H. pylori slyD, a novel virulence factor, is associated with Wnt pathway protein expression during gastric disease progression

The role of the tumor microenvironment and inflammatory pathways in driving drug resistance in gastric cancer: A systematic review and meta-analysis

Tumor microenvironment (TME) plays a pivotal role in progression and low responsiveness to chemotherapy of gastric cancer (GC). The cascade of events that culminate with a sustained and chronic activation of inflammatory pathways underlies gastric tumorigenesis. Infiltrating immune cells enrolling in crosstalk with cancer cells that regulate inflammatory and immune status, generating an immunosuppressive TME that influences the response to therapy. Here we discuss the role of TME and the activation of inflammatory pathways to comprehend strategies to improve drug response. Furthermore, we provides systematic insight the role of TME cytotypes and related signatures reinforcing the critical roles of TAMs and Tregs, in promoting GC chemoresistance and tumor progression.

Helicobacter pylori SlyD stabilizes TPT1 via hnRNPK and enhances OCT1-mediated CDX2 transcriptional activation to drive gastric intestinal metaplasia

BACKGROUND

Gastric intestinal metaplasia (GIM) represents an important precancerous lesion in intestinal-type gastric cancer, triggered by persistent Helicobacter pylori (H. pylori) infection. In a previous study, we unveiled SlyD as a novel virulence factor of H. pylori, establishing its role in GIM induction through TPT1. However, the underlying mechanism remains undetermined.

METHODS

Gastric epithelial cells were stimulated with H. pylori 26695, a SlyD inactivated mutant (ΔSlyD), and purified HpSlyD protein, respectively. Real-time qPCR and western blot were subsequently used to assess the expression levels of hnRNPK, TPT1, OCT1, and GIM markers. RNA sequencing was employed to identify differentially expressed genes associated with H. pylori SlyD infection. Protein stability was evaluated using cycloheximide. Molecular interactions were investigated through co-immunoprecipitation, chromatin immunoprecipitation, and dual-luciferase reporter assays. Additionally, molecular docking was utilized to predict TPT1 inhibitors. Immunohistochemistry staining was conducted to validate hnRNPK, TPT1, OCT1, and CDX2 expression in gastric tissue samples from both human and Mongolian gerbils.

RESULTS

H. pylori SlyD upregulates TPT1 and induces the expression of GIM markers through hnRNPK. The interaction between hnRNPK and TPT1 enhances TPT1 protein stability, with H. pylori SlyD intensifying this association. TPT1 promotes the expression of GIM markers mediated via OCT1, which binds to CDX2 promoter region, thereby modulating its transcriptional activity. Dihydroartemisinin has the potential to target TPT1, inhibiting the H. pylori SlyD-induced expression of GIM markers.

CONCLUSIONS

In vitro and in vivo experiments verified that H. pylori SlyD enhances TPT1 stability through hnRNPK, leading to OCT1-mediated transcriptional activation of CDX2 and the initiation of the GIM process. Our study offers novel perspectives on the pathogenesis of H. pylori-related gastric precancerous conditions.

Research on drug treatment and the novel signaling pathway of chronic atrophic gastritis

BACKGROUND

Chronic atrophic gastritis (CAG) is a global digestive system disease and one of the important causes of gastric cancer. The incidence of CAG has been increasing yearly worldwide.

PURPOSE

This article reviews the latest research on the common causes and future therapeutic targets of CAG as well as the pharmacological effects of corresponding clinical drugs. We provide a detailed theoretical basis for further research on possible methods for the treatment of CAG and reversal of the CAG process.

RESULTS

CAG often develops from chronic gastritis, and its main pathological manifestation is atrophy of the gastric mucosa, which can develop into gastric cancer. The drug treatment of CAG can be divided into agents that regulate gastric acid secretion, eradicate Helicobacter. pylori (H. pylori), protect gastric mucous membrane, or inhibit inflammatory factors according to their mechanism of action. Although there are limited specific drugs for the treatment of CAG, progress is being made in defining the pathogenesis and therapeutic targets of the disease. Growing evidence shows that NF-κB, PI3K/AKT, Wnt/ β-catenin, MAPK, Toll-like receptors (TLRs), Hedgehog, and VEGF signaling pathways play an important role in the development of CAG.

Effects of Helicobacter pylori and Moluodan on the Wnt/β-catenin signaling pathway in mice with precancerous gastric cancer lesions

BACKGROUND

Helicobacter pylori (H. pylori) is the primary risk factor for gastric cancer (GC), the Wnt/β-Catenin signaling pathway is closely linked to tumourigenesis. GC has a high mortality rate and treatment cost, and there are no drugs to prevent the progression of gastric precancerous lesions to GC. Therefore, it is necessary to find a novel drug that is inexpensive and preventive to against GC.

