H. pylori-induced NF-κB-PIEZO1-YAP1-CTGF axis drives gastric cancer progression and cancer-associated fibroblast-mediated tumour microenvironment remodelling

Signalling pathways in a nutshell: from pathogenesis to therapeutical implications in prostate cancer

From tumorigenesis to the establishment of local or metastatic high-grade tumours, an integral part of the cellular lifespan relies on various signalling pathways. Particular pathways that allow cells to proliferate by creating a network of new blood vessels have been documented, whereas other pathways are primarily involved with a migration to distant body parts, partially through the process of epithelial-mesenchymal transition (EMT). This review will discuss the different signalling pathways, such as TGF-β, Cripto-1, Wnt pathways, Hedgehog, Notch and NF-κB pathways, and how they promote tumour initiation and progression by influencing diverse cellular processes and EMT in general and in benign and malignant prostate tumours. This review will discuss only the critical pathways. Therefore, many other types of signalling pathways which are related to prostate cancer will not be discussed. Possibilities for further investigation will be mentioned, as many underlying mechanisms involved in these pathways have potential as targets in future tumour therapy. This review will also introduce some novel clinical trials relating to the inhibition of signalling pathways and their clinical outcomes.

Decoding the role of intratumoral microbiota in gastric cancer

Intratumoral microbiota are increasingly recognized for their impact on gastric cancer, with growing evidence highlighting their complexity and significance. This review synthesizes current knowledge on the origins, heterogeneity, detection, and mechanistic roles of intratumoral microbiota in gastric carcinogenesis. In gastric cancer, intratumoral microbiota can originate from mucosal disruption and may migrate from normal adjacent tissues or be influenced by the TME. It exhibits spatial and functional heterogeneity within gastric cancer. Despite challenges in the detection of intratumoral microbiota, advances in deep sequencing and spatial omics have enhanced our understanding of microbial diversity and functionality. Mechanistically, intratumoral microbiota influence gastric cancer development through genetic and epigenetic alterations, signaling pathway modulation, metabolic reprogramming, and regulation of chronic inflammation and immune responses. These insights underscore the microbiota's dual function in both promoting and hindering tumor advancement. Therapeutically, the microbiota's impact on chemotherapy resistance and immune modulation presents opportunities for novel interventions. Integrating microbiome analysis into cancer research and leveraging microbial therapies may enable more effective, personalized treatment strategies. Future research should further elucidate the intricate microbe-tumor interactions to advance clinical applications and improve outcomes for gastric cancer patients.

Metabolic alterations and immune heterogeneity in gastric cancer metastasis

Cellular metabolic reprogramming supports tumor proliferation, invasion, and metastasis by enhancing resistance to stress and immune clearance. Understanding these metabolic changes within the tumor microenvironment is vital to developing effective therapies. We conducted single-cell RNA sequencing on 11 gastric cancer (GC) samples and eight metastatic lesions, analyzing 92,842 cells across eight cell types, including cancer cells, stromal cells, and immune cells. Our findings highlight that the mitochondrial ATP synthase subunit ATP5MC2 uniquely alters during early GC metastasis. Experiments and clinical data confirmed that ATP5MC2 upregulation facilitates cancer cell proliferation, invasion, and metastasis. Constructing a single-cell atlas revealed significant immune cell heterogeneity associated with GC metastasis and its molecular subtypes. This study underscores the role of ATP5MC2-driven metabolic changes and diverse immune landscapes in promoting GC metastasis, offering new avenues for anti-metastatic treatment development.

Molecular mechanisms of metastatic peritoneal dissemination in gastric adenocarcinoma

Peritoneal dissemination portends a dismal prognosis in patients with gastric adenocarcinoma in the context of limited effective treatments. The underlying cellular processes that drive gastric peritoneal carcinomatosis remain unclear, limiting the application of novel targeted therapies. In this comprehensive review, we aimed to identify and summarize all existing context-dependent molecular mechanisms that have been implicated in peritoneal dissemination and peritoneal carcinomatosis establishment from primary gastric adenocarcinoma. We applied a multilevel examination including data from in vivo murine models using human gastric cancer cell lines, in vitro technique-based studies, ex vivo models, and genomic/proteomic and molecular profiling analyses to report on various aspects of gastric cancer peritoneal metastasis biology. Mechanisms promoting peritoneal dissemination were grouped into three main functional categories: (1) intrinsic cancer cell biology, (2) cancer cell-peritoneal surface adhesion, and (3) peritoneal tumor microenvironment. We identified significant overlap among the three categories, indicating a complex interplay between multiple molecular mechanisms. By interrupting these pathways, peritoneal-directed therapies have the potential to improve quality and length of life in patients with high-risk primary gastric cancer.

