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Sun J, Shu J, Shi D, Liu W, Zhang Y, Luo B. Effects of methylation and imprinting expression of Insulin-like growth factor 2 gene in gastric cancer. Cancer Biomark 2023; 38:355-366. [PMID: 37718779 DOI: 10.3233/cbm-230105] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
BACKGROUND Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC) is a common malignant tumor associated with EBV infection. Insulin-like growth factor 2 (IGF2) is an imprinted gene and a key protein that regulates growth, especially during normal fetal development. Loss of imprinting (LOI), is a common epigenetic anomaly in a variety of human cancers. However, the promoter methylation, imprinting status and function of IGF2 gene in GC are unclear. OBJECTIVE To explore the role of IGF2 in the occurrence and development of gastric cancer. METHODS The biological function of IGF2 in gastric cancer was investigated by Transwell, wound healing, CCK-8 and flow cytometry assays. IGF2 imprinting status and gene promoter methylation in gastric cancer tissues were detected by PCR-RFLP and BGS. RESULTS The results showed that the expression of IGF2 was higher in GC tissues than adjacent tissues. IGF2 gene promoter methylation and LOI were significantly higher in EBVaGC tissues than in EBV-negative gastric cancer (EBVnGC) tissues. The high expression of IGF2 in gastric cancer can promote the migration and proliferation of gastric cancer cells. CONCLUSION Our data suggest that IGF2 is involved in the occurrence and development of gastric cancer. Targeting IGF2 may be a potential therapeutic target for gastric cancer.
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Affiliation(s)
- Jiting Sun
- Department of Pathogenic Biology, School of Basic Medicine, Qingdao University, Qingdao, Shandong, China
| | - Jun Shu
- Department of Pathogenic Biology, School of Basic Medicine, Qingdao University, Qingdao, Shandong, China
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences, and Shanghai Institute of Infectious Disease and Biosecurity, Fudan University, Shanghai, China
| | - Duo Shi
- Department of Pathogenic Biology, School of Basic Medicine, Qingdao University, Qingdao, Shandong, China
| | - Wen Liu
- Department of Pathogenic Biology, School of Basic Medicine, Qingdao University, Qingdao, Shandong, China
| | - Yan Zhang
- Department of Pathogenic Biology, School of Basic Medicine, Qingdao University, Qingdao, Shandong, China
- Department of Clinical Laboratory, Zibo Central Hospital, Zibo, Shandong, China
| | - Bing Luo
- Department of Pathogenic Biology, School of Basic Medicine, Qingdao University, Qingdao, Shandong, China
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Zhang Y, Hu S, Li J, Shi D, Luo B. The promoter aberrant methylation status of TMEM130 is associated with gastric cancer. Dig Liver Dis 2022; 54:819-825. [PMID: 34162508 DOI: 10.1016/j.dld.2021.05.035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 05/10/2021] [Accepted: 05/24/2021] [Indexed: 12/24/2022]
Abstract
BACKGROUND AND AIMS Gastric cancer (GC) is a malignant tumor that seriously affects human health and Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC) is a molecular subtype of GC. This study aims to determine the relationship between the methylation status of the TMEM130 gene and GC, and to explore the influence of EBV infection. METHODS qRT-PCR was conducted to investigate the transcriptional expression of TMEM130 in GC. BSP and MSP assays were used to detect the methylation level of the TMEM130 promoter. The cell migration ability was detected by Transwell and western blot after transfection of TMEM130 plasmids in GC cells. RESULTS The transcriptional expression of TMEM130 decreased in GC with hypermethylation of the promoter region. The DNA methyltransferase inhibitor could increase the mRNA expression of TMEM130. Moreover, hypermethylation of the TMEM130 promoter in GC tissues was associated with EBV infection. Overexpression of TMEM130 in GC cell lines suppresses cell migration ability. CONCLUSION This study was the first to research the expression and function of TMEM130 and found that TMEM130 gene hypermethylation might contribute to GC migration and EBV infection as a cause of hypermethylation of the TMEM130 gene. TMEM130 is a promising biomarker for the diagnosis of GC.
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Affiliation(s)
- Yan Zhang
- Department of Pathogeny Biology, Basic Medicine College, Qingdao University, Qingdao 266071, China; Department of Clinical Laboratory, Zibo Central Hospital, ZiBo 255000, China
| | - Shunxia Hu
- Department of Clinical Laboratory, Women and Children's Hospital, Qingdao University, Qingdao 266000, China
| | - Jun Li
- Department of Pathogeny Biology, Basic Medicine College, Qingdao University, Qingdao 266071, China
| | - Duo Shi
- Department of Pathogeny Biology, Basic Medicine College, Qingdao University, Qingdao 266071, China
| | - Bing Luo
- Department of Pathogeny Biology, Basic Medicine College, Qingdao University, Qingdao 266071, China.
