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Fukayama M, Kunita A, Kaneda A. Gastritis-Infection-Cancer Sequence of Epstein-Barr Virus-Associated Gastric Cancer. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1045:437-457. [PMID: 29896679 DOI: 10.1007/978-981-10-7230-7_20] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Epstein-Barr virus-associated gastric cancer (EBVaGC) is a representative EBV-infected epithelial neoplasm, which is now included as one of the four subtypes of The Cancer Genome Atlas molecular classification of gastric cancer. In this review, we portray a gastritis-infection-cancer sequence of EBVaGC. This virus-associated type of gastric cancer demonstrates clonal growth of EBV-infected epithelial cells within the mucosa of atrophic gastritis. Its core molecular abnormality is the EBV-specific hyper-epigenotype of CpG island promoter methylation, which induces silencing of tumor suppressor genes. This is due to the infection-induced disruption of the balance between DNA methylation and DNA demethylation activities. Abnormalities in the host cell genome, including phosphatidylinositol-4,5-biphosphate 3-kinase catalytic subunit α (PIK3CA), AT-rich interaction domain 1A (ARID1A), and programmed death-ligand 1 (PD-L1), are associated with the development and progression of EBVaGC. Furthermore, posttranscriptional modulation affects the transformation processes of EBV-infected cells, such as epithelial mesenchymal transition and anti-apoptosis, via cellular and viral microRNAs (miRNAs). Once established, cancer cells of EBVaGC remodel their microenvironment, at least partly, via the delivery of exosomes containing cellular and viral miRNAs. After exosomes are incorporated, these molecules change the functions of stromal cells, tuning the microenvironment for EBVaGC. During this series of events, EBV hijacks and uses cellular machineries, such as DNA methylation and the miRNA delivery system. This portrait of gastritis-infection-cancer sequences highlights the survival strategies of EBV in the stomach epithelial cells and may be useful for the integration of therapeutic modalities against EBV-driven gastric cancer.
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Affiliation(s)
- Masashi Fukayama
- Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
| | - Akiko Kunita
- Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Atsushi Kaneda
- Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan
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52
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Kim HG, Ryu SY, Lee KH, Lee JH, Kim DY. Quantitative analysis of COX-2 promoter methylation in gastric carcinoma. Ann Surg Treat Res 2018; 95:55-63. [PMID: 30079321 PMCID: PMC6073046 DOI: 10.4174/astr.2018.95.2.55] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 11/28/2017] [Accepted: 12/22/2017] [Indexed: 11/30/2022] Open
Abstract
Purpose To determine the occurrence of COX-2 methylation in gastric carcinoma (GC), the status and level of CpG methylation in the promoter region of cyclooxygenase-2 (COX-2) were analyzed in early and advanced GCs, as well as in normal gastric tissues. Methods The extent of promoter methylation of the COX-2 gene was assessed quantitatively using pyrosequencing in 60 early and 60 advanced GCs samples harvested upon gastrectomy, and 40 normal gastric mucosa samples from patients with benign gastric diseases as controls. Results The methylation frequency for the COX-2 gene was significantly higher in early than in advanced GCs (40.0% vs. 20.0%, P < 0.05). A significant difference was found in COX-2 methylation between GCs and normal gastric tissues (30.0% vs. 10.0%, by PS; P < 0.05). COX-2 gene methylation was significantly associated with the depth of invasion (P = 0.003), lymph node metastasis (P = 0.009), distant metastasis (P = 0.036), and TNM staging (P = 0.007). The overall survival of patients with COX-2 methylation was significantly lower than that of patients without COX-2 methylation (P = 0.005). Conclusion These results demonstrated that COX-2 promoter methylation was significantly higher in tumor tissues, and was an early event for GC, thus, COX-2 gene methylation may be important in the initial development of gastric carcinogenesis. Thus, GCs with methylation in COX-2 may not be good candidates for treatment with COX-2 inhibitors. Furthermore, COX-2 methylation could be a significant prognostic factor predicting a favorable effect on GC patient outcome when downregulated.
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Affiliation(s)
- Ho Goon Kim
- Division of Gastroenterologic Surgery, Department of Surgery, Chonnam National University Medical School, Gwangju, Korea
| | - Seong Yeob Ryu
- Division of Gastroenterologic Surgery, Department of Surgery, Chonnam National University Medical School, Gwangju, Korea
| | - Kyung Hwa Lee
- Department of Pathology, Chonnam National University Medical School, Gwangju, Korea
| | - Jae Hyuk Lee
- Department of Pathology, Chonnam National University Medical School, Gwangju, Korea
| | - Dong Yi Kim
- Division of Gastroenterologic Surgery, Department of Surgery, Chonnam National University Medical School, Gwangju, Korea
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53
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Li L, Ma BBY, Chan ATC, Chan FKL, Murray P, Tao Q. Epstein-Barr Virus-Induced Epigenetic Pathogenesis of Viral-Associated Lymphoepithelioma-Like Carcinomas and Natural Killer/T-Cell Lymphomas. Pathogens 2018; 7:pathogens7030063. [PMID: 30022006 PMCID: PMC6161003 DOI: 10.3390/pathogens7030063] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 07/13/2018] [Accepted: 07/17/2018] [Indexed: 12/13/2022] Open
Abstract
Cancer genome studies of Epstein-Barr virus (EBV)-associated tumors, including lymphoepithelioma-like carcinomas (LELC) of nasopharyngeal (NPC), gastric (EBVaGC) and lung tissues, and natural killer (NK)/T-cell lymphoma (NKTCL), reveal a unique feature of genomic alterations with fewer gene mutations detected than other common cancers. It is known now that epigenetic alterations play a critical role in the pathogenesis of EBV-associated tumors. As an oncogenic virus, EBV establishes its latent and lytic infections in B-lymphoid and epithelial cells, utilizing hijacked cellular epigenetic machinery. EBV-encoded oncoproteins modulate cellular epigenetic machinery to reprogram viral and host epigenomes, especially in the early stage of infection, using host epigenetic regulators. The genome-wide epigenetic alterations further inactivate a series of tumor suppressor genes (TSG) and disrupt key cellular signaling pathways, contributing to EBV-associated cancer initiation and progression. Profiling of genome-wide CpG methylation changes (CpG methylome) have revealed a unique epigenotype of global high-grade methylation of TSGs in EBV-associated tumors. Here, we have summarized recent advances of epigenetic alterations in EBV-associated tumors (LELCs and NKTCL), highlighting the importance of epigenetic etiology in EBV-associated tumorigenesis. Epigenetic study of these EBV-associated tumors will discover valuable biomarkers for their early detection and prognosis prediction, and also develop effective epigenetic therapeutics for these cancers.
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Affiliation(s)
- Lili Li
- Cancer Epigenetics Laboratory, Department of Clinical Oncology, State Key Laboratory of Oncology in South China, Sir YK Pao Center for Cancer and Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China.
| | - Brigette B Y Ma
- Cancer Epigenetics Laboratory, Department of Clinical Oncology, State Key Laboratory of Oncology in South China, Sir YK Pao Center for Cancer and Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China.
| | - Anthony T C Chan
- Cancer Epigenetics Laboratory, Department of Clinical Oncology, State Key Laboratory of Oncology in South China, Sir YK Pao Center for Cancer and Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China.
| | - Francis K L Chan
- Institute of Digestive Disease and State Key Laboratory of Digestive Diseases, Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong, China.
| | - Paul Murray
- School of Cancer Sciences, University of Birmingham, Birmingham B15 2TT, UK.
| | - Qian Tao
- Cancer Epigenetics Laboratory, Department of Clinical Oncology, State Key Laboratory of Oncology in South China, Sir YK Pao Center for Cancer and Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China.
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Nishikawa J, Iizasa H, Yoshiyama H, Shimokuri K, Kobayashi Y, Sasaki S, Nakamura M, Yanai H, Sakai K, Suehiro Y, Yamasaki T, Sakaida I. Clinical Importance of Epstein⁻Barr Virus-Associated Gastric Cancer. Cancers (Basel) 2018; 10:cancers10060167. [PMID: 29843478 PMCID: PMC6024931 DOI: 10.3390/cancers10060167] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 05/13/2018] [Accepted: 05/24/2018] [Indexed: 12/17/2022] Open
Abstract
Epstein⁻Barr virus-associated gastric carcinoma (EBVaGC) is the most common malignancy caused by EBV infection. EBVaGC has definite histological characteristics similar to gastric carcinoma with lymphoid stroma. Clinically, EBVaGC has a significantly low frequency of lymph node metastasis compared with EBV-negative gastric cancer, resulting in a better prognosis. The Cancer Genome Atlas of gastric adenocarcinomas proposed a molecular classification divided into four molecular subtypes: (1) EBVaGC; (2) microsatellite instability; (3) chromosomal instability; and (4) genomically stable tumors. EBVaGC harbors a DNA methylation phenotype, PD-L1 and PD-L2 overexpression, and frequent alterations in the PIK3CA gene. We review clinical importance of EBVaGC and discuss novel therapeutic applications for EBVaGC.
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Affiliation(s)
- Jun Nishikawa
- Department of Laboratory Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi 755-8505, Japan.
| | - Hisashi Iizasa
- Department of Microbiology, Shimane University Faculty of Medicine, 89-1 Enyacho, Izumo, Shimane 693-8501, Japan.
| | - Hironori Yoshiyama
- Department of Microbiology, Shimane University Faculty of Medicine, 89-1 Enyacho, Izumo, Shimane 693-8501, Japan.
| | - Kanami Shimokuri
- Department of Laboratory Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi 755-8505, Japan.
| | - Yuki Kobayashi
- Department of Laboratory Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi 755-8505, Japan.
| | - Sho Sasaki
- Department of Gastroenterology and Hepatology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi 755-8505, Japan.
| | - Munetaka Nakamura
- Department of Gastroenterology and Hepatology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi 755-8505, Japan.
| | - Hideo Yanai
- Department of Clinical Research, National Hospital Organization Kanmon Medical Center, 1-1 Sotoura, Chofu, Shimonoseki, Yamaguchi 752-8510, Japan.
| | - Kohei Sakai
- Department of Oncology and Laboratory Medicine, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi 755-8505, Japan.
| | - Yutaka Suehiro
- Department of Oncology and Laboratory Medicine, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi 755-8505, Japan.
| | - Takahiro Yamasaki
- Department of Oncology and Laboratory Medicine, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi 755-8505, Japan.
| | - Isao Sakaida
- Department of Gastroenterology and Hepatology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi 755-8505, Japan.
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Kato M, Hayashi Y, Fukumoto K, Nagai K, Tsujii Y, Shinzaki S, Iijima H, Takehara T. Early gastric cancer with lymphoid stroma presenting as a subepithelial lesion diagnosed by endoscopic submucosal dissection. Clin J Gastroenterol 2018; 11:382-385. [PMID: 29637432 DOI: 10.1007/s12328-018-0855-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Accepted: 03/21/2018] [Indexed: 12/19/2022]
Abstract
A 53-year-old man underwent an esophagogastroduodenoscopy that showed a 20-mm subepithelial lesion in the middle gastric body. Endoscopic ultrasound revealed a hypoechoic mass located in the submucosa. Biopsy specimens revealed a benign gastric mucosa with severe lymphocytic infiltration in the submucosa. Malignant lymphoma or gastric cancer with lymphoid stroma was suspected. We performed endoscopic submucosal dissection for definitive diagnosis. Histological examination showed undifferentiated adenocarcinoma, which showed positive Epstein-Barr virus-encoded RNA in situ hybridization results, invading the submucosa mixed with dense lymphocytic infiltration. Thus, Epstein-Barr virus-positive gastric cancer with lymphoid stroma was diagnosed. Gastric cancer with lymphoid stroma is a rare subtype of gastric cancer, which is associated with Epstein-Barr virus infection; it sometimes appears as a subepithelial lesion, which makes it difficult to diagnose using standard biopsy. Endoscopic submucosal dissection was useful in obtaining a sufficient tissue for full histological assessment, including immunostaining.
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Affiliation(s)
- Minoru Kato
- Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka Suita, Osaka, 565-0871, Japan
| | - Yoshito Hayashi
- Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka Suita, Osaka, 565-0871, Japan
| | - Kenji Fukumoto
- Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka Suita, Osaka, 565-0871, Japan
| | - Kengo Nagai
- Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka Suita, Osaka, 565-0871, Japan
| | - Yoshiki Tsujii
- Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka Suita, Osaka, 565-0871, Japan
| | - Shinichiro Shinzaki
- Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka Suita, Osaka, 565-0871, Japan
| | - Hideki Iijima
- Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka Suita, Osaka, 565-0871, Japan
| | - Tetsuo Takehara
- Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka Suita, Osaka, 565-0871, Japan.
