Diversity of 3’ variable region of cagA gene in Helicobacter pylori strains isolated from Chinese population

Abstract Background: The cytotoxin-associated gene A (cagA) is one of the most important virulence factors of Helicobacter pylori (H. pylori). There is a highly polymorphic Glu-Pro-Ile-Tyr-Ala (EPIYA) repeat region in the C-terminal of CagA protein. This repeat region is thought to play an important role in the pathogenesis of gastrointestinal diseases. The aim of this study was to investigate the diversity of cagA 3’ variable region and the amino acid polymorphisms in the EPIYA segments of the CagA C-terminal region of H. pylori, and their association with gastroduodenal diseases.Methods: A total of 515 H. pylori strains from patients in 14 different geographical regions of China were collected. The genomic DNA from each strain was extracted and the cagA 3’ variable region was amplified by polymerase chain reaction (PCR). The PCR products were sequenced and analyzed using MEGA 7.0 software.Results: A total of 503 (97.7%) H. pylori strains were cagA-positive and 1,587 EPIYA motifs were identified, including 12 types of EPIYA or EPIYA-like sequences. In addition to the four reported major segments, several rare segments (e.g., B’, B’’ and D’) were defined and 20 different sequence types (e.g., ABD, ABC) were found in our study. A total of 481 (95.6%) strains carried the East Asian type CagA, and the ABD subtypes were most prevalent (82.1%). Only 22 strains carried the Western type CagA, which include AC, ABC, ABCC and ABCCCC subtypes. The CagA-ABD subtype had statistical difference in different geographic regions (P = 0.006). There are seven amino acid polymorphisms in the sequences surrounding the EPIYA motifs, among which amino acid residue 893 and 894 had a statistical difference with gastric cancer (P = 0.004).Conclusions: In this study, 503 CagA sequences was studied and analyzed in depth. In Chinese population, most H. pylori strains are of the CagA-ABD subtype and its presence was associated with gastroduodenal diseases. Amino acid polymorphisms at residue 893 and 894 flanking the EPIYA motif had a statistically significant association with gastric cancer.

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Diversity of 3′ variable region of cagA gene in Helicobacter pylori strains isolated from Chinese population

Gut Pathogens ◽

10.1186/s13099-021-00419-3 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Zhijing Xue ◽

Yuanhai You ◽

Lihua He ◽

Yanan Gong ◽

Lu Sun ◽

...

Keyword(s):

Gastric Cancer ◽

Helicobacter Pylori ◽

Amino Acid ◽

Chinese Population ◽

Statistical Difference ◽

Variable Region ◽

Repeat Region ◽

Geographical Regions ◽

H Pylori ◽

Epiya Motifs

Abstract Background The cytotoxin-associated gene A (cagA) is one of the most important virulence factors of Helicobacter pylori (H. pylori). There is a highly polymorphic Glu-Pro-Ile-Tyr-Ala (EPIYA) repeat region in the C-terminal of CagA protein. This repeat region is thought to play an important role in the pathogenesis of gastrointestinal diseases. The aim of this study was to investigate the diversity of cagA 3′ variable region and the amino acid polymorphisms in the EPIYA segments of the CagA C-terminal region of H. pylori, and their association with gastroduodenal diseases. Methods A total of 515 H. pylori strains from patients in 14 different geographical regions of China were collected. The genomic DNA from each strain was extracted and the cagA 3′ variable region was amplified by polymerase chain reaction (PCR). The PCR products were sequenced and analyzed using MEGA 7.0 software. Results A total of 503 (97.7%) H. pylori strains were cagA-positive and 1,587 EPIYA motifs were identified, including 12 types of EPIYA or EPIYA-like sequences. In addition to the four reported major segments, several rare segments (e.g., B′, B″ and D′) were defined and 20 different sequence types (e.g., ABD, ABC) were found in our study. A total of 481 (95.6%) strains carried the East Asian type CagA, and the ABD subtypes were most prevalent (82.1%). Only 22 strains carried the Western type CagA, which included AC, ABC, ABCC and ABCCCC subtypes. The CagA-ABD subtype had statistical difference in different geographical regions (P = 0.006). There were seven amino acid polymorphisms in the sequences surrounding the EPIYA motifs, among which amino acids 893 and 894 had a statistical difference with gastric cancer (P = 0.004). Conclusions In this study, 503 CagA sequences were studied and analyzed in depth. In Chinese population, most H. pylori strains were of the CagA-ABD subtype and its presence was associated with gastroduodenal diseases. Amino acid polymorphisms at residues 893 and 894 flanking the EPIYA motifs had a statistically significant association with gastric cancer.