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Wang HY, Sun L, Li P, Liu W, Zhang ZG, Luo B. Sequence Variations of Epstein-Barr Virus-Encoded Small Noncoding RNA and Latent Membrane Protein 1 in Hematologic Tumors in Northern China. Intervirology 2021; 64:69-80. [PMID: 33709967 DOI: 10.1159/000510398] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Accepted: 07/17/2020] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE To investigate the relationship between hematologic tumors and Epstein-Barr virus (EBV)-encoded small noncoding RNA (EBER) variations as well as latent membrane protein 1 (LMP1) variations. METHODS Patients with leukemia and myelodysplastic syndrome (MDS) were selected as subjects. Genotypes 1/2 and genotypes F/f were analyzed using the nested PCR technology, while EBER and LMP1 subtypes were analyzed by the nested PCR and DNA sequencing. RESULTS Type 1 was more dominant than type 2, found in 59 out of 82 (72%) leukemia and in 31 out of 35 (88.6%) MDS, while type F was more prevalent than type f in leukemia (83/85, 97.6%) and MDS (29/31, 93.5%) samples. The distribution of EBV genotypes 1/2 was not significantly different among leukemia, MDS, and healthy donor groups, neither was that of EBV genotypes F/f. EB-6m prototype was the dominant subtype of EBER in leukemia and MDS (73.2% [30/41] and 83.3% [10/12], respectively). The frequency of EB-6m was lower than that of healthy people (96.7%, 89/92), and the difference was significant (p < 0.05). China 1 subtype was the dominant subtype of LMP1 in leukemia and MDS (70% [28/40] and 90% [9/10], respectively), and there was no significant difference in the distribution of LMP1 subtypes among the 3 groups (p > 0.05). CONCLUSION The distribution of EBV 1/2, F/f, EBER, and LMP1 subtypes in leukemia and MDS was similar to that in the background population in Northern China, which means that these subtypes may be rather region-restricted but not associated with leukemia and MDS pathogenesis.
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Affiliation(s)
- Hai-Yu Wang
- Department of Pathogenic Biology, Qingdao University Medical College, Qingdao, China.,Department of Infection-Control, The First People's Hospital of Lianyungang, Lianyungang, China
| | - Lingling Sun
- Department of Pathology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Ping Li
- Department of Blood Transfusion, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Wen Liu
- Department of Pathogenic Biology, Qingdao University Medical College, Qingdao, China
| | - Zhong-Guang Zhang
- Department of Pathogenic Biology, Qingdao University Medical College, Qingdao, China,
| | - Bing Luo
- Department of Pathogenic Biology, Qingdao University Medical College, Qingdao, China
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LMP2A induces DNA methylation and expression repression of AQP3 in EBV-associated gastric carcinoma. Virology 2019; 534:87-95. [PMID: 31220652 DOI: 10.1016/j.virol.2019.06.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 05/14/2019] [Accepted: 06/11/2019] [Indexed: 12/27/2022]
Abstract
Epstein-Barr virus (EBV)-associated gastric carcinoma (EBVaGC) is a unique type of gastric carcinomas that promoter hypermethylation of tumor-related genes is extremely frequent to be found. Aquaporin 3 (AQP3) is a small membrane transport protein that plays a crucial role in cancer progression and metastasis. However, there is no experimental study on the expression of AQP3 in EBVaGC and the regulation mechanism of EBV on AQP3. In this study, the loss of AQP3 was contributed by the hypermethylation status of AQP3 promoter in EBVaGC which was caused by elevated expression of DNMT3a. In addition, stable and transient transfection system in SGC7901 showed that viral latent membrane protein 2A (LMP2A) activated phosphorylated ERK and up-regulated DNMT3a. Taken together, LMP2A induced the phosphorylation of ERK, which activated DNMT3a transcription and caused AQP3 expression loss through CpG island methylation of AQP3 promoter in EBVaGC.
