• BMB Reports
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• v.38 no.6
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• pp.755-762
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• 2005

Epstein-Barr virus (EBV) infects more than 90% of the world's population and has a potential oncogenic nature. A histone deacetylase (HDAC) inhibitor, trichostatin A (TSA), has shown potential ability in cancer chemoprevention and treatment, but its effect on EBV-infected Akata cells has not been examined. This study investigated the effect of TSA on the proliferation and apoptosis of the cells. TSA inhibited cell growth and induced cytotoxicity in the EBV infected Akata cells. TSA treatment sensitively induced apoptosis in the cell, which was demonstrated by the increased number of positively stained cells in the TUNEL assay, the migration of many cells to the sub-$G_0/G_1$ phase in flow cytometric analysis, and the ladder formation of genomic DNA. Western blot analysis showed that caspase-dependent pathways are involved in the TSA-induced apoptosis of EBV-infected Akata cells. Overall, this study shows that EBV-infected B lymphomas are quite sensitive to TSA-provoked apoptosis.

• Molecules and Cells
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• v.27 no.2
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• pp.143-148
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• 2009

EBV-transformed lymphoblastoid cell lines (LCLs) are used as a resource for human genetic, immunological, and pharmacogenomic studies. We investigated the biological activity of 20 LCL strains during continuous long-term subculture up to a passage number of 160. Out of 20 LCL strains, 17 proliferated up to a passage number of 160, at which point LCLs are generally considered as "immortalized". The other three LCL strains lost the ability to proliferate at an average passage number of 41, during which these LCLs may have undergone cellular crisis. These non-immortal LCL strains exhibited no telomerase activity, decreased EBV gene expression, and a lower copy number of the EBV genome and mitochondrial DNA when compared with immortal LCLs. Thus, this study suggests that sustained EBV viral activity as well as telomerase activity may be required for complete LCL immortalization.

• Laboratory Medicine Online
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• v.1 no.2
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• pp.110-114
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• 2011

There have been a few reports of hemophagocytic lymphohistiocytosis (HLH) with chromosomal abnormalities. Clonal chromosomal abnormalities in HLH patients are usually found in association with hematologic malignancies and rarely with epstein-barr virus (EBV) infection. Here, we report a fatal case of HLH with clonal karyotype abnormalities. A 75-yr-old man was admitted with persistent anorexia and high fever. Laboratory data revealed pancytopenia, hypofibrinogenemia, hyperferritinemia, prolonged prothrombin time and activated partial thromboplastin time, and marked elevated level of serum transaminases. In real time-PCR using whole blood, EBV DNA was not detected but cytomegalovirus (CMV) DNA was detected. The bone marrow aspiration smear showed hyperplasia of mature histiocytes with prominent hemophagocytosis. In chromosomal analysis of bone marrow aspirates, complex chromosomal abnormalities were found. In spite of steroid pulse therapy and antibiotic treatment, he died of disseminated intravascular coagulopathy.

• Journal of Pharmaceutical Investigation
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• v.33 no.4
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• pp.267-272
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• 2003

Herpes simplex virus (HSV) thymidine kinase (TK) has been widely used for suicidal gene therapy in combination with nucleoside analogs such as ganciclovir (GCV). The use of HSV-TK is limited due to the side effect of GCV at high concentrations. Previous studies showed that stable transfectants of mutant HSV-TK with enhanced affinity to GCV were killed at lower GCV concentrations. In this study, we tested whether mutant HSV-TK can provide enhanced suicidal effect when transiently transfected with Epstein-Barr virus (EBV)-based plasmid. EBV-based plasmid which contains OriP and EBNA-1 sequence is well known for a stable episomal maintenance in human cells. Optimal transfection condition was assessed for SNU-638 gastric cancer cell line using polyetylnimine (PEI). Maximum transfection efficiency was achieved when DNA:PEI was 1:3 (w/v). Cytotoxicities of mutant and wild type HSV-TK were compared before and after partially selecting transfected cells. The cells were sensitive to $100\;{\mu}g/ml$ hygromycin. Following GCV treatment, more cells were killed after hygromycin selection than before selection. The mutant HSV-TK showed enhanced cytotoxicity compared with the wild type HSV-TK. Our results suggest that the EBV-based plasmid encoding mutant HSV-TK may be useful to treat the diseases caused by uncontrolled cell proliferation such as cancer and rheumatoid arthritis.

• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.964-969
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• 1998

To investigated the anticarcinogenic activity of 70% ethanol extracts from various cereal in vitro, antimutagenic activity, inhibitory effect of DNA strand scission and tumor promotion were examined. The antimutagenic activity of the beans such as black bean and small red bean was generally higher than that of cereals examined. However inhibitory activity of 70% ethanolic extracts against DNA strand scission induced mitomycin C showed that millet, job's tear, black bean and soy bean among cereals and beans tested in this study inhibited effectively the DNA strand scission. Antioxidative activity of some cereal extracts determined by using linoleic acid model system showed that Job's tear, millet and black bean were higher antioxidative activity than other cereals and beans. Conventional short-term antipromoter assay system using activation of Epstein Barr virus (EBV) clearly demonstrated that sorghum, buckwheat, black bean and small red bean have inhibitory effects on promotion in cellular carcinogenesis.

• Pediatric Infection and Vaccine
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• v.14 no.2
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• pp.171-178
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• 2007

Purpose : We investigated clinical characteristics of real-time PCR proven EBV viremia patients who were not serologically diagnosed but clinically suspected, and compared it to serologically proven EBV infected patients. Methods : The study population consisted of 45 patients, who were suspected acute EBV infection at Wonju Christian Hospital Department of Pediatrics, Yonsei University Wonju College of Medicine from Jan. 2004 to Dec. 2006. real-time PCR of cell free serum was performed to prove EBV viremia. Then we chose $102.5copies/{\mu}g$ DNA as a suitable cutoff level for EBV associated diseases. Results : There are 4 patients diagnosed as EBV infection by serologically and 15 patients diagnosed as EBV viremia by real-time PCR quantitative measurement. The most common presenting symptoms and signs of EBV viremia was fever in 11 cases (73%). Atypical lymphocytosis was found in 4 cases (27%). Increased AST, ALT levels were observed in 13 cases (87%), 12 cases (80%), respectively. We could diagnose 5 cases of EBV viremia younger than one year of age. They revealed clinical symptoms which could be found in EBV infection. The serologically diagnosed patients had hepatomegaly and splenomegaly in 3 cases (75%). All serologically confirmed patients have leukocytosis above $20,000/mm^3$, among them 2 cases (50%) had higher percentage (>15%) of atypical lymphocytes. The AST/ALT level above 50 IU/L were demonstrated in all cases. Conclusion : Serologically unproven real-time PCR EBV viremia patients revealed similar clinical findings with that of serologically proven EBV infected patients. So, it is meaningful to perform EBV real-time PCR for the diagnosis of EBV infection especially for the cases younger than 1 year of age.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7583-7587
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• 2015

Epstein-Barr virus (EBV) is an extremely common herpesvirus that may cause asymptomatic infection or various diseases, including infectious mononucleosis, certain lymphoproliferative diseases and several types of neoplasms. Vaccine development is an important strategy to reduce the burden of EBV-associated diseases and the timing of vaccinations should be before primary infection occurs. In the past, more than 90% of Thai children were infected with EBV in early childhood. Now, due to the improved healthcare system in Thailand, we aim to determine current prevalence of EBV infection among people in different age groups. A total of 538 sera were collected from residents of Khon Kaen province in northeastern Thailand for detecting anti-EBV IgG. Sera of infants under 2-years-old were also tested for anti-EBV IgM and EBV-DNA. The prevalence of anti-EBV IgG was 47.1% (95% CI: 23.3-70.8) in infants aged 0-6 months, 34.9% (95% CI: 23.1-46.7) in those aged 6-24 months, 87.9% (95% CI: 79.5-96.3) in children aged 3-5 years and then maintained at above 95% through adulthood. These seropositivity rates among Thai children remain similar to those found in a previous study conducted 20 years ago. Thai children are still exposed to EBV from an early age. Therefore, a prophylactic vaccine should be given within the first two years of life.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.1705-1712
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• 2016