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56
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Na SJ, Park HL, O JH, Lee SY, Song KY, Kim SH. Correlation Between Infection Status of Epstein-Barr Virus and 18F-Fluorodeoxyglucose Uptake in Patients with Advanced Gastric Cancer. ACTA ACUST UNITED AC 2018; 31:749-753. [PMID: 28652452 DOI: 10.21873/invivo.11126] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 05/18/2017] [Accepted: 05/27/2017] [Indexed: 12/11/2022]
Abstract
BACKGROUND Epstein-Barr virus-associated gastric cancer (EBVaGC) is one of the four molecular subtypes of gastric cancer, as defined by the classification recently proposed by The Cancer Genome Atlas. We evaluated the correlation between EBV positivity and 18F-fluorodeoxyglucose (18F-FDG) uptake by positron emission tomography/computed tomography (PET/CT) in patients with gastric cancer. MATERIALS AND METHODS We retrospectively enrolled patients with gastric cancer who underwent pretreatment 18F-FDG PET/CT and subsequent surgical resection, and then were diagnosed with advanced gastric cancer (pathologic stage ≥T2 with any N stage). Maximum standardized uptake values (SUVmax) of gastric cancer were measured by pretreatment 18F-FDG PET/CT. EBV sequences were detected by in situ hybridization (ISH) techniques. We analyzed the correlation between EBV positivity, clinicopathologic features and metabolic activity of the primary tumor. RESULTS A total of 205 patients were included and 15 (7.3%) patients were identified as having EBV-positive gastric cancer. Age, gender, tumor location, and histological type showed no significant differences between EBV-positive and negative groups. EBV-positive cancer is significantly more frequent in the higher-metabolic-tumor group than in the lower one (p=0.032). The mean SUVmax of gastric cancers showed significant differences between EBV-positive and negative groups (9.9±4.2 vs. 7.0±4.8, p=0.026). CONCLUSION The infection status of EBV was significantly related to the 18F-FDG uptake of primary tumors in patients with advanced gastric cancer.
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Affiliation(s)
- Sae Jung Na
- Department of Radiology, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Hye Lim Park
- Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Joo Hyun O
- Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Sung Yong Lee
- Department of Radiology, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Kyo Young Song
- Department of Surgery, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Sung Hoon Kim
- Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
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57
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Hu SL, Kong XY, Cheng ZD, Sun YB, Shen G, Xu WP, Wu L, Xu XC, Jiang XD, Huang DB. Promoter methylation of p16, Runx3, DAPK and CHFR genes is frequent in gastric carcinoma. TUMORI JOURNAL 2018; 96:726-33. [DOI: 10.1177/030089161009600515] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Aims and background Transcriptional silencing induced by hypermethylation of CpG islands in the promoter regions of genes is believed to be an important mechanism of carcinogenesis in human cancers including gastric cancer. A number of reports on methylation of various genes in gastric cancer have been published, but most of these studies focused on cancer tissues or only a single gene. In this study, we determined the promoter hypermethylation status and mRNA expression of 4 genes: p16, Runx3, DAPK and CHFR. Methods Methylation-specific polymerase chain reaction (MSP) was used to determine the methylation status of p16, Runx3, DAPK and CHFR gene promoters in cancer and adjacent normal gastric mucosa specimens from 70 patients with gastric cancer, as well as normal gastric biopsy samples from 30 people without cancer serving as controls. In addition, the mRNA expression of p16, Runx3, DAPK and CHFR was investigated in 34 gastric cancer patients by RT-PCR. Bisulfite DNA sequence analysis was applied to check the positive samples detected by MSP. Results When carcinoma specimens were compared with adjacent normal gastric mucosa samples, a significant increase in promoter methylation of p16, Runx3, DAPK and CHFR was observed, while all 30 histologically normal gastric specimens were methylation free for all 4 genes. The methylation rate of the 4 genes increased from normal stomach tissue to tumor-adjacent gastric mucosa to gastric cancer tissue. Concurrent methylation in 2 or more genes was found in 22.9% of tumor-adjacent normal gastric mucosa and 75.7% of cancer tissues. No correlation was found between hypermethylation and other clinicopathological parameters such as sex, age, and tumor location. However, the frequency of DAPK and CHFR methylation in cancer tissues was significantly associated with the extent of differentiation and lymph node metastasis (P <0.05) and the frequency of Runx3 methylation was significantly associated with tumor size (P <0.05). Weak expression and loss of expression of the 4 genes was observed in cancer tissues and was significantly associated with promoter hypermethylation (P <0.05). Conclusions Promoter hypermethylation of p16, Runx3, DAPK and CHFR is frequent in gastric cancer. DAPK and CHFR promoter hypermethylation may be an important help in evaluating the differentiation grade and lymph node status of gastric cancer. Weak gene expression and loss of gene expression due to promoter hypermethylation may be a cancer-specific event. Free full text available at www.tumorionline.it
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Affiliation(s)
- Shi-Lian Hu
- Department of Geriatrics, Affiliated Anhui Province Hospital, Anhui Medical University, Hefei
| | - Xiang-Yong Kong
- Department of Geriatrics, Affiliated Anhui Province Hospital, Anhui Medical University, Hefei
| | - Zhao-Dong Cheng
- Department of Geriatrics, Affiliated Anhui Province Hospital, Anhui Medical University, Hefei
| | - Yu-Bei Sun
- Department of Oncology, Anhui Province Hospital, Hefei
| | - Gan Shen
- Cadre's Ward of Anhui PPC Hospital, Hefei
| | | | - Lei Wu
- Anhui Evidence-based Medicine Center, Hefei
| | - Xiu-Cai Xu
- Anhui Provincial Hospital Center Lab, Hefei, China
| | - Xiao-Dong Jiang
- Department of Geriatrics, Affiliated Anhui Province Hospital, Anhui Medical University, Hefei
| | - Da-Bing Huang
- Department of Geriatrics, Affiliated Anhui Province Hospital, Anhui Medical University, Hefei
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Alarcón A, Figueroa U, Espinoza B, Sandoval A, Carrasco-Aviño G, Aguayo FR, Corvalan AH. Epstein-Barr Virus–Associated Gastric Carcinoma: The Americas’ Perspective. Gastric Cancer 2017. [DOI: 10.5772/intechopen.70201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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DNA hypermethylation induced by Epstein-Barr virus in the development of Epstein-Barr virus-associated gastric carcinoma. Arch Pharm Res 2017; 40:894-905. [PMID: 28779374 DOI: 10.1007/s12272-017-0939-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 07/27/2017] [Indexed: 12/12/2022]
Abstract
Epstein-Barr virus (EBV)-associated gastric carcinoma (EBVaGC) is a recently recognized disease entity defined by the presence of EBV in gastric carcinoma cells. EBV infection causes major epigenetic alterations in the EBV genome and its cellular host genome, suggesting that EBV acts as a direct epigenetic driver for EBVaGC. One of the major epigenetic events in the viral and cellular genomes to control transcription is DNA hypo- or hyper-methylation. Particularly, local and global hypermethylation have been reported in EBVaGC. It is therefore important to understand the molecular mechanisms of DNA hypermethylation during EBVaGC carcinogenesis. To understand the functional roles of DNA methylation and suggest therapeutic target candidates for EBVaGC, we reviewed recent literature reporting DNA hypermethylation in EBVaGC. We summarized the identified candidate genes that are markedly hypermethylated in EBVaGC, which can potentially be targets for chemotherapies with demethylating agents.
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60
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Epstein-Barr virus: a master epigenetic manipulator. Curr Opin Virol 2017; 26:74-80. [PMID: 28780440 DOI: 10.1016/j.coviro.2017.07.017] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 07/10/2017] [Accepted: 07/18/2017] [Indexed: 12/29/2022]
Abstract
Like all herpesviruses, the ability of Epstein-Barr virus (EBV) to establish life-long persistent infections is related to a biphasic viral lifecycle that involves latency and reactivation/lytic replication. Memory B cells serve as the EBV latency compartment where silencing of viral gene expression allows maintenance of the viral genome, avoidance of immune surveillance, and life-long carriage. Upon viral reactivation, viral gene expression is induced for replication, progeny virion production, and viral spread. EBV uses the host epigenetic machinery to regulate its distinct viral gene expression states. However, epigenetic manipulation by EBV affects the host epigenome by reprogramming cells in ways that leave long-lasting, oncogenic phenotypes. Such virally-induced epigenetic alterations are evident in EBV-associated cancers.
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61
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Rhee YY, Kim KJ, Kang GH. CpG Island Methylator Phenotype-High Colorectal Cancers and Their Prognostic Implications and Relationships with the Serrated Neoplasia Pathway. Gut Liver 2017; 11:38-46. [PMID: 27885175 PMCID: PMC5221859 DOI: 10.5009/gnl15535] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 03/29/2016] [Indexed: 12/20/2022] Open
Abstract
The concept of a CpG island methylator phenotype (CIMP) was first introduced by Toyota and Issa to describe a subset of colorectal cancers (CRCs) with concurrent hypermethylation of multiple CpG island loci. The concept of CIMP as a molecular carcinogenesis mechanism was consolidated by the identification of the serrated neoplasia pathway, in which CIMP participates in the initiation and progression of serrated adenomas. Distinct clinicopathological and molecular features of CIMP-high (CIMP-H) CRCs have been characterized, including proximal colon location, older age of onset, female preponderance, and frequent associations of high-level microsatellite instability and BRAF mutations. CIMP-H CRCs arise in sessile or traditional serrated adenomas and thus tend to display the morphological characteristics of serrated adenomas, including epithelial serration, vesicular nuclei, and abundant cytoplasm. Both the frequent association of CIMP and poor prognosis and different responses of CRCs to adjuvant therapy depending on CIMP status indicate clinical implications. In this review, we present an overview of the literature documenting the relevant findings of CIMP-H CRCs and their relationships with the serrated neoplasia pathway.
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Affiliation(s)
- Ye-Young Rhee
- Department of Pathology, Seoul National University College of Medicine, Seoul, Korea
| | - Kyung-Ju Kim
- Department of Pathology, Seoul National University College of Medicine, Seoul, Korea
| | - Gyeong Hoon Kang
- Department of Pathology, Seoul National University College of Medicine, Seoul, Korea
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62
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Nishikawa J, Iizasa H, Yoshiyama H, Nakamura M, Saito M, Sasaki S, Shimokuri K, Yanagihara M, Sakai K, Suehiro Y, Yamasaki T, Sakaida I. The Role of Epigenetic Regulation in Epstein-Barr Virus-Associated Gastric Cancer. Int J Mol Sci 2017; 18:ijms18081606. [PMID: 28757548 PMCID: PMC5577998 DOI: 10.3390/ijms18081606] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 07/19/2017] [Accepted: 07/22/2017] [Indexed: 02/07/2023] Open
Abstract
The Epstein–Barr virus (EBV) is detected in about 10% of gastric carcinoma cases throughout the world. In EBV-associated gastric carcinoma (EBVaGC), all tumor cells harbor the clonal EBV genome. The expression of latent EBV genes is strictly regulated through the methylation of EBV DNA. The methylation of viral DNA regulates the type of EBV latency, and methylation of the tumor suppressor genes is a key abnormality in EBVaGC. The methylation frequencies of several tumor suppressor genes and cell adhesion molecules are significantly higher in EBVaGC than in control cases. EBV-derived microRNAs repress translation from viral and host mRNAs. EBV regulates the expression of non-coding RNA in gastric carcinoma. With regard to the clinical application of demethylating agents against EBVaGC, we investigated the effects of decitabine against the EBVaGC cell lines. Decitabine inhibited the cell growth of EBVaGC cells. The promoter regions of p73 and Runt-related transcription factor 3(RUNX3) were demethylated, and their expression was upregulated by the treatment. We review the role of epigenetic regulation in the development and maintenance of EBVaGC and discuss the therapeutic application of DNA demethylating agents for EBVaGC.