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Efficient Epstein-Barr Virus Progeny Production Mediated by Cancer-Derived LMP1 and Virally-Encoded microRNAs. Microorganisms 2019; 7:microorganisms7050119. [PMID: 31052238 PMCID: PMC6560388 DOI: 10.3390/microorganisms7050119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 04/25/2019] [Accepted: 04/28/2019] [Indexed: 12/22/2022] Open
Abstract
Epstein-Barr virus (EBV) genomes, particularly their latent genes, are heterogeneous among strains. The heterogeneity of EBV-encoded latent membrane protein 1 (LMP1) raises the question of whether there are functional differences between LMP1 expressed by cancer-associated EBV and that by non-cancerous strains. Here, we used bacterial artificial chromosome (BAC)-cloned EBV genomes retaining all virally encoded microRNA (miRNA) genes to investigate the functions of cancer-derived LMP1 in the context of the EBV genome. HEK293 cells were stably transfected with EBV-BAC clone DNAs encoding either nasopharyngeal carcinoma (NPC)-derived CAO-LMP1 (LMP1CAO) or LMP1 from a prototype B95-8 strain of EBV (LMP1B95-8). When an EBV-BAC clone DNA encoding LMP1CAO was stably transfected into HEK293 cells, it generated many more stable transformants than the control clone encoding LMP1B95-8. Furthermore, stably transfected HEK293 cells exhibited highly efficient production of progeny virus. Importantly, deletion of the clustered viral miRNA genes compromised the ability to produce progeny viruses. These results indicate that cancer-derived LMP1 and viral miRNAs together are necessary for efficient production of progeny virus, and that the resulting increase in efficiency contributes to EBV-mediated epithelial carcinogenesis.
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Li J, Liu X, Liu M, Che K, Luo B. Methylation and expression of Epstein-Barr virus latent membrane protein 1, 2A and 2B in EBV-associated gastric carcinomas and cell lines. Dig Liver Dis 2016; 48:673-80. [PMID: 27026080 DOI: 10.1016/j.dld.2016.02.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Revised: 02/06/2016] [Accepted: 02/15/2016] [Indexed: 12/11/2022]
Abstract
BACKGROUND Promoter CpG methylation of Epstein-Barr virus (EBV) genome plays an essential role in maintaining viral latency. Latent membrane protein (LMP) 1, 2A and 2B of EBV exert multiple oncogenic properties by activating multiple signal pathways and modulating the expression of various oncogenes. AIMS To study the methylation and expression of LMP1, 2A and LMP2B in EBV-positive cell lines and EBV-associated tumors. METHODS The methylation profiles of LMP1p, LMP2Ap and LMP2Bp were evaluated by methylation-specific PCR (MSP) and bisulfite sequencing PCR (BSP), as well as their expression by quantitative real-time (qRT)-PCR in 41 EBV-associated carcinomas (EBVaGCs) and 5 EBV-positive cell lines. RESULTS All LMP promoters were methylated at different degrees in EBV-positive cell lines and hypermethylated in EBV-associated gastric carcinomas, while unmethylated LMP2Ap alleles were detected in B95-8 cell line. Following 5-aza-2'-deoxycytidine (5-aza) treatment, the LMP1 expression was restored along with concomitant promoter demethylation; changes of LMP2A and LMP2B expression were different in different cells. CONCLUSION Methylation of LMP1, 2A and 2B promoters mediates the silencing of LMP1, 2A and 2B in EBV-associated carcinomas and cell lines in varying degrees, and could be reactivated by demethylation agent and thus may contribute to the therapy of EBVaGCs.
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Affiliation(s)
- Jing Li
- Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China; Department of Medical Microbiology, Qingdao University Medical College, Qingdao, China
| | - Xia Liu
- Department of Central Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Mengyang Liu
- Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Kui Che
- Department of Central Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Bing Luo
- Department of Medical Microbiology, Qingdao University Medical College, Qingdao, China.
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7
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Identification and Characterization of Epstein-Barr Virus Genomes in Lung Carcinoma Biopsy Samples by Next-Generation Sequencing Technology. Sci Rep 2016; 6:26156. [PMID: 27189712 PMCID: PMC4870493 DOI: 10.1038/srep26156] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 04/27/2016] [Indexed: 12/13/2022] Open
Abstract
Epstein-Barr virus (EBV) has been detected in the tumor cells of several cancers, including some cases of lung carcinoma (LC). However, the genomic characteristics and diversity of EBV strains associated with LC are poorly understood. In this study, we sequenced the EBV genomes isolated from four primary LC tumor biopsy samples, designated LC1 to LC4. Comparative analysis demonstrated that LC strains were more closely related to GD1 strain. Compared to GD1 reference genome, a total of 520 variations in all, including 498 substitutions, 12 insertions, and 10 deletions were found. Latent genes were found to harbor the most numbers of nonsynonymous mutations. Phylogenetic analysis showed that all LC strains were closely related to Asian EBV strains, whereas different from African/American strains. LC2 genome was distinct from the other three LC genomes, suggesting at least two parental lineages of EBV among the LC genomes may exist. All LC strains could be classified as China 1 and V-val subtype according to the amino acid sequence of LMP1 and EBNA1, respectively. In conclusion, our results showed the genomic diversity among EBV genomes isolated from LC, which might facilitate to uncover the previously unknown variations of pathogenic significance.
