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Rajendra K, Sharma P. Viral Pathogens in Oesophageal and Gastric Cancer. Pathogens 2022; 11:476. [PMID: 35456151 PMCID: PMC9029269 DOI: 10.3390/pathogens11040476] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 04/10/2022] [Accepted: 04/12/2022] [Indexed: 12/24/2022] Open
Abstract
Tumour virology was born with the discovery by Peyton Rous in 1911 of a filterable agent in chicken cellular extracts that caused neoplasia in healthy chickens. Universally, 20% of all human cancers have a viral aetiology. Viruses are involved at various stages of the carcinogenesis pathway, depending on the viral pathogen, and likely require co-factors. Multiple risk factors have been associated with oesophageal and gastric malignancy, including carcinogenic pathogens. These viruses and bacteria include human papillomavirus (HPV) [oesophageal cancer], Epstein-Barr virus (EBV) [proximal stomach cancer], and Helicobacter pylori (HP) [non-cardia stomach cancer]. Viruses such as EBV have been firmly established as causal for up to 10% of gastric cancers. HPV is associated with 13 to 35% of oesophageal adenocarcinoma but its role is unclear in oesophageal squamous cell carcinomas. The causal relationship between hepatitis B (HBV), cytomegalovirus (CMV), HPV, and John Cunningham (JCV) and gastric neoplasia remains indeterminate and warrants further study. The expression of viral antigens by human tumours offers preventive and therapeutic potential (including vaccination) and has already been harnessed with vaccines for HPV and HBV. Future goals include viral protein-based immunotherapy and monoclonal antibodies for the treatment of some of the subset of EBV and HPV-induced gastro-esophageal cancers.
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Affiliation(s)
- Kishen Rajendra
- School of Medicine, The International Medical University, Kuala Lumpur 57000, Malaysia
| | - Prateek Sharma
- Division of Gastroenterology and Hepatology, Veterans Affairs Medical Center, Kansas City, MO 64128, USA;
- School of Medicine, University of Kansas, Kansas City, MO 66160, USA
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2
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Firoz A, Ali HM, Rehman S, Rather IA. Gastric Cancer and Viruses: A Fine Line between Friend or Foe. Vaccines (Basel) 2022; 10:vaccines10040600. [PMID: 35455349 PMCID: PMC9025827 DOI: 10.3390/vaccines10040600] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/28/2022] [Accepted: 04/11/2022] [Indexed: 02/01/2023] Open
Abstract
Gastric cancer (GC) is a significant health concern worldwide, with a GLOBOCAN estimate of 1.08 million novel cases in 2020. It is the leading cause of disability-adjusted life years lost to cancer, with the fourth most common cancer in males and the fifth most common cancer in females. Strategies are pursued across the globe to prevent gastric cancer progression as a significant fraction of gastric cancers have been linked to various pathogenic (bacterial and viral) infections. Early diagnosis (in Asian countries), and non-invasive and surgical treatments have helped manage this disease with 5-year survival for stage IA and IB tumors ranging between 60% and 80%. However, the most prevalent aggressive stage III gastric tumors undergoing surgery have a lower 5-year survival rate between 18% and 50%. These figures point to a need for more efficient diagnostic and treatment strategies, for which the oncolytic viruses (OVs) appear to have some promise. OVs form a new therapeutic agent class that induces anti-tumor immune responses by selectively killing tumor cells and inducing systemic anti-tumor immunity. On the contrary, several oncogenic viruses have been shown to play significant roles in malignancy progression in the case of gastric cancer. Therefore, this review evaluates the current state of research and advances in understanding the dual role of viruses in gastric cancer.
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Affiliation(s)
- Ahmad Firoz
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (A.F.); (H.M.A.)
- Princess Dr Najla Bint Saud Al-Saud Center for Excellence Research in Biotechnology, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Hani Mohammed Ali
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (A.F.); (H.M.A.)
- Princess Dr Najla Bint Saud Al-Saud Center for Excellence Research in Biotechnology, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Suriya Rehman
- Department of Epidemic Disease Research, Institute for Research and Medical Consultation (IRMC), Imam Abdulrahman Bin Faisal University (IAU), Dammam 31441, Saudi Arabia
- Correspondence: (S.R.); (I.A.R.)
| | - Irfan A. Rather
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (A.F.); (H.M.A.)
- Correspondence: (S.R.); (I.A.R.)
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3
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Zhang W, Cui N, Ye J, Yang B, Sun Y, Kuang H. Curcumin's prevention of inflammation-driven early gastric cancer and its molecular mechanism. CHINESE HERBAL MEDICINES 2022; 14:244-253. [PMID: 36117672 PMCID: PMC9476644 DOI: 10.1016/j.chmed.2021.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 10/29/2021] [Accepted: 11/27/2021] [Indexed: 02/07/2023] Open
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4
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Li W, Okabe A, Usui G, Fukuyo M, Matsusaka K, Rahmutulla B, Mano Y, Hoshii T, Funata S, Hiura N, Fukayama M, Tan P, Ushiku T, Kaneda A. Activation of EHF via STAT3 phosphorylation by LMP2A in Epstein-Barr virus-positive gastric cancer. Cancer Sci 2021; 112:3349-3362. [PMID: 34014591 PMCID: PMC8353921 DOI: 10.1111/cas.14978] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 05/07/2021] [Accepted: 05/14/2021] [Indexed: 12/13/2022] Open
Abstract
Epstein‐Barr virus (EBV) is associated with approximately 10% of gastric cancers (GCs). We previously showed that EBV infection of gastric epithelial cells induces aberrant DNA methylation in promoter regions, which causes silencing of critical tumor suppressor genes. Here, we analyzed gene expressions and active histone modifications (H3K4me3, H3K4me1, and H3K27ac) genome‐widely in EBV‐positive GC cell lines and in vitro EBV‐infected GC cell lines to elucidate the transcription factors contributing to tumorigenesis through enhancer activation. Genes associated with “signaling of WNT in cancer” were significantly enriched in EBV‐positive GC, showing increased active β‐catenin staining. Genes neighboring activated enhancers were significantly upregulated, and EHF motif was significantly enriched in these active enhancers. Higher expression of EHF in clinical EBV‐positive GC compared with normal tissue and EBV‐negative GC was confirmed by RNA‐seq using The Cancer Genome Atlas cohort, and by immunostaining using our cohort. EHF knockdown markedly inhibited cell proliferation. Moreover, there was significant enrichment of critical cancer pathway–related genes (eg, FZD5) in the downstream of EHF. EBV protein LMP2A caused upregulation of EHF via phosphorylation of STAT3. STAT3 knockdown was shown to inhibit cellular growth of EBV‐positive GC cells, and the inhibition was rescued by EHF overexpression. Our data highlighted the important role of EBV infection in gastric tumorigenesis via enhancer activation.
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Affiliation(s)
- Wenzhe Li
- Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Atsushi Okabe
- Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Genki Usui
- 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
| | - Keisuke Matsusaka
- Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan.,Department of Pathology, Chiba University Hospital, Chiba, Japan
| | - Bahityar Rahmutulla
- Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Yasunobu Mano
- Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Takayuki Hoshii
- 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
| | - Nobuhiro Hiura
- Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Masashi Fukayama
- Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Patrick Tan
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, Singapore City, Singapore
| | - Tetsuo Ushiku
- 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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5
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Zhu L, Li X, Yuan Y, Dong C, Yang M. APC Promoter Methylation in Gastrointestinal Cancer. Front Oncol 2021; 11:653222. [PMID: 33968756 PMCID: PMC8103321 DOI: 10.3389/fonc.2021.653222] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 03/30/2021] [Indexed: 12/30/2022] Open
Abstract
The adenomatous polyposis coli (APC) gene, known as tumor suppressor gene, has the two promoters 1A and 1B. Researches on APC have usually focused on its loss-of-function variants causing familial adenomatous polyposis. Hypermethylation, however, which is one of the key epigenetic alterations of the APC CpG sequence, is also associated with carcinogenesis in various cancers. Accumulating studies have successively explored the role of APC hypermethylation in gastrointestinal (GI) tumors, such as in esophageal, colorectal, gastric, pancreatic, and hepatic cancer. In sporadic colorectal cancer, the hypermethylation of CpG island in APC is even considered as one of the primary causative factors. In this review, we systematically summarized the distribution of APC gene methylation in various GI tumors, and attempted to provide an improved general understanding of DNA methylation in GI tumors. In addition, we included a robust overview of demethylating agents available for both basic and clinical researches. Finally, we elaborated our findings and perspectives on the overall situation of APC gene methylation in GI tumors, aiming to explore the potential research directions and clinical values.
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Affiliation(s)
- Lila Zhu
- Department of Medical Oncology, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xinyu Li
- Department of Medical Oncology, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Ying Yuan
- Department of Medical Oncology, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Cancer Institute, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Caixia Dong
- Department of Medical Oncology, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Mengyuan Yang
- Department of Medical Oncology, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Cancer Institute, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
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6
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Palrasu M, Zaika E, El-Rifai W, Que J, Zaika AI. Role of Bacterial and Viral Pathogens in Gastric Carcinogenesis. Cancers (Basel) 2021; 13:1878. [PMID: 33919876 PMCID: PMC8070847 DOI: 10.3390/cancers13081878] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/02/2021] [Accepted: 04/11/2021] [Indexed: 01/10/2023] Open
Abstract
Gastric cancer (GC) is one of the deadliest malignancies worldwide. In contrast to many other tumor types, gastric carcinogenesis is tightly linked to infectious events. Infections with Helicobacter pylori (H. pylori) bacterium and Epstein-Barr virus (EBV) are the two most investigated risk factors for GC. These pathogens infect more than half of the world's population. Fortunately, only a small fraction of infected individuals develops GC, suggesting high complexity of tumorigenic processes in the human stomach. Recent studies suggest that the multifaceted interplay between microbial, environmental, and host genetic factors underlies gastric tumorigenesis. Many aspects of these interactions still remain unclear. In this review, we update on recent discoveries, focusing on the roles of various gastric pathogens and gastric microbiome in tumorigenesis.
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Affiliation(s)
- Manikandan Palrasu
- Department of Surgery, University of Miami, Miami, FL 33136, USA; (M.P.); (E.Z.); (W.E.-R.)
| | - Elena Zaika
- Department of Surgery, University of Miami, Miami, FL 33136, USA; (M.P.); (E.Z.); (W.E.-R.)
| | - Wael El-Rifai
- Department of Surgery, University of Miami, Miami, FL 33136, USA; (M.P.); (E.Z.); (W.E.-R.)
- Department of Veterans Affairs, Miami VA Healthcare System, Miami, FL 33136, USA
| | - Jianwen Que
- Department of Medicine, Columbia University Medical Center, New York, NY 10032, USA;
| | - Alexander I. Zaika
- Department of Surgery, University of Miami, Miami, FL 33136, USA; (M.P.); (E.Z.); (W.E.-R.)
- Department of Veterans Affairs, Miami VA Healthcare System, Miami, FL 33136, USA
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7
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Fan Y, Ying H, Wu X, Chen H, Hu Y, Zhang H, Wu L, Yang Y, Mao B, Zheng L. The mutational pattern of homologous recombination (HR)-associated genes and its relevance to the immunotherapeutic response in gastric cancer. Cancer Biol Med 2020; 17:1002-1013. [PMID: 33299649 PMCID: PMC7721103 DOI: 10.20892/j.issn.2095-3941.2020.0089] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 06/19/2020] [Indexed: 12/24/2022] Open
Abstract
Objective: Currently, there is an urgent need to identify immunotherapeutic biomarkers to increase the benefit of immune checkpoint inhibitors (ICIs) for patients with gastric cancer (GC). Homologous recombination deficiency (HRD) can modify the tumor immune microenvironment by increasing the presence of tumor-infiltrating lymphocytes and therefore might serve as a biomarker of immunotherapeutic response. We aimed to analyze the mutational pattern of HR-associated genes in Chinese patients with GC and its relevance to the tumor immune profile and clinical immunotherapeutic response. Methods: A panel of 543 cancer-associated genes was used to analyze genomic profiles in a cohort comprising 484 Chinese patients with GC. Correlations between HR gene mutations and tumor immunity or clinical outcomes were identified via bioinformatic analysis using 2 GC genomic datasets (TCGA and MSK-IMPACT). Results: Fifty-one of the 484 (10.54%) patients carried at least one somatic mutation in an HR gene; ATM (16/484, 3.31%) was among the most frequently mutated HR genes in the Chinese cohort. Mutations in HR genes were associated with elevated tumor mutational burden, enhanced immune activity, and microsatellite instability status. In the MSK-IMPACT cohort comprising 49 patients with stomach adenocarcinoma or gastroesophageal junction adenocarcinoma treated with ICIs, patients with HR-mut GC (n = 12) had significantly better overall survival than those with HR-wt GC (n = 37) (log-rank test, P < 0.05). Conclusions: Our data suggest that detection of somatic mutations in HR genes might aid in identifying patients who might benefit from immune checkpoint blockade therapy.