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MESH Headings
- Antimetabolites, Antineoplastic/pharmacology
- Antimetabolites, Antineoplastic/therapeutic use
- Azacitidine/analogs & derivatives
- Azacitidine/pharmacology
- Azacitidine/therapeutic use
- Core Binding Factor Alpha 3 Subunit/genetics
- CpG Islands/drug effects
- DNA Methylation/drug effects
- DNA, Viral/genetics
- Decitabine
- Epigenesis, Genetic/drug effects
- Epstein-Barr Virus Infections/drug therapy
- Epstein-Barr Virus Infections/genetics
- Epstein-Barr Virus Infections/virology
- Gene Expression Regulation, Neoplastic/drug effects
- Gene Expression Regulation, Viral/drug effects
- Herpesvirus 4, Human/drug effects
- Herpesvirus 4, Human/genetics
- Herpesvirus 4, Human/pathogenicity
- Humans
- MicroRNAs/genetics
- RNA, Viral/genetics
- Stomach Neoplasms/drug therapy
- Stomach Neoplasms/genetics
- Stomach Neoplasms/virology
- Tumor Protein p73/genetics
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Affiliation(s)
- Jun Nishikawa
- Department of Laboratory Science, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi 755-8505, Japan.
| | - Hisashi Iizasa
- Department of Microbiology, Shimane University Faculty of Medicine, 89-1 Enyacho, Izumo City, Shimane 693-8501, Japan.
| | - Hironori Yoshiyama
- Department of Microbiology, Shimane University Faculty of Medicine, 89-1 Enyacho, Izumo City, Shimane 693-8501, Japan.
| | - Munetaka Nakamura
- Department of Gastroenterology and Hepatology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi 755-8505, Japan.
| | - Mari Saito
- Department of Gastroenterology and Hepatology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi 755-8505, Japan.
| | - Sho Sasaki
- Department of Gastroenterology and Hepatology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi 755-8505, Japan.
| | - Kanami Shimokuri
- Department of Laboratory Science, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi 755-8505, Japan.
| | - Masashi Yanagihara
- Department of Laboratory Science, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi 755-8505, Japan.
| | - Kouhei Sakai
- Department of Oncology and Laboratory Medicine, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi 755-8505, Japan.
| | - Yutaka Suehiro
- Department of Oncology and Laboratory Medicine, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi 755-8505, Japan.
| | - Takahiro Yamasaki
- Department of Oncology and Laboratory Medicine, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi 755-8505, Japan.
| | - Isao Sakaida
- Department of Gastroenterology and Hepatology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi 755-8505, Japan.
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63
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Funata S, Matsusaka K, Yamanaka R, Yamamoto S, Okabe A, Fukuyo M, Aburatani H, Fukayama M, Kaneda A. Histone modification alteration coordinated with acquisition of promoter DNA methylation during Epstein-Barr virus infection. Oncotarget 2017; 8:55265-55279. [PMID: 28903418 PMCID: PMC5589657 DOI: 10.18632/oncotarget.19423] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 07/11/2017] [Indexed: 12/23/2022] Open
Abstract
Aberrant DNA hypermethylation is a major epigenetic mechanism to inactivate tumor suppressor genes in cancer. Epstein-Barr virus positive gastric cancer is the most frequently hypermethylated tumor among human malignancies. Herein, we performed comprehensive analysis of epigenomic alteration during EBV infection, by Infinium HumanMethylation 450K BeadChip for DNA methylation and ChIP-sequencing for histone modification alteration during EBV infection into gastric cancer cell line MKN7. Among 7,775 genes with increased DNA methylation in promoter regions, roughly half were “DNA methylation-sensitive” genes, which acquired DNA methylation in the whole promoter regions and thus were repressed. These included anti-oncogenic genes, e.g. CDKN2A. The other half were “DNA methylation-resistant” genes, where DNA methylation is acquired in the surrounding of promoter regions, but unmethylated status is protected in the vicinity of transcription start site. These genes thereby retained gene expression, and included DNA repair genes. Histone modification was altered dynamically and coordinately with DNA methylation alteration. DNA methylation-sensitive genes significantly correlated with loss of H3K27me3 pre-marks or decrease of active histone marks, H3K4me3 and H3K27ac. Apoptosis-related genes were significantly enriched in these epigenetically repressed genes. Gain of active histone marks significantly correlated with DNA methylation-resistant genes. Genes related to mitotic cell cycle and DNA repair were significantly enriched in these epigenetically activated genes. Our data show that orchestrated epigenetic alterations are important in gene regulation during EBV infection, and histone modification status in promoter regions significantly associated with acquisition of de novo DNA methylation or protection of unmethylated status at transcription start site.
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Affiliation(s)
- Sayaka Funata
- Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan.,Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Keisuke Matsusaka
- Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Ryota Yamanaka
- Genome Science Division, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Shogo Yamamoto
- Genome Science Division, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Atsushi Okabe
- Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Masaki Fukuyo
- Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Hiroyuki Aburatani
- Genome Science Division, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Masashi Fukayama
- Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Atsushi Kaneda
- Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan
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64
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Matsusaka K, Funata S, Fukuyo M, Seto Y, Aburatani H, Fukayama M, Kaneda A. Epstein-Barr virus infection induces genome-wide de novo DNA methylation in non-neoplastic gastric epithelial cells. J Pathol 2017; 242:391-399. [PMID: 28418084 DOI: 10.1002/path.4909] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 03/08/2017] [Accepted: 04/03/2017] [Indexed: 12/14/2022]
Abstract
Epstein-Barr virus (EBV)-positive gastric cancer (GC) shows a higher DNA methylation epigenotype. EBV infection can causally induce genome-wide aberrant DNA methylation, as previously demonstrated by in vitro infection experiments in the low-methylation GC cell line MKN7. However, whether EBV exerts DNA methylation remodelling properties in non-neoplastic epithelial cells remains unclear. Here we performed post-infection time-series DNA methylation analyses using the immortalized normal gastric epithelial cell line GES1. Genome-wide analysis using Illumina's Infinium 450 k BeadArray demonstrated global de novo DNA methylation from post-infection day 17, which was completed by 28 days in a manner similar to that observed in MKN7 cells. De novo methylation of all types of GC-specific methylation marker genes was observed, indicating that EBV infection is sufficient for gastric epithelial cells to acquire an EBV-positive GC epigenotype. Pyrosequencing demonstrated that methylation of the viral genome preceded that of the host cellular genome, suggesting the existence of well-ordered mechanisms that induce methylation. Spatiotemporal representation with differential models revealed dynamic alterations of DNA methylation in promoter regions, occurring from lower-CpG peripheral regions and extending to higher-CpG core regions. In summary, EBV infection exerted powerful pressure to induce global de novo DNA methylation in non-neoplastic cells within a month in a spatiotemporally well-ordered manner. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Affiliation(s)
- Keisuke Matsusaka
- Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Sayaka Funata
- Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan.,Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Masaki Fukuyo
- Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Yasuyuki Seto
- Department of Gastrointestinal Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hiroyuki Aburatani
- Genome Science Division, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Masashi Fukayama
- Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Atsushi Kaneda
- Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan
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65
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Sonohara F, Inokawa Y, Hayashi M, Kodera Y, Nomoto S. Epigenetic modulation associated with carcinogenesis and prognosis of human gastric cancer. Oncol Lett 2017; 13:3363-3368. [PMID: 28529571 DOI: 10.3892/ol.2017.5912] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 02/14/2017] [Indexed: 12/17/2022] Open
Abstract
Gastric cancer (GC) is a leading cause of cancer-related death, particularly in Asia. Epidemiological and other clinical studies have identified an association between a number of risk factors, including Helicobacter pylori, and GC. A number of studies have also examined genetic changes associated with the development and progression of GC. When considering the clinical significance of the expression of a specific gene, its epigenetic modulation should be considered. Epigenetic modulation appears to be a primary driver of changes in gastric tissue that promotes carcinogenesis and progression of GC and other neoplasms. The role of epigenetic modulation in GC carcinogenesis and progression has been widely studied in recent years. In the present review, recent results of epigenetic modulation associated with GC and their effects on clinical outcome are examined, with particular respect to DNA methylation, histone modulation and non-coding RNA. A number of studies indicate that epigenetic changes in the expression of specific genes critically affect their clinical significance and further study may reveal epigenetic changes as the basis for targeted molecular therapy or novel biomarkers that predict GC prognosis or extension of this often fatal disease.
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Affiliation(s)
- Fuminori Sonohara
- Department of Gastroenterological Surgery, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan.,Department of Surgery, Aichi-Gakuin University School of Dentistry, Nagoya, Aichi 464-8651, Japan
| | - Yoshikuni Inokawa
- Department of Gastroenterological Surgery, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan.,Department of Surgery, Aichi-Gakuin University School of Dentistry, Nagoya, Aichi 464-8651, Japan
| | - Masamichi Hayashi
- Department of Gastroenterological Surgery, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan
| | - Yasuhiro Kodera
- Department of Gastroenterological Surgery, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan
| | - Shuji Nomoto
- Department of Gastroenterological Surgery, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan.,Department of Surgery, Aichi-Gakuin University School of Dentistry, Nagoya, Aichi 464-8651, Japan
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66
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Singh S, Jha HC. Status of Epstein-Barr Virus Coinfection with Helicobacter pylori in Gastric Cancer. JOURNAL OF ONCOLOGY 2017; 2017:3456264. [PMID: 28421114 PMCID: PMC5379099 DOI: 10.1155/2017/3456264] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 02/14/2017] [Indexed: 12/14/2022]
Abstract
Epstein-Barr virus is a ubiquitous human herpesvirus whose primary infection causes mononucleosis, Burkett's lymphoma, nasopharyngeal carcinoma, autoimmune diseases, and gastric cancer (GC). The persistent infection causes malignancies in lymph and epithelial cells. Helicobacter pylori causes gastritis in human with chronic inflammation. This chronic inflammation is thought to be the cause of genomic instability. About 45%-word population have a probability of having both pathogens, namely, H. pylori and EBV. Approximately 180 per hundred thousand population is developing GC along with many gastric abnormalities. This makes GC the third leading cause of cancer-related death worldwide. Although lots of research are carried out individually for EBV and H. pylori, still there are very few reports available on coinfection of both pathogens. Recent studies suggested that EBV and H. pylori coinfection increases the occurrence of GC as well as the early age of GC detection comparing to individual infection. The aim of this review is to present status on coinfection of both pathogens and their association with GC.
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Affiliation(s)
- Shyam Singh
- Centre for Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, India
| | - Hem Chandra Jha
- Centre for Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, India
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67
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Mechanisms for the induction of gastric cancer by Helicobacter pylori infection: aberrant DNA methylation pathway. Gastric Cancer 2017; 20:8-15. [PMID: 27718135 DOI: 10.1007/s10120-016-0650-0] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 09/23/2016] [Indexed: 02/07/2023]
Abstract
Multiple pathogenic mechanisms by which Helicobacter pylori infection induces gastric cancer have been established in the last two decades. In particular, aberrant DNA methylation is induced in multiple driver genes, which inactivates them. Methylation profiles in gastric cancer are associated with specific subtypes, such as microsatellite instability. Recent comprehensive and integrated analyses showed that many cancer-related pathways are more frequently altered by aberrant DNA methylation than by mutations. Aberrant DNA methylation can even be present in noncancerous gastric mucosae, producing an "epigenetic field for cancerization." Mechanistically, H. pylori-induced chronic inflammation, but not H. pylori itself, plays a direct role in the induction of aberrant DNA methylation. The expression of three inflammation-related genes, Il1b, Nos2, and Tnf, is highly associated with the induction of aberrant DNA methylation. Importantly, the degree of accumulated aberrant DNA methylation is strongly correlated with gastric cancer risk. A recent multicenter prospective cohort study demonstrated the utility of epigenetic cancer risk diagnosis for metachronous gastric cancer. Suppression of aberrant DNA methylation by a demethylating agent was shown to inhibit gastric cancer development in an animal model. Induction of aberrant DNA methylation is the major pathway by which H. pylori infection induces gastric cancer, and this can be utilized for translational opportunities.
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68
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Singh S, Guruprasad L. N6-Adenosine DNA Methyltransferase from H. pylori 98-10 Strain in Complex with DNA and AdoMet: Structural Insights from in Silico Studies. J Phys Chem B 2017; 121:365-378. [PMID: 28054779 DOI: 10.1021/acs.jpcb.6b08433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Helicobacter pylori is a primitive Gram-negative bacterium that resides in the acidic environment of the human gastrointestinal tract, and some strains of this bacterium cause gastric ulcers and cancer. DNA methyltransferases (MTases) are promising drug targets for the treatment of cancer and other diseases that are also caused by epigenetic alternations of the genome. The N6-adenine-specific DNA MTase from H. pylori (M. Hpy N6mA) catalyzes the transfer of a methyl group from the cofactor S-adenosyl-l-methionine (AdoMet) to the flipped adenine of the substrate DNA. In this work, we report the sequence analyses, three-dimensional structure modeling, and molecular dynamics simulations of M. Hpy N6mA, when complexed with AdoMet as well as DNA. We analyzed the protein-DNA interactions prominently established by the flipped cytosine and the interactions between protein cofactors in the active site. The comparable orientation of AdoMet in both systems confirms that AdoMet is in a catalytically competent orientation in the bimolecular system that is retained upon DNA binding in the termolecular system of M. Hpy N6mA. In both systems, AdoMet is stabilized in the binding pocket by hydrogen bonding (Thr84, Glu99, Asp122, and Phe123) as well as van der Waals (Ile100, Phe160, Arg104, and Cys76) interactions. We propose that the contacts made by flipped adenine DA6 with Asn138 (N6 and N1 atom of DA6) and Pro139 (N6) and π-stacking interactions with Phe141 and Phe219 play an important role in the methylation mechanism at the N6 position in our N6mA model. Specific recognition of DNA is mediated by residues 143-155, 183-189, 212-220, 280-293, and 308-325. These findings are further supported by alanine scanning mutagenesis studies. The conserved residues in distantly related sequences of the small domain are important in DNA binding. Results reported here elucidate the sequence, structure, and binding features necessary for the recognition between cofactor AdoMet and substrate DNA by the vital epigenetic enzyme, M. Hpy N6mA.