Lactic acid bacteria target NF-κB signaling to alleviate gastric inflammation

Helicobacter pylori (H. pylori) infection and the resulting gastric inflammation are major contributors to gastric cancer development. Probiotics, particularly Lactobacillus, are promising for their anti-inflammatory potential, yet their exact mechanisms in inhibiting H. pylori-induced inflammation are unclear. In our previous study, Lactiplantibacillus plantarum ZJ316 (L. plantarum ZJ316) demonstrated strong anti-inflammatory effects against H. pylori infection in vivo, but its precise mechanisms were not fully understood. Here, we aimed to investigate how L. plantarum ZJ316 inhibits the inflammatory response to H. pylori infection. Our results demonstrated that L. plantarum ZJ316 effectively reduced the expression of pro-inflammatory cytokines in H. pylori-infected AGS cells. Mechanistically, L. plantarum ZJ316 inhibited the NF-κB signaling pathway by preventing the degradation of IκBα, suppressing p65 phosphorylation, and blocking the nuclear translocation of phosphorylated p65. Treatment with the NF-κB inhibitor BAY 11-7082 further decreased tumor necrosis factor-α (TNF-α), interleukin-8 (IL-8), and interleukin-1β (IL-1β) levels, confirming the inhibitory effect of L. plantarum ZJ316 on the NF-κB pathway. In H. pylori-infected mice, oral administration of L. plantarum ZJ316 significantly alleviated inflammatory cell infiltration, reduced TNF-α and pepsinogen II (PGII) levels, and increased interleukin-10 (IL-10) levels in serum. A comparative metagenomic analysis of the gastric microbiota revealed a decrease in Prevotella and Desulfovibrio, alongside an increase in Ligilactobacillus and Akkermansia, supporting the protective effects of L. plantarum ZJ316 and correlating with their decreased inflammatory response. In summary, administration of L. plantarum ZJ316 demonstrated robust anti-inflammatory effects against H. pylori infection by suppressing NF-κB signaling and promoting favorable changes in the gastric microbiota composition. Therefore, L. plantarum ZJ316 holds promise as a novel functional food for protecting the body against H. pylori infection.

Advancements in the Pathogenesis, Diagnosis, and Therapeutic Implications of Intestinal Bacteria

Intestinal bacteria form one of the most complex microbial communities in the human body, playing a crucial role in maintaining host health and contributing to the development of various diseases. Here, we provide a comprehensive overview of the composition and function of intestinal bacteria, the factors affecting their homeostasis, and their association and mechanisms with a range of diseases (e.g., inflammatory bowel diseases, colorectal cancer, metabolic diseases). Additionally, their advanced potential in disease diagnosis and treatment is highlighted. Therapies, such as chemotherapy, radiotherapy, and immunotherapy, are significantly impacted by intestinal bacteria, with research indicating that bacteria can enhance chemoimmunotherapy efficiency by affecting T cell recruitment and immune cell infiltration. Fecal microbiota transplantation has emerged as a promising option for treating recurrent Clostridium difficile infections and certain metabolic and neurological disorders. Gut bacteria-related serum metabolites serve as non-invasive indicators for diagnosing CRC, while fecal immunochemical tests offer promising applications in CRC screening. Future research is needed to better understand the causal relationships between intestinal bacteria and diseases, develop more precise diagnostic tools, and evaluate the effectiveness and safety of microbiome-targeted therapies in clinical treatment. This study provides deeper insights into the role of intestinal bacteria in human health and disease, providing a scientific basis for innovative therapeutic strategies that have the potential to transform the landscape of healthcare.