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Diversity of 3’ Variable Region of cagA Gene in Helicobacter Pylori Strains Isolated from Chinese Population

10.21203/rs.3.rs-127429/v1 ◽

2020 ◽

Author(s):

zhijing Xue ◽

Yuanhai You ◽

Lihua He ◽

Yanan Gong ◽

Lu Sun ◽

...

Keyword(s):

Gastric Cancer ◽

Helicobacter Pylori ◽

Amino Acid ◽

Chinese Population ◽

Statistical Difference ◽

Variable Region ◽

Repeat Region ◽

Geographical Regions ◽

H Pylori ◽

Epiya Motifs

Abstract Background: CagA is one of the most important virulence factors of Helicobacter pylori (H. pylori). There is a highly polymorphic Glu-Pro-Ile-Tyr-Ala (EPIYA) repeat region in the CagA 3’ variable region. This repeat region is thought to play an important role in the pathogenesis of gastrointestinal diseases. The aim of this study was to investigate the diversity of CagA 3’ variable region and the amino acid polymorphisms in the EPIYA segments, and their association with gastroduodenal diseases.Methods: A total of 515 H. pylori isolates from patients in 14 different geographical regions of China were collected and the genomic DNA was extracted. The 3’ variable region of the cagA was amplified by polymerase chain reaction (PCR) and then followed by DNA sequencing, and the amino acid sequences were analyzed with MEGA 7.0 software.Results: A total of 503 (97.7%) H. pylori isolates were cagA-positive and 1,587 EPIYA motifs were obtained, including 12 types of EPIYA or EPIYA-like sequences. In addition to the four reported major segments, several rare segments (e.g., B’, B’’ and D’) were defined and 20 different sequence types (e.g., ABD, ABC) were found in our study. A total of 481 (95.6%) strains were East Asian type, most of them were ABD subtype (82.1%). Only 22 strains were Western type, including types AC, ABC, ABCC and ABCCCC. The CagA-ABD subtype had statistical difference in different geographic regions (P=0.006). There are seven amino acid polymorphisms in the sequences surrounding the EPIYA motifs, among which amino acid residue 893 and 894 had a statistical difference with gastric cancer (P=0.004).Conclusions: In this study, 503 CagA sequences was studied and analyzed in depth. In Chinese population, most H. pylori isolates are of the CagA-ABD subtype and its presence was associated with gastroduodenal disease. Amino acid polymorphisms at residue 893 and 894 flanking the EPIYA motif had a statistically significant association with gastric cancer.

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The endemic Helicobacter pylori population in Southern Vietnam has both South East Asian and European origins

Gut Pathogens ◽

10.1186/s13099-021-00452-2 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Trang Hoa Nguyen ◽

Trang Thi My Ho ◽

Thien-Phuc Nguyen-Hoang ◽

Shamsul Qumar ◽

Thuc Tran Dang Pham ◽

...

Keyword(s):

Gastric Cancer ◽

Helicobacter Pylori ◽

East Asian ◽

Repeat Region ◽

Global Context ◽

Southern Vietnam ◽

Geographical Regions ◽

Allelic Type ◽

Comparative Genomics Analysis ◽

H Pylori

Abstract Background The burden of Helicobacter pylori-induced gastric cancer varies based on predominant H. pylori population in various geographical regions. Vietnam is a high H. pylori burden country with the highest age-standardized incidence rate of gastric cancer (16.3 cases/100,000 for both sexes) in Southeast Asia, despite this data on the H. pylori population is scanty. We examined the global context of the endemic H. pylori population in Vietnam and present a contextual and comparative genomics analysis of 83 H. pylori isolates from patients in Vietnam. Results There are at least two major H. pylori populations are circulating in symptomatic Vietnamese patients. The majority of the isolates (~ 80%, 66/83) belong to the hspEastAsia and the remaining belong to hpEurope population (~ 20%, 17/83). In total, 66 isolates (66/83) were cagA positive, 64 were hspEastAsia isolates and two were hpEurope isolates. Examination of the second repeat region revealed that most of the cagA genes were ABD type (63/66; 61 were hspEastAsia isolates and two were hpEurope isolates). The remaining three isolates (all from hspEastAsia isolates) were ABC or ABCC types. We also detected that 4.5% (3/66) cagA gene from hspEastAsia isolates contained EPIYA-like sequences, ESIYA at EPIYA-B segments. Analysis of the vacA allelic type revealed 98.8% (82/83) and 41% (34/83) of the strains harboured the s1 and m1 allelic variant, respectively; 34/83 carried both s1m1 alleles. The most frequent genotypes among the cagA positive isolates were vacA s1m1/cagA + and vacA s1m2/cagA + , accounting for 51.5% (34/66) and 48.5% (32/66) of the isolates, respectively. Conclusions There are two predominant lineages of H. pylori circulating in Vietnam; most of the isolates belong to the hspEastAsia population. The hpEurope population is further divided into two smaller clusters.