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Affiliation(s)
- Swati Singh
- School of Chemistry, University of Hyderabad , Hyderabad 500046, India
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69
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Kim DH, Chang MS, Yoon CJ, Middeldorp JM, Martinez OM, Byeon SJ, Rha SY, Kim SH, Kim YS, Woo JH. Epstein-Barr virus BARF1-induced NFκB/miR-146a/SMAD4 alterations in stomach cancer cells. Oncotarget 2016; 7:82213-82227. [PMID: 27438138 PMCID: PMC5347686 DOI: 10.18632/oncotarget.10511] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 05/12/2016] [Indexed: 12/21/2022] Open
Abstract
Epstein-Barr virus (EBV)-encoded BamHI-A rightward frame 1 (BARF1) is a putative viral oncogene in EBV-infected stomach cancer. The aim of the present study was to investigate BARF1-induced cellular protein and microRNA alterations. In this study, BARF1-expressing stomach cancer cells showed a high rate of proliferation, high levels of NFκB, and miR-146a upregulation, which was reversed by NFκB knockdown. During BARF1-induced NFκB upregulation, hCSF1 receptor level was unchanged. Knockdown of BARF1 in the naturally EBV-infected YCCEL1 stomach cancer cells suppressed cell proliferation, and downregulated NFκB and miR-146a. SMAD4 was identified as a miR-146a target and was downregulated in BARF1-expressing cells, whereas SMAD4 expression was restored by anti-miR-146a. Knockdown of BARF1 in YCCEL1 cells upregulated SMAD4, and this effect was reversed by miR-146a overexpression. Transfection of BARF1-expressing cells with pCEP4-SMAD4 abolished the cell proliferating effect of BARF1. In stomach cancer tissues, miR-146a was expressed at higher levels, and more frequent NFκB nuclear positivity immunohistochemically, but not of SMAD4 nuclear loss was found in the EBV-positive group compared with the EBV-negative group. In conclusion, EBV-encoded BARF1 promotes cell proliferation in stomach cancer by upregulating NFκB and miR-146a and downregulating SMAD4, thereby contributing to EBV-induced stomach cancer progression.
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Affiliation(s)
- Dong Ha Kim
- Asan Institute for Life Sciences, Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Mee Soo Chang
- Department of Pathology, Seoul National University Boramae Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Chan Jin Yoon
- Asan Institute for Life Sciences, Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Jaap M. Middeldorp
- Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands
| | - Olivia M. Martinez
- Department of Surgery/Division of Abdominal Transplantation, Stanford University School of Medicine, Stanford, CA, USA
| | - Sun-ju Byeon
- Department of Pathology, Seoul National University Boramae Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Sun Young Rha
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Sung Han Kim
- Asan Institute for Life Sciences, Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Yang Soo Kim
- Asan Institute for Life Sciences, Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Jun Hee Woo
- Asan Institute for Life Sciences, Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
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70
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Bhat AA, Wani HA, Waza AA, Malik RA, Masood A, Jeelani S, Kadla S, Majid S. Diminished expression of MGMT & RASSF1A genes in gastric cancer in ethnic population of Kashmir. J Gastrointest Oncol 2016; 7:989-995. [PMID: 28078123 DOI: 10.21037/jgo.2016.06.07] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Cancer initiation and progression are accompanied by profound changes in DNA. DNA methylation that was the first epigenetic alterations identified in cancer. DNA hypermethylation at promoter sites is closely associated with down regulation of protein and as major participant in the development and progression of series of human tumors. Therefore we hypothesized that promoter hypermethylation of RASSF1A & MGMT gene could influence susceptibility to gastric cancer (GC) as well, and we conducted this study to test the hypothesis in Kashmiri population. METHODS A hospital based case-control study; including 200 GC cases and 200 matched controls from patients who went surgical resection. Promoter hypermethylation was determined by Methylation Specific Polymerase chain reaction. The expression of MGMT & RASSF1A protein was examined by Western blotting technique. RESULTS Frequency of promoter region hypermethylation of MGMT gene were 46.5% in cases and 5.5% in controls (P<0.05) while as in case of RASSF1A frequency was 44% in cases and 4.5% in controls (P<0.05). Further, frequency of hypermethylation of both genes was found predominant in males, aged and advanced pathological stage subjects. Loss of MGMT expression was found in 46.5% cases (P<0.05) while as loss of RASSF1A expression was found in 40.5% cases (P<0.05). In both genes a positive correlation was observed between promoter CpG island hypermethylation and down regulation of respective proteins. CONCLUSIONS These findings indicate that promoter hypermethylation at CpG island may be responsible for reduction of expression at protein level which may be an initial event in carcinogenesis and the progression of GC.
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Affiliation(s)
- Arif Akbar Bhat
- Department of Biochemistry, Government Medical College Srinagar (Research Centre University of Kashmir), Srinagar, India
| | - Hilal Ahmad Wani
- Multidisciplinary Research Unit, Government Medical College Srinagar, Srinagar, India
| | - Ajaz Ahmad Waza
- Department of Biotechnology, University of Kashmir, Hazratbal Srinagar, India
| | | | - Akbar Masood
- Department of Biochemistry, University of Kashmir, Hazratbal Srinagar, Srinagar, India
| | | | | | - Sabhiya Majid
- Department of Biochemistry, Government Medical College Srinagar (Research Centre University of Kashmir), Srinagar, India
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71
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Luo S, Chen J, Mo X. The association of PTEN hypermethylation and breast cancer: a meta-analysis. Onco Targets Ther 2016; 9:5643-50. [PMID: 27672335 PMCID: PMC5026181 DOI: 10.2147/ott.s111684] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
OBJECTIVE Phosphatase and tensin homolog (PTEN) deleted on chromosome 10, as a tumor suppressor gene, is crucial for the development of both familial and sporadic breast cancer (BC). The aim of this study was to perform a meta-analysis to evaluate the clinicopathological significance of PTEN promoter hypermethylation in BC. METHODS A comprehensive literature search was made in PubMed, Embase, Google Scholar, Chinese database (China National Knowledge Infrastructure [CNKI]), and Web of Science. The analysis of pooled data was performed with Review Manager 5.2. The fixed-effects or random-effects models were used to evaluate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS The meta-analysis included eight studies and a total of 923 patients. The frequency of PTEN promoter hypermethylation was significantly increased in ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) compared to normal breast tissues (OR =22.53, P=0.0002 and OR =22.86, P<0.00001, respectively). However, the frequency of PTEN promoter hypermethylation was similar between IDC and DCIS. Additionally, PTEN methylation was not significantly correlated to estrogen receptor (ER) or human epidermal growth factor type 2 (HER-2) status in patients with BC. CONCLUSION PTEN promoter hypermethylation is significantly associated with the risk of DCIS and IDC, suggesting PTEN promoter hypermethylation is a valuable biomarker for diagnosis of BC.
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Affiliation(s)
- Shanshan Luo
- Department of Gastrointestinal Surgery, Tumor Hospital of Guangxi Medical University, Nanning, Guangxi, People's Republic of China
| | - Jiansi Chen
- Department of Gastrointestinal Surgery, Tumor Hospital of Guangxi Medical University, Nanning, Guangxi, People's Republic of China
| | - Xianwei Mo
- Department of Gastrointestinal Surgery, Tumor Hospital of Guangxi Medical University, Nanning, Guangxi, People's Republic of China
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72
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Huh CW, Jung DH, Kim H, Kim H, Youn YH, Park H, Kim JW, Choi SH, Noh SH, Kim JH. Clinicopathologic features of gastric carcinoma with lymphoid stroma in early gastric cancer. J Surg Oncol 2016; 114:769-772. [PMID: 27450278 DOI: 10.1002/jso.24385] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Accepted: 07/10/2016] [Indexed: 12/16/2022]
Abstract
BACKGROUND AND OBJECTIVES Gastric carcinoma with lymphoid stroma (GCLS) is a rare variant of gastric cancer. The aims of this study were to investigate the clinicopathologic features of GCLS in early gastric cancer (EGC). METHODS Analysis included 3,385 patients who were diagnosed with EGC after surgery between 2005 and 2012. This study compared GCLS with non-GCLS patients in terms of clinicopathological features including lymph node metastasis (LNM). RESULTS Forty-one (1.2%) patients were diagnosed as GCLS among those with EGC. When GCLS and non-GCLS patients were compared, the GCLS group showed a greater predominance among males, greater tendency towards proximal location, a more elevated gross appearance, and deeper submucosal invasion. In particular, more than 90% of GCLS cases showed deep submucosal invasion. The LNM rate was significantly lower in GCLS than non-GCLS cases after adjustment for depth of invasion. Among the GCLS group, there was no LNM in the cases with lesions confined to the mucosa or submucosal invasive lesions with tumor size ≤10 mm. CONCLUSIONS In EGC, GCLS showed deeper submucosal invasion and a lower LNM rate compared with non-GCLS. Thus, clinical considerations of GCLS may be helpful to decide on a specific cancer treatment. J. Surg. Oncol. 2016;114:769-772. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Cheal Wung Huh
- Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Da Hyun Jung
- Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Hyunki Kim
- Department of Pathology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Hoguen Kim
- Department of Pathology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Young Hoon Youn
- Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Hyojin Park
- Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Jong Won Kim
- Department of Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Seung Ho Choi
- Department of Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Sung Hoon Noh
- Department of Surgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Jie-Hyun Kim
- Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
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73
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Cha HJ, Kim K, Kim M, Choi H, Kim YM, Suh JH. Concurrent Gastric Adenocarcinoma of Fundic Gland Type and Carcinoma with Lymphoid Stroma: A Rare Case Report. Case Rep Gastroenterol 2016; 10:292-301. [PMID: 27462199 PMCID: PMC4939682 DOI: 10.1159/000444277] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 01/26/2016] [Indexed: 12/30/2022] Open
Abstract
Both gastric adenocarcinoma of fundic gland type (ADC-FG) and carcinoma with lymphoid stroma (lymphoepithelioma-like carcinoma, LELC) are relatively rare. Epstein-Barr virus (EBV) has been implicated in the pathogenesis of LELC. However, the pathogenesis of ADC-FG, as well as the role of EBV in the carcinogenesis of LELC, remain unclear and under debate. The current study presents a case of concurrent ADC-FG and LELC in the stomach in a 69-year-old man. Total gastrectomy was performed, and two separate masses were identified. Upon histological and immunohistochemical examination, the mass located in the lower body was determined to be LELC and the mass in the upper body was diagnosed as ADC-FG. The lesions were characterized by different mucin phenotypes and EBV in situ results. In the lower-body mass, EBV in situ hybridization expression was diffusely strongly positive, but MUC2, MUC5AC, MUC6, and CD10 were all negative. On the other hand, in the upper-body mass, the results were positive for MUC6 but negative for MUC2, MUC5AC, CD10, and EBV by in situ hybridization. The remaining gastric tissue was unremarkable, and perigastric lymph node metastases were absent. Seven months after the gastrectomy, a postoperative computed tomography scan revealed no recurrence or metastasis.