Helicobacter pylori and gastric cancer: mechanisms and new perspectives

Gastric cancer remains a significant global health challenge, with Helicobacter pylori (H. pylori) recognized as a major etiological agent, affecting an estimated 50% of the world's population. There has been a rapidly expanding knowledge of the molecular and pathogenetic mechanisms of H. pylori over the decades. This review summarizes the latest research advances to elucidate the molecular mechanisms underlying the H. pylori infection in gastric carcinogenesis. Our investigation of the molecular mechanisms reveals a complex network involving STAT3, NF-κB, Hippo, and Wnt/β-catenin pathways, which are dysregulated in gastric cancer caused by H. pylori. Furthermore, we highlight the role of H. pylori in inducing oxidative stress, DNA damage, chronic inflammation, and cell apoptosis-key cellular events that pave the way for carcinogenesis. Emerging evidence also suggests the effect of H. pylori on the tumor microenvironment and its possible implications for cancer immunotherapy. This review synthesizes the current knowledge and identifies gaps that warrant further investigation. Despite the progress in our previous knowledge of the development in H. pylori-induced gastric cancer, a comprehensive investigation of H. pylori's role in gastric cancer is crucial for the advancement of prevention and treatment strategies. By elucidating these mechanisms, we aim to provide a more in-depth insights for the study and prevention of H. pylori-related gastric cancer.

Facilitation of Tumor Stroma-Targeted Therapy: Model Difficulty and Co-Culture Organoid Method

Background: Tumors, as intricate ecosystems, comprise oncocytes and the highly dynamic tumor stroma. Tumor stroma, representing the non-cancerous and non-cellular composition of the tumor microenvironment (TME), plays a crucial role in oncogenesis and progression, through its interactions with biological, chemical, and mechanical signals. This review aims to analyze the challenges of stroma mimicry models, and highlight advanced personalized co-culture approaches for recapitulating tumor stroma using patient-derived tumor organoids (PDTOs). Methods: This review synthesizes findings from recent studies on tumor stroma composition, stromal remodeling, and the spatiotemporal heterogeneities of the TME. It explores popular stroma-related models, co-culture systems integrating PDTOs with stromal elements, and advanced techniques to improve stroma mimicry. Results: Stroma remodeling, driven by stromal cells, highlights the dynamism and heterogeneity of the TME. PDTOs, derived from tumor tissues or cancer-specific stem cells, accurately mimic the tissue-specific and genetic features of primary tumors, making them valuable for drug screening. Co-culture models combining PDTOs with stromal elements effectively recreate the dynamic TME, showing promise in personalized anti-cancer therapy. Advanced co-culture techniques and flexible combinations enhance the precision of tumor-stroma recapitulation. Conclusions: PDTO-based co-culture systems offer a promising platform for stroma mimicry and personalized anti-cancer therapy development. This review underscores the importance of refining these models to advance precision medicine and improve therapeutic outcomes.

Is Chronic Ice Water Ingestion a Risk Factor for Gastric Cancer Development? An Evidence-Based Hypothesis Focusing on East Asian Populations

This article introduces a novel risk factor for gastric cancer (GC) by analyzing available epidemiological data from East Asian populations. A significantly higher age-standardized GC rate was observed in Japanese and Korean populations than in Chinese populations, despite nearly identical ethnicity, food habits, obesity rates, and alcohol consumption. Given the pivotal role of environmental factors in GC development, particularly for the intestinal type, a thorough evaluation of the lifestyles of these three populations was conducted to identify commonalities and disparities. It was observed that Japanese and Korean individuals prefer consuming ice water, while Chinese individuals tend to drink warm water, potentially influenced by traditional Chinese medicine disciplines. Considering the key features of GC development, a literature review was conducted to investigate the mechanisms through which the consumption of ice water might contribute to GC initiation and progression. Mechanistically, exposing gastric cells to hypothermia can increase the risk of carcinogenesis through multiple pathways. This includes the promotion of Helicobacter pylori colonization, prolonged gastric inflammation, and mitochondrial dysfunction in gastric cells. Furthermore, drinking ice water can enhance the survival, proliferation, and invasion of GC cells by releasing cold shock proteins, increasing gastric acid secretion, and delaying gastric emptying. Additionally, hypothermia can boost the immune evasion of cancer cells by weakening the antitumor immune system and activating different components of the tumor microenvironment. This paper also explores the association between exposure of GC cells to hypothermia and current insights into cancer hallmarks. These findings may partially elucidate the higher incidence of GC in Japanese and Korean populations and provide a clue for future experimental studies.Graphical abstract available for this article.

