AIM: To investigate the role of nuclear factor κB(NF-κB) in the regulation of Epstein-Barr virus(EBV) latent membrane protein 1(LMP1) in EBV transformed cells. METHODS: LMP1 expression was examined in EBV transforme...AIM: To investigate the role of nuclear factor κB(NF-κB) in the regulation of Epstein-Barr virus(EBV) latent membrane protein 1(LMP1) in EBV transformed cells. METHODS: LMP1 expression was examined in EBV transformed human B lymphocytes with modulation of NF-κB activity. RESULTS: EBV infection is associated with several human cancers. EBV LMP1 is required for efficient transformation of adult primary B cells in vitro, and is expressed in several pathogenic stages of EBVassociated cancers. Regulation of EBV LMP1 involves both viral and cellular factors. LMP1 activates NF-κB signaling pathway that is a part of the EBV transformation program. However, the relation between NF-κB and LMP1 expression is not well established yet. In this report, we found that blocking the NF-κB activity by Inhibitor of κB stimulated LMP1 expression, while the overexpression of NF-κB repressed LMP1 expression in EBV-transformed IB4 cells. In addition, LMP1 repressed its own promoter activities in reporter assays, and the repression was associated with the activation of NF-κB. Moreover, NF-κB alone is sufficient to repress LMP1 promoter activities. CONCLUSION: Our data suggest LMP1 may repress its own expression through NF-κB in EBV transformed cells and shed a light on LMP1 regulation during EBV transformation.展开更多
Objective: Early diagnosis of nasopharyngeal carcinoma (NPC) is an important method to improve the survival rate.However,the sensitivity and specificity of the screening protocols which was widely used in clinic now a...Objective: Early diagnosis of nasopharyngeal carcinoma (NPC) is an important method to improve the survival rate.However,the sensitivity and specificity of the screening protocols which was widely used in clinic now are considered to be unsatisfactory.Epstein-Barr virus (EBV)-encoded latent membrane protein-1 (LMP-1) is one of the proteins that have been suggested to be a classic oncogene with transformation properties.The current study set out to discuss the clinical significance of LMP-1 on the screening of NPC.Methods: Three hundred patients who visited our institution (Department of Radiation Oncology,Fujian Provincial Cancer Hospital,Fuzhou,China) with ENT symptoms between 2007 and 2008 were involved in this study,and all of them were agreed to be involved in this investigation.Not only did they undergo nasopharyngeal swab to obtain cells for the LMP-1 polymerase chain reaction (PCR) analysis,but also nasopharyngeal biopsy were taken to identify the diagnosis.Results: An amount of DNA that was sufficient for PCR was extracted from 243 (81%) swab samples,the positive rate of LMP-1 of those with non-nasopharyngeal carcinoma was 3.85% (4/108),which was much lower than those with nasopharyngeal carcinoma (P < 0.05).By detecting LMP-1 in nasopharyngeal swabs,NPC was diagnosed with a sensitivity of 88.15% (119 of 135 patients),specificity of 96.30% (104 of 108 patients),a positive predictive value of 95.2% (119 of 123 patients),a negative predictive value of 86.67% (104 of 120 patients),accuracy of 91.77%,and Youden index of 84.45%.Conclusion: The nasopharyngeal swab coupled with PCR-based EBV LMP-1 detection have high sensitivity and specificity,and also good repeatability,it could serve as part of the screening program for high-risk populations.展开更多