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Affiliation(s)
- Hee Jeong Cha
- Department of Pathology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Republic of Korea
| | - Kyungbin Kim
- Department of Pathology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Republic of Korea
| | - Misung Kim
- Department of Pathology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Republic of Korea
| | - Hyejeong Choi
- Department of Pathology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Republic of Korea
| | - Young Min Kim
- Department of Pathology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Republic of Korea
| | - Jae Hee Suh
- Department of Pathology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Republic of Korea
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van Zuylen WJ, Rawlinson WD, Ford CE. The Wnt pathway: a key network in cell signalling dysregulated by viruses. Rev Med Virol 2016; 26:340-55. [PMID: 27273590 DOI: 10.1002/rmv.1892] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 05/04/2016] [Accepted: 05/12/2016] [Indexed: 12/19/2022]
Abstract
Viruses are obligate parasites dependent on host cells for survival. Viral infection of a cell activates a panel of pattern recognition receptors that mediate antiviral host responses to inhibit viral replication and dissemination. Viruses have evolved mechanisms to evade and subvert this antiviral host response, including encoding proteins that hijack, mimic and/or manipulate cellular processes such as the cell cycle, DNA damage repair, cellular metabolism and the host immune response. Currently, there is an increasing interest whether viral modulation of these cellular processes, including the cell cycle, contributes to cancer development. One cellular pathway related to cell cycle signalling is the Wnt pathway. This review focuses on the modulation of this pathway by human viruses, known to cause (or associated with) cancer development. The main mechanisms where viruses interact with the Wnt pathway appear to be through (i) epigenetic modification of Wnt genes; (ii) cellular or viral miRNAs targeting Wnt genes; (iii) altering specific Wnt pathway members, often leading to (iv) nuclear translocation of β-catenin and activation of Wnt signalling. Given that diverse viruses affect this signalling pathway, modulating Wnt signalling could be a generalised critical process for the initiation or maintenance of viral pathogenesis, with resultant dysregulation contributing to virus-induced cancers. Further study of this virus-host interaction may identify options for targeted therapy against Wnt signalling molecules as a means to reduce virus-induced pathogenesis and the downstream consequences of infection. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Wendy J van Zuylen
- Serology and Virology Division, SEALS Microbiology, Prince of Wales Hospital, Sydney, Australia.,School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - William D Rawlinson
- Serology and Virology Division, SEALS Microbiology, Prince of Wales Hospital, Sydney, Australia.,School of Medical Sciences, University of New South Wales, Sydney, Australia.,School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Caroline E Ford
- Metastasis Research Group, School of Women's and Children's Health, University of New South Wales, Sydney, Australia.
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75
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Cho J, Kang MS, Kim KM. Epstein-Barr Virus-Associated Gastric Carcinoma and Specific Features of the Accompanying Immune Response. J Gastric Cancer 2016; 16:1-7. [PMID: 27104020 PMCID: PMC4834615 DOI: 10.5230/jgc.2016.16.1.1] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 03/14/2016] [Indexed: 12/13/2022] Open
Abstract
Epstein-Barr virus-associated gastric carcinoma (EBVaGC) is one of the four subtypes of gastric carcinoma (GC), as defined by the novel classification recently proposed by The Cancer Genome Atlas. EBVaGC has several clinicopathological features such as longer survival and higher frequency of lymphoepithelioma-like carcinoma (LELC) and carcinoma with Crohn's disease-like lymphoid reaction that distinguish it from EBV-negative GC. The intensity and pattern of host cellular immune response in GC have been found to significantly correlate with the prognosis of patients with GC, suggesting that immune reaction and tumor microenvironment have critical roles in the progression of GC, and in particular, EBVaGC. Here, we reviewed the cellular and molecular mechanisms underlying prominent immune reactions in patients with EBVaGC. In EBVaGC, deregulation of the expression of immune response-related genes promotes marked intra- or peritumoral immune cell infiltration. The expression of programmed death receptor-ligand 1 is known to be increased in EBVaGC, and therefore, it has been proposed as a favorable prognostic factor for patients with EBVaGC, albeit some data supporting this claim are controversial. Overall, the underlying mechanisms and clinical significance of the host cellular immune response in patients with EBVaGC have not been thoroughly elucidated. Therefore, further research is necessary to better understand the role of tumor microenvironment in EBVaGC.
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Affiliation(s)
- Junhun Cho
- Department of Pathology & Translational Genomics, Samsung Medical Center, Seoul, Korea
| | - Myung-Soo Kang
- Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Kyoung-Mee Kim
- Department of Pathology & Translational Genomics, Samsung Medical Center, Seoul, Korea
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76
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Bae JM, Kim EH. Epstein-Barr Virus and Gastric Cancer Risk: A Meta-analysis With Meta-regression of Case-control Studies. J Prev Med Public Health 2016; 49:97-107. [PMID: 27055546 PMCID: PMC4829373 DOI: 10.3961/jpmph.15.068] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 02/01/2016] [Indexed: 12/13/2022] Open
Abstract
Objectives: Research on how the risk of gastric cancer increases with Epstein-Barr virus (EBV) infection is lacking. In a systematic review that investigated studies published until September 2014, the authors did not calculate the summary odds ratio (SOR) due to heterogeneity across studies. Therefore, we include here additional studies published until October 2015 and conduct a meta-analysis with meta-regression that controls for the heterogeneity among studies. Methods: Using the studies selected in the previously published systematic review, we formulated lists of references, cited articles, and related articles provided by PubMed. From the lists, only case-control studies that detected EBV in tissue samples were selected. In order to control for the heterogeneity among studies, subgroup analysis and meta-regression were performed. Results: In the 33 case-control results with adjacent non-cancer tissue, the total number of test samples in the case and control groups was 5280 and 4962, respectively. In the 14 case-control results with normal tissue, the total number of test samples in case and control groups was 1393 and 945, respectively. Upon meta-regression, the type of control tissue was found to be a statistically significant variable with regard to heterogeneity. When the control tissue was normal tissue of healthy individuals, the SOR was 3.41 (95% CI, 1.78 to 6.51; I-squared, 65.5%). Conclusions: The results of the present study support the argument that EBV infection increases the risk of gastric cancer. In the future, age-matched and sex-matched case-control studies should be conducted.
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Affiliation(s)
- Jong-Myon Bae
- Department of Preventive Medicine, Jeju National University School of Medicine, Jeju, Korea
| | - Eun Hee Kim
- Department of Preventive Medicine, Jeju National University School of Medicine, Jeju, Korea
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Role of Viral miRNAs and Epigenetic Modifications in Epstein-Barr Virus-Associated Gastric Carcinogenesis. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:6021934. [PMID: 26977250 PMCID: PMC4764750 DOI: 10.1155/2016/6021934] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 01/12/2016] [Accepted: 01/14/2016] [Indexed: 01/26/2023]
Abstract
MicroRNAs are short (21–23 nucleotides), noncoding RNAs that typically silence posttranscriptional gene expression through interaction with target messenger RNAs. Currently, miRNAs have been identified in almost all studied multicellular eukaryotes in the plant and animal kingdoms. Additionally, recent studies reported that miRNAs can also be encoded by certain single-cell eukaryotes and by viruses. The vast majority of viral miRNAs are encoded by the herpesviruses family. These DNA viruses including Epstein-Barr virus encode their own miRNAs and/or manipulate the expression of cellular miRNAs to facilitate respective infection cycles. Modulation of the control pathways of miRNAs expression is often involved in the promotion of tumorigenesis through a specific cascade of transduction signals. Notably, latent infection with Epstein-Barr virus is considered liable of causing several types of malignancies, including the majority of gastric carcinoma cases detected worldwide. In this review, we describe the role of the Epstein-Barr virus in gastric carcinogenesis, summarizing the functions of the Epstein-Barr virus-encoded viral proteins and related epigenetic alterations as well as the roles of Epstein-Barr virus-encoded and virally modulated cellular miRNAs.
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Abstract
Viral and bacterial infections are involved in the development of human cancers, such as liver, nasopharyngeal, cervical, head and neck, and gastric cancers. Aberrant DNA methylation is frequently present in these cancers, and some of the aberrantly methylated genes are causally involved in cancer development and progression. Notably, aberrant DNA methylation can be present even in non-cancerous or precancerous tissues, and its levels correlate with the risk of cancer development, producing a so-called 'epigenetic field for cancerization'. Mechanistically, most viral or bacterial infections induce DNA methylation indirectly via chronic inflammation, but recent studies have indicated that some viruses have direct effects on the epigenetic machinery of host cells. From a translational viewpoint, a recent multicenter prospective cohort study demonstrated that assessment of the extent of alterations in DNA methylation in non-cancerous tissues can be used to predict cancer risk. Furthermore, suppression of aberrant DNA methylation was shown to be a useful strategy for cancer prevention in an animal model. Here, we review the involvement of aberrant DNA methylation in various types of infection-associated cancers, along with individual induction mechanisms, and we discuss the application of these findings for cancer prevention, diagnosis, and therapy.
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Affiliation(s)
- Naoko Hattori
- Division of Epigenomics, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045, Japan
| | - Toshikazu Ushijima
- Division of Epigenomics, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045, Japan.
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79
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Lim B, Kim JH, Kim M, Kim SY. Genomic and epigenomic heterogeneity in molecular subtypes of gastric cancer. World J Gastroenterol 2016; 22:1190-1201. [PMID: 26811657 PMCID: PMC4716030 DOI: 10.3748/wjg.v22.i3.1190] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 09/08/2015] [Accepted: 10/13/2015] [Indexed: 02/06/2023] Open
Abstract
Gastric cancer is a complex disease that is affected by multiple genetic and environmental factors. For the precise diagnosis and effective treatment of gastric cancer, the heterogeneity of the disease must be simplified; one way to achieve this is by dividing the disease into subgroups. Toward this effort, recent advances in high-throughput sequencing technology have revealed four molecular subtypes of gastric cancer, which are classified as Epstein-Barr virus-positive, microsatellite instability, genomically stable, and chromosomal instability subtypes. We anticipate that this molecular subtyping will help to extend our knowledge for basic research purposes and will be valuable for clinical use. Here, we review the genomic and epigenomic heterogeneity of the four molecular subtypes of gastric cancer. We also describe a mutational meta-analysis and a reanalysis of DNA methylation that were performed using previously reported gastric cancer datasets.
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80
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Epigenetic Alterations in Epstein-Barr Virus-Associated Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 879:39-69. [DOI: 10.1007/978-3-319-24738-0_3] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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81
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Gefroh-Grimes HA, Gidal BE. Antiepileptic drugs in patients with malignant brain tumor: beyond seizures and pharmacokinetics. Acta Neurol Scand 2016; 133:4-16. [PMID: 25996875 DOI: 10.1111/ane.12437] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/21/2015] [Indexed: 02/06/2023]
Abstract
In neurological malignancies, antiepileptic drugs (AEDs) are frequently used to control the seizure activity that accompanies the disorder. There is a growing body of evidence on the importance of AED selection for reasons other than pharmacokinetics (PK) properties. Epigenetic modifications may occur in glioblastomas, such as changes in gene methylation and histone acetylation states. Secondary mechanisms of AED drug action which impact these epigenetic modifications could play a significant role in patient survival outcomes. Both valproic acid (VPA) and carbamazepine have histone deacetylase (HDAC) inhibitory activities, and levetiracetam and VPA reduce the activity of O6-methylguanine-DNA methyltransferase (MGMT), a DNA-repair molecule implicated in resistance to alkylating agents used for chemotherapy. The use of AEDs for purposes other than seizure prophylaxis and their selection based on non-PK properties present a potential paradigm shift in the field of neuro-oncology.
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Affiliation(s)
- H. A. Gefroh-Grimes
- Pharmacy Practice Division; School of Pharmacy; University of Wisconsin-Madison; Madison WI USA
| | - B. E. Gidal
- School of Pharmacy & Department of Neurology; University of Wisconsin-Madison; Madison WI USA
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82
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Host Gene Expression Is Regulated by Two Types of Noncoding RNAs Transcribed from the Epstein-Barr Virus BamHI A Rightward Transcript Region. J Virol 2015; 89:11256-68. [PMID: 26311882 DOI: 10.1128/jvi.01492-15] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 08/21/2015] [Indexed: 12/22/2022] Open
Abstract
UNLABELLED In Epstein-Barr virus-infected epithelial cancers, the alternatively spliced BamHI A rightward transcripts (BARTs) are the most abundant viral polyadenylated RNA. The BART introns form the template for the production of 44 microRNAs (miRNAs), and the spliced and polyadenylated exons form nuclear non-protein-coding RNAs. Analysis of host cell transcription by RNA-seq during latency in AGS cells identified a large number of reproducibly changed genes. Genes that were downregulated were enriched for BART miRNA targets. Bioinformatics analysis predicted activation of the myc pathway and downregulation of XBP1 as likely mediators of the host transcriptional changes. Effects on XBP1 activity were not detected in these cells; however, myc activation was confirmed through use of a myc-responsive luciferase reporter. To identify potential regulatory properties of the spliced, polyadenylated BART RNAs, a full-length cDNA clone of one of the BART isoforms was obtained and expressed in the Epstein-Barr virus (EBV)-negative AGS cells. The BART cDNA transcript remained primarily nuclear yet induced considerable and consistent changes in cellular transcription, as profiled by RNA-seq. These transcriptional changes significantly overlapped the transcriptional changes induced during latent EBV infection of these same cells, where the BARTs are exclusively nuclear and do not encode proteins. These data suggest that the nuclear BART RNAs are functional long noncoding RNAs (lncRNAs). The abundant expression of multiple forms of noncoding RNAs that contribute to growth regulation without expression of immunogenic proteins would be an important mechanism for viral oncogenesis in the presence of a functional immune system. IMPORTANCE Infection with Epstein-Barr virus (EBV) is nearly ubiquitous in the human population; however, it does contribute to the formation of multiple types of cancer. In immunocompromised patients, EBV causes multiple types of lymphomas by expressing viral oncogenes that promote growth and survival of infected B lymphocytes. EBV-positive gastric carcinoma does not require immune suppression, and the viral oncoproteins that are frequent targets for an immunological response are not expressed. This study demonstrates using transcriptional analysis that the expression of various classes of viral non-protein-coding RNAs likely contribute to the considerable changes in the host transcriptional profile in the AGS gastric cancer cell line. This is the first report to show that the highly expressed polyadenylated BamHI A rightward transcripts (BART) viral transcript in gastric carcinoma is in fact a functional viral long noncoding RNA. These studies provide new insight into how EBV can promote transformation in the absence of viral protein expression.
