. These findings suggest a new model with a number of challenges towards our understanding, molecular targeting and therapeutic intervention in NPC.
基金Supported by the Education Fund for Scientific Research in Fujian Province,No.97A068
文摘AIM:To evaluate the multiple biomarkers of colorectal tumor and their potential usage in early diagnosis of colorectal cancers. METHODS:Multiple biomarkers (DNA contents,AgNOR, PCNA,p53,c-erbB-2) in 10 normal colorectal mucosae,37 colorectal adenomas and 55 colorectal cancers were analyzed quantitatively in the computed processing imaging system. Discrimination patterns were employed to evaluate the significance of single and multiple indices in diagnosis of colorectal cancers. RESULTS:The mean values of the analyzed parameters increased in order of the normal mucosa,adenoma and adenocarcinoma,and this tendency reflected the progression of colorectal malignancy.The parameters including DNA index,positive rates,densities of AgNOR,c-erbB-2,and p53, shape and density of nucleus were relatively valuable for diagnoses.Then a diagnostic discrimination model was established.The samples were confirmed with the model, the sensitivity rates in cancer group and adenoma group were 96.36% and 89.19%,respectively.The value of proliferating cell nuclear antigen (PCNA) in early diagnosis of colorectal cancers was uncertain. CONCLUSION:The quantitative evaluation of some parameters for colorectal tumor can provide reproducible data for differential diagnosis.The established diagnostic discrimination model may be of clinicopathological value, and can make the early diagnosis of colorectal cancer possible.