Novel immunotherapeutic approaches in gastric cancer

Gastric cancer is a malignant tumor that ranks third in cancer-related deaths worldwide. Early-stage gastric cancer can often be effectively managed through surgical resection. However, the majority of cases are diagnosed in advanced stages, where outcomes with conventional radiotherapy and chemotherapy remain unsatisfactory. Immunotherapy offers a novel approach to treating molecularly heterogeneous gastric cancer by modifying the immunosuppressive tumor microenvironment. Immune checkpoint inhibitors and adoptive cell therapy are regarded as promising modalities in cancer immunotherapy. Food and Drug Administration-approved programmed death-receptor inhibitors, such as pembrolizumab, in combination with chemotherapy, have significantly extended overall survival in gastric cancer patients and is recommended as a first-line treatment. Despite challenges in solid tumor applications, adoptive cell therapy has demonstrated efficacy against various targets in gastric cancer treatment. Among these approaches, chimeric antigen receptor-T cell therapy research is the most widely explored and chimeric antigen receptor-T cell therapy targeting claudin18.2 has shown acceptable safety and robust anti-tumor capabilities. However, these advancements primarily remain in preclinical stages and further investigation should be made to promote their clinical application. This review summarizes the latest research on immune checkpoint inhibitors and adoptive cell therapy and their limitations, as well as the role of nanoparticles in enhancing immunotherapy.

Anticancer and Antioxidant Activities of Methanolic Extract of Ziziphus Spina-Christi Leaves against Human Gastric Carcinoma Cells

Background

Ziziphus spina-christi (Rhamnaceae) is employed in Middle Eastern countries for the treatment of different diseases. Earlier reports revealed that it is cytotoxic to oral cancer cells.

Objective

The current study determined the antioxidant activity and the anticancer potential of methanolic extract of Z. spina-christi against gastric carcinoma.

Materials and Methods

LC-MS analysis was used to determine the different phytoconstituents predicted to be present in the extract. The effect of the Z. spina-christi leaf extract against human gastric carcinoma (AGS) cell lines was evaluated using MTT assay and cellular apoptosis techniques. A ferric-reducing antioxidant power assay was used to assess the antioxidant effect.

Results and Conclusion

The LC-MS analysis revealed 24 phytoconstituents and Z. spina-christi extract was cytotoxic on AGS cells with an IC50 value of 125.1 μg/ml. Incubation of AGS cells with the extract decreased the percentage of live cells with a significant increase in late apoptotic phase and necrotic phase in the cellular apoptosis assay. The Z. spina-christi extract showed a potent antioxidant effect. The results show that Z. spina-christi extract possesses cytotoxic and antioxidant actions.

Molecular Mechanism for Malignant Progression of Gastric Cancer Within the Tumor Microenvironment

Gastric cancer (GC) is one of the most common cancers worldwide. Most patients are diagnosed at the progressive stage of GC, and progress in the development of effective anti-GC drugs has been insufficient. The tumor microenvironment (TME) regulates various functions of tumor cells, and interactions between the cellular and molecular components of the TME-e.g., inflammatory cells, fibroblasts, vasculature cells, and innate and adaptive immune cells-promote the aggressiveness of cancer cells and dissemination to distant organs. This review summarizes the roles of various TME cells and molecules in regulating the malignant progression and metastasis of GC. We also address the important roles of signaling pathways in mediating the interaction between cancer cells and the different components of the GC TME. Finally, we discuss the implications of these molecular mechanisms for developing novel and effective therapies targeting molecular and cellular components of the GC TME to control the malignant progression of GC.

Effects of Infection with Different Types of Helicobacter pylori on Gastric Secretion Function: A Cross-Sectional Clinical Study

Purpose

Helicobacter pylori (Hp)-related gastropathies are accompanied by alterations in gastric secretion function, but the effects of infection of different Hp strains on gastric function are not yet well-elucidated. Our cross-sectional clinical study aim to research the effects of infection with different Hp types on gastric function.

Patients and Methods

We analyzed 525 patients' serum cytotoxin-associated protein gene A (CagA), vacuolating cytotoxin-associated protein gene A (VacA), urease (Ure), Gastrin-17 (G-17), Pepsinogen I (PGI), Pepsinogen II (PGII) and PGI/PGII ratio (PGR).