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83
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Ben Dhiab M, Ziadi S, Louhichi T, Ben Gacem R, Ksiaa F, Trimeche M. Investigation of miR9-1, miR9-2 and miR9-3 Methylation in Hodgkin Lymphoma. Pathobiology 2015; 82:195-202. [PMID: 26337487 DOI: 10.1159/000432402] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 05/15/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND miR9 is an important tumor suppressor microRNA regulated by DNA methylation in various types of cancers. METHODS We analyzed the methylation status of the 3 members of the miR9 family in 58 cases of Hodgkin lymphoma (HL) in comparison to 15 reactive lymph nodes. We also assessed the relationships between miR9 methylation and Epstein-Barr virus (EBV) infection and several clinicopathological parameters. RESULTS We found that 84.5% of HL cases had a methylation in at least 1 of the 3 loci of miR9, whereas none of the nontumoral samples was methylated. The highest rate of methylation was found in miR9-2 (5q14.3) in 74.1% of the HL cases, followed by miR9-3 (15q26.1) in 56.9% and miR9-1 (1q22) in only 8.6% (p < 0.001). The promoter methylation of miR9-3 was more frequent in patients older than 15 years than in children (p = 0.02) and among women rather than men (p = 0.02). However, no significant correlation was found between miR9 methylation and EBV infection. CONCLUSION These results indicate that miR9 methylation, especially miR9-2, is a frequent event in HL and may be involved in HL pathogenesis, irrespective of EBV infection.
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Affiliation(s)
- Myriam Ben Dhiab
- Department of Pathology, Farhat Hached University Hospital, Sousse, Tunisia
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84
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Abe H, Kaneda A, Fukayama M. Epstein-Barr Virus-Associated Gastric Carcinoma: Use of Host Cell Machineries and Somatic Gene Mutations. Pathobiology 2015; 82:212-23. [DOI: 10.1159/000434683] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 05/27/2015] [Indexed: 11/19/2022] Open
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85
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Molecular classification of gastric adenocarcinoma: translating new insights from the cancer genome atlas research network. Curr Treat Options Oncol 2015; 16:17. [PMID: 25813036 DOI: 10.1007/s11864-015-0331-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Gastric cancer is a heterogenous cancer, which may be classified into several distinct subtypes based on pathology and epidemiology, each with different initiating pathological processes and each possibly having different tumor biology. A classification of gastric cancer should be important to select patients who can benefit from the targeted therapies or to precisely predict prognosis. The Cancer Genome Atlas (TCGA) study collaborated with previous reports regarding subtyping gastric cancer but also proposed a refined classification based on molecular characteristics. The addition of the new molecular classification strategy to a current classical subtyping may be a promising option, particularly stratification by Epstein-Barr virus (EBV) and microsatellite instability (MSI) statuses. According to TCGA study, EBV gastric cancer patients may benefit the programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) antibodies or phosphoinositide 3-kinase (PI3K) inhibitors which are now being developed. The discoveries of predictive biomarkers should improve patient care and individualized medicine in the management since the targeted therapies may have the potential to change the landscape of gastric cancer treatment, moreover leading to both better understanding of the heterogeneity and better outcomes. Patient enrichment by predictive biomarkers for new treatment strategies will be critical to improve clinical outcomes. Additionally, liquid biopsies will be able to enable us to monitor in real-time molecular escape mechanism, resulting in better treatment strategies.
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86
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Choi E, Byeon SJ, Kim SH, Lee HJ, Kwon HJ, Ahn H, Kim DH, Chang MS. Implication of Leptin-Signaling Proteins and Epstein-Barr Virus in Gastric Carcinomas. PLoS One 2015; 10:e0130839. [PMID: 26147886 PMCID: PMC4493019 DOI: 10.1371/journal.pone.0130839] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Accepted: 05/26/2015] [Indexed: 02/07/2023] Open
Abstract
We investigated the clinicopathological implications of leptin-signaling proteins and Epstein-Barr virus (EBV)-infection status in gastric carcinomas. Immunohistochemistry for leptin signalling-related proteins (leptin, leptin-receptor, pSTAT3, ERK, pAkt, mTOR and HIF-1 alpha), and in situ hybridization for EBV-encoded small RNAs was performed in 343 cases of gastric carcinomas. The siRNA against leptin-receptor was transfected into three stomach cancer cell lines, and western blot for caspase 3 was performed. The TNM stage was a prognostic factor in all 343 patients, and was negatively correlated with expression of leptin, pSTAT3, ERK, pAkt, mTOR and HIF-1 alpha (P < 0.05). Leptin-receptor expression was correlated with poor survival in 207 patients of the advanced gastric cancer (AGC) subgroup, 139 of the Lauren diffuse group, and in 160 patients with lymph node metastasis (P < 0.05, respectively). Additionally, in stomach cancer cells, cleaved caspase 3 level increased by leptin-receptor inhibition, that is, apoptosis increased. Interestingly, EBV-positive AGC (n = 29) tended to show better survival of patients than EBV-negative AGC (n = 178) (P = 0.06). pAkt expression was related with a good survival of 32 patients (9%) in the EBV-positive subgroup, but was not an independent prognostic factor. Among, leptin signaling-related proteins, expressions of leptin-receptor and mTOR were different between EBV-positive subgroup and EBV-negative subgroup (P < 0.05, respectively). In conclusion, leptin-signaling proteins and EBV status show different significance on patient survival, according to subsets of gastric carcinomas. The leptin-receptor may predict poor patient prognosis in the AGC, Lauren diffuse and lymph node metastasis subgroups, while EBV-positive status can show a good prognosis in the AGC. Each leptin signaling-related protein may be differently involved in carcinogenesis of EBV-negative and EBV-positive subsets.
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Affiliation(s)
- Euno Choi
- Department of Pathology, Seoul National University Boramae Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Sun-ju Byeon
- Department of Surgery, Seoul National University Boramae Hospital, Seoul, Korea
| | - Soo Hee Kim
- Department of Pathology, Seoul National University Boramae Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Hyun Ju Lee
- Department of Pathology, Seoul National University Boramae Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Hyeong Ju Kwon
- Department of Pathology, Seoul National University Boramae Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - HyeSeong Ahn
- Department of Surgery, Seoul National University Boramae Hospital, Seoul, Korea
| | - Dong Ha Kim
- Department of Pathology, Seoul National University Boramae Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Mee Soo Chang
- Department of Pathology, Seoul National University Boramae Hospital, Seoul National University College of Medicine, Seoul, Korea
- * E-mail:
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87
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Navari M, Etebari M, De Falco G, Ambrosio MR, Gibellini D, Leoncini L, Piccaluga PP. The presence of Epstein-Barr virus significantly impacts the transcriptional profile in immunodeficiency-associated Burkitt lymphoma. Front Microbiol 2015; 6:556. [PMID: 26113842 PMCID: PMC4462103 DOI: 10.3389/fmicb.2015.00556] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 05/20/2015] [Indexed: 11/20/2022] Open
Abstract
Burkitt lymphoma (BL) is an aggressive neoplasm derived from mature, antigen-experienced B-lymphocytes. Three clinical/epidemiological variants have been recognized, named sporadic, endemic and immunodeficiency-associated BL (ID-BL). Although they are listed within a unique entity in the current WHO Classification, recent evidence indicated genetic and transcriptional differences among the three sub-groups. Further, the presence of latently persisting Epstein-Barr virus (EBV) has been associated with specific features in endemic and sporadic cases. In this study, we explored for the first time whether EBV infection could be related with a specific molecular profile in immunodeficiency-associated cases. We studied 30 BL cases, including nine occurring in HIV-positive patients (5 EBV-positive and 4 EBV-negative) by gene and microRNA (miRNA) expression profiling. We found that ID-BL presented with different profiles based on EBV presence. Specifically, 252 genes were differentially expressed, some of them being involved in intracellular signaling and apoptosis regulation. Furthermore, 28 miRNAs including both EBV-encoded (N = 18) and cellular (N = 10) ones were differentially regulated. Of note, genes previously demonstrated to be targeted by such miRNA were consistently found among differentially expressed genes, indicating the relevant contribution of miRNA to the molecular profile of the examined cases. Grippingly, 17 out of the 252 differentially expressed genes turned out to be potentially targeted by both cellular and EBV-encoded miRNA, suggesting a complex interaction and not excluding a potential synergism. In conclusion, we documented transcriptional differences based on the presence of EBV in ID-BL, and suggested a complex interaction between cellular and viral molecules in the determination of the global molecular profile of the tumor.
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Affiliation(s)
- Mohsen Navari
- Hematopathology Section, Department of Experimental, Diagnostic, and Specialty Medicine, S. Orsola-Malpighi Hospital, Bologna University School of Medicine Bologna, Italy ; Department of Basic Sciences, Torbat Heydariyeh University of Medical Sciences Torbat Heydariyeh, Iran
| | - Maryam Etebari
- Hematopathology Section, Department of Experimental, Diagnostic, and Specialty Medicine, S. Orsola-Malpighi Hospital, Bologna University School of Medicine Bologna, Italy
| | - Giulia De Falco
- School of Biological and Chemical Sciences, Queen Mary University of London London, UK
| | - Maria R Ambrosio
- Department of Medical Biotechnology, University of Siena Siena, Italy
| | - Davide Gibellini
- Microbiology and Virology Unit, Department of Pathology and Diagnostic, University of Verona Verona, Italy
| | - Lorenzo Leoncini
- Department of Medical Biotechnology, University of Siena Siena, Italy
| | - Pier Paolo Piccaluga
- Hematopathology Section, Department of Experimental, Diagnostic, and Specialty Medicine, S. Orsola-Malpighi Hospital, Bologna University School of Medicine Bologna, Italy
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88
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Ramadan RA, Zaki MA, Awad AM, El-Ghalid LA. Aberrant methylation of promoter region of SPINT2/HAI-2 gene: an epigenetic mechanism in hepatitis C virus-induced hepatocarcinogenesis. Genet Test Mol Biomarkers 2015; 19:399-404. [PMID: 26030814 DOI: 10.1089/gtmb.2015.0025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Epigenetic changes, including DNA methylation, are recognized as one of the potential mechanisms involved in the pathogenesis of hepatocellular carcinoma (HCC). AIMS We aimed to study the methylation status of the promoter region of Serine peptidase inhibitor/hepatocyte growth factor activator inhibitor type 2 (SPINT2/HAI-2) tumor suppressor gene in hepatitis C virus (HCV)-infected cirrhotic patients with and without HCC. METHODS Methyl-specific polymerase (MSP) chain reaction was used to detect CpG methylation of the SPINT2/HAI-2 gene promoter in peripheral blood samples of 30 HCC and 50 HCV cirrhotic cases, along with 50 normal individuals. RESULTS Aberrant methylation showed a stepwise increase in frequency from 40% in controls to 64% in HCV cirrhotics, and 66.7% in HCC cases with a significant difference among the studied groups (p=0.021). The combined patient groups had an increased risk of aberrant methylation with an odds ratio (OR) of 2.52, a 95% confidence interval (CI) of 1.23-5.14, and a p-value of 0.05 that became more statistically significant after adjusting for age (OR=2.4, 95% CI=1.13-5.26, p-value=0.012), thereby confirming the association between HCV infection and aberrant methylation. CONCLUSIONS Our study highlights the role of promoter hypermethylation in the multistep process of hepatocarcinogenesis, providing potential clinical applications in diagnosis and prognosis.