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Affiliation(s)
- Yue Fan
- Department of integrated Traditional Chinese Medicine and Western Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Haifeng Ying
- Department of Traditional Chinese Medicine, Ruijin Hospital, Shanghai Jiaotong University, Shanghai 200025, China
| | - Xueying Wu
- Genecast Precision Medicine Technology Institute, Beijing 100191, China
| | - Huan Chen
- Genecast Precision Medicine Technology Institute, Beijing 100191, China
| | - Ying Hu
- Center of Integrative Medicine, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China
| | - Henghui Zhang
- Genecast Precision Medicine Technology Institute, Beijing 100191, China
| | - Lijia Wu
- Genecast Precision Medicine Technology Institute, Beijing 100191, China
| | - Ying Yang
- Genecast Precision Medicine Technology Institute, Beijing 100191, China
| | - Beibei Mao
- Genecast Precision Medicine Technology Institute, Beijing 100191, China
| | - Lan Zheng
- Department of Traditional Chinese Medicine, Ruijin Hospital, Shanghai Jiaotong University, Shanghai 200025, China
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8
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Epstein-Barr virus-associated gastric cancer: A distinct subtype. Cancer Lett 2020; 495:191-199. [PMID: 32979463 DOI: 10.1016/j.canlet.2020.09.019] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/28/2020] [Accepted: 09/21/2020] [Indexed: 12/11/2022]
Abstract
Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC) is a common malignant tumor associated with EBV infection. The molecular classification of gastric carcinoma indicates that EBVaGC is a distinct subtype in terms of oncogenesis and molecular features. Viral proteins, Bam-HI-A rightward transcripts (BART) miRNAs, and Bam-HI A rightward frame 1 (BARF1) promote oncogenesis after EBV infection via the induction of methylation, regulation of host gene expression, and malignant transformation. Together with abnormal mutations and amplification of the host genome as driving factors, interactions between the EBV genome and host genome accelerate carcinogenesis. The molecular profile of EBVaGC is that of EBV driving DNA hypermethylation, frequent phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) mutations, and the overexpression of Janus kinase 2 (JAK2), programmed death ligand-1 (PD-L1), and PD-L2. Clinically, the frequency of lymph node metastasis is lower, and the prognosis is better for EBVaGC than EBV-negative gastric cancer (EBVnGC). Pathologically, EBVaGC is a gastric adenocarcinoma with lymphoid stroma. This review interprets how the EBV genome is involved in the oncogenesis of gastric cancer and describes the molecular and clinicopathological features of EBVaGC.
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Tumor cell-expressed IL-15Rα drives antagonistic effects on the progression and immune control of gastric cancer and is epigenetically regulated in EBV-positive gastric cancer. Cell Oncol (Dordr) 2020; 43:1085-1097. [PMID: 32767257 DOI: 10.1007/s13402-020-00542-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 06/04/2020] [Accepted: 06/10/2020] [Indexed: 10/23/2022] Open
Abstract
PURPOSE Epstein-Barr virus associated gastric cancer (EBVaGC) often exhibits a favorable prognosis that correlates with highly methylated viral and host genes and significant immune cell infiltration compared to EBV-negative gastric cancers (GCs). Previously, it has been reported that expression of the IL-15 receptor α (IL-15Rα) is down-regulated in EBVaGC via promoter hypermethylation. In the present study, we offer a novel explanation for this puzzle by associating IL-15Rα expression with infiltration of lymphocytes in GC lesions. METHODS We investigated the expression of IL-15Rα by RT-PCR, Western-blotting and immunohistochemistry in GC cell lines and primary tissues, respectively. IL-15Rα promoter methylation was analyzed using genomic methylation sequencing. The growth behavior of GC cells was analyzed using MTT, flow cytometry, colony formation, transwell invasion and scratch wound healing assays. Demethylation of IL-15Rα was carried out using 5-Aza-CdR, and rIL-15 was added to evaluate growth promoting effects of the IL-15/IL-15Rα complex. Human peripheral blood mononuclear cells (PBMCs) were co-cultured with GC cells with/without the addition of rIL-15, after which the phosphorylation of STAT5 in PBMCs was evaluated using flow cytometry to estimate the activation of these immune cells through IL-15 binding to IL-2Rβ/γ receptors by in trans presentation. RESULTS We found that EBV-positive GC cells (AE) expressed IL-15Rα at a significantly lower level than EBV-negative GC cells (AGS) due to promoter hypermethylation. In the absence of immune cells, IL-15Rα on the cancer cell surface induced a malignant phenotype, including augmented cell growth, migration and invasion, and decreased apoptosis. 5-Aza-CdR reverted AE cells to a more malignant phenotype similar to AGS cells, which may be attributed to activation of the STAT1, STAT3 and ERK1/2 pathways. However, when PBMCs were added to the GC cell cultures, these immune cells were activated as detected by increased pSTAT5 levels. Also, more GC cells underwent apoptosis. These effects were enhanced by the addition of rIL-15 and, subsequently, confirmed in EBVaGC patient samples exhibiting increased expression of T cell surface markers and activation of immune co-stimulating pathways. CONCLUSIONS Our findings suggest a mechanistic explanation for the clinical association of EBVaGC with a lower IL-15Rα expression, a better prognosis and an increased lymphocyte infiltration. We propose that in highly infiltrated GCs the IL-15/IL-15Rα complex on the GC cell surface may present IL-15 in trans to IL-2Rβ/γ-expressing immune cells to activate these cells in the tumor microenvironment.