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Shen ZC, Luo B, Chen JN, Chao Y, Shao CK, Liu QQ, Wang Y. High prevalence of the EBER variant EB-8m in endemic nasopharyngeal carcinomas. PLoS One 2015; 10:e0121420. [PMID: 25807550 PMCID: PMC4373760 DOI: 10.1371/journal.pone.0121420] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 02/01/2015] [Indexed: 01/26/2023] Open
Abstract
Epstein-Barr virus (EBV)-encoded small RNAs (EBERs) are the most highly expressed transcripts in all EBV-associated tumors and are involved in both lymphoid and epithelioid carcinogenesis. Our previous study on Chinese isolates from non-endemic area of nasopharyngeal carcinoma (NPC) identified new EBER variants (EB-8m and EB-10m) which were less common but relatively more frequent in NPC cases than healthy donors. In the present study, we determined the EBER variants in NPC cases and healthy donors from endemic and non-endemic areas of NPC within China and compared the EBER variants, in relation to the genotypes at BamHI F region (prototype F and f variant), between population groups and between two areas. According to the phylogenetic tree, four EBER variants (EB-6m, EB-8m, EB-10m and B95-8) were identified. EB-6m was dominant in all population groups except for endemic NPC group, in which EB-8m was dominant. EB-8m was more common in endemic NPC cases (82.0%, 41/50) than non-endemic NPC cases (33.7%, 32/95) (p<0.0001), and it was also more frequent in healthy donors from endemic area (32.4%, 24/74) than healthy donors from non-endemic area (1.1%, 1/92) (p<0.0001). More importantly, the EB-8m was more prevalent in NPC cases than healthy donors in both areas (p<0.0001). The f variant, which has been suggested to associate with endemic NPC, demonstrated preferential linkage with EB-8m in endemic isolates, however, the EB-8m variant seemed to be more specific to NPC isolates than f variant. These results reveal high prevalence of EBER EB-8m variant in endemic NPC cases, suggesting an association between NPC development and EBV isolates carrying EB-8m variant. Our finding identified a small healthy population group that shares the same viral strain which predominates in NPC cases. It could be interesting to carry extensive cohort studies following these individuals to evaluate the risk to develop NPC.
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Affiliation(s)
- Zhi-chao Shen
- Department of Medical Microbiology, Qingdao University Medical College, Qingdao, People’s Republic of China
| | - Bing Luo
- Department of Medical Microbiology, Qingdao University Medical College, Qingdao, People’s Republic of China
| | - Jian-ning Chen
- Department of Pathology, The Third Affiliated Hospitals of Sun Yat-sen University, Guangzhou, People’s Republic of China
| | - Yan Chao
- Department of Clinical Laboratory, Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou, People’s Republic of China
| | - Chun-kui Shao
- Department of Pathology, The Third Affiliated Hospitals of Sun Yat-sen University, Guangzhou, People’s Republic of China
| | - Qian-qian Liu
- Department of Medical Microbiology, Qingdao University Medical College, Qingdao, People’s Republic of China
| | - Yun Wang
- Department of Medical Microbiology, Qingdao University Medical College, Qingdao, People’s Republic of China
- * E-mail:
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Abstract
What is wild-type Epstein-Barr virus and are there genetic differences in EBV strains that contribute to some of the EBV-associated diseases? Recent progress in DNA sequencing has resulted in many new Epstein-Barr virus (EBV) genome sequences becoming available. EBV isolates worldwide can be grouped into type 1 and type 2, a classification based on the EBNA2 gene sequence. Type 1 transforms human B cells into lymphoblastoid cell lines much more efficiently than type 2 EBV and molecular mechanisms that may account for this difference in cell transformation are now becoming understood. Study of geographic variation of EBV strains independent of the type 1/type 2 classification and systematic investigation of the relationship between viral strains, infection and disease are now becoming possible. So we should consider more directly whether viral sequence variation might play a role in the incidence of some EBV-associated diseases.
