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Wu T, Wu L. The Role and Clinical Implications of the Retinoblastoma (RB)-E2F Pathway in Gastric Cancer. Front Oncol 2021; 11:655630. [PMID: 34136392 PMCID: PMC8201093 DOI: 10.3389/fonc.2021.655630] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 05/07/2021] [Indexed: 12/24/2022] Open
Abstract
Gastric cancer is the most common malignant tumor in the digestive tract, with very high morbidity and mortality in developing countries. The pathogenesis of gastric cancer is a complex biological process mediated by abnormal regulation of proto-oncogenes and tumor suppressor genes. Although there have been some in-depth studies on gastric cancer at the molecular level, the specific mechanism has not been fully elucidated. RB family proteins (including RB, p130, and p107) are involved in cell cycle regulation, a process that largely depends on members of the E2F gene family that encode transcriptional activators and repressors. In gastric cancer, inactivation of the RB-E2F pathway serves as a core transcriptional mechanism that drives cell cycle progression, and is regulated by cyclins, cyclin-dependent kinases, cyclin-dependent kinase inhibitors, p53, Helicobacter pylori and some other upstream molecules. The E2F proteins are encoded by eight genes (i.e. E2F1 to E2F8), each of which may play a specific role in gastric cancer. Interestingly, a single E2F such as E2F1 can activate or repress transcription, and enhance or inhibit cell proliferation, depending on the cell environment. Thus, the function of the E2F transcription factor family is very complex and needs further exploration. Importantly, the presence of H. pylori in stomach mucosa may affect the RB and p53 tumor suppressor systems, thereby promoting the occurrence of gastric cancer. This review aims to summarize recent research progress on important roles of the complex RB-E2F signaling network in the development and effective treatment of gastric cancer.
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Affiliation(s)
| | - Lizhao Wu
- Department of Pathophysiology, College of Basic Medical Sciences, China Medical University, Shenyang, China
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2
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Sokolova O, Naumann M. Manifold role of ubiquitin in Helicobacter pylori infection and gastric cancer. Cell Mol Life Sci 2021; 78:4765-4783. [PMID: 33825941 PMCID: PMC8195768 DOI: 10.1007/s00018-021-03816-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 02/22/2021] [Accepted: 03/18/2021] [Indexed: 02/07/2023]
Abstract
Infection with H. pylori induces a strong host cellular response represented by induction of a set of molecular signaling pathways, expression of proinflammatory cytokines and changes in proliferation. Chronic infection and inflammation accompanied by secretory dysfunction can result in the development of gastric metaplasia and gastric cancer. Currently, it has been determined that the regulation of many cellular processes involves ubiquitinylation of molecular effectors. The binding of ubiquitin allows the substrate to undergo a change in function, to interact within multimolecular signaling complexes and/or to be degraded. Dysregulation of the ubiquitinylation machinery contributes to several pathologies, including cancer. It is not understood in detail how H. pylori impacts the ubiquitinylation of host substrate proteins. The aim of this review is to summarize the existing literature in this field, with an emphasis on the role of E3 ubiquitin ligases in host cell homeodynamics, gastric pathophysiology and gastric cancer.
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Affiliation(s)
- Olga Sokolova
- Medical Faculty, Otto Von Guericke University, Institute of Experimental Internal Medicine, 39120 Magdeburg, Germany
| | - Michael Naumann
- Medical Faculty, Otto Von Guericke University, Institute of Experimental Internal Medicine, 39120 Magdeburg, Germany
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Wang W, Qin JJ, Rajaei M, Li X, Yu X, Hunt C, Zhang R. Targeting MDM2 for novel molecular therapy: Beyond oncology. Med Res Rev 2019; 40:856-880. [PMID: 31587329 DOI: 10.1002/med.21637] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 08/20/2019] [Accepted: 08/21/2019] [Indexed: 12/14/2022]
Abstract
The murine double minute 2 (MDM2) oncogene exerts major oncogenic activities in human cancers; it is not only the best-documented negative regulator of the p53 tumor suppressor, but also exerts p53-independent activities. There is an increasing interest in developing MDM2-based targeted therapies. Several classes of MDM2 inhibitors have been evaluated in preclinical models, with a few entering clinical trials, mainly for cancer therapy. However, noncarcinogenic roles for MDM2 have also been identified, demonstrating that MDM2 is involved in many chronic diseases and conditions such as inflammation and autoimmune diseases, dementia and neurodegenerative diseases, heart failure and cardiovascular diseases, nephropathy, diabetes, obesity, and sterility. MDM2 inhibitors have been shown to have promising therapeutic efficacy for treating inflammation and other nonmalignant diseases in preclinical evaluations. Therefore, targeting MDM2 may represent a promising approach for treating and preventing these nonmalignant diseases. In addition, a better understanding of how MDM2 works in nonmalignant diseases may provide new biomarkers for their diagnosis, prognostic prediction, and monitoring of therapeutic outcome. In this review article, we pay special attention to the recent findings related to the roles of MDM2 in the pathogenesis of several nonmalignant diseases, the therapeutic potential of its downregulation or inhibition, and its use as a biomarker.
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Affiliation(s)
- Wei Wang
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas.,Drug Discovery Institute, University of Houston, Houston, Texas
| | - Jiang-Jiang Qin
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas
| | - Mehrdad Rajaei
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas
| | - Xin Li
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas
| | - Xiaoyi Yu
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas
| | - Courtney Hunt
- Drug Discovery Institute, University of Houston, Houston, Texas
| | - Ruiwen Zhang
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas.,Drug Discovery Institute, University of Houston, Houston, Texas
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N-Acetylcysteine Reduces ROS-Mediated Oxidative DNA Damage and PI3K/Akt Pathway Activation Induced by Helicobacter pylori Infection. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:1874985. [PMID: 29854076 PMCID: PMC5944265 DOI: 10.1155/2018/1874985] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Accepted: 03/14/2018] [Indexed: 01/14/2023]
Abstract
Background H. pylori infection induces reactive oxygen species- (ROS-) related DNA damage and activates the PI3K/Akt pathway in gastric epithelial cells. N-Acetylcysteine (NAC) is known as an inhibitor of ROS; the role of NAC in H. pylori-related diseases is unclear. Aim The aim of this study was to evaluate the role of ROS and the protective role of NAC in the pathogenesis of H. pylori-related diseases. Method An in vitro coculture system and an in vivo Balb/c mouse model of H. pylori-infected gastric epithelial cells were established. The effects of H. pylori infection on DNA damage and ROS were assessed by the comet assay and fluorescent dichlorofluorescein assay. The level of PI3K/Akt pathway-related proteins was evaluated by Western blotting. The protective role of N-acetylcysteine (NAC) was also evaluated with in vitro and in vivo H. pylori infection models. Results The results revealed that, in vitro and in vivo, H. pylori infection increased the ROS level and induced DNA damage in gastric epithelial cells. NAC treatment effectively reduced the ROS level and inhibited DNA damage in GES-1 cells and the gastric mucosa of Balb/c mice. H. pylori infection induced ROS-mediated PI3K/Akt pathway activation, and NAC treatment inhibited this effect. However, the gastric mucosa pathological score of the NAC-treated group was not significantly different from that of the untreated group. Furthermore, chronic H. pylori infection decreased APE-1 expression in the gastric mucosa of Balb/c mice. Conclusions An increased ROS level is a critical mechanism in H. pylori pathogenesis, and NAC may be beneficial for the treatment of H. pylori-related gastric diseases linked to oxidative DNA damage.
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Yang Z, Cao X, Xu W, Xie C, Chen J, Zhu Y, Lu N. Phosphorylation of phosphatase and tensin homolog induced by Helicobacter pylori promotes cell invasion by activation of focal adhesion kinase. Oncol Lett 2017; 15:1051-1057. [PMID: 29399165 PMCID: PMC5772772 DOI: 10.3892/ol.2017.7430] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 10/18/2017] [Indexed: 02/06/2023] Open
Abstract
Phosphorylation of the phosphatase and tensin homolog (PTEN) tumor suppressor at Ser380/Thr382/Thr383 residues is a novel mechanism underlying PTEN inactivation in gastric carcinogenesis, which may be triggered by Helicobacter pylori infection. To investigate this further, the effect of H. pylori infection on PTEN phosphorylation and the subsequent activation of focal adhesion kinase (FAK), were evaluated in gastric tissue samples from Mongolian gerbils and in the human gastric epithelial mucosa cell line GES-1 using immunohistochemistry, western blotting and Transwell assays. The in vivo and in vitro results of the present study demonstrated that H. pylori infection induced the phosphorylation and inactivation of PTEN at Ser380/Thr382/383, and the subsequent phosphorylation and activation of FAK at Tyr397. Gastric epithelial cell invasion was also increased. Furthermore, stable expression of a dominant-negative PTEN mutant inhibited the enhanced FAK activation and cell invasion induced by H. pylori infection. These results suggest that the mechanism underlying H. pylori-induced carcinogenesis may involve promoting cell invasion through the phosphorylation of PTEN and the activation of FAK.