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Gastric cancer: genome damaged by bugs. Oncogene 2020; 39:3427-3442. [PMID: 32123313 PMCID: PMC7176583 DOI: 10.1038/s41388-020-1241-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 02/18/2020] [Accepted: 02/20/2020] [Indexed: 12/20/2022]
Abstract
Gastric cancer (GC) is one of the leading causes of cancer-related death worldwide. The role of the microorganisms in gastric tumorigenesis attracts much attention in recent years. These microorganisms include bacteria, virus, and fungi. Among them, Helicobacter pylori (H. pylori) infection is by far the most important risk factor for GC development, with special reference to the early-onset cases. H. pylori targets multiple cellular components by utilizing various virulence factors to modulate the host proliferation, apoptosis, migration, and inflammatory response. Epstein–Barr virus (EBV) serves as another major risk factor in gastric carcinogenesis. The virus protein, EBER noncoding RNA, and EBV miRNAs contribute to the tumorigenesis by modulating host genome methylation and gene expression. In this review, we summarized the related reports about the colonized microorganism in the stomach and discussed their specific roles in gastric tumorigenesis. Meanwhile, we highlighted the therapeutic significance of eradicating the microorganisms in GC treatment.
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11
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Polakovicova I, Jerez S, Wichmann IA, Sandoval-Bórquez A, Carrasco-Véliz N, Corvalán AH. Role of microRNAs and Exosomes in Helicobacter pylori and Epstein-Barr Virus Associated Gastric Cancers. Front Microbiol 2018; 9:636. [PMID: 29675003 PMCID: PMC5895734 DOI: 10.3389/fmicb.2018.00636] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 03/19/2018] [Indexed: 12/17/2022] Open
Abstract
Emerging evidence suggests that chronic inflammation caused by pathogen infection is connected to the development of various types of cancer. It is estimated that up to 20% of all cancer deaths is linked to infections and inflammation. In gastric cancer, such triggers can be infection of the gastric epithelium by either Helicobacter pylori (H. pylori), a bacterium present in half of the world population; or by Epstein-Barr virus (EBV), a double-stranded DNA virus which has recently been associated with gastric cancer. Both agents can establish lifelong inflammation by evolving to escape immune surveillance and, under certain conditions, contribute to the development of gastric cancer. Non-coding RNAs, mainly microRNAs (miRNAs), influence the host innate and adaptive immune responses, though long non-coding RNAs and viral miRNAs also alter these processes. Reports suggest that chronic infection results in altered expression of host miRNAs. In turn, dysregulated miRNAs modulate the host inflammatory immune response, favoring bacterial survival and persistence within the gastric mucosa. Given the established roles of miRNAs in tumorigenesis and innate immunity, they may serve as an important link between H. pylori- and EBV-associated inflammation and carcinogenesis. Example of this is up-regulation of miR-155 in H. pylori and EBV infection. The tumor environment contains a variety of cells that need to communicate with each other. Extracellular vesicles, especially exosomes, allow these cells to deliver certain type of information to other cells promoting cancer growth and metastasis. Exosomes have been shown to deliver not only various types of genetic information, mainly miRNAs, but also cytotoxin-associated gene A (CagA), a major H. pylori virulence factor. In addition, a growing body of evidence demonstrates that exosomes contain genetic material of viruses and viral miRNAs and proteins such as EBV latent membrane protein 1 (LMP1) which are delivered into recipient cells. In this review, we focus on the dysregulated H. pylori- and EBV-associated miRNAs while trying to unveil possible causal mechanisms. Moreover, we discuss the role of exosomes as vehicles for miRNA delivery in H. pylori- and EBV-related carcinogenesis.
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Affiliation(s)
- Iva Polakovicova
- Advanced Center for Chronic Diseases, Pontificia Universidad Católica de Chile, Santiago, Chile.,UC Center for Investigational Oncology, Pontificia Universidad Católica de Chile, Santiago, Chile.,Department of Hematology-Oncology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Sofia Jerez
- Department of Hematology-Oncology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Ignacio A Wichmann
- Advanced Center for Chronic Diseases, Pontificia Universidad Católica de Chile, Santiago, Chile.,UC Center for Investigational Oncology, Pontificia Universidad Católica de Chile, Santiago, Chile.,Department of Hematology-Oncology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Nicolás Carrasco-Véliz
- Advanced Center for Chronic Diseases, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Alejandro H Corvalán
- Advanced Center for Chronic Diseases, Pontificia Universidad Católica de Chile, Santiago, Chile.,UC Center for Investigational Oncology, Pontificia Universidad Católica de Chile, Santiago, Chile.,Department of Hematology-Oncology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
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12
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Costa NR, Gil da Costa RM, Medeiros R. A viral map of gastrointestinal cancers. Life Sci 2018; 199:188-200. [PMID: 29476768 DOI: 10.1016/j.lfs.2018.02.025] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 02/16/2018] [Indexed: 12/12/2022]
Abstract
Cancers of the gastrointestinal tract (GIT) are expected to account for approximately 20% of all cancers in 2017. Apart from their high incidence, GIT cancers show high mortality rates, placing these malignancies among the most prominent public health issues of our time. Cancers of the GIT are the result of a complex interplay between host genetic factors and environmental factors and frequently arise in the context of a continued active inflammatory response. Several tumor viruses are able to elicit such chronic inflammatory responses. In fact, several viruses have an impact on GIT tumor initiation and progression, as well as on patients' response to therapy and prognosis, through direct and indirect mechanisms. In this review, we have gathered information on different viruses' rates of infection, viral-driven specific carcinogenesis mechanisms and viral-related impact on the prognosis of cancers of the GIT (specifically in organs that have an interface with the environment - esophagus, stomach, intestines and anus). Overall, while some viral infections show a strong causal relation with specific gastrointestinal cancers, these represent a relatively small fraction of GIT malignancies. Other types of cancer, like Esophageal Squamous Cell Carcinoma, require further studies to confirm the carcinogenic role of some viral agents.