Epstein-Barr virus (EBV) encoded latent membrane protein 1 (LMP1) is considered to be the major oncogenic protein of EBV encoded proteins, and also it has always been the core of the oncogenic mechanism of EBV. Tradit...Epstein-Barr virus (EBV) encoded latent membrane protein 1 (LMP1) is considered to be the major oncogenic protein of EBV encoded proteins, and also it has always been the core of the oncogenic mechanism of EBV. Traditional receptor theory demonstrates that cell surface receptors exert biological functions on the membrane, which neither enter into the nucleus nor directly affect the transcription of the target genes. But, advanced studies on nuclear transloca-tion of the epidermal growth factor receptor (EGFR) family have greatly developed our knowl-edge of the biological function of cell surface receptors. In this study, we used Tet-on LMP1 HNE2 cell line as a cell model, which is a dual-stable LMP1 integrated NPC cell line and the ex-pression of LMP1 in which could be regulated by Tet system. We found that LMP1 could regulate the nuclear translocation of EGFR in a dose-dependent manner from both quantitative and qualitative levels through the Western blot analysis and the immunofluorescent analysis with a laser scanning confocal microscope. We further demonstrated that the nuclear localization se-quence of EGFR played some roles in the location of the protein within the nucleus under LMP1 regulation, and the nuclear accumulation of EGFR regulated by LMP1 was in a ligand-independent manner. These findings provide a novel view that the regulation of LMP1 on the nuclear translocation of EGFR is critical for the process of nasopharyngeal carcinoma.展开更多
Dear Editor,Epstein-Barr virus(EBV,also termed human herpesvirus-4)was the first identified human tumor virus.Since its discovery in 1964,studies have shown that EBV infects over 90%of all people by the time they are ...Dear Editor,Epstein-Barr virus(EBV,also termed human herpesvirus-4)was the first identified human tumor virus.Since its discovery in 1964,studies have shown that EBV infects over 90%of all people by the time they are adults(Williams and Crawford 2006).EBV infection can result in mucocutaneous and systemic diseases,ranging from selflimited illnesses to aggressive malignancies,including B cell Hodgkin lymphoma and nasopharyngeal carcinoma.In vitro,EBV transforms resting B cells into proliferating blast cells(Pope et al.1968).展开更多
Viruses have been shown to be responsible for 10%-15% of cancer cases. Epstein-Barr virus(EBV) is the first virus to be associated with human malignancies. EBV can cause many cancers, including Burkett's lymphoma,...Viruses have been shown to be responsible for 10%-15% of cancer cases. Epstein-Barr virus(EBV) is the first virus to be associated with human malignancies. EBV can cause many cancers, including Burkett's lymphoma, Hodgkin's lymphoma, post-transplant lymphoproliferative disorders, nasopharyngeal carcinoma and gastric cancer. Evidence shows that phosphoinositide 3-kinase/protein kinase B(PI3K/Akt) plays a key role in EBV-induced malignancies. The main EBV oncoproteins latent membrane proteins(LMP) 1 and LMP2 A can activate the PI3K/Akt pathway, which, in turn, affects cell survival, apoptosis, proliferation and genomic instability via its downstream target proteins to cause cancer. It has also been demonstrated that the activation of the PI3K/Akt pathway can result in drug resistance to chemotherapy. Thus, the inhibition of this pathway can increase the therapeutic efficacy of EBV-associated cancers. For example, PI3 K inhibitor Ly294002 has been shown to increase the effect of 5-fluorouracil in an EBV-associated gastric cancer cell line. At present, dual inhibitors of PI3 K and its downstream target mammalian target of rapamycin have been used in clinical trials and may be included in treatment regimens for EBV-associated cancers.展开更多