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Affiliation(s)
- Zhen Yang
- Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Ximei Cao
- Department of Gastroenterology, First Peoples' Hospital of Jiujiang, Jiujiang, Jiangxi 332000, P.R. China
| | - Wenting Xu
- Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Chuan Xie
- Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Jiang Chen
- Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Yin Zhu
- Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Nonghua Lu
- Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
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Yang Z, Xie C, Xu W, Liu G, Cao X, Li W, Chen J, Zhu Y, Luo S, Luo Z, Lu N. Phosphorylation and inactivation of PTEN at residues Ser380/Thr382/383 induced by Helicobacter pylori promotes gastric epithelial cell survival through PI3K/Akt pathway. Oncotarget 2016; 6:31916-26. [PMID: 26376616 PMCID: PMC4741650 DOI: 10.18632/oncotarget.5577] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 08/19/2015] [Indexed: 02/07/2023] Open
Abstract
Phosphorylation of PTEN at residues Ser380/Thr382/383 leads to loss of phosphatase activity and tumor suppressor function. Here, we found that phosphorylation of PTEN at residues Ser380/Thr382/383 was increased with gastric carcinogenesis, and more importantly, Helicobacter pylori was a trigger of this modification in chronic non-atrophic gastritis. H. pylori could phosphorylate and inactivate PTEN in vivo and in vitro, resulting in survival of gastric epithelial cells. Furthermore, stable expression of dominant-negative mutant PTEN or inhibition of Akt prevented the enhanced survival induced by H. pylori. These results indicate that PTEN phosphorylation at residues Ser380/Thr382/383 is a novel mechanism of PTEN inactivation in gastric carcinogenesis, and H. pylori triggers this modification, resulting in activation of the PI3K/Akt pathway and promotion of cell survival.
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Affiliation(s)
- Zhen Yang
- Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Chuan Xie
- Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Wenting Xu
- Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Gongmeizi Liu
- Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Ximei Cao
- Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Wei Li
- Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Jiang Chen
- Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Yin Zhu
- Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Shiwen Luo
- Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.,Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Zhijun Luo
- The Medical College of Nanchang University, Nanchang, Jiangxi, China.,Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA
| | - Nonghua Lu
- Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
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Yang Z, Li W, He C, Xie C, Zhu Y, Lu NH. Potential effect of chronic Helicobacter pylori infection on glucose metabolism of Mongolian gerbils. World J Gastroenterol 2015; 21:12593-12604. [PMID: 26640335 PMCID: PMC4658613 DOI: 10.3748/wjg.v21.i44.12593] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Revised: 06/19/2015] [Accepted: 09/14/2015] [Indexed: 02/06/2023] Open
Abstract
AIM: To assess the effect of Helicobacter pylori (H. pylori) infection on metabolic parameters in Mongolian gerbils.
METHODS: A total of 40 male, 5- to 8-wk-old, specific-pathogen-free Mongolian gerbils (30-50 g) were randomly allocated into two groups: a control group (n = 20) and an H. pylori group (n = 20). After a two-week acclimation period, the control group was administered Brucella broth and the H. pylori group was challenged intra-gastrically five times every other day with approximately 109/CFU H. pylori ATCC43504 (CagA+, VacA+). Each group was then divided into two subgroups, which were sacrificed at either 6 or 12 mo. The control and H. pylori subgroups each contained 10 Mongolian gerbils. Body weight, abdominal circumference, and body length were measured, and body mass index (BMI) and Lee’s index were calculated. Biochemical assays were used to detect serum indexes, including glucose, glycated hemoglobin (GHb), glycated hemoglobin A1c (HbA1c), triacylglycerol, and total cholesterol, using an automatic biochemistry analyzer. Inflammatory cytokines, including interleukin (IL)-1β, IL-2, IL-4, IL-10, IL-12, tumor necrosis factor-α (TNF-α) and interferon (IFN)-γ, were assayed using ELISA. The expression of insulin and insulin-like growth factor 1 (IGF-1) was detected by immunohistochemistry, and islet apoptosis was measured using the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay.