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Genomic differentiation within East Asian Helicobacter pylori

10.1101/2021.06.05.447026 ◽

2021 ◽

Author(s):

Yuanhai You ◽

Kaisa Thorell ◽

Lihua He ◽

Koji Yahara ◽

Yoshio Yamaoka ◽

...

Keyword(s):

Gastric Cancer ◽

Helicobacter Pylori ◽

Amino Acid ◽

Cancer Incidence ◽

Outer Membrane Proteins ◽

East Asian ◽

Fixation Index ◽

3D Protein Structure ◽

Local Conditions ◽

H Pylori

The East Asian region, including China, Japan and Korea, accounts for half of gastric cancer deaths. However, different areas have contrasting gastric cancer incidence and the population structure of Helicobacter pylori in this ethnically diverse region is yet unknown. We aimed to investigate genomic differences in H. pylori between these areas to identify sequence polymorphisms associated with increased cancer risk. We analysed 381 H. pylori genomes collected from different areas of the three countries using phylogenetic and population genetic tools to characterize population differentiation. The functional consequences of Single Nucleotide Polymorphisms (SNPs) with a highest fixation index (Fst) between subpopulations were examined by mapping amino-acid changes on 3D protein structure, solved or modelled. 329/381 genomes belonged to the previously identified hspEAsia population indicating that import of bacteria from other regions of the world has been uncommon. Seven sub-regional clusters were found within hspEAsia, related to sub-populations with various ethnicities, geographies and gastric cancer risks. Sub-population-specific amino-acid changes were found in multi-drug exporters (hefC), transporters (frpB-4), outer membrane proteins (hopI), and several genes involved in host interaction, such as catalase, involved in H2O2 entrance, and a flagellin site mimicking host glycosylation. Several of the top hits including frpB-4, hefC, alpB/hopB, and hofC. were also differentiated within the Americas, indicating that a handful of genes may be key to local geographic adaptation. H. pylori within East Asia are not homogeneous but have become differentiated geographically at multiple loci that have facilitated adaptation to local conditions and hosts. This has important implications for further evaluation of these changes in relation to the varying gastric cancer incidence between geographical areas in this region.

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Heterogeneity in the Activity of Mexican Helicobacter pylori Strains in Gastric Epithelial Cells and Its Association with Diversity in the cagA Gene

Infection and Immunity ◽

10.1128/iai.01951-06 ◽

2007 ◽

Vol 75 (7) ◽

pp. 3445-3454 ◽

Cited By ~ 44

Author(s):

Adriana Reyes-Leon ◽

John C. Atherton ◽

Richard H. Argent ◽

J. L. Puente ◽

J. Torres

Keyword(s):

Helicobacter Pylori ◽

Epithelial Cells ◽

Morphological Changes ◽

Cell Activity ◽

Variable Region ◽

Gastric Epithelial Cells ◽

Type Iv ◽

H Pylori ◽

Epiya Motifs ◽

In Cells

ABSTRACT Helicobacter pylori CagA is translocated into gastric epithelial cells by a type IV secretion system and interacts with the Src homology 2 phosphatase, altering cell morphology. Multiple EPIYA motifs in CagA are associated with increased activity in cells and with gastric cancer. The aim of this work was to study the heterogeneity in activity in cells of multiple H. pylori single colonies isolated from a single patient and its association with polymorphism in cagA. The presence of cagA, cagE, cagT, and cag10 was studied with 318 H. pylori isolates from the antra and corpora of 18 patients. AGS gastric epithelial cells were infected with 75 isolates, and interleukin-8 (IL-8) secretion, cytoskeletal changes, CagA translocation, and tyrosine phosphorylation were measured. The cagA 3′-variable region was sequenced for 30 isolates to determine the number and types of EPIYA motifs. Isolates from an individual stomach were usually genetically related and had quantitatively similar phenotypic effects on cells (IL-8 induction and cytoskeletal changes). However, strains from different patients with similar CagA EPIYA motif patterns varied widely in these phenotypes. Among isolates with an EPIYA-ABC pattern, the phenotype was variable: IL-8 induction ranged from 200 to 1,200 pg/ml, and morphological changes occurred in 20 to 70% of cells. In several cases, cagA sequence diversity appeared to explain the lack of CagA activity, as isolates with an EPIYA-ACC pattern or a modified B motif had reduced cell activity. cag pathogenicity island-positive H. pylori isolates displayed a high level of heterogeneity in the capacity to induce IL-8 secretion and morphological changes; an absent or modified B motif was associated with low activity.

