AIM: To study the effects of hepatitis C virus (HCV) core and non-structural 5A (NS5A) proteins on nuclear factor-κB (NF-κ@B) activity for understanding their biological function on chronic hepatitis caused by HCV i...AIM: To study the effects of hepatitis C virus (HCV) core and non-structural 5A (NS5A) proteins on nuclear factor-κB (NF-κ@B) activity for understanding their biological function on chronic hepatitis caused by HCV infection. METHODS: Luciferase assay was used to measure the activity of NF-κB in three different cell lines cotransfected with a series of deletion mutants of core protein alone or together with NS5A protein using pNF- κB-Luc as a reporter plasmid. Western blot and indirect immunofluorescence assays were used to confirm the expression of proteins and to detect their subcellular localization, respectively. Furthermore, Western blot was also used to detect the expression levels of NF-κB/p65, NF-κB/p50, and inhibitor κB-a(IκB-a). RESULTS: The wild-type core protein (C191) and its mutant segments (C173 and C158) could activate NF-κB in Huh7 cells only and activation caused by (C191) could be enhanced by NS5A protein. Moreover, the full-length core protein and its different deletion mutants alone or together with NS5A protein did not enhance the expression level of NF-κB. The NF-κB activity was augmented due to the dissociation of NF-κB-IκB complex and the degradation of IκB-a. CONCLUSION:NF-κB is the key transcription factor that can activate many genes that are involved in the cellular immune response and inflammation. Coexpression of the full-length core protein along with NS5A can enhance the NF- κB activation, and this activation may play a significant role in chronic liver diseases including hepatocellular carcinoma associated with HCV infection.展开更多
Objective： To study apoptotic effects of synthetic retinoic acid 6-[3-（1-adamantyl）-4-hydroxyphenyl]-2-naphthalene carboxylic acid（AHPN） on human skin malignant melanoma A375 cells in comparison with the natural ...Objective： To study apoptotic effects of synthetic retinoic acid 6-[3-（1-adamantyl）-4-hydroxyphenyl]-2-naphthalene carboxylic acid（AHPN） on human skin malignant melanoma A375 cells in comparison with the natural ligand all-trans-retinoic acid（ATRA） in vitro and the mechanisms related to the actions of AHPN. Methods：MTT assay was used to determine the anti-proliferative effects of AHPN and ATRA on A375 cells. Flow cytometry was performed to investigate the influence of AHPN and ATRA on cell cycle and cell apoptosis. In addition, transfection and luciferase activity assays were employed to explore the mechanisms of how AHPN executes its proapoptotic function. Results：Firstly, AHPN promoted apoptosis and GI arrest in A375 cells compared with ATRA. Secondly, the activity of NF-K B in A375 cells treated with AHPN increased 2-3 times compared with solvent DMSO treatment. Conclusion：AHPN, in comparison with ATRA, is a more effective alternative for therapy of malignant melanoma. The potentially proapoptotic function of AHPN requires activation of NF-K B.展开更多
基金Supported by the Ph D Program Foundation of Ministry of Education of China, No. 20010486015
文摘AIM: To study the effects of hepatitis C virus (HCV) core and non-structural 5A (NS5A) proteins on nuclear factor-κB (NF-κ@B) activity for understanding their biological function on chronic hepatitis caused by HCV infection. METHODS: Luciferase assay was used to measure the activity of NF-κB in three different cell lines cotransfected with a series of deletion mutants of core protein alone or together with NS5A protein using pNF- κB-Luc as a reporter plasmid. Western blot and indirect immunofluorescence assays were used to confirm the expression of proteins and to detect their subcellular localization, respectively. Furthermore, Western blot was also used to detect the expression levels of NF-κB/p65, NF-κB/p50, and inhibitor κB-a(IκB-a). RESULTS: The wild-type core protein (C191) and its mutant segments (C173 and C158) could activate NF-κB in Huh7 cells only and activation caused by (C191) could be enhanced by NS5A protein. Moreover, the full-length core protein and its different deletion mutants alone or together with NS5A protein did not enhance the expression level of NF-κB. The NF-κB activity was augmented due to the dissociation of NF-κB-IκB complex and the degradation of IκB-a. CONCLUSION:NF-κB is the key transcription factor that can activate many genes that are involved in the cellular immune response and inflammation. Coexpression of the full-length core protein along with NS5A can enhance the NF- κB activation, and this activation may play a significant role in chronic liver diseases including hepatocellular carcinoma associated with HCV infection.
文摘Objective： To study apoptotic effects of synthetic retinoic acid 6-[3-（1-adamantyl）-4-hydroxyphenyl]-2-naphthalene carboxylic acid（AHPN） on human skin malignant melanoma A375 cells in comparison with the natural ligand all-trans-retinoic acid（ATRA） in vitro and the mechanisms related to the actions of AHPN. Methods：MTT assay was used to determine the anti-proliferative effects of AHPN and ATRA on A375 cells. Flow cytometry was performed to investigate the influence of AHPN and ATRA on cell cycle and cell apoptosis. In addition, transfection and luciferase activity assays were employed to explore the mechanisms of how AHPN executes its proapoptotic function. Results：Firstly, AHPN promoted apoptosis and GI arrest in A375 cells compared with ATRA. Secondly, the activity of NF-K B in A375 cells treated with AHPN increased 2-3 times compared with solvent DMSO treatment. Conclusion：AHPN, in comparison with ATRA, is a more effective alternative for therapy of malignant melanoma. The potentially proapoptotic function of AHPN requires activation of NF-K B.