RESULTS: At each time point, body weight, abdominal circumference, BMI, and Lee’s index were increased after H. pylori infection. However, these differences were not significant. H. pylori infection significantly increased the GHb (5.45 ± 0.53 vs 4.98 ± 0.22, P < 0.05) and HbA1c (4.91 ± 0.61 vs 4.61 ± 0.15, P < 0.05) levels at 12 mo. We observed no significant differences in serum biochemical indexes, including fasting blood glucose, triacylglycerol and total cholesterol, at 6 or 12 mo after infection. H. pylori infection significantly increased the expression of IGF-1 (P < 0.05). Insulin levels from the pancreas and the apoptotic rate of islet β-cells remained unchanged. Also, we observed no significant differences among cytokines levels, including IL-1β, IL-2, IL-4, IL-10, IL-12, TNF-α and IFN-γ. IL-4 was the only exception, which increased at 6 (44.36 ± 25.17 vs 17.38 ± 3.47, P < 0.05) and 12 mo (33.41 ± 10.00 vs 18.91 ± 5.31, P < 0.05) after H. pylori infection.
CONCLUSION: Long-term H. pylori infection is significantly associated with high levels of HbA1c in Mongolian gerbils, indicating a potential role of H. pylori infection in glucose dysregulation.
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Helicobacter pylori Infection Activates the Akt-Mdm2-p53 Signaling Pathway in Gastric Epithelial Cells. Dig Dis Sci 2015; 60:876-86. [PMID: 25480405 DOI: 10.1007/s10620-014-3470-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2014] [Accepted: 11/27/2014] [Indexed: 02/07/2023]
Abstract
BACKGROUNDS AND AIMS Although Helicobacter pylori is widely accepted as a causative factor of many gastric diseases, the signaling pathways affected by H. pylori and subsequent effects on cell apoptosis and proliferation remain unclear. Here, we investigated the molecular mechanisms mediating H. pylori infection in gastric epithelial cells. METHODS Tissues from 160 patients with various gastric diseases with or without H. pylori infection were obtained and analyzed by immunohistochemistry for Akt, pAkt, Mdm2, p53, and Bax expression. In vitro, human gastric epithelial cells, GES-1, were incubated with H. pylori culture filtrates. Cell viability was measured by MTT assay. Apoptosis was evaluated by Annexin V/PI double staining followed by flow cytometry, DNA electrophoresis, and comet assay. mRNA and protein expression was assessed by RT-PCR and Western blot analysis. RESULTS In patient tissues, H. pylori infection was associated with significantly elevated levels of pAkt in chronic nonatrophic gastritis (CNAG), Mdm2 in dysplasia, p53 in metaplastic atrophy (MA), and Bax in CNAG and MA. In vitro, H. pylori culture filtrates reduced GES-1 cell viability in a time- and dose-dependent manner, induced G0/G1 arrest, triggered apoptosis, and increased DNA fragmentation. Mdm2 and Bax mRNA expression and pAkt, Mdm2, p53, and Bax protein expression were significantly upregulated when treated with H. pylori culture filtrates. Akt inhibition by LY294002 decreased Mdm2 expression, upregulated p53, and enhanced H. pylori-induced growth inhibition of GES-1 cells. CONCLUSIONS These findings suggest that Akt-Mdm2-p53 signaling is involved in the molecular response of GES-1 cells to H. pylori infection.
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Song B, Duan ZY, Zhong YH, Lei N, Yang YQ, Luo KY. Meta-analysis of the MDM2 T309G polymorphism and gastric cancer risk. Asian Pac J Cancer Prev 2015; 14:6649-51. [PMID: 24377582 DOI: 10.7314/apjcp.2013.14.11.6649] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mdm2 binds to the amino-terminus of p53 to induce its degradation and a single nucleotide polymorphism in the MDM2 promoter region (T309G) has been reported to increase the risk of several carcinomas, such as gastric cancer. However, the results of published studies to analyze the association between MDM2 T309G and gastric cancer havve often conflicted. METHODS To better illustrate the filiation between MDM2 T309G and gastric cancer, we performed a meta-analysis. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the strength of the relationship. The pooled ORs were performed for 4 models, additive, recessive, co-dominant model, and dominant. RESULTS Nine published case-control studies including 3,225 gastric cancer cases and 4,118 controls were identified. The MDM2 T309G polymorphism was associated with a significantly increased risk of gastric cancer risk when all studies were pooled into the meta-analysis (GG versus TT, OR=1.57; 95%CI=1.57-2.12; p=0.003) and GG versus GT/TT, OR=1.52; 95%CI=1.217-1.90; p<0.001). Furthermore, Egger<s test did not show any evidence of publication bias (P = 0.608 for GG versus TT). CONCLUSION Our results suggest that the MDM2 T309G polymorphism is indeed associated with a significantly increased risk of gastric cancer.
