Surface Antigen Profiling of Helicobacter pylori-Infected and -Uninfected Gastric Cancer Cells Using Antibody Microarray

CD27 as a Diagnostic Biomarker and Its Role in Immune Heterogeneity and Predicting Clinical Drug Responses in Hashimoto's Thyroiditis

Objective

To identify key genes and potential molecular mechanisms associated with Hashimoto's thyroiditis (HT) to provide new insights for the development of diagnostic and therapeutic targets for this disease.

Methods

Differential expression analysis and weighted gene co-expression network analysis (WGCNA) were conducted to identify the differentially expressed genes (DEGs) associated with HT. A protein-protein interaction (PPI) network was used to obtain hub genes, with CD27 emerging as the key gene in HT. Gene Ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, Gene Set Enrichment Analysis (GSEA), and HT-infiltrating immune cell components as well as functions were performed to further investigate the role and potential mechanism of CD27 in cohorts with high and low expression of CD27.

Results

CD27 was found to be upregulated in HT tissues and showed considerable clinical utility in HT. The CD27 of the high-expression cohort exhibited a higher enrichment in immune-related biological processes than the low-expression group. Cell-type Identification by Estimating Relative Subsets of RNA Transcripts (CIBERSORT) analysis revealed that several activated HT-infiltrating immune cells were strongly associated with CD27, suggesting that CD27 has the potential to be a marker for the immune state in HT.

Conclusion

In our study, CD27 was found to contribute to predicting clinical outcomes in patients with HT, including disease status and response to immunotherapy. CD27 is a promising biomarker for HT microenvironment remodeling, offering insights into new therapeutic approaches to improve treatment of HT.

Helicobacter Pylori and Gastric Cancer Progression

Gastric cancer (GC) remains the fifth most common malignant tumor and the third leading cause of cancer death, despite the decline in incidence and mortality worldwide over the past five decades. Currently, the roles of Helicobacter pylori (H. pylori) in the development of GC have been established. The effects of H. pylori are mediated through interactions of H. pylori pathogen-associated molecular patterns (PAMPs) with pattern-recognition receptors (PRRs) located on immune and epithelial cells. It is known that this interaction leads to the generation of reactive oxygen species (ROS), activation of the mechanisms of angiogenesis, epithelial-mesenchymal transformation (EMT), and immunological tolerance. Not all this excludes the possibility that H. pylori may have an effect not only on the induction, but also on the mechanisms of GC progression. In this review, we will consider the main structural elements of the innate immune system and the mechanisms of their interaction with H. pylori; the possible role of H. pylori in GC progression; relationship of H. pylori with clinical and pathological characteristics and prognosis of GC, as well as data on the effect of eradication therapy on long-term results of GC patient treatment.

New insight on the role of Helicobacter pylori cagA in the expression of cell surface antigens with important biological functions in gastric carcinogenesis

BACKGROUND

Expression of cluster of differentiation (CD) antigens changes according to disease status and inflammation. Profiles of CD antigens expression in gastric cancer patients are different based on the status of H. pylori infection.

AIMS

We conducted this study to profile CD antigen markers in gastric adenocarcinoma cells (AGS cell line) infected with distinct cytotoxin-associated gene A (cagA) genotypes of H. pylori clinical isolates.

METHODS

The AGS cells were infected with H. pylori isolates with different cagA genotypes, and CD antigens expression was determined using DotScan™ antibody microarray. Formation of "hummingbird" phenotype was determined, and the percentage was calculated.

RESULTS

H. pylori strains harboring cagA upregulated the expression of CD antigen involved in cancer stem cell formation (CD55), but downregulated CD antigens involved in immune regulation (CD40 and CD186) and cell adhesion (CD44). CD54 (neutrophil adhesion) and CD71 (iron transfer) were highly downregulated in the gastric cells infected with Western cagA isolates compared with East Asian isolates. CD antigen expression was different in the cells infected with H. pylori harboring different CagA EPIYA (Glu-Pro-Ile-Tyr-Ala) numbers, in which higher repression of CD54 and CD15 (Lewis x antigen) were observed in the isolate with the highest number of EPIYA motif. Furthermore, higher downregulation of CD15 was observed in the infected gastric cells with high percentage of "hummingbird" phenotype than that of low percentage of "hummingbird" phenotype.

CONCLUSION

Our study demonstrated the critical roles of CD antigens in the CagA pathogenesis and should be investigated further.

The Roles of Immune Cells in Gastric Cancer: Anti-Cancer or Pro-Cancer?