Epstein-Barr virus (EBV) encoded latent membrane protein 1 (LMP1) may trigger the transcription factor AP-1 including c-Jun and c-fos. In this report, using a Tet-on LMP1 HNE2 cell line which is a dual-stable LMP1 int...Epstein-Barr virus (EBV) encoded latent membrane protein 1 (LMP1) may trigger the transcription factor AP-1 including c-Jun and c-fos. In this report, using a Tet-on LMP1 HNE2 cell line which is a dual-stable LMP1 integrated nasopharyngeal carcinoma (NPC) cell line and the expression of LMP1 in which could be regulated by the Tet-on system, we show that Jun B can efficiently form a new heterodimeric complex with the c-Jun protein under the regulation of LMP1, phosphorylation of c-Jun (ser 63, ser 73) and Jun B is involved in the process of the new heterodimeric formation. We also find that this heterodimeric form can bind to the AP-1 consensus sequence. Transfection studies suggest that JNK interaction protein (JIP) could inhibit the heterodimer formation of c-Jun and Jun B through blocking the AP-1 signaling pathway triggered by LMP1. The interaction and function between c-Jun protein and Jun B protein increase the repertoire of possible regulatory complexes by LMP1 that could play an important role in the regulation of transcription of specific cellular genes in the process of genesis of nasopharyngeal carcinoma.展开更多
背景与目的:EB病毒编码的潜伏膜蛋白1(latent membrane protein 1,LMP1)在鼻咽癌的浸润和转移过程中起重要的作用。本实验目的在于研究EB病毒LMP1对人鼻咽癌细胞转移能力的影响和探讨其中的相关机制。方法:应用免疫细胞化学RT-PCR法和We...背景与目的:EB病毒编码的潜伏膜蛋白1(latent membrane protein 1,LMP1)在鼻咽癌的浸润和转移过程中起重要的作用。本实验目的在于研究EB病毒LMP1对人鼻咽癌细胞转移能力的影响和探讨其中的相关机制。方法:应用免疫细胞化学RT-PCR法和Western blot检测LMP1、E-cadherin和intercellular adhesion molecule-1 (ICAM-1)在人高分化鼻咽癌细胞系CNE1和转染了LMP1基因的CNE1-GL细胞中的表达。应用细胞-细胞粘附实验、细胞-基质粘附实验、划痕实验和细胞运动实验观察LMP1对鼻咽癌细胞粘附和运动能力的影响。结果:免疫细胞化学结果显示:LMP1在CNE1和CNE1-GL细胞中的阳性率分别为0和(96.60±3.03)%(P<0.01);E-cadherin蛋白的阳性率分别为(37.47±1.50)%和(19.53±1.92)%(P<0.01);ICAM-1蛋白的阳性率分别为(5.27±1.45)%和(93.33±4.23)%(P<0.01)。RT-PCR和Westernblot结果表明,与CNE1细胞相比较,CNE1-GL细胞中E-cadherin的mRNA和蛋白表达明显降低(P<0.01),而ICAM-1的mRNA和蛋白表达则明显升高(P<0.01)。肿瘤细胞同质粘附实验显示,CNE1-GL细胞的同质粘附能力较CNE1细胞弱(P<0.05)。肿瘤细胞-基质粘附实验得出CNE1-GL细胞的异质粘附能力(A值=0.60±0.03)较CNE1细胞(A值=0.46±0.01)强(P<0.01)。肿瘤细胞运动实验显示,穿过PVPF膜的CNE1-GL细胞数多于CNE1细胞(119.3±6.0 vs 46.3±7.0,P<0.05)。结论:LMP1通过抑制E-cadherin表达、促进ICAM-1表达从而抑制肿瘤细胞的同质粘附能力、增强其异质粘附能力和运动能力来参与鼻咽癌的侵袭和转移。展开更多
基金Supported by Grants from the NIH CA138213,RR15635Department of Defense W81XWH-12-1-0225(Luwen Zhang)Qianli Wang was partially supported by Undergraduate Creative Activities and Research Experiences and Beckman Scholars Program
文摘AIM: To investigate the role of nuclear factor κB(NF-κB) in the regulation of Epstein-Barr virus(EBV) latent membrane protein 1(LMP1) in EBV transformed cells. METHODS: LMP1 expression was examined in EBV transformed human B lymphocytes with modulation of NF-κB activity. RESULTS: EBV infection is associated with several human cancers. EBV LMP1 is required for efficient transformation of adult primary B cells in vitro, and is expressed in several pathogenic stages of EBVassociated cancers. Regulation of EBV LMP1 involves both viral and cellular factors. LMP1 activates NF-κB signaling pathway that is a part of the EBV transformation program. However, the relation between NF-κB and LMP1 expression is not well established yet. In this report, we found that blocking the NF-κB activity by Inhibitor of κB stimulated LMP1 expression, while the overexpression of NF-κB repressed LMP1 expression in EBV-transformed IB4 cells. In addition, LMP1 repressed its own promoter activities in reporter assays, and the repression was associated with the activation of NF-κB. Moreover, NF-κB alone is sufficient to repress LMP1 promoter activities. CONCLUSION: Our data suggest LMP1 may repress its own expression through NF-κB in EBV transformed cells and shed a light on LMP1 regulation during EBV transformation.