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Affiliation(s)
- Paul J Farrell
- Section of Virology, Department of Medicine, Imperial College, St Mary's Campus, Norfolk Place, London, W2 1PG, UK.
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10
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Epstein-barr virus sequence variation-biology and disease. Pathogens 2012; 1:156-74. [PMID: 25436768 PMCID: PMC4235690 DOI: 10.3390/pathogens1020156] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 10/16/2012] [Accepted: 10/30/2012] [Indexed: 12/12/2022] Open
Abstract
Some key questions in Epstein-Barr virus (EBV) biology center on whether naturally occurring sequence differences in the virus affect infection or EBV associated diseases. Understanding the pattern of EBV sequence variation is also important for possible development of EBV vaccines. At present EBV isolates worldwide can be grouped into Type 1 and Type 2, a classification based on the EBNA2 gene sequence. Type 1 EBV is the most prevalent worldwide but Type 2 is common in parts of Africa. Type 1 transforms human B cells into lymphoblastoid cell lines much more efficiently than Type 2 EBV. Molecular mechanisms that may account for this difference in cell transformation are now becoming clearer. Advances in sequencing technology will greatly increase the amount of whole EBV genome data for EBV isolated from different parts of the world. Study of regional variation of EBV strains independent of the Type 1/Type 2 classification and systematic investigation of the relationship between viral strains, infection and disease will become possible. The recent discovery that specific mutation of the EBV EBNA3B gene may be linked to development of diffuse large B cell lymphoma illustrates the importance that mutations in the virus genome may have in infection and human disease.
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Epigenetic silencing of WNT5A in Epstein-Barr virus-associated gastric carcinoma. Arch Virol 2012; 158:123-32. [PMID: 23001722 DOI: 10.1007/s00705-012-1481-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2012] [Accepted: 08/07/2012] [Indexed: 12/13/2022]
Abstract
Epstein-Barr virus (EBV) is responsible for the development of multiple tumors, including EBV-associated gastric carcinoma (EBVaGC), but little is known about its mechanisms in EBVaGC. WNT5A expression and promoter methylation were measured in 5 EBV-positive and 15 EBV-negative GC cell lines. The methylation status of 23 EBV-positive and 25 EBV-negative paired tumor/normal tissue samples was also examined. EBV-positive GC had no or very low expression of WNT5A but a high level of methylation in the promoter region. In contrast, EBV-negative GC had higher WNT5A expression and a lower level of promoter methylation. The reduced WNT5A expression could be restored by treatment with Aza, a methyltransferase inhibitor. Increased expression of WNT5A in vitro inhibited β-catentin expression in EBVaGC cells (SNU719). These results suggest that hypermethylation of WNT5A induced by EBV may contribute to the development of EBVaGC. Ectopic introduction of WNT5A may have preventive/therapeutic potential for tumors with silenced WNT5A.
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Methylation and Expression of Retinoblastoma and Transforming Growth Factor-β1 Genes in Epstein-Barr Virus-Associated and -Negative Gastric Carcinomas. Gastroenterol Res Pract 2012; 2012:906017. [PMID: 23008701 PMCID: PMC3447358 DOI: 10.1155/2012/906017] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 08/08/2012] [Accepted: 08/13/2012] [Indexed: 12/26/2022] Open
Abstract
Background. Retinoblastoma (RB) and transforming growth factor-β1 (TGF-β1) are important tumor-related factors. Methods. A series of 30 EBV-associated gastric carcinoma (EBVaGC) and 38 matched EBV-negative gastric carcinoma (EBVnGC) tissues were examined for the promoter methylation of RB by methylation-specific PCR (MSP) method. The expression of RB and TGF-β1 in gastric carcinoma tissues was detected by immunohistochemistry. Results. The methylation rate of RB gene in EBVaGC and EBVnGC was 80.0% (24/30) and 50.0% (19/38), respectively. The difference of RB methylation rate between EBVaGC and EBVnGC was significant (χ2 = 6.490, P = 0.011). There was no significant difference for RB expression between EBVaGC (43.3%, 13/30) and EBVnGC (63.2%, 24/38), and also for TGF-β1 between EBVaGC (56.7%, 17/30) and EBVnGC (63.2%, 24/38). RB methylation was not reversely correlated with RB expression in gastric carcinoma tissues (χ2 = 2.943, P = 0.086, r = 0.208). RB methylation, loss expression of RB, and TGF-β1 expression were significantly associated with tumor invasion and lymph node metastasis (P < 0.05), but was not associated with sex, age, histological subtype (differentiation status) and tumor location. Conclusions. Methylation of RB is a common event in gastric carcinomas and EBV induces methylation of RB in EBVaGC, which may contribute to the development of gastric carcinomas. EBV has no significant effect on induction of TGF-β1 expression. Detection of RB methylation, RB expression, and TGF-β1 expression may be helpful to judge the status of tumor invasion and lymph node metastasis in gastric carcinomas.
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Kawaguchi A, Kanai K, Satoh Y, Touge C, Nagata K, Sairenji T, Inoue Y. The evolution of Epstein-Barr virus inferred from the conservation and mutation of the virus glycoprotein gp350/220 gene. Virus Genes 2009; 38:215-23. [PMID: 19153826 DOI: 10.1007/s11262-008-0323-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2008] [Accepted: 12/18/2008] [Indexed: 12/11/2022]
Abstract
To study variations of Epstein-Barr virus (EBV), we analyzed the gp350/220 gene for several cell lines and Japanese wild isolates using direct sequencing. The N-terminal region was highly conserved in all EBVs except for Jijoye/P3HR-1 and a few isolates. The variation of the region coincided with EBV types A and B (also referred to as types 1 and 2) and were, respectively, designated as the types a and b. The type A/a was detected in most Japanese cell lines and wild isolates, and was classified as China1 type with latent membrane protein (LMP) 1 gene. The type B/b was detected in only a few wild isolates with the Med and China2 types. The C-terminus had more diversity than the N-terminus and lacked the divergence between types A/a and B/b. The phylogenetic analyses of the gp350/220 and LMP1 genes may suggest a mode of EBV evolution into types A/a and B/b and then to LMP1 subtypes.
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Affiliation(s)
- Asako Kawaguchi
- Divison of Ophthalmology and Visual Science, Faculty of Medicine, Tottori University, Yonago, Japan
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Kanai K, Satoh Y, Yamanaka H, Kawaguchi A, Horie K, Sugata K, Hoshikawa Y, Sata T, Sairenji T. The vIL-10 gene of the Epstein-Barr virus (EBV) is conserved in a stable manner except for a few point mutations in various EBV isolates. Virus Genes 2007; 35:563-9. [PMID: 17763933 DOI: 10.1007/s11262-007-0153-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2007] [Accepted: 07/25/2007] [Indexed: 10/22/2022]
Abstract
A gene of the Epstein-Barr virus (EBV), BamHI-C fragment rightward reading frame 1 (BCRF1), codes viral interleukin-10 (vIL-10), which is a close homolog to human IL-10. EBV strain variations are known at EBV latent membrane protein 1 (LMP1), and the distinct forms of LMP1 have been identified. In order to further elucidate the variations of EBV strains, the BCRF1 (vIL-10) gene was analyzed using PCR-direct sequencing in African Burkitt's lymphoma (BL) cell lines Raji, P3HR-1, EB1 and Daudi, Japanese BL cell line Akata, lymphoblastoid cell line OB and 22 wild EBV isolates from eight gastric carcinoma tissues and 14 throat washes. We found only five variations of the vIL-10 gene in them with one silent mutation and three non-silent mutations. Raji had no mutation to the prototype gene of B95-8. EB1 and P3HR-1 had non-silent mutations in the sequences leading to the arginine/serine and threonine/proline interchanges at residues 4 and 166, respectively. The silent mutation was detected at valine 102 in Daudi and also in the Japanese cell lines Akata, OB and 20 (90.9%) of the wild EBV isolates. The type of variations in the vIL-10 gene had a common relationship with those in the LMP1 gene. All of the variants of valine 102 had China1-type LMP1 sequences except for Daudi with Med-type LMP1 and other minorities with B95-8 type LMP1. The conservativeness of vIL-10 with a few variations suggests the indispensability of the vIL-10 gene in EBV and that the variations of the vIL-10 gene may depend upon the geographical prevalence of the EBV strains. This is the first report regarding the variations of the vIL-10 gene in cell lines and other wild isolates.
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Affiliation(s)
- Kyosuke Kanai
- Division of Biosignaling, Department of Biomedical Sciences, School of Life Science, Faculty of Medicine, Tottori University, Yonago 683-8503, Japan
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