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Affiliation(s)
- Bo Song
- Department of General Surgery, The Fourth Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China E-mail :
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Xie C, Xu LY, Yang Z, Cao XM, Li W, Lu NH. Expression of γH2AX in various gastric pathologies and its association with Helicobacter pylori infection. Oncol Lett 2013; 7:159-163. [PMID: 24348841 PMCID: PMC3861580 DOI: 10.3892/ol.2013.1693] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 11/12/2013] [Indexed: 12/29/2022] Open
Abstract
Phosphorylation of H2AX at Ser 139 (γH2AX) is a biomarker of DNA double-strand breaks (DSBs). The present study aimed to explore the association between γH2AX levels and gastric pathology and Helicobacter pylori (H. pylori) infection. Gastric biopsies were obtained from 302 H. pylori-negative and -positive patients, including those with chronic gastritis (CG), intestinal metaplasia (IM), dysplasia (Dys) and gastric cancer (GC). Proteins were extracted from five gastric epithelial cell lines and from 10 specimens of matched GC and adjacent normal tissues. The expression of γH2AX, a biomarker for the detection of DNA DSBs, in gastric tissues was detected by immunohistochemistry and western blotting. The expression of γH2AX progressively increased in tissues according to pathological stage from CG to Dys, but was slightly decreased in GC. H. pylori infection was associated with increased γH2AX expression, IM and Dys. Overexpression of γH2AX in GC was found to correlate with tumor location, gross appearance, differentiation, depth of invasion, TNM stage and lymph node metastasis. The results indicated that DSBs appear to be an early molecular event in gastric carcinogenesis, which may be associated with H. pylori infection. Moreover, immunohistochemical staining of γH2AX was found to correlate with a number of clinicopathological characteristics. The expression of γH2AX may serve as a valuable biomarker for the diagnosis and progression of GC.
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Affiliation(s)
- Chuan Xie
- Department of Gastroenterology, The First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Li-Yao Xu
- Department of Gastroenterology, The First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Zhen Yang
- Department of Gastroenterology, The First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Xi-Mei Cao
- Department of Gastroenterology, The First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Wei Li
- Department of Gastroenterology, The First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Nong-Hua Lu
- Department of Gastroenterology, The First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi 330006, P.R. China
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Li W, Xie C, Yang Z, Chen J, Lu NH. Abnormal DNA-PKcs and Ku 70/80 expression may promote malignant pathological processes in gastric carcinoma. World J Gastroenterol 2013; 19:6894-901. [PMID: 24187467 PMCID: PMC3812491 DOI: 10.3748/wjg.v19.i40.6894] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2013] [Revised: 09/04/2013] [Accepted: 09/15/2013] [Indexed: 02/06/2023] Open
Abstract
AIM To determine the expression of the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) and the Ku70/Ku80 heterodimer (Ku 70/80) in gastric carcinoma. METHODS Gastric biopsies were obtained from 146 gastric carcinoma patients [Helicobacter pylori (H. pylori)-negative: 89 and H. pylori-positive: 57] and 34 from normal subjects (H. pylori-negative: 16 and H. pylori-positive: 18) via surgery and endoscopic detection from April 2011 to August 2012 at the First Affiliated Hospital of Nanchang University. Pathological diagnosis and classification were made according to the criteria of the World Health Organization and the updated Sydney system. An ''in-house'' rapid urease test and modified Giemsa staining were employed to detect H. pylori infection. The expression of DNA-PKcs and the Ku 70/80 protein was detected by immunohistochemistry. RESULTS Overall, the positive rates of both DNA-PKcs and Ku 70/80 were significantly increased in gastric cancer (χ(2) = 133.04, P < 0.001 for DNA-PKcs and χ(2) = 13.06, P < 0.01 for Ku) compared with normal gastric mucosa. There was hardly any detectable expression of DNA-PKcs in normal gastric mucosa, and the positive rate of DNA-PKcs protein expression in patients with a normal gastric mucosa was 0% (0/34), whereas the rate in