Results

The PGII levels (8.19 ± 5.44 vs 5.98 ± 10.75, P = 0.013) were higher in the Hp infected group than in the uninfected, while the PGR levels (16.81 ± 8.22 vs 23.23 ± 8.36, P < 0.001) were lower. The PGR levels were higher in the uninfected group (23.23 ± 8.36, P < 0.001) than in Hp-I (16.47 ± 7.45) and Hp-II infected groups (17.39 ± 8.98). In the uninfected group, the G-17 level was positively correlated with the levels of PGI (Pearson coefficient = 0.177, P = 0.001), PGII (Pearson coefficient = 0.140, P = 0.008) and age (Pearson coefficient = 0.121, P = 0.022), negatively with the PGR levels (Pearson coefficient = -0.201, P < 0.001). In the Hp-I (Pearson coefficient = -0.003, P = 0.975) and Hp-II (Pearson coefficient = 0.018, P = 0.161) infected groups, the G-17 levels were not correlated with age.

Conclusion

Hp-I with CagA and/or VacA positive and Hp-II without cytotoxicity can reduce gastric secretion function regardless of age and sex. Gastric function in patients with Hp eradication was similar to that in those without Hp infection. G-17 rises physiologically with age, but infection with Hp will affect it.

Effects of intratumoral microbiota on tumorigenesis, anti-tumor immunity, and microbe-based cancer therapy

Intratumoral microbiota (IM) has emerged as a significant component of the previously thought sterile tumor microenvironment (TME), exerting diverse functions in tumorigenesis and immune modulation. This review outlines the historical background, classification, and diversity of IM, elucidating its pivotal roles in oncogenicity, cancer development, and progression, alongside its influence on anti-tumor immunity. The signaling pathways through which IM impacts tumorigenesis and immunity, including reactive oxygen species (ROS), β-catenin, stimulator of interferon genes (STING), and other pathways [NF-κB, Toll-like receptor (TLR), complement, RhoA/ROCK, PKR-like ER kinase (PERK)], are discussed comprehensively. Furthermore, we briefly introduce the clinical implications of IM, emphasizing its potential as a target for novel cancer therapies, diagnostic biomarkers, and prognostic indicators. Notably, microbe-based therapeutic strategies such as fecal microbiome transplantation (FMT), probiotics regulation, bacteriotherapy, bacteriophage therapy, and oncolytic virotherapy are highlighted. These strategies hold promise for enhancing the efficacy of current cancer treatments and warrant further exploration in clinical settings.

Single-cell RNA sequencing to map tumor heterogeneity in gastric carcinogenesis paving roads to individualized therapy

Gastric cancer (GC) is a highly heterogeneous disease with a complex tumor microenvironment (TME) that encompasses multiple cell types including cancer cells, immune cells, stromal cells, and so on. Cancer-associated cells could remodel the TME and influence the progression of GC and therapeutic response. Single-cell RNA sequencing (scRNA-seq), as an emerging technology, has provided unprecedented insights into the complicated biological composition and characteristics of TME at the molecular, cellular, and immunological resolutions, offering a new idea for GC studies. In this review, we discuss the novel findings from scRNA-seq datasets revealing the origin and evolution of GC, and scRNA-seq is a powerful tool for investigating transcriptional dynamics and intratumor heterogeneity (ITH) in GC. Meanwhile, we demonstrate that the vital immune cells within TME, including T cells, B cells, macrophages, and stromal cells, play an important role in the disease progression. Additionally, we also overview that how scRNA-seq facilitates our understanding about the effects on individualized therapy of GC patients. Spatial transcriptomes (ST) have been designed to determine spatial distribution and capture local intercellular communication networks, enabling a further understanding of the relationship between the spatial background of a particular cell and its functions. In summary, scRNA-seq and other single-cell technologies provide a valuable perspective for molecular and pathological disease characteristics and hold promise for advancing basic research and clinical practice in GC.