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Affiliation(s)
- Natália R Costa
- Molecular Oncology and Viral Pathology Group, IPO-Porto Research Center (CI-IPOP), Portuguese Institute of Oncology of Porto (IPO-Porto), Porto, Portugal.
| | - Rui M Gil da Costa
- Molecular Oncology and Viral Pathology Group, IPO-Porto Research Center (CI-IPOP), Portuguese Institute of Oncology of Porto (IPO-Porto), Porto, Portugal; LEPABE, Faculty of Engineering, University of Porto, Porto, Portugal
| | - Rui Medeiros
- Molecular Oncology and Viral Pathology Group, IPO-Porto Research Center (CI-IPOP), Portuguese Institute of Oncology of Porto (IPO-Porto), Porto, Portugal; Faculty of Medicine of the University of Porto (FMUP), Porto, Portugal; CEBIMED, Faculty of Health Sciences, Fernando Pessoa University, Porto, Portugal; Research Department, Portuguese League Against Cancer (Liga Portuguesa Contra o Cancro-Núcleo Regional do Norte), Porto, Portugal
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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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14
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Skierucha M, Milne ANA, Offerhaus GJA, Polkowski WP, Maciejewski R, Sitarz R. Molecular alterations in gastric cancer with special reference to the early-onset subtype. World J Gastroenterol 2016; 22:2460-74. [PMID: 26937134 PMCID: PMC4768192 DOI: 10.3748/wjg.v22.i8.2460] [Citation(s) in RCA: 39] [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: 09/22/2015] [Revised: 11/06/2015] [Accepted: 12/30/2015] [Indexed: 02/06/2023] Open
Abstract
Currently, gastric cancer (GC) is one of the most frequently diagnosed neoplasms, with a global burden of 723000 deaths in 2012. It is the third leading cause of cancer-related death worldwide. There are numerous possible factors that stimulate the pro-carcinogenic activity of important genes. These factors include genetic susceptibility expressed in a single-nucleotide polymorphism, various acquired mutations (chromosomal instability, microsatellite instability, somatic gene mutations, epigenetic alterations) and environmental circumstances (e.g., Helicobcter pylori infection, EBV infection, diet, and smoking). Most of the aforementioned pathways overlap, and authors agree that a clear-cut pathway for GC may not exist. Thus, the categorization of carcinogenic events is complicated. Lately, it has been claimed that research on early-onset gastric carcinoma (EOGC) and hereditary GC may contribute towards unravelling some part of the mystery of the GC molecular pattern because young patients are less exposed to environmental carcinogens and because carcinogenesis in this setting may be more dependent on genetic factors. The comparison of various aspects that differ and coexist in EOGCs and conventional GCs might enable scientists to: distinguish which features in the pathway of gastric carcinogenesis are modifiable, discover specific GC markers and identify a specific target. This review provides a summary of the data published thus far concerning the molecular characteristics of GC and highlights the outstanding features of EOGC.
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Hypermethylation of the interferon regulatory factor 5 promoter in Epstein-Barr virus-associated gastric carcinoma. J Microbiol 2015; 53:70-6. [PMID: 25557482 DOI: 10.1007/s12275-014-4654-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 11/26/2014] [Accepted: 11/27/2014] [Indexed: 12/21/2022]
Abstract
Interferon regulatory factor-5 (IRF-5), a member of the mammalian IRF transcription factor family, is regulated by p53, type I interferon and virus infection. IRF-5 participates in virus-induced TLR-mediated innate immune responses and may play a role as a tumor suppressor. It was suppressed in various EBV-infected transformed cells, thus it is valuable to identify the suppression mechanism. We focused on a promoter CpG islands methylation, a kind of epigenetic regulation in EBV-associated Burkitt's lymphomas (BLs) and gastric carcinomas. IRF-5 is not detected in most of EBV-infected BL cell lines due to hypermethylation of IRF-5 distal promoter (promoter-A), which was restored by a demethylating agent, 5-aza-2'-deoxycytidine. Hypomethylation of CpG islands in promoter-A was observed only in EBV type III latent infected BL cell lines (LCL and Mutu III). Similarly, during EBV infection to Akata-4E3 cells, IRF-5 was observed at early time periods (2 days to 8 weeks), concomitant unmethylation of promoter-A, but suppressed in later infection periods as observed in latency I BL cell lines. Moreover, hypermethylation in IRF-5 promoter-A region was also observed in EBV-associated gastric carcinoma (EBVaGC) cell lines or primary gastric carcinoma tissues, which show type I latent infection. In summary, IRF-5 is suppressed by hypermethylation of its promoter-A in most of EBV-infected transformed cells, especially BLs and EBVaGC. EBV-induced carcinogenesis takes an advantage of proliferative effects of TLR signaling, while limiting IRF-5 mediated negative effects in the establishment of EBVaGCs.
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Calcagno DQ, de Arruda Cardoso Smith M, Burbano RR. Cancer type-specific epigenetic changes: gastric cancer. Methods Mol Biol 2015; 1238:79-101. [PMID: 25421656 DOI: 10.1007/978-1-4939-1804-1_5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Gastric cancer (GC) remains a major cause of mortality despite declining rate in the world. Epigenetic alterations contribute significantly to the development and progression of gastric tumors. Epigenetic refers to the number of modifications of the chromatin structure that affect gene expression without altering the primary sequence of DNA, and these changes lead to transcriptional activation or silencing of the gene. Over the years, the study of epigenetic processes has increased, and novel therapeutic approaches have emerged. This chapter summarizes the main epigenomic mechanisms described recently involved in gastric carcinogenesis, focusing on the roles that aberrant DNA methylation, histone modifications (histone acetylation and methylation), and miRNAs (oncogenic and tumor suppressor function of miRNA) play in the onset and progression of gastric tumors. Clinical implications of these epigenetic alterations in GC are also discussed.