Simple Summary

Gastric cancer is still one of the leading causes of death caused by cancer in developing countries. The emerging role of immunotherapy in cancer treatment has led to more research to elucidate the roles of essential immune cells in gastric cancer prognosis. We reviewed the roles of immune cells including T cells, B cells, dendritic cells, macrophages and natural killer cells in gastric cancer. Although the studies conducted on the roles of immune cells in gastric cancer pathogenesis produced conflicting results, understanding the roles of immune cells in gastric cancer will help us to harness them for application in immunotherapy for better prognosis and management of gastric cancer patients.

Abstract

Despite the fact that the incidence of gastric cancer has declined over the last decade, it is still the world’s leading cause of cancer-related death. The diagnosis of early gastric cancer is difficult, as symptoms of this cancer only manifest at a late stage of cancer progression. Thus, the prognosis of gastric cancer is poor, and the current treatment for improving patients’ outcomes involves the application of surgery and chemotherapy. Immunotherapy is one of the most recent therapies for gastric cancer, whereby the immune system of the host is programmed to combat cancer cells, and the therapy differs based upon the patient’s immune system. However, an understanding of the role of immune cells, namely the cell-mediated immune response and the humoral immune response, is pertinent for applications of immunotherapy. The roles of immune cells in the prognosis of gastric cancer have yielded conflicting results. This review discusses the roles of immune cells in gastric cancer pathogenesis, specifically, T cells, B cells, macrophages, natural killer cells, and dendritic cells, as well as the evidence presented thus far. Understanding how cancer cells interact with immune cells is of paramount importance in designing treatment options for gastric cancer immunotherapy.

Epidemiology and role of Helicobacter pylori virulence factors in gastric cancer carcinogenesis

Infection with Helicobacter pylori is associated with the development of gastric cancer. Although the prevalence of gastric cancer has declined throughout years due to improvement in early screening strategy, mortality due to gastric cancer has not changed. Incidence and mortality due to gastric cancer are higher in developing countries as compared to developed countries. Diagnosis and prognosis of gastric cancer are still poor with patients usually diagnosed with cancer at an advanced stage. Eradication of H. pylori is pertinent for the prevention of gastric cancer. However, the rise in antimicrobial resistance among H. pylori isolates has complicated the prevention strategy. H. pylori express multiple virulence factors for survival in the hostile acid gastric environment. The expression of oncogenic protein cytotoxin-associated gene A (CagA), vacuolating cytotoxin A (VacA), and outer inflammatory protein is essential for H. pylori to exert pathogenesis towards the host. Interestingly, <3% of H. pylori-infected subjects develop gastric cancer, suggesting a unique way of interaction between the host's immune response and H. pylori virulence factors. This article is aimed to review the epidemiology and role of H. pylori in gastric carcinogenesis. A better understanding of the interaction between H. pylori virulence factors and host is required for better gastric cancer prevention.

A Review of Gastric Cancer Research in Malaysia

Incidence rates of gastric cancer in Malaysia has declined by 48% among males and 31% among females in the latest reporting period of 13 years. Malays used to have age-standardized-rates only a fifth of those in Chinese and Indians, but the incidence among them is slightly rising even as the rates drop in the other races. Besides ethnicity, a low level of education, high intake of salted fish and vegetables, H pylori infection and smoking are risk factors. Consumption of fresh fruit and vegetable is protective. Variation in the strains of H pylori infection affect gastric cancer risk, with hspEAsia isolates among Chinese appearing linked to a high incidence than with hpAsia2 or hpEurope strains among Indians and Malays. It was reported in the 1980s that only about 3% of patients presented with early gastric cancer, but more encouraging rates reaching 27% with Stage 1 and 2 disease have been reported in the twenty-first century from leading centres. More tumours occur in the distal stomach except in Kelantan, where the incidence is low and main site is the cardia. Prompt endoscopy is advocated and open access, with direct referrals, to such services using a weighted scoring system should be more utilized. In view of the high rate of late disease laparoscopic staging unnecessary laparotomy needs to be avoided. Late presentation of gastric cancer however, is still predominant and the mortality to incidence ratio is relatively high. Besides seeking to reduce risk factors and achieve early detection, implementation of improved care for patients with late disease must be promoted in Malaysia.

Current applications of antibody microarrays

The concept of antibody microarrays is one of the most versatile approaches within multiplexed immunoassay technologies. These types of arrays have increasingly become an attractive tool for the exploratory detection and study of protein abundance, function, pathways, and potential drug targets. Due to the properties of the antibody microarrays and their potential use in basic research and clinical analytics, various types of antibody microarrays have already been developed. In spite of the growing number of studies utilizing this technique, few reviews about antibody microarray technology have been presented to reflect the quality and future uses of the generated data. In this review, we provide a summary of the recent applications of antibody microarray techniques in basic biology and clinical studies, providing insights into the current trends and future of protein analysis.