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Increased Production of Matrix Metalloproteinases in Helicobacter pylori Infection that Stimulates Gastric Cancer Stem Cells

International Journal of Veterinary Science ◽

10.37422/ijvs/20.043 ◽

2020 ◽

Keyword(s):

Gastric Cancer ◽

Stem Cells ◽

Helicobacter Pylori ◽

Cancer Stem Cells ◽

Histopathological Examination ◽

Physiological Saline ◽

Rrna Gene ◽

Peptic Ulcers ◽

Gastric Cancer Stem Cells ◽

H Pylori

Background and aim: Helicobacter pylori (H. pylori) is an incriminated pathogen causing diseases in both animals and humans and considered a zoonotic pathogen. H. pylori infection is considered a cause of gastric cancer, which rests a significant health care challenge. This study analyzes the expression pattern of matrix metalloprotein 2 (MMP-2) in patients with Helicobacter pylori-associated gastritis and the effect of H. pylori on gastric cancer stem cells, as well as study the role of helicon bacteriosis in dog in transmission of H. pylori infection to human. Materials and methods: Fifty-five of each sample (gastric biopsy, blood and stool) were collected from patients suffering from dyspepsia, chronic vomiting and perforated peptic ulcers and also from apparent healthy dogs. The investigation detected H. pylori by serological and histopathological examination. Biopsies were stored in physiological saline for identification of H. pylori by conventional time PCR. MMP-2 and Gastric cancer stem cells were then identified by immunohistochemistry. Results: Serological identification for H. pylori Antigen and Antibodies revealed (63% human, 50% dogs) and (87% human, 90% dogs) respectively were positive. Genotyping of H. pylori based on 16S rRNA gene showed 54.5% of human and 35% of dogs were positive. Immunohistochemistry revealed strong expression of CD44 in H. pylori- associated gastric cancer cases, MMP-2 expression was observed in all neoplastic lesions associated with H. pylori infection. Conclusion: H. pylori infection affects gastric mucosa and induces changes in gastric stem cells altering their differentiation and increased expression of MMP’s and CD44with a resultant potentiation of oncogenic alteration. In addition the up-regulation of both markers could be an instrumental to interpret the origination of gastric cancer.

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The correlation between lncRNAs and Helicobacter pylori in gastric cancer

Pathogens and Disease ◽

10.1093/femspd/ftaa004 ◽

2019 ◽

Vol 77 (9) ◽

Author(s):

Narges Dastmalchi ◽

Seyed Mahdi Banan Khojasteh ◽

Mirsaed Miri Nargesi ◽

Reza Safaralizadeh

Keyword(s):

Gastric Cancer ◽

Helicobacter Pylori ◽

Molecular Mechanisms ◽

Gastrointestinal Diseases ◽

Mechanisms Of Action ◽

Molecular Pathways ◽

Gastric Diseases ◽

Non Coding Rnas ◽

H Pylori ◽

The Relationship

ABSTRACT Helicobacter pylori infection performs a key role in gastric tumorigenesis. Long non-coding RNAs (lncRNAs) have demonstrated a great potential to be regarded as effective malignancy biomarkers for various gastrointestinal diseases including gastric cancer (GC). The present review highlights the relationship between lncRNAs and H. pylori in GC. Several studies have examined not only the involvement of lncRNAs in H. pylori-associated GC progression but also their molecular mechanisms of action. Among the pertinent studies, some have addressed the effects of H. pylori infection on modulatory networks of lncRNAs, while others have evaluated the effects of changes in the expression level of lncRNAs in H. pylori-associated gastric diseases, especially GC. The relationship between lncRNAs and H. pylori was found to be modulated by various molecular pathways.

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Helicobacter pylori Outer Membrane Vesicles and Extracellular Vesicles from Helicobacter pylori-Infected Cells in Gastric Disease Development

International Journal of Molecular Sciences ◽

10.3390/ijms22094823 ◽

2021 ◽

Vol 22 (9) ◽

pp. 4823

Author(s):

María Fernanda González ◽

Paula Díaz ◽

Alejandra Sandoval-Bórquez ◽

Daniela Herrera ◽

Andrew F. G. Quest

Keyword(s):