gastric cancer (GC) was 93.8% (137/146). The difference between the two groups was statistically significant. Additionally, the positive rate of Ku 70/80 was 79.4% (27/34) in normal gastric mucosa and 96.6% (141/146) in gastric cancer. The DNA-PKcs protein level was significantly increased in gastric cancer (Mann-Whitney U = 39.00, P < 0.001), compared with normal gastric mucosa. In addition, there was a significant difference in the expression of Ku 70/80 (Mann-Whitney U = 1117.00, P < 0.001) between gastric cancer and normal gastric mucosa. There was also a significant difference in Ku70/80 protein expression between GC patients with and without H. pylori infection (P < 0.05). Spearman analysis showed a negative correlation between tumor differentiation and DNA-PKcs expression (r = -0.447, P < 0.05). Moreover, Ku70/80 expression was negatively correlated with both clinical stage (r = -0.189, P < 0.05) and H. pylori colonization (r = -0.168, P < 0.05). CONCLUSION Overall, this research demonstrated that enhanced DNA-PKcs and Ku 70/80 expression may be closely associated with gastric carcinoma.
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Helicobacter pylori infection and expressions of apoptosis-related proteins p53, ASPP2 and iASPP in gastric cancer and precancerous lesions. ACTA ACUST UNITED AC 2013; 61:199-202. [PMID: 23528480 DOI: 10.1016/j.patbio.2013.02.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Accepted: 02/15/2013] [Indexed: 12/30/2022]
Abstract
AIMS There has been limited information about the relations between Helicobacter pylori infection and expressions of apoptosis-related proteins p53, ASPP and iASPP in gastric cancer and precancerous lesions. METHODS H. pylori in gastric mucosa were identified by W-S staining and rapid urease test. Expression of apoptosis-related proteins P53, ASPP2 and iASPP in the gastric tissues were determined by immunohistochemistry. RESULTS The concentrations of H. pylori and expressions of p53 and iASPP in gastric carcinoma group and precancerous lesion group were higher than in benign gastric diseases group (P<0.05). The expressions of ASPP2 in gastric carcinoma and precancerous lesion group were lower than in benign gastric diseases group (P<0.05). The expressions of p53 and iASPP in H. pylori positive group were higher than in H. pylori negative group (P<0.05), whereas ASPP2 in H. pylori positive group were lower than in H. pylori negative group (P<0.05). CONCLUSION There was a higher rate H. pylori infection, an increased expression of apoptosis inhibitor iASPP, and decreased expression of apoptosis stimulator ASPP2 in gastric cancer or precancerous tissues. These results suggest that H. pylori may cause gastric cancer by up-regulating iASPP and down-regulating ASPP2.
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Yang Z, Yuan XG, Chen J, Lu NH. Is NEDD4-1 a negative regulator of phosphatase and tensin homolog in gastric carcinogenesis? World J Gastroenterol 2012; 18:6345-6348. [PMID: 23180960 PMCID: PMC3501788 DOI: 10.3748/wjg.v18.i43.6345] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [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
The expression of phosphatase and tensin homolog (PTEN), a tumor suppressor gene, is frequently down-regulated in gastric carcinomas due to mutation, loss of heterozygosity, and promoter hypermethylation. However, it is unknown if additional mechanisms may account for the down-regulation of PTEN expression. While neuronal precursor cell-expressed developmentally down-regulated 4-1 (NEDD4-1) is believed to be a potential dual regulator of PTEN, there are conflicting reports regarding their interaction. To gain further insight into the role of NEDD4-1 and its association with PTEN in gastric carcinoma development, we measured the protein expression of NEDD4-1 and PTEN in gastric mucosae with various pathological lesions and found that NEDD4-1 increased from normal gastric mucosa to intestinal metaplasia and decreased from dysplasia to gastric carcinoma. These changes did not correlate with PTEN expression changes during gastric carcinogenesis. Moreover, we found similar results in protein levels in the primary tumors and adjacent non-tumorous tissues. These results differ from a previous report showing that expression of NEDD4-1 is up-regulated in gastric carcinomas, and show a more complex pattern of NEDD4-1 gene expression during gastric carcinogenesis.
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