Cancer-associated fibroblasts promote proliferation, angiogenesis, metastasis and immunosuppression in gastric cancer

Despite advances in surgery, radiotherapy and immunotherapy, the mortality rate for gastric cancer remains one of the highest in the world. A large body of evidence has demonstrated that cancer-associated fibroblasts (CAFs), as core members of the stroma, can secrete cytokines, proteins and exosomes to create a tumour microenvironment that is conducive to cancer cell survival. CAFs can also interact with cancer cells to form a complex signalling network, enabling cancer cells to more easily metastasise to other organs and tissues in the body and develop metastatic foci. In this review, we provide an overview of the CAFs concept and activators. We focus on elucidating their effects on immune cells, intratumoural vasculature, extracellular matrix, as well as cancer cell activity, metastatic power and metabolism, and on enhancing the metastatic ability of cancer cells through activation of JAK/STAT, NF/κB and CXCL12/CXCR4. Various therapeutic agents targeting CAFs are also under development and are expected to improve the prognosis of gastric cancer in combination with existing treatment options.

Human patient derived organoids: an emerging precision medicine model for gastrointestinal cancer research

Gastrointestinal cancers account for approximately one-third of the total global cancer incidence and mortality with a poor prognosis. It is one of the leading causes of cancer-related deaths worldwide. Most of these diseases lack effective treatment, occurring as a result of inappropriate models to develop safe and potent therapies. As a novel preclinical model, tumor patient-derived organoids (PDOs), can be established from patients' tumor tissue and cultured in the laboratory in 3D architectures. This 3D model can not only highly simulate and preserve key biological characteristics of the source tumor tissue in vitro but also reproduce the in vivo tumor microenvironment through co-culture. Our review provided an overview of the different in vitro models in current tumor research, the derivation of cells in PDO models, and the application of PDO model technology in gastrointestinal cancers, particularly the applications in combination with CRISPR/Cas9 gene editing technology, tumor microenvironment simulation, drug screening, drug development, and personalized medicine. It also elucidates the ethical status quo of organoid research and the current challenges encountered in clinical research, and offers a forward-looking assessment of the potential paths for clinical organoid research advancement.

H. pylori-induced NF-κB-PIEZO1-YAP1-CTGF axis drives gastric cancer progression and cancer-associated fibroblast-mediated tumour microenvironment remodelling

BACKGROUND

Gastric cancer (GC) is one of the most common tumours in East Asia countries and is associated with Helicobacter pylori infection. H. pylori utilizes virulence factors, CagA and VacA, to up-regulate pro-inflammatory cytokines and activate NF-κB signaling. Meanwhile, the PIEZO1 upregulation and cancer-associated fibroblast (CAF) enrichment were found in GC progression. However, the mechanisms of PIEZO1 upregulation and its involvement in GC progression have not been fully elucidated.

METHODS

The CAF enrichment and clinical significance were investigated in animal models and primary samples. The expression of NF-κB and PIEZO1 in GC was confirmed by immunohistochemistry staining, and expression correlation was analysed in multiple GC datasets. GSEA and Western blot analysis revealed the YAP1-CTGF axis regulation by PIEZO1. The stimulatory effects of CTGF on CAFs were validated by the co-culture system and animal studies. Patient-derived organoid and peritoneal dissemination models were employed to confirm the role of the PIEZO1-YAP1-CTGF cascade in GC.

RESULTS

Both CAF signature and PIEZO1 were positively correlated with H. pylori infection. PIEZO1, a mechanosensor, was confirmed as a direct downstream of NF-κB to promote the transformation from intestinal metaplasia to GC. Mechanistic studies revealed that PIEZO1 transduced the oncogenic signal from NF-κB into YAP1 signaling, a well-documented oncogenic pathway in GC progression. PIEZO1 expression was positively correlated with the YAP1 signature (CTGF, CYR61, and c-Myc, etc.) in primary samples. The secreted CTGF by cancer cells stimulated the CAF infiltration to form a stiffened collagen-enrichment microenvironment, thus activating PIEZO1 to form a positive feedback loop. Both PIEZO1 depletion by shRNA and CTGF inhibition by Procyanidin C1 enhanced the efficacy of 5-FU in suppressing the GC cell peritoneal metastasis.

CONCLUSION

This study elucidates a novel driving PIEZO1-YAP1-CTGF force, which opens a novel therapeutic avenue to block the transformation from precancerous lesions to GC. H. pylori-NF-κB activates the PIEZO1-YAP1-CTGF axis to remodel the GC microenvironment by promoting CAF infiltration. Targeting PIEZO1-YAP1-CTGF plus chemotherapy might serve as a potential therapeutic option to block GC progression and peritoneal metastasis.