AIM

To explore the effects of H. pylori and Moluodan on the Wnt/β-Catenin signaling pathway and precancerous lesions of GC (PLGC).

METHODS

Mice were divided into the control, N-methyl-N-nitrosourea (MNU), H. pylori + MNU, and Moluodan groups. We first created an H. pylori infection model in the H. pylori + MNU and Moluodan groups. A PLGC model was created in the remaining three groups except for the control group. Moluodan was fed to mice in the Moloudan group ad libitum. The general condition of mice were observed during the whole experiment period. Gastric tissues of mice were grossly and microscopically examined. Through quantitative real-time PCR (qRT-PCR) and Western blotting analysis, the expression of relevant genes were detected.

RESULTS

Mice in the H. pylori + MNU group showed the worst performance in general condition, gastric tissue visual and microscopic observation, followed by the MNU group, Moluodan group and the control group. QRT-PCR and Western blotting analysis were used to detect the expression of relevant genes, the results showed that the H. pylori + MNU group had the highest expression, followed by the MNU group, Moluodan group and the control group.

CONCLUSION

H. pylori can activate the Wnt/β-catenin signaling pathway, thereby facilitating the development and progression of PLGC. Moluodan suppressed the activation of the Wnt/β-catenin signaling pathway, thereby decreasing the progression of PLGC.

Inflammatory microenvironment in gastric premalignant lesions: implication and application

Gastric precancerous lesions (GPL) are a major health concern worldwide due to their potential to progress to gastric cancer (GC). Understanding the mechanism underlying the transformation from GPL to GC can provide a fresh insight for the early detection of GC. Although chronic inflammation is prevalent in the GPL, how the inflammatory microenvironment monitored the progression of GPL-to-GC are still elusive. Inflammation has been recognized as a key player in the progression of GPL. This review aims to provide an overview of the inflammatory microenvironment in GPL and its implications for disease progression and potential therapeutic applications. We discuss the involvement of inflammation in the progression of GPL, highlighting Helicobacter pylori (H. pylori) as a mediator for inflammatory microenvironment and a key driver to GC progression. We explore the role of immune cells in mediating the progression of GPL, and focus on the regulation of inflammatory molecules in this disease. Furthermore, we discuss the potential of targeting inflammatory pathways for GPL. There are currently no specific drugs for GPL treatment, but traditional Chinese Medicine (TCM) and natural antioxidants, known as antioxidant and anti-inflammatory properties, exhibit promising effects in suppressing or reversing the progression of GPL. Finally, the challenges and future perspectives in the field are proposed. Overall, this review highlights the central role of the inflammatory microenvironment in the progression of GPL, paving the way for innovative therapeutic approaches in the future.

Jian-Pi-Yi-Qi-Fang ameliorates chronic atrophic gastritis in rats through promoting the proliferation and differentiation of gastric stem cells

Background

Jian-Pi-Yi-Qi-Fang (JPYQF) is a traditional Chinese medicine (TCM) herbal formula for treating chronic atrophic gastritis (CAG) in the clinic; however, its related mechanism remains unclear. The purpose of this study was to explore the potential mechanisms of JPYQF in treating CAG by examining proteins and genes related to the proliferation and differentiation of gastric stem cells and Wnt signaling.

Methods

A CAG model was established in Sprague-Dawley (SD) rats which were induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and ranitidine. We randomly divided 25 CAG rats into 5 groups: the model group, positive drug group, low-dose group of JPYQF (JPYQF-L), middle-dose group of JPYQF (JPYQF-M), and high-dose group of JPYQF (JPYQF-H), with 5 rats of the same age classified into the control group. The body weight of rats was measured and their gastric morphology was visually assessed. Furthermore, pathological analysis of rat gastric tissue was performed. The expression levels of proteins and genes associated with the proliferation and differentiation of gastric stem cells and Wnt signaling were measured via immunohistochemistry and reverse transcription quantitative polymerase chain reaction (RT-qPCR).

Results

Compared with the model group, treatment with JPYQF increased the body weight of the rats, and relieved the gastric atrophy and inflammation. Compared with the control group, the protein and messenger RNA (mRNA) expression levels of gastric stem cell proliferation and differentiation markers Lgr5, Sox2, Ki67, PCNA, Muc5AC, and Wnt signaling initiator Wnt3A and enhancer R-spondin-1 (Rspo1) were decreased in the model group. Treatment with JPYQF increased the protein and mRNA expression levels of these markers.