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Affiliation(s)
- Danielle Queiroz Calcagno
- Núcleo de Pesquisas em Oncologia, Universidade Federal do Pará, Rua dos Mundurucus, 4487, Guamá, CEP 66073-000 Belém, PA, Brazil,
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17
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Liang Q, Yao X, Tang S, Zhang J, Yau TO, Li X, Tang CM, Kang W, Lung RWM, Li JW, Chan TF, Xing R, Lu Y, Lo KW, Wong N, To KF, Yu C, Chan FKL, Sung JJY, Yu J. Integrative identification of Epstein-Barr virus-associated mutations and epigenetic alterations in gastric cancer. Gastroenterology 2014; 147:1350-62.e4. [PMID: 25173755 DOI: 10.1053/j.gastro.2014.08.036] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 08/21/2014] [Accepted: 08/23/2014] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS The mechanisms by which Epstein-Barr virus (EBV) contributes to the development of gastric cancer are unclear. We investigated EBV-associated genomic and epigenomic variations in gastric cancer cells and tumors. METHODS We performed whole-genome, transcriptome, and epigenome sequence analyses of a gastric adenocarcinoma cell line (AGS cells), before and after EBV infection. We then looked for alterations in gastric tumor samples, with (n = 34) or without (n = 100) EBV infection, collected from patients at the Prince of Wales Hospital, Chinese University of Hong Kong (from 1998 through 2004), or the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China (from 1999 through 2006). RESULTS Transcriptome analysis showed that infected cells expressed 9 EBV genes previously detected in EBV-associated gastric tumors and 71 EBV genes not previously reported in gastric tumors. Ten viral genes that had not been reported previously in gastric cancer but were expressed most highly in EBV-infected cells also were expressed in primary EBV-positive gastric tumors. Whole-genome sequence analysis identified 45 EBV-associated nonsynonymous mutations. These mutations, in genes such as AKT2, CCNA1, MAP3K4, and TGFBR1, were associated significantly with EBV-positive gastric tumors, compared with EBV-negative tumors. An activating mutation in AKT2 was associated with reduced survival times of patients with EBV-positive gastric cancer (P = .006); this mutation was found to dysregulate mitogen-activated protein kinase signaling. Integrated epigenome and transcriptome analyses identified 216 genes transcriptionally down-regulated by EBV-associated hypermethylation; methylation of ACSS1, FAM3B, IHH, and TRABD increased significantly in EBV-positive tumors. Overexpression of Indian hedgehog (IHH) and TraB domain containing (TRABD) increased proliferation and colony formation of gastric cancer cells, whereas knockdown of these genes reduced these activities. We found 5 signaling pathways (axon guidance, focal adhesion formation, interactions among cytokines and receptors, mitogen-activated protein kinase signaling, and actin cytoskeleton regulation) to be affected commonly by EBV-associated genomic and epigenomic alterations. CONCLUSIONS By using genomic, transcriptome, and epigenomic comparisons of EBV infected vs noninfected gastric cancer cells and tumor samples, we identified alterations in genes, gene expression, and methylation that affect different signaling networks. These might be involved in EBV-associated gastric carcinogenesis.
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Affiliation(s)
- Qiaoyi Liang
- Institute of Digestive Disease and Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China; The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen, China
| | | | | | - Jingwan Zhang
- Institute of Digestive Disease and Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China; The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen, China
| | - Tung On Yau
- Institute of Digestive Disease and Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China; The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen, China
| | - Xiaoxing Li
- Institute of Digestive Disease and Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China; The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen, China
| | - Ceen-Ming Tang
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Wei Kang
- Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Hong Kong, China
| | - Raymond W M Lung
- Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Hong Kong, China
| | - Jing Woei Li
- School of Life Sciences, Hong Kong Bioinformatics Centre, The Chinese University of Hong Kong, Hong Kong, China
| | - Ting Fung Chan
- School of Life Sciences, Hong Kong Bioinformatics Centre, The Chinese University of Hong Kong, Hong Kong, China
| | - Rui Xing
- Laboratory of Molecular Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Cancer Hospital/Institute, Beijing, China
| | - Youyong Lu
- Laboratory of Molecular Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Cancer Hospital/Institute, Beijing, China
| | - Kwok Wai Lo
- Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Hong Kong, China
| | - Nathalie Wong
- Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Hong Kong, China
| | - Ka Fai To
- Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Hong Kong, China
| | | | - Francis K L Chan
- Institute of Digestive Disease and Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China; The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen, China
| | - Joseph J Y Sung
- Institute of Digestive Disease and Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China; The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen, China
| | - Jun Yu
- Institute of Digestive Disease and Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China; The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen, China.
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Wang Y, Feng X, Jia R, Liu G, Zhang M, Fan D, Gao S. Microarray expression profile analysis of long non-coding RNAs of advanced stage human gastric cardia adenocarcinoma. Mol Genet Genomics 2014; 289:291-302. [PMID: 24414129 DOI: 10.1007/s00438-013-0810-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 12/30/2013] [Indexed: 02/07/2023]
Abstract
Gastric cardia adenocarcinoma (GCA) is a unique malignant tumor for its characteristics different from gastric and esophageal cancer epidemiologically and pathologically. The incidence of GCA has steadily increased for the last three decades and many patients are diagnosed with advanced stage because of the lack of typical and obvious symptoms at an early stage. To gain insight into the molecular mechanisms of GCA of advanced stage, we investigated the microarray expression profile of long non-coding RNAs of 12 advanced stage GCA patients. Long non-coding RNAs (lncRNAs) lack protein-coding potential and are over 200 bp in length. LncRNAs are known to be involved in the multifactor and multistep processes of tumor development and metastasis. In this study, we performed lncRNA transcriptome profiling of GCA biopsy tissue from 12 GCA patients who were confirmed by pathology to have developed lymph node metastasis and 12 paired non-cancerous gastric cardia tissues to determine if a gene expression profile unique to the lymph node metastasis group could be detected. Comparison of differentially expressed transcripts between the groups identified eight pathways that corresponded to down-regulated transcripts and 18 pathways that corresponded to up-regulated transcripts (p value cut-off 0.05). Gene ontology analysis showed that the up-regulated transcripts were most highly enriched in SRP-dependent cotranslational protein targeting to membrane, cytosolic ribosome, and structural constituent of ribosome, and the down-regulated transcripts were highly enriched in carboxylic acid transport, focal adhesion, and cation binding. This study shows that lncRNAs dysregulation exerts important roles in human GCA lymph node metastasis, indicating that lncRNAs are novel candidate biomarkers for the clinical diagnosis of advanced stage GCA and that could be targets for further therapy.