Background: The aim of this study was to determine and evaluate the association of different viral infections, with hepatitis B and C viruses, Epstein-Barr virus, cytomegalovirus and human herpes virus-8 (HBV, HCV, EBV, CMV, HHV-8) with the risk of lymphomas (Hodgkin and non-Hodgkin) among Egyptian patients, and correlate with the histopathological staging and typing as well as the prevalence of combined infections. Materials and Methods: A total of 100 newly diagnosed lymphoma patients with 100 healthy age and sex matched normal controls were assayed for viral infection using enzyme linked immunosorbant assay (ELISA) followed by real time polymerase chain reaction (RT-PCR). Results: Our results showed a high statistical significant difference between cases and controls as regards clinical and laboratory findings (P<0.001 and=0.003). A high statistical difference was seen for the association of most viruses and lymphoma cases (p<0.001) except for positive HBs Ag, positive CMV IgG and HHV-8 (p=0.37, 0.70 and 1.0 respectively). No statistical significant difference was found between Hodgkin (HL) and non-Hodgkin (NHL) as regards viral prevalence except HCV antigen, 57.1% for HL and 26.5% for NHL (p = 0.03). Only, HBV DNA showed a high significant value among infiltrated bone marrow cases (p=0.003) and finally, a high significant association of 2 combined viral infections with infiltrated bone marrow lymphoma cases (p=0.04). Conclusions: Our results showed that infection with HBV, HCV, CMV and EBV were associated with increased risk of lymphoma among the Egyptian population. Detection of new associations between infectious agents and risk of cancer development will facilitate progress in elaboration of prophylactic measures, early diagnostic methods and, hopefully, novel therapy of malignant tumours.

• Journal of Microbiology and Biotechnology
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• v.10 no.6
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• pp.844-850
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• 2000

The specific binding and internalization of viral particles is an essential step for the successful infection of viral pathogens. In the case of the hepatitis B virus (HBV), virions bind to the host cell via the preS domain of the viral surface antigen and are subsequently internalized by endocytosis. HBV-preS specific receptors are primarily expressed on hepatocytes, however, viral DNA and proteins have also been detected in extrahepatic sites, suggsting that celluar recepators for HBV may also exist on extrahepatic cells. Recently, an EBV-transformed B-cell line was identified onto which the preS region binds in a receptor-ligand specific manner. In this study, this specific interaction was further characterized, and the binding region within the preS protein was locaized. Also the internalization after host cell attachment was visualized and analyzed by fluorescence-labeled HBV-preS1 proteins using confocal microscopy. Energy depletion by sodium azide treatment effectively inhibited the internalization of the membrane-bound preS1 ligands, thereby indicating an energy-dependent receptor-mediated endocytotic pathway. Accordingly, the interaction of HBV-pres! with this specific B-cell line may serve as an effective model for an infection pathway in extrahepatic cells.

• Biomolecules & Therapeutics
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• v.26 no.6
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• pp.591-598
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• 2018

Epigenetic silencing is considered to be a major mechanism for loss of activity in tumor suppressors. Reversal of epigenetic silencing by using inhibitors of DNA methyltransferase (DNMT) or histone deacetylases (HDACs) such as 5-Aza-CdR and FK228 has shown to enhance cytotoxic activities of several anticancer agents. This study aims to assess the combinatorial effects of genesilencing reversal agents (5-Aza-CdR and FK228) and oxaliplatin in gastric cancer cells, i.e., Epstein-Barr virus (EBV)-negative SNU-638 and EBV-positive SNU-719 cells. The doublet combinatorial treatment of 5-Aza-CdR and FK228 exhibited synergistic effects in both cell lines, and this was further corroborated by Zta expression induction in SNU-719 cells. Three drug combinations as 5-Aza-CdR/FK228 followed by oxaliplatin, however, resulted in antagonistic effects in both cell lines. Simultaneous treatment with FK228 and oxaliplatin induced synergistic and additive effects in SNU-638 and SNU-719 cells, respectively. Three drug combinations as 5-Aza-CdR prior to FK228/oxaliplatin, however, again resulted in antagonistic effects in both cell lines. This work demonstrated that efficacy of doublet synergistic combination using DNMT or HDACs inhibitors can be compromised by adding the third drug in pre- or post-treatment approach in gastric cancer cells. This implies that the development of clinical trial protocols for triplet combinations using gene-silencing reversal agents should be carefully evaluated in light of their potential antagonistic effects.