Gastric Cancer ◽

Helicobacter Pylori ◽

Outer Membrane ◽

Extracellular Vesicles ◽

Membrane Vesicles ◽

Outer Membrane Vesicles ◽

Host Cells ◽

Gastric Epithelium ◽

Infected Cells ◽

H Pylori

Extracellular vesicles (EVs) are cell-derived vesicles important in intercellular communication that play an essential role in host-pathogen interactions, spreading pathogen-derived as well as host-derived molecules during infection. Pathogens can induce changes in the composition of EVs derived from the infected cells and use them to manipulate their microenvironment and, for instance, modulate innate and adaptive inflammatory immune responses, both in a stimulatory or suppressive manner. Gastric cancer is one of the leading causes of cancer-related deaths worldwide and infection with Helicobacter pylori (H. pylori) is considered the main risk factor for developing this disease, which is characterized by a strong inflammatory component. EVs released by host cells infected with H. pylori contribute significantly to inflammation, and in doing so promote the development of disease. Additionally, H. pylori liberates vesicles, called outer membrane vesicles (H. pylori-OMVs), which contribute to atrophia and cell transformation in the gastric epithelium. In this review, the participation of both EVs from cells infected with H. pylori and H. pylori-OMVs associated with the development of gastric cancer will be discussed. By deciphering which functions of these external vesicles during H. pylori infection benefit the host or the pathogen, novel treatment strategies may become available to prevent disease.

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Role of TNF-α-Inducing Protein Secreted by Helicobacter pylori as a Tumor Promoter in Gastric Cancer and Emerging Preventive Strategies

Toxins ◽

10.3390/toxins13030181 ◽

2021 ◽

Vol 13 (3) ◽

pp. 181

Author(s):

Masami Suganuma ◽

Tatsuro Watanabe ◽

Eisaburo Sueoka ◽

In Kyoung Lim ◽

Hirota Fujiki

Keyword(s):

Gastric Cancer ◽

Helicobacter Pylori ◽

Cell Surface Receptor ◽

Tumor Promoter ◽

Cancer Development ◽

Human Gastric Cancer ◽

Tnf Α ◽

Surface Receptor ◽

H Pylori ◽

Factor Α

The tumor necrosis factor-α (TNF-α)-inducing protein (tipα) gene family, comprising Helicobacter pylori membrane protein 1 (hp-mp1) and tipα, has been identified as a tumor promoter, contributing to H. pylori carcinogenicity. Tipα is a unique H. pylori protein with no similarity to other pathogenicity factors, CagA, VacA, and urease. American H. pylori strains cause human gastric cancer, whereas African strains cause gastritis. The presence of Tipα in American and Euro-Asian strains suggests its involvement in human gastric cancer development. Tipα secreted from H. pylori stimulates gastric cancer development by inducing TNF-α, an endogenous tumor promoter, through its interaction with nucleolin, a Tipα receptor. This review covers the following topics: tumor-promoting activity of the Tipα family members HP-MP1 and Tipα, the mechanism underlying this activity of Tipα via binding to the cell-surface receptor, nucleolin, the crystal structure of rdel-Tipα and N-terminal truncated rTipα, inhibition of Tipα-associated gastric carcinogenesis by tumor suppressor B-cell translocation gene 2 (BTG2/TIS21), and new strategies to prevent and treat gastric cancer. Thus, Tipα contributes to the carcinogenicity of H. pylori by a mechanism that differs from those of CagA and VacA.

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Helicobacter pylori Virulence Factors—Mechanisms of Bacterial Pathogenicity in the Gastric Microenvironment

Cells ◽

10.3390/cells10010027 ◽

2020 ◽

Vol 10 (1) ◽

pp. 27

Author(s):

Jacek Baj ◽

Alicja Forma ◽

Monika Sitarz ◽

Piero Portincasa ◽

Gabriella Garruti ◽

...

Keyword(s):

Gastric Cancer ◽

Helicobacter Pylori ◽

Gastric Mucosa ◽

Virulence Factors ◽

Premalignant Lesions ◽

Bacterial Pathogenicity ◽

Current State ◽

Genetic And Environmental Factors ◽

H Pylori ◽

Stimulation Of

Gastric cancer constitutes one of the most prevalent malignancies in both sexes; it is currently the fourth major cause of cancer-related deaths worldwide. The pathogenesis of gastric cancer is associated with the interaction between genetic and environmental factors, among which infection by Helicobacter pylori (H. pylori) is of major importance. The invasion, survival, colonization, and stimulation of further inflammation within the gastric mucosa are possible due to several evasive mechanisms induced by the virulence factors that are expressed by the bacterium. The knowledge concerning the mechanisms of H. pylori pathogenicity is crucial to ameliorate eradication strategies preventing the possible induction of carcinogenesis. This review highlights the current state of knowledge and the most recent findings regarding H. pylori virulence factors and their relationship with gastric premalignant lesions and further carcinogenesis.

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