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Affiliation(s)
- Ying Wang
- Oncology Department of the First Affiliated Hospital of Henan University of Science and Technology, No. 24 Jinghua Road, Luoyang, Henan, China
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Mao YT, Liu JL, Wang Z, Chen YY, Chen JQ. Relationship between hMLH1 methylation, microsatellite instability and gastric cancer. Shijie Huaren Xiaohua Zazhi 2013; 21:3954-3960. [DOI: 10.11569/wcjd.v21.i35.3954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Gastric cancer is one of the most common malignant tumors, and its development is a very complicated process. Although great progress has been made in the understanding of gastric cancer, its exact mechanism is still unclear. The human mutL homolog 1 (hMLH1), a main member of the mismatch repair system, participates in mismatch repair during DNA replication, and plays an important role in maintaining genome stability. The reduction or loss of hMLH1 expression, which often shows as microsatellite instability (MSI), is closely related to the development, treatment and prognosis of gastric cancer, and the main reason is hMLH1 promoter methylation. In this paper, we will review the recent progress in understanding the relationship between hMLH1 methylation, MSI and development, treatment and prognosis of gastric cancer.
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20
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Zhang JC, Gao B, Yu ZT, Liu XB, Lu J, Xie F, Luo HJ, Li HP. Promoter hypermethylation of p14 (ARF) , RB, and INK4 gene family in hepatocellular carcinoma with hepatitis B virus infection. Tumour Biol 2013; 35:2795-802. [PMID: 24254306 DOI: 10.1007/s13277-013-1372-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 10/28/2013] [Indexed: 01/14/2023] Open
Abstract
Both hepatitis B virus (HBV) and gene methylation play important roles in hepatocarcinogenesis. However, their association between HBV infection and gene methylation is not fully understood. Cell cycle control involving RB1 gene-related cell inhibitors is one of the main regulatory pathways were reported to be altered in hepatocellular carcinoma (HCC). The purpose of this research is to assess the methylation status of p14 (ARF) and INK4 gene family (p14 (ARF) , p15 (INK4B) , p16 (INK4A) , and p18 (INK4C) ) in HCC with HBV infection and HCC without it, and discuss possible role of HBV-induced hypermethylation in the mechanism of hepatocarcinogenesis. Methylation status of RB, p14 (ARF) , and INK4 gene family in 64 case of HCC with HBV infection and 24 cases without it were detected by methylation-specific polymerase chain reaction, and HBV-DNA of the plasma were detected by quantitative real-time polymerase chain reaction. p14 (ARF) , p15 (INK4B) , p16 (INK4A) , and RB hypermethylation were observed in 30 (34.1%), 50 (56.8%), 62 (70.5%), and 24(27.3%) of 88 hepatocellular carcinomas, respectively. Methylation frequencies of them between HCC with HBV infection and HCC without it were 43.8% versus 8.3 % (p14 (ARF) ), 68.9% versus 25% (p15 (INK4B) ), 90.6% versus 16.7% ( p16 (INK4A) ), and 28.1 % versus 25% (RB), respectively. In HBV-associated HCC, the numbers of methylated genes were also more than HCC without virus infection, more than two methylated genes were seen in 48 of 64 (75 %) cases; more than three methylated genes were found in 32 of 64 (50%); correspondently, no one case has more than two genes methylated. p18 (INK4C) methylation product was not found in cancerous or non-cancerous tissues of 88 HCC. HBV infection is associated with p14 (ARF) , p15 (INK4B) , p16 (INK4A) , and RB gene methylation (P = 0.048, 0.035, 0.02); HBV-DNA replication is associated with p14 (ARF) , p15 (INK4B) , p16 (INK4A) , and RB gene methylation (P = 0.048, 0.035, 0.02); high rate of p14 (ARF) , p15 (INK4B) , and p16 (INK4A) in HCC with HBV infection suggests that HBV-induced hypermethylation may be one of the mechanisms of HBV involved in hepatocellular carcinogenesis.
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Affiliation(s)
- Ji-Cai Zhang
- Department of Laboratory Medicine, Taihe Hospital Affiliated to Hubei University of Medicine, Shiyan, 442000, People's Republic of China
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Guo H, Wang T, Su HX. Epstein-Barr virus and gastric cancer. Shijie Huaren Xiaohua Zazhi 2013; 21:1616-1622. [DOI: 10.11569/wcjd.v21.i17.1616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Gastric cancer ranks second among malignancies in terms of global incidence. Epstein-Barrvirus (EBV)-associated gastric carcinoma (EBVaGC) is a recently recognized entity, which is defined by the presence of EBV in gastric carcinoma cells. EBVaGC represents about 10% of gastric carcinoma cases worldwide. It is estimated that there are over 80000 new EBVaGC cases in the world annually. EBVaGC shows some distinct clinical and pathological characteristics. The observation that EBV-encoded small RNA is expressed in cancer cells but not in surrounding normal epithelial cells strongly suggests that EBV plays an etiological role in gastric carcinogenesis. In this review, we discuss the relationship between EBV and gastric carcinogenesis.
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Calcagno DQ, Gigek CO, Chen ES, Burbano RR, Smith MDAC. DNA and histone methylation in gastric carcinogenesis. World J Gastroenterol 2013; 19:1182-92. [PMID: 23482412 PMCID: PMC3587474 DOI: 10.3748/wjg.v19.i8.1182] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 06/13/2012] [Accepted: 06/28/2012] [Indexed: 02/06/2023] Open
Abstract
Epigenetic alterations contribute significantly to the development and progression of gastric cancer, one of the leading causes of cancer death worldwide. Epigenetics refers to the number of modifications of the chromatin structure that affect gene expression without altering the primary sequence of DNA, and these changes lead to transcriptional activation or silencing of the gene. Over the years, the study of epigenetic processes has increased, and novel therapeutic approaches that target DNA methylation and histone modifications have emerged. A greater understanding of epigenetics and the therapeutic potential of manipulating these processes is necessary for gastric cancer treatment. Here, we review recent research on the effects of aberrant DNA and histone methylation on the onset and progression of gastric tumors and the development of compounds that target enzymes that regulate the epigenome.
