The diagnosis of pancreatic patients and their relatives cancer is devastating for as the incidence rate is approximately the same as mortality rate. Only a small percentage, which ranges from 0.4% to 4% of patients w...The diagnosis of pancreatic patients and their relatives cancer is devastating for as the incidence rate is approximately the same as mortality rate. Only a small percentage, which ranges from 0.4% to 4% of patients who have been given this diagnosis, will be alive at five years. At the time of diagnosis, 80% of pancreatic cancer patients have unresectable or metastatic disease. Moreover, the therapeutic alternatives offered by chemotherapy or radiotherapy are few, if not zero. For all these reasons, there is an imperative need of analyzing and understanding the primitive lesions that lead to invasive pancreatic adenocarcinoma. Molecular pathology of these lesions is the key of our understanding of the mechanisms underlying the development of this cancer and will probably help us in earlier diagnosis and better therapeutic results. This review focuses on medical research on pancreatic cancer models and the underlying genetic alterations.展开更多
Objective: To evaluate whether realgar could down-regulate human telomerase reverse transcriptase (hTERT) gene expression and telomerase activity in acute promyelocytic leukemia cell line-NB4 cells. Methods: The expre...Objective: To evaluate whether realgar could down-regulate human telomerase reverse transcriptase (hTERT) gene expression and telomerase activity in acute promyelocytic leukemia cell line-NB4 cells. Methods: The expression of hTERT-mRNA was analyzed by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). Telomerase activity was determined by polymerase chain reaction enzyme-linked immunoassay (PCR-ELISA). Flow cytometry using PI staining was applied to analyze the cell cycle and apoptosis. Results: Treatment of NB4 cells with 155, 300, 600 μg/L realgar reduced telomerase activity significantly accompanying with decrease of hTERT-mRNA and increasing cell apoptosis. G2/M phase arrest appeared when treated with realgar in 300, 600 μg/L. Conclusion: It is suggested that telomerase activity of NB4 cells can be specifically inhibited by realgar through the down-regulation of hTERT gene expression. G2/M phase arrest and apoptosis by realgar in NB4 cells might be related to the reduction of telomerase activity and hTERT-mRNA expression.展开更多
Objective: To induce changes in biological character of human liver cancer cell line SMMC-7721 by blocking the expression of telomerase genes hTRT and to explore its value in cancer gene therapy. Methods: The vehicle ...Objective: To induce changes in biological character of human liver cancer cell line SMMC-7721 by blocking the expression of telomerase genes hTRT and to explore its value in cancer gene therapy. Methods: The vehicle for eukaryotic expression of antisense hTRT was constructed and then transfected into SMMC-7721 cells. The effects of antisense hTRT gene on telomerase activity, cancer cell growth and malignant phenotypes were analyzed. Results: The obtained transfectants that could express antisense hTRT gene stably showed marked decrease in telomerase activity; the shortening of telomere was obvious; cells presented contact growth inhibition; in nude mice transplantation, the rate of tumor induction dramatically decreased. Conclusion: Antisense hTRT gene expression can significantly inhibit telomerase activity of cancer cells and decrease malignant phenotypes in vitro and in vivo. Therefore, as a telomerase inhibitor, antisense hTRT gene may be a new pathway for cancer therapy.展开更多
文摘The diagnosis of pancreatic patients and their relatives cancer is devastating for as the incidence rate is approximately the same as mortality rate. Only a small percentage, which ranges from 0.4% to 4% of patients who have been given this diagnosis, will be alive at five years. At the time of diagnosis, 80% of pancreatic cancer patients have unresectable or metastatic disease. Moreover, the therapeutic alternatives offered by chemotherapy or radiotherapy are few, if not zero. For all these reasons, there is an imperative need of analyzing and understanding the primitive lesions that lead to invasive pancreatic adenocarcinoma. Molecular pathology of these lesions is the key of our understanding of the mechanisms underlying the development of this cancer and will probably help us in earlier diagnosis and better therapeutic results. This review focuses on medical research on pancreatic cancer models and the underlying genetic alterations.
基金Supported by Xi'an Foundation of Science and Technology Program(200016)
文摘Objective: To evaluate whether realgar could down-regulate human telomerase reverse transcriptase (hTERT) gene expression and telomerase activity in acute promyelocytic leukemia cell line-NB4 cells. Methods: The expression of hTERT-mRNA was analyzed by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). Telomerase activity was determined by polymerase chain reaction enzyme-linked immunoassay (PCR-ELISA). Flow cytometry using PI staining was applied to analyze the cell cycle and apoptosis. Results: Treatment of NB4 cells with 155, 300, 600 μg/L realgar reduced telomerase activity significantly accompanying with decrease of hTERT-mRNA and increasing cell apoptosis. G2/M phase arrest appeared when treated with realgar in 300, 600 μg/L. Conclusion: It is suggested that telomerase activity of NB4 cells can be specifically inhibited by realgar through the down-regulation of hTERT gene expression. G2/M phase arrest and apoptosis by realgar in NB4 cells might be related to the reduction of telomerase activity and hTERT-mRNA expression.
基金Supported by National 973 Project of China(No.G2000057001)
文摘Objective: To induce changes in biological character of human liver cancer cell line SMMC-7721 by blocking the expression of telomerase genes hTRT and to explore its value in cancer gene therapy. Methods: The vehicle for eukaryotic expression of antisense hTRT was constructed and then transfected into SMMC-7721 cells. The effects of antisense hTRT gene on telomerase activity, cancer cell growth and malignant phenotypes were analyzed. Results: The obtained transfectants that could express antisense hTRT gene stably showed marked decrease in telomerase activity; the shortening of telomere was obvious; cells presented contact growth inhibition; in nude mice transplantation, the rate of tumor induction dramatically decreased. Conclusion: Antisense hTRT gene expression can significantly inhibit telomerase activity of cancer cells and decrease malignant phenotypes in vitro and in vivo. Therefore, as a telomerase inhibitor, antisense hTRT gene may be a new pathway for cancer therapy.