基金Supported by a grant from Medical Innovation Fund Project of Fujian Provincial Health Bureau (No.2007-CXB-4)
文摘Objective: Early diagnosis of nasopharyngeal carcinoma (NPC) is an important method to improve the survival rate.However,the sensitivity and specificity of the screening protocols which was widely used in clinic now are considered to be unsatisfactory.Epstein-Barr virus (EBV)-encoded latent membrane protein-1 (LMP-1) is one of the proteins that have been suggested to be a classic oncogene with transformation properties.The current study set out to discuss the clinical significance of LMP-1 on the screening of NPC.Methods: Three hundred patients who visited our institution (Department of Radiation Oncology,Fujian Provincial Cancer Hospital,Fuzhou,China) with ENT symptoms between 2007 and 2008 were involved in this study,and all of them were agreed to be involved in this investigation.Not only did they undergo nasopharyngeal swab to obtain cells for the LMP-1 polymerase chain reaction (PCR) analysis,but also nasopharyngeal biopsy were taken to identify the diagnosis.Results: An amount of DNA that was sufficient for PCR was extracted from 243 (81%) swab samples,the positive rate of LMP-1 of those with non-nasopharyngeal carcinoma was 3.85% (4/108),which was much lower than those with nasopharyngeal carcinoma (P < 0.05).By detecting LMP-1 in nasopharyngeal swabs,NPC was diagnosed with a sensitivity of 88.15% (119 of 135 patients),specificity of 96.30% (104 of 108 patients),a positive predictive value of 95.2% (119 of 123 patients),a negative predictive value of 86.67% (104 of 120 patients),accuracy of 91.77%,and Youden index of 84.45%.Conclusion: The nasopharyngeal swab coupled with PCR-based EBV LMP-1 detection have high sensitivity and specificity,and also good repeatability,it could serve as part of the screening program for high-risk populations.
基金This work was supported by the National Natural Science Foundation for Distinguished Young Scholar of China(No.3952502)State Key Basic Research Program,Fundamental Investigation on Human Carcinogenesis of China(No.G1998051201)National Natural Science Foundation of China(Grant No.30300407).
文摘Epstein-Barr virus (EBV) encoded latent membrane protein 1 (LMP1) is considered to be the major oncogenic protein of EBV encoded proteins, and also it has always been the core of the oncogenic mechanism of EBV. Traditional receptor theory demonstrates that cell surface receptors exert biological functions on the membrane, which neither enter into the nucleus nor directly affect the transcription of the target genes. But, advanced studies on nuclear transloca-tion of the epidermal growth factor receptor (EGFR) family have greatly developed our knowl-edge of the biological function of cell surface receptors. In this study, we used Tet-on LMP1 HNE2 cell line as a cell model, which is a dual-stable LMP1 integrated NPC cell line and the ex-pression of LMP1 in which could be regulated by Tet system. We found that LMP1 could regulate the nuclear translocation of EGFR in a dose-dependent manner from both quantitative and qualitative levels through the Western blot analysis and the immunofluorescent analysis with a laser scanning confocal microscope. We further demonstrated that the nuclear localization se-quence of EGFR played some roles in the location of the protein within the nucleus under LMP1 regulation, and the nuclear accumulation of EGFR regulated by LMP1 was in a ligand-independent manner. These findings provide a novel view that the regulation of LMP1 on the nuclear translocation of EGFR is critical for the process of nasopharyngeal carcinoma.
基金supported by the National Natural Science Foundation of China (Grant Numbers: 81402542 and 81772166)the scholarship of Pujiang Talents in Shanghai to Fang Wei (Grant Number: 14PJ1405600)
文摘Dear Editor,Epstein-Barr virus(EBV,also termed human herpesvirus-4)was the first identified human tumor virus.Since its discovery in 1964,studies have shown that EBV infects over 90%of all people by the time they are adults(Williams and Crawford 2006).EBV infection can result in mucocutaneous and systemic diseases,ranging from selflimited illnesses to aggressive malignancies,including B cell Hodgkin lymphoma and nasopharyngeal carcinoma.In vitro,EBV transforms resting B cells into proliferating blast cells(Pope et al.1968).