Conclusions

The Wnt signaling of CAG rats may be in a low activation state, which inhibits the proliferation and differentiation of gastric stem cells, so that gland cells cannot be replenished in time to repair the damaged gastric mucosa. The TCM formula JPYQF could enhance Wnt signaling to promote the restricted proliferation and normal differentiation of gastric stem cells, thereby improving gastric mucosal atrophy in CAG rats, which provides a novel and robust theoretical basis for CAG treatment.

Helicobacter pylori infection induces stem cell-like properties in Correa cascade of gastric cancer

Gastric cancer (GC) is the fourth leading cause of cancer-related death. Its poor prognosis is attributed to unclear pathogenesis. Currently, the most widely accepted model for elucidating the mechanism of GC is the Correa cascade, which covers several histological lesions of the gastric mucosa. GC stem cells (CSCs) are crucial for oncogenesis in the Correa cascade and GC progression. As Helicobacter pylori (H. pylori) is the etiological factor in the Correa cascade, growing evidence suggests that enhancement of gastric stem cell-like properties and increase in CSCs correlate with H. pylori infection. In this paper, we review recent studies that present pathogenic mechanisms by which H. pylori induces gastric stem cell-like properties and CSCs, which may supplement the existing Correa model of GC. First, the dysfunction of developmental signaling pathways associated with H. pylori infection leads to the enhancement of gastric stemness. Second, H. pylori infection promotes alteration of the gastric mucosal microenvironment. In addition, epithelial-mesenchymal transition (EMT) may contribute to H. pylori-induced gastric stemness. Taken together, understanding these pathogeneses will provide potential therapeutic targets for the treatment of CSCs and malignant GC in H. pylori induced-Correa cascade of GC.

Jianpiyiqi formula ameliorates chronic atrophic gastritis in rats by modulating the Wnt/β-catenin signaling pathway

Jianpiyiqi formula is a Traditional Chinese Medicine (TCM) prescription and is used for the clinical treatment of patients with chronic atrophic gastritis (CAG). The aim of the present study was to examine the underlying mechanisms of Jianpiyiqi formula treatment for CAG via the Wnt/β-catenin signaling pathway. The high-performance liquid chromatography (HPLC) chromatogram of Jianpiyiqi formula was constructed. A CAG rat model induced by N-methyl-N'-nitro-N-nitrosoguanidine and ranitidine was established. The body weight and food intake of the rats was recorded and rat gastric morphology was visually examined. Pathological analysis of rat gastric tissue was also performed. The levels of gastrin (GAS), pepsin (PP), somatostatin (SS) and prostaglandin E₂ (PGE₂) in rat serum were detected using ELISAs. The expression levels of proteins and genes associated with the Wnt/β-catenin signaling pathway were measured via immunohistochemistry and reverse transcription-quantitative PCR. The HPLC chromatogram of Jianpiyiqi formula was determined and as active components, liquiritin and hesperidin were identified from the chromatogram. Compared with the blank group, the body weight and feed intake of the rats were decreased, and gastric mucosal atrophy and inflammation appeared in the model group. Treatment with Jianpiyiqi formula increased the body weight and feed intake of the rats, as well as relieved the gastric atrophy and inflammation. The contents of GAS, PP, SS and PGE₂ were significantly reduced in the model group compared with the blank group. Jianpiyiqi formula significantly increased GAS, PP, SS and PGE₂ levels in serum of rats with CAG. In the model group, Wnt1, β-catenin and cyclin D1 protein expression levels were increased, and glycogen synthase kinase-3β (GSK-3β) protein expression levels were decreased. Jianpiyiqi formula decreased the protein expression levels of Wnt1, β-catenin and cyclin D1 and increased the protein expression levels of GSK-3β. Compared with the blank group, the mRNA expression levels of Wnt1, Wnt5a, β-catenin, cyclin D1 and MMP7 were upregulated, and the mRNA expression levels of GSK-3β were downregulated in the model group. Treatment with Jianpiyiqi formula downregulated the mRNA expression levels of Wnt1, Wnt5a, β-catenin, cyclin D1 and MMP7 and upregulated the mRNA expression levels of GSK-3β. All of the experimental results indicated that Jianpiyiqi formula exerted a therapeutic effect on rats with CAG and inhibited the activation of the Wnt/β-catenin signaling pathway. Thus, Jianpiyiqi formula, as an effective TCM prescription for treating patients with CAG, may be more widely used in the clinic.