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Zhao J, Liang Q, Cheung KF, Kang W, Lung RWM, Tong JHM, To KF, Sung JJY, Yu J. Genome-wide identification of Epstein-Barr virus-driven promoter methylation profiles of human genes in gastric cancer cells. Cancer 2013; 119:304-12. [PMID: 22833454 DOI: 10.1002/cncr.27724] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Revised: 05/01/2012] [Accepted: 05/30/2012] [Indexed: 12/13/2022]
Abstract
BACKGROUND Aberrant methylation of tumor-related genes has been reported in Epstein-Barr virus (EBV)-associated gastric cancers. This study sought to profile EBV-driven hypermethylation in EBV-infected cells. METHODS The EBV-positive AGS gastric cancer cell line (AGS-EBV) and EBV-negative AGS cells were used in this study. DNA methyltransferase-3b (DNMT3b) activity was assessed by EpiQuick activity assay, and genome-wide DNA methylation profiles were assessed by methyl-DNA immunoprecipitation microarray assay. RESULTS EBV infection was confirmed in AGS-EBV cells by EBV-encoded RNA in situ hybridization. Expression and activity of DNA methyltransferase-3b (DNMT3b) was significantly increased in AGS-EBV compared to AGS. Ectopic expression of LMP2A (latent membrane protein 2A) in AGS increased activity of DNMT3b. A total of 1065 genes were differentially methylated by EBV infection (fold-changes ≥ 2, P < .05) in AGS-EBV compared to AGS cells. The majority of the differentially methylated genes (83.2%, 886 of 1065 genes) had cytosine-guanine dinucleotide (CpG) hypermethylation in AGS-EBV (fold-changes 2.43∼65.2) versus that found in AGS cells. Gene ontology analysis revealed that hypermethylated genes were enriched in the important cancer pathways (≥ 10 genes each, P ≤ .05) including mitogen-activated protein kinase signaling, cell adhesion molecules, wnt signaling pathway, and so forth. Six novel hypermethylated candidates (IL15RA, REC8, SSTR1, EPHB6, MDGA2, and SCARF2) were further validated. Higher levels of DNA methylation were confirmed for all these genes in AGS-EBV cells by bisulfite genomic sequencing. Furthermore, these candidates were silenced or down-regulated in AGS-EBV cells, but can be restored by demethylation treatment. CONCLUSIONS EBV infection in AGS cells induced aberrant CpG hypermethylation of 886 genes involving in important cancer-related pathways. Induction of promoter methylation by EBV is regulated by up-regulation of DNMT3b through LMP2A.
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MESH Headings
- Cell Cycle Proteins/genetics
- Cell Line, Tumor
- CpG Islands
- DNA (Cytosine-5-)-Methyltransferases/genetics
- DNA (Cytosine-5-)-Methyltransferases/metabolism
- DNA Methylation
- Enzyme Activation
- Epigenesis, Genetic
- Epstein-Barr Virus Infections/virology
- Gene Expression
- Gene Expression Regulation, Neoplastic
- Genome, Human
- Herpesvirus 4, Human/physiology
- Host-Pathogen Interactions
- Humans
- Promoter Regions, Genetic
- Receptor Protein-Tyrosine Kinases/genetics
- Receptors, Eph Family
- Receptors, Interleukin-15/genetics
- Receptors, Somatostatin/genetics
- Sequence Analysis, DNA
- Stomach Neoplasms/genetics
- Stomach Neoplasms/virology
- Viral Matrix Proteins/genetics
- Viral Matrix Proteins/metabolism
- DNA Methyltransferase 3B
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Affiliation(s)
- Junhong Zhao
- Institute of Digestive Disease and Department of Medicine and Therapeutics, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China
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de Lima MAP, Ferreira MVP, Barros MAP, Pardini MIDMC, Ferrasi AC, Rabenhorst SHB. Epstein-Barr virus-associated gastric carcinoma in Brazil: comparison between in situ hybridization and polymerase chain reaction detection. Braz J Microbiol 2012; 43:393-404. [PMID: 24031845 PMCID: PMC3769002 DOI: 10.1590/s1517-838220120001000048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2011] [Indexed: 01/07/2023] Open
Abstract
Epstein-Barr virus (EBV) has been associated with 10% of gastric carcinomas. The aim of this study was to determine the frequency of EBV in gastric carcinomas in Brazil assessed by in situ hybridization (ISH) and PCR, which would contribute to the characterization of the clinical and pathological aspects of EBV-associated gastric carcinomas. One hundred and ninety-two gastric carcinoma cases were collected at hospitals in two Brazilian states. Seventy-three out of 151 cases were PCR(+), while 11/160 cases were ISH(+). Nine out of eleven ISH(+) cases displayed a diffuse staining pattern and 2 out of 11 a focal pattern. Both techniques showed that the EBV(+) cases were characterized by their association with males, older patients, lower gastric region, intestinal type, advanced stage and poorly to moderately differentiated tumors. The concordance between the two techniques was 55.8% (Cohen's kappa index = 0.034). Four cases were ISH(+)/PCR(-), while 49 cases were PCR(+)/ISH(-). Only two cases showed stained lymphocytes by ISH and one of them was PCR(-). The observed discrepancy between the two techniques could not be explained just by the elevated accuracy of PCR. ISH(+)/PCR(-) carcinomas may be encountered if EBV is not present in the whole tumor tissue or if there are polymorphisms in the sequences of the viral genome amplified. On the other hand, the high frequency of PCR(+) results associated with the absence of ISH staining in lymphocytes and/or tumors cells suggests that the virus may be present in tumor cells or other cell types without expressing EBER1, the target of the ISH technique.
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Affiliation(s)
- Marcos Antonio Pereira de Lima
- Setor de Microbiologia, Departamento de Patologia e Medicina Legal, Universidade Federal do Ceará , Fortaleza, CE , Brasil
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