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Affiliation(s)
- Ragaa A Ramadan
- 1 Department of Chemical Pathology, Alexandria University , Alexandria, Egypt
| | - Moyassar A Zaki
- 1 Department of Chemical Pathology, Alexandria University , Alexandria, Egypt
| | - Ahmed M Awad
- 1 Department of Chemical Pathology, Alexandria University , Alexandria, Egypt
| | - Lamiaa A El-Ghalid
- 2 Department of Internal Medicine, Medical Research Institute, Alexandria University , Alexandria, Egypt
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89
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Abstract
Epstein-Barr virus (EBV) infection is found in a subset of gastric cancers. Previous reviews have exclusively focused on EBV-encoded small RNA (EBER) positivity in gastric cancer tissues, but a comprehensive evaluation of other type of studies is lacking.We searched the PubMed database up to September, 2014, and performed a systematic review.We considered studies comparing EBV nucleic acids positivity in gastric cancer tissue with positivity in either adjacent non-tumor tissue of cancer patients or non-tumor mucosa from healthy individuals, patients with benign gastric diseases, or deceased individuals. We also considered studies comparing EBV antibodies in serum from cancer patients and healthy controls.Selection of potentially eligible studies and data extraction were performed by 2 independent reviewers. Due to the heterogeneity of studies, we did not perform formal meta-analysis.Forty-seven studies (8069 cases and 1840 controls) were identified. EBER positivity determined by in situ hybridization (ISH) was significantly higher in cancer tissues (range 5.0%-17.9%) than in adjacent mucosa from the same patients or biopsies from all control groups (almost 0%). High EBV nuclear antigen-1 (EBNA-1) positivity by PCR was found in gastric cancer tissues, but most were not validated by ISH or adjusted for inflammatory severity and lymphocyte infiltration. Only 4 studies tested for EBV antibodies, with large variation in the seropositivities of different antibodies in both cases and controls, and did not find an association between EBV seropositivity and gastric cancer.In summary, tissue-based ISH methods strongly suggest an association between EBV infection and gastric cancer, but PCR method alone is invalid to confirm such association. Very limited evidence from serological studies and the lack of novel antibodies warrant further investigations to identify potential risk factors of EBV for gastric cancer.
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Affiliation(s)
- Xin-Zu Chen
- From the Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany (X-ZC, HC, FAC, HB); Department of Gastrointestinal Surgery (X-ZC, J-KH); Laboratory of Gastric Cancer, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China (X-ZC, J-KH); and German Cancer Consortium (DKTK), Heidelberg, Germany (HB)
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90
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Lochhead P, Chan AT, Nishihara R, Fuchs CS, Beck AH, Giovannucci E, Ogino S. Etiologic field effect: reappraisal of the field effect concept in cancer predisposition and progression. Mod Pathol 2015; 28:14-29. [PMID: 24925058 PMCID: PMC4265316 DOI: 10.1038/modpathol.2014.81] [Citation(s) in RCA: 145] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 02/12/2014] [Accepted: 04/02/2014] [Indexed: 02/07/2023]
Abstract
The term 'field effect' (also known as field defect, field cancerization, or field carcinogenesis) has been used to describe a field of cellular and molecular alteration, which predisposes to the development of neoplasms within that territory. We explore an expanded, integrative concept, 'etiologic field effect', which asserts that various etiologic factors (the exposome including dietary, lifestyle, environmental, microbial, hormonal, and genetic factors) and their interactions (the interactome) contribute to a tissue microenvironmental milieu that constitutes a 'field of susceptibility' to neoplasia initiation, evolution, and progression. Importantly, etiological fields predate the acquisition of molecular aberrations commonly considered to indicate presence of filed effect. Inspired by molecular pathological epidemiology (MPE) research, which examines the influence of etiologic factors on cellular and molecular alterations during disease course, an etiologically focused approach to field effect can: (1) broaden the horizons of our inquiry into cancer susceptibility and progression at molecular, cellular, and environmental levels, during all stages of tumor evolution; (2) embrace host-environment-tumor interactions (including gene-environment interactions) occurring in the tumor microenvironment; and, (3) help explain intriguing observations, such as shared molecular features between bilateral primary breast carcinomas, and between synchronous colorectal cancers, where similar molecular changes are absent from intervening normal colon. MPE research has identified a number of endogenous and environmental exposures which can influence not only molecular signatures in the genome, epigenome, transcriptome, proteome, metabolome and interactome, but also host immunity and tumor behavior. We anticipate that future technological advances will allow the development of in vivo biosensors capable of detecting and quantifying 'etiologic field effect' as abnormal network pathology patterns of cellular and microenvironmental responses to endogenous and exogenous exposures. Through an 'etiologic field effect' paradigm, and holistic systems pathology (systems biology) approaches to cancer biology, we can improve personalized prevention and treatment strategies for precision medicine.
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Affiliation(s)
- Paul Lochhead
- Gastrointestinal Research Group, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
| | - Andrew T Chan
- 1] Division of Gastroenterology, Massachusetts General Hospital, Boston, MA, USA [2] Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Reiko Nishihara
- 1] Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA [2] Department of Nutrition, Harvard School of Public Health, Boston, MA, USA
| | - Charles S Fuchs
- 1] Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA [2] Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Andrew H Beck
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Edward Giovannucci
- 1] Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA [2] Department of Nutrition, Harvard School of Public Health, Boston, MA, USA [3] Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA
| | - Shuji Ogino
- 1] Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA [2] Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA [3] Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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91
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Park S, Choi MG, Kim KM, Kim HS, Jung SH, Lee JH, Noh JH, Sohn TS, Bae JM, Kim S. Lymphoepithelioma-like carcinoma: a distinct type of gastric cancer. J Surg Res 2014; 194:458-463. [PMID: 25592274 DOI: 10.1016/j.jss.2014.12.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 11/28/2014] [Accepted: 12/03/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND Lymphoepithelioma-like carcinoma (LELC) is a rare type of gastric carcinoma and has histologic features of intense lymphocytic infiltration. In this study, we attempted to analyze the clinicopathologic characteristics and survival outcome of patients with LELC compared with those with non-lymphoepithelioma-like carcinoma (NLELC). METHODS We studied 4282 patients who underwent gastrectomies to treat gastric cancer at the Department of Surgery of the Samsung Medical Center in Seoul, between January 2008 and December 2010. The clinicopathologic features and clinical outcomes of patients with LELC (n = 46) were compared with those with NLELC (n = 4236). In situ hybridization for Epstein-Barr virus (EBV) positivity was performed on the tissue of patients with LELC (n = 46) and NLELC (n = 1247). RESULTS The patients with LELC are male predominant and had more upper locations, more indeterminate Lauren classifications, lower T stages, less lymphatic invasion, and more positive EBV in situ hybridization compared with those of the NLELC group (80.4% versus 6.5%). Age, histologic type, Lauren type, the location of the tumor, the depth of the invasion, lymph node metastasis, and venous invasion were independent prognostic factors; however, the LELC type itself was not predictive of outcome. The 5-y survival rate of the LELC group (97.7%) was better than that of the NLELC group (89.4%); however, this difference was not statistically significant (P = 0.127). CONCLUSIONS The results of our study suggest that LELC is a less advanced disease than NLELC in terms of depth of invasion and lymphatic invasion at diagnosis. However, our study does not examine LELC as an independent prognostic factor of gastric cancer. Further studies are needed to explore its associations with EBV and a distinct pathway of carcinogenesis from NLELC.
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Affiliation(s)
- Sungmin Park
- Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Min-Gew Choi
- Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
| | - Kyoung-Mee Kim
- Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Hye Seung Kim
- Biostatistics and Clinical Epidemiology Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Sin-Ho Jung
- Biostatistics and Clinical Epidemiology Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jun Ho Lee
- Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jae Hyung Noh
- Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Tae Sung Sohn
- Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jae Moon Bae
- Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Sung Kim
- Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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92
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Li L, Zhang Y, Fan Y, Sun K, Su X, Du Z, Tsao SW, Loh TKS, Sun H, Chan ATC, Zeng YX, Chan WY, Chan FK, Tao Q. Characterization of the nasopharyngeal carcinoma methylome identifies aberrant disruption of key signaling pathways and methylated tumor suppressor genes. Epigenomics 2014; 7:155-73. [PMID: 25479246 DOI: 10.2217/epi.14.79] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
AIMS Nasopharyngeal carcinoma (NPC) is a common tumor consistently associated with Epstein-Barr virus infection and prevalent in South China, including Hong Kong, and southeast Asia. Current genomic sequencing studies found only rare mutations in NPC, indicating its critical epigenetic etiology, while no epigenome exists for NPC as yet. MATERIALS & METHODS We profiled the methylomes of NPC cell lines and primary tumors, together with normal nasopharyngeal epithelial cells, using methylated DNA immunoprecipitation (MeDIP). RESULTS We observed extensive, genome-wide methylation of cellular genes. Epigenetic disruption of Wnt, MAPK, TGF-β and Hedgehog signaling pathways was detected. Methylation of Wnt signaling regulators (SFRP1, 2, 4 and 5, DACT2, DKK2 and DKK3) was frequently detected in tumor and nasal swab samples from NPC patients. Functional studies showed that these genes are bona fide tumor-suppressor genes for NPC. CONCLUSION The NPC methylome shows a special high-degree CpG methylation epigenotype, similar to the Epstein-Barr virus-infected gastric cancer, indicating a critical epigenetic etiology for NPC pathogenesis.
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Affiliation(s)
- Lili Li
- Cancer Epigenetics Laboratory, Department of Clinical Oncology, State Key Laboratory of Oncology in South China, Sir YK Pao Center for Cancer, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong
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93
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Nishikawa J, Yoshiyama H, Iizasa H, Kanehiro Y, Nakamura M, Nishimura J, Saito M, Okamoto T, Sakai K, Suehiro Y, Yamasaki T, Oga A, Yanai H, Sakaida I. Epstein-barr virus in gastric carcinoma. Cancers (Basel) 2014; 6:2259-74. [PMID: 25386788 PMCID: PMC4276965 DOI: 10.3390/cancers6042259] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 09/27/2014] [Accepted: 10/28/2014] [Indexed: 12/28/2022] Open
Abstract
The Epstein-Barr virus (EBV) is detected in about 10% of gastric carcinoma cases throughout the world. In EBV-associated gastric carcinoma, all tumor cells harbor the clonal EBV genome. Gastric carcinoma associated with EBV has distinct clinicopathological features, occurs predominately in men and in younger-aged individuals, and presents a generally diffuse histological type. Most cases of EBV-associated gastric carcinoma exhibit a histology rich in lymphocyte infiltration. The immunological reactiveness in the host may represent a relatively preferable prognosis in EBV-positive cases. This fact highlights the important role of EBV in the development of EBV-associated gastric carcinoma. We have clearly proved direct infection of human gastric epithelialcells by EBV. The infection was achieved by using a recombinant EBV. Promotion of growth by EBV infection was observed in the cells. Considerable data suggest that EBV may directly contribute to the development of EBV-associated GC. This tumor-promoting effect seems to involve multiple mechanisms, because EBV affects several host proteins and pathways that normally promote apoptosis and regulate cell proliferation.
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Affiliation(s)
- Jun Nishikawa
- Department of Gastroenterology and Hepatology, Yamaguchi University Graduate School of Medicine, Minami-Kogushi 1-1-1, Ube, Yamaguchi 755-8505, Japan.
| | - Hironori Yoshiyama
- Department of Microbiology, Shimane University Faculty of Medicine, 89-1 Enyacho, Izumo City, Shimane 693-8501, Japan.
| | - Hisashi Iizasa
- Department of Microbiology, Shimane University Faculty of Medicine, 89-1 Enyacho, Izumo City, Shimane 693-8501, Japan.
| | - Yuichi Kanehiro
- Department of Microbiology, Shimane University Faculty of Medicine, 89-1 Enyacho, Izumo City, Shimane 693-8501, Japan.
| | - Munetaka Nakamura
- Department of Gastroenterology and Hepatology, Yamaguchi University Graduate School of Medicine, Minami-Kogushi 1-1-1, Ube, Yamaguchi 755-8505, Japan.
| | - Junichi Nishimura
- Department of Gastroenterology and Hepatology, Yamaguchi University Graduate School of Medicine, Minami-Kogushi 1-1-1, Ube, Yamaguchi 755-8505, Japan.
| | - Mari Saito
- Department of Gastroenterology and Hepatology, Yamaguchi University Graduate School of Medicine, Minami-Kogushi 1-1-1, Ube, Yamaguchi 755-8505, Japan.
| | - Takeshi Okamoto
- Department of Gastroenterology and Hepatology, Yamaguchi University Graduate School of Medicine, Minami-Kogushi 1-1-1, Ube, Yamaguchi 755-8505, Japan.
| | - Kouhei Sakai
- Department of Oncology and Laboratory Medicine, Yamaguchi University Graduate School of Medicine, Minami-Kogushi 1-1-1, Ube, Yamaguchi 755-8505, Japan.
| | - Yutaka Suehiro
- Department of Oncology and Laboratory Medicine, Yamaguchi University Graduate School of Medicine, Minami-Kogushi 1-1-1, Ube, Yamaguchi 755-8505, Japan.
| | - Takahiro Yamasaki
- Department of Oncology and Laboratory Medicine, Yamaguchi University Graduate School of Medicine, Minami-Kogushi 1-1-1, Ube, Yamaguchi 755-8505, Japan.
| | - Atsunori Oga
- Department of Pathology, Yamaguchi University Graduate School of Medicine, Minami-Kogushi 1-1-1, Ube, Yamaguchi 755-8505, Japan.
| | - Hideo Yanai
- Department of Clinical Research, National Hospital Organization Kanmon Medical Center, 1-1 Sotoura, Chofu, Shimonoseki, Yamaguchi 752-8510, Japan.
| | - Isao Sakaida
- Department of Gastroenterology and Hepatology, Yamaguchi University Graduate School of Medicine, Minami-Kogushi 1-1-1, Ube, Yamaguchi 755-8505, Japan.
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94
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Li L, Zhang Y, Guo BB, Chan FKL, Tao Q. Oncogenic induction of cellular high CpG methylation by Epstein-Barr virus in malignant epithelial cells. CHINESE JOURNAL OF CANCER 2014; 33:604-8. [PMID: 25322866 PMCID: PMC4308656 DOI: 10.5732/cjc.014.10191] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Epstein-Barr virus (EBV) is a well-known human herpesvirus associated with virtually all nasopharyngeal carcinoma (NPC) and ∼10% of gastric cancer (GC) worldwide. Increasing evidence shows that acquired genetic and epigenetic alterations lead to the initiation and progression of NPC and GC. However, even deep whole exome sequencing studies showed a relatively low frequency of gene mutations in NPC and EBV-associated GC (EBVaGC), suggesting a predominant role of epigenetic abnormities, especially promoter CpG methylation, in the pathogenesis of NPC and EBVaGC. High frequencies of promoter methylation of tumor suppressor genes (TSGs) have been frequently reported in NPC and EBVaGC, with several EBV-induced methylated TSGs identified. Further characterization of the epigenomes (genome-wide CpG methylation profile—methylome) of NPC and EBVaGC shows that these EBV-associated tumors display a unique high CpG methylation epigenotype with more extensive gene methylation accumulation, indicating that EBV acts as a direct epigenetic driver for these cancers. Mechanistically, oncogenic modulation of cellular CpG methylation machinery, such as DNA methyltransferases (DNMTs), by EBV-encoded viral proteins accounts for the EBV-induced high CpG methylation epigenotype in NPC and EBVaGC. Thus, uncovering the EBV-associated unique epigenotype of NPC and EBVaGC would provide new insight into the molecular pathogenesis of these unique EBV-associated tumors and further help to develop pharmacologic strategies targeting cellular methylation machinery in these malignancies.
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Affiliation(s)
- Lili Li
- Cancer Epigenetics Laboratory, Department of Clinical Oncology, State Key Laboratory of Oncology in South China, Sir YK Pao Center for Cancer and Li Ka Shing Institute of Health Sciences, Hong Kong SAR, China.
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95
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Shi J, Qu YP, Hou P. Pathogenetic mechanisms in gastric cancer. World J Gastroenterol 2014; 20:13804-13819. [PMID: 25320518 PMCID: PMC4194564 DOI: 10.3748/wjg.v20.i38.13804] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 01/15/2014] [Accepted: 05/29/2014] [Indexed: 02/06/2023] Open
Abstract
Gastric cancer (GC) is a major public health issue as the fourth most common cancer and the second leading cause of cancer-related death. Recent advances have improved our understanding of its molecular pathogenesis, as best exemplified by elucidating the fundamental role of several major signaling pathways and related molecular derangements. Central to these mechanisms are the genetic and epigenetic alterations in these signaling pathways, such as gene mutations, copy number variants, aberrant gene methylation and histone modification, nucleosome positioning, and microRNAs. Some of these genetic/epigenetic alterations represent effective diagnostic and prognostic biomarkers and therapeutic targets for GC. This information has now opened unprecedented opportunities for better understanding of the molecular mechanisms of gastric carcinogenesis and the development of novel therapeutic strategies for this cancer. The pathogenetic mechanisms of GC are the focus of this review.
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96
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Nakamura J, Tanaka T, Kitajima Y, Noshiro H, Miyazaki K. Methylation-mediated gene silencing as biomarkers of gastric cancer: A review. World J Gastroenterol 2014; 20:11991-12006. [PMID: 25232236 PMCID: PMC4161787 DOI: 10.3748/wjg.v20.i34.11991] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2013] [Revised: 01/29/2014] [Accepted: 04/09/2014] [Indexed: 02/06/2023] Open
Abstract
Despite a decline in the overall incidence of gastric cancer (GC), the disease remains the second most common cause of cancer-related death worldwide and is thus a significant global health problem. The best means of improving the survival of GC patients is to screen for and treat early lesions. However, GC is often diagnosed at an advanced stage and is associated with a poor prognosis. Current diagnostic and therapeutic strategies have not been successful in decreasing the global burden of the disease; therefore, the identification of reliable biomarkers for an early diagnosis, predictive markers of recurrence and survival and markers of drug sensitivity and/or resistance is urgently needed. The initiation and progression of GC depends not only on genetic alterations but also epigenetic changes, such as DNA methylation and histone modification. Aberrant DNA methylation is the most well-defined epigenetic change in human cancers and is associated with inappropriate gene silencing. Therefore, an increasing number of genes methylated at the promoter region have been targeted as possible biomarkers for different purposes, including early detection, classification, the assessment of the tumor prognosis, the development of therapeutic strategies and patient follow-up. This review article summarizes the current understanding and recent evidence regarding DNA methylation markers in GC with a focus on the clinical potential of these markers.
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97
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Kaneda A, Matsusaka K, Sakai E, Funata S. DNA methylation accumulation and its predetermination of future cancer phenotypes. J Biochem 2014; 156:63-72. [PMID: 24962701 DOI: 10.1093/jb/mvu038] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Aberant DNA methylation is a common epigenomic alteration in carcinogenesis. Comprehensive analyses of DNA methylation have stratified gastrointestinal cancer into several subgroups according to specific DNA methylation accumulation. In gastric cancer, Helicobacter pylori infection is a cause of methylation accumulation in apparently normal mucosa. Epstein-Barr virus infection is another methylation inducer that causes more genome-wide methylation, resulting in the formation of unique epigenotype with extensive methylation. In colorectal carcinogenesis, accumulation of high levels of methylation in combination with BRAF mutation is characteristic of the serrated pathway, but not of the adenoma-carcinoma sequence through conventional adenoma. In a de novo pathway, laterally spreading tumours generate intermediate- and low-methylation epigenotypes, accompanied by different genetic features and different macroscopic morphologies. These methylation epigenotypes, with specific genomic aberrations, are mostly completed by the adenoma stage, and additional molecular aberration, such as TP53 mutation, is suggested to lead to cancer development with the corresponding epigenotype. Accumulation of DNA methylation and formation of the epigenotype is suggested to occur during the early stages of carcinogenesis and predetermines the future cancer type.
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Affiliation(s)
- Atsushi Kaneda
- Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan; CREST, Japan Science and Technology Agency, Saitama 332-0012, Japan; Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan; and Department of Gastroenterology, Yokohama City University School of Medicine, Yokohama 236-0004, JapanDepartment of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan; CREST, Japan Science and Technology Agency, Saitama 332-0012, Japan; Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan; and Department of Gastroenterology, Yokohama City University School of Medicine, Yokohama 236-0004, Japan
| | - Keisuke Matsusaka
- Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan; CREST, Japan Science and Technology Agency, Saitama 332-0012, Japan; Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan; and Department of Gastroenterology, Yokohama City University School of Medicine, Yokohama 236-0004, JapanDepartment of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan; CREST, Japan Science and Technology Agency, Saitama 332-0012, Japan; Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan; and Department of Gastroenterology, Yokohama City University School of Medicine, Yokohama 236-0004, Japan
| | - Eiji Sakai
- Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan; CREST, Japan Science and Technology Agency, Saitama 332-0012, Japan; Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan; and Department of Gastroenterology, Yokohama City University School of Medicine, Yokohama 236-0004, JapanDepartment of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan; CREST, Japan Science and Technology Agency, Saitama 332-0012, Japan; Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan; and Department of Gastroenterology, Yokohama City University School of Medicine, Yokohama 236-0004, Japan
| | - Sayaka Funata
- Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan; CREST, Japan Science and Technology Agency, Saitama 332-0012, Japan; Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan; and Department of Gastroenterology, Yokohama City University School of Medicine, Yokohama 236-0004, JapanDepartment of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan; CREST, Japan Science and Technology Agency, Saitama 332-0012, Japan; Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan; and Department of Gastroenterology, Yokohama City University School of Medicine, Yokohama 236-0004, Japan
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98
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Yau TO, Tang CM, Yu J. Epigenetic dysregulation in Epstein-Barr virus-associated gastric carcinoma: Disease and treatments. World J Gastroenterol 2014; 20:6448-6456. [PMID: 24914366 PMCID: PMC4047330 DOI: 10.3748/wjg.v20.i21.6448] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 03/13/2014] [Indexed: 02/06/2023] Open
Abstract
Epstein-Barr virus (EBV)-associated gastric carcinoma (EBVaGC) comprises nearly 10% of gastric carcinoma cases worldwide. Recently, it was recognised to have unique clinicopathologic characteristics, including male predominance, lower rates of lymph node involvement, and better prognosis. EBVaGC is further characterised by abnormal hypermethylation of tumour suppressor gene promoter regions, causing down-regulation of their expression. In the present review, we critically discuss the role of EBV in gastric carcinogenesis, summarising the role of viral proteins and microRNAs with respect to aberrant methylation in EBVaGC. Given the role of epigenetic dysregulation in tumourigenesis, epigenetic modifiers may represent a novel therapeutic strategy.
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Polymicrobial infection and bacterium-mediated epigenetic modification of DNA tumor viruses contribute to pathogenesis. mBio 2014; 5:e01015-14. [PMID: 24781742 PMCID: PMC4010825 DOI: 10.1128/mbio.01015-14] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The human body plays host to a wide variety of microbes, commensal and pathogenic. In addition to interacting with their host, different microbes, such as bacteria and viruses, interact with each other, sometimes in ways that exacerbate disease. In particular, gene expression of a number of viruses, including Kaposi’s sarcoma-associated herpesvirus (KSHV), Epstein-Barr virus (EBV), and human immunodeficiency virus (HIV), is known to be regulated by epigenetic modifications induced by bacteria. These viruses establish latent infection in their host cells and can be reactivated by bacterial products. Viral reactivation has been suggested to contribute to periodontal disease and AIDS. In addition, bacterium-virus interactions may play a role in cancers, such as Kaposi’s sarcoma, gastric cancer, and head and neck cancer. It is important to consider the effects of coexisting bacterial infections when studying viral diseases in vivo.
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100
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Matsusaka K, Funata S, Fukayama M, Kaneda A. DNA methylation in gastric cancer, related to Helicobacter pylori and Epstein-Barr virus. World J Gastroenterol 2014; 20:3916-3926. [PMID: 24744581 PMCID: PMC3983447 DOI: 10.3748/wjg.v20.i14.3916] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Revised: 01/08/2014] [Accepted: 02/17/2014] [Indexed: 02/06/2023] Open
Abstract
Gastric cancer is a leading cause of cancer death worldwide, and significant effort has been focused on clarifying the pathology of gastric cancer. In particular, the development of genome-wide analysis tools has enabled the detection of genetic and epigenetic alterations in gastric cancer; for example, aberrant DNA methylation in gene promoter regions is thought to play a crucial role in gastric carcinogenesis. The etiological viewpoint is also essential for the study of gastric cancers, and two distinct pathogens, Helicobacter pylori (H. pylori) and Epstein-Barr virus (EBV), are known to participate in gastric carcinogenesis. Chronic inflammation of the gastric epithelium due to H. pylori infection induces aberrant polyclonal methylation that may lead to an increased risk of gastric cancer. In addition, EBV infection is known to cause extensive methylation, and EBV-positive gastric cancers display a high methylation epigenotype, in which aberrant methylation extends to not only Polycomb repressive complex (PRC)-target genes in embryonic stem cells but also non-PRC-target genes. Here, we review aberrant DNA methylation in gastric cancer and the association between methylation and infection with H. pylori and EBV.
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