文摘Viruses have been shown to be responsible for 10%-15% of cancer cases. Epstein-Barr virus(EBV) is the first virus to be associated with human malignancies. EBV can cause many cancers, including Burkett's lymphoma, Hodgkin's lymphoma, post-transplant lymphoproliferative disorders, nasopharyngeal carcinoma and gastric cancer. Evidence shows that phosphoinositide 3-kinase/protein kinase B(PI3K/Akt) plays a key role in EBV-induced malignancies. The main EBV oncoproteins latent membrane proteins(LMP) 1 and LMP2 A can activate the PI3K/Akt pathway, which, in turn, affects cell survival, apoptosis, proliferation and genomic instability via its downstream target proteins to cause cancer. It has also been demonstrated that the activation of the PI3K/Akt pathway can result in drug resistance to chemotherapy. Thus, the inhibition of this pathway can increase the therapeutic efficacy of EBV-associated cancers. For example, PI3 K inhibitor Ly294002 has been shown to increase the effect of 5-fluorouracil in an EBV-associated gastric cancer cell line. At present, dual inhibitors of PI3 K and its downstream target mammalian target of rapamycin have been used in clinical trials and may be included in treatment regimens for EBV-associated cancers.
文摘Epstein-Barr virus (EBV) encoded latent membrane protein 1 (LMP1) may trigger the transcription factor AP-1 including c-Jun and c-fos. In this report, using a Tet-on LMP1 HNE2 cell line which is a dual-stable LMP1 integrated nasopharyngeal carcinoma (NPC) cell line and the expression of LMP1 in which could be regulated by the Tet-on system, we show that Jun B can efficiently form a new heterodimeric complex with the c-Jun protein under the regulation of LMP1, phosphorylation of c-Jun (ser 63, ser 73) and Jun B is involved in the process of the new heterodimeric formation. We also find that this heterodimeric form can bind to the AP-1 consensus sequence. Transfection studies suggest that JNK interaction protein (JIP) could inhibit the heterodimer formation of c-Jun and Jun B through blocking the AP-1 signaling pathway triggered by LMP1. The interaction and function between c-Jun protein and Jun B protein increase the repertoire of possible regulatory complexes by LMP1 that could play an important role in the regulation of transcription of specific cellular genes in the process of genesis of nasopharyngeal carcinoma.
文摘背景与目的:EB病毒编码的潜伏膜蛋白1(latent membrane protein 1,LMP1)在鼻咽癌的浸润和转移过程中起重要的作用。本实验目的在于研究EB病毒LMP1对人鼻咽癌细胞转移能力的影响和探讨其中的相关机制。方法:应用免疫细胞化学RT-PCR法和Western blot检测LMP1、E-cadherin和intercellular adhesion molecule-1 (ICAM-1)在人高分化鼻咽癌细胞系CNE1和转染了LMP1基因的CNE1-GL细胞中的表达。应用细胞-细胞粘附实验、细胞-基质粘附实验、划痕实验和细胞运动实验观察LMP1对鼻咽癌细胞粘附和运动能力的影响。结果:免疫细胞化学结果显示:LMP1在CNE1和CNE1-GL细胞中的阳性率分别为0和(96.60±3.03)%(P<0.01);E-cadherin蛋白的阳性率分别为(37.47±1.50)%和(19.53±1.92)%(P<0.01);ICAM-1蛋白的阳性率分别为(5.27±1.45)%和(93.33±4.23)%(P<0.01)。RT-PCR和Westernblot结果表明,与CNE1细胞相比较,CNE1-GL细胞中E-cadherin的mRNA和蛋白表达明显降低(P<0.01),而ICAM-1的mRNA和蛋白表达则明显升高(P<0.01)。肿瘤细胞同质粘附实验显示,CNE1-GL细胞的同质粘附能力较CNE1细胞弱(P<0.05)。肿瘤细胞-基质粘附实验得出CNE1-GL细胞的异质粘附能力(A值=0.60±0.03)较CNE1细胞(A值=0.46±0.01)强(P<0.01)。肿瘤细胞运动实验显示,穿过PVPF膜的CNE1-GL细胞数多于CNE1细胞(119.3±6.0 vs 46.3±7.0,P<0.05)。结论:LMP1通过抑制E-cadherin表达、促进ICAM-1表达从而抑制肿瘤细胞的同质粘附能力、增强其异质粘附能力和运动能力来参与鼻咽癌的侵袭和转移。
