Hereditary diffuse gastric cancer (HDGC). An overview

A Japanese family of hereditary diffuse gastric cancer with a germline pathogenic variant of CTNN1A detected via comprehensive genome profiling

CTNNA1 codes α-1 catenin, a molecule that functions in intercellular adhesion in combination with E-cadherin (coded by CDH1). A germline pathogenic variant (GPV) of CTNNA1 increases the risk of hereditary diffuse gastric cancer (HDGC); however, this GPV has not been reported in Japan. A 35-year-old Japanese man with an advanced gastric cancer underwent comprehensive genome profiling (CGP), which led to the detection of a CTNNA1 GPV (p.Q662*). His gastric cancer tissues demonstrated a loss of α-1 catenin expression. His mother with a history of gastric signet-ring cell carcinoma had undergone genetic counseling 2 years ago, because of her broad family history of young-onset gastric cancer. Then, she had undergone germline multigene panel testing (MGPT) that included CDH1 but not CTNNA1, and no GPV had been detected. Here, Japanese precision cancer medicine revealed a GPV of a gene rarely associated with HDGC, that could not be detected by common MGPTs.

Racial/ethnic differences in risk factors for non-cardia gastric cancer: an analysis of the Multiethnic Cohort (MEC) Study

PURPOSE

Gastric cancer (GC) incidence rates show notable differences by racial/ethnic groups in the US. We sought to determine whether stratification by race/ethnicity would reveal unique risk factors for development of non-cardia gastric cancer (NCGC) for US population.

METHODS

Analysis included 1,112 incident cases of NCGC and 190,883 controls from the Multiethnic Cohort Study, a prospective US cohort study that recruited individuals living in Hawaii and California, aged 45-75 years from 5 races/ethnicities. Descriptive analysis and Cox regression models examined the association of risk factors for GC and calculate hazard ratios for each race/ethnicity, adjusting for sociodemographic and dietary variables.

RESULTS

Increasing age and male sex were risk factors for NCGC for most race/ethnicities. Higher risk was associated with: GC family history for Latino and Japanese American individuals [HRs range from 1.75 to 1.98]; foreign-born for Japanese American individuals [HR: 1.52, 95% CI 1.11-2.09]; lower education for African American, Japanese American, and Native Hawaiian individuals [HRs range from 1.30 to 1.74]; daily alcohol consumption for African American individuals[HR: 1.56, 95% CI 1.04-2.35]; current smoking for Latino and Japanese American individuals [HRs range from 1.89 to 1.94]; sodium consumption in the highest quartile for White individuals [HR: 2.55, 95% CI 1.23-5.26] compared to the lowest quartile; fruit consumption in the 2nd, 3rd, and 4th highest quartile for Native Hawaiian individuals [HRs range from 2.19 to 2.60] compared to the lowest quartile; diabetes for African American individuals [HR: 1.79, 95% CI 1.21-2.64]; and gastric/duodenal ulcers for Native Hawaiian individuals [HR: 1.82, 95% CI 1.04-3.18].

CONCLUSION

Analyses by racial/ethnic group revealed differing risk factors for NCGC. Increased knowledge of the varying pathways to GC can support personalized GC prevention strategies and risk stratification tools for early detection.

Advancing gastric cancer treatment: nanotechnology innovations and future prospects

Gastric cancer (GC) is the fifth most common cancer worldwide, particularly prevalent in Asia, especially in China, where both its incidence and mortality rates are significantly high. Meanwhile, nanotechnology has demonstrated great potential in the treatment of GC. In particular, nanodrug delivery systems have improved therapeutic efficacy and targeting through various functional modifications, such as targeting peptides, tumor microenvironment responsiveness, and instrument-based methods. For instance, silica (SiO2) has excellent biocompatibility and can be used as a drug carrier, with its porous structure enhancing drug loading capacity. Polymer nanoparticles regulate drug release rates and mechanisms by altering material composition and preparation methods. Lipid nanoparticles efficiently encapsulate hydrophilic drugs and promote cellular uptake, while carbon-based nanoparticles can be used in biosensors and drug delivery. Targets such as integrins, HER2 receptors, and the tumor microenvironment have been used to improve drug efficacy in GC treatment. Nanodrug delivery techniques not only enhance drug efficacy and delivery capabilities but also selectively target tumor cells. Currently, there is a lack of systematic summarization and synthesis regarding the relationship between nanodrug delivery systems and GC treatment, which to some extent hinders researchers and clinicians from efficiently searching for and referencing related studies, thereby reducing work efficiency. This study aims to systematically summarize the existing research on the relationship between nanodrug delivery systems and GC treatment, making it easier for professionals to search and reference, and thereby promoting further research on the role of nanodrug delivery systems and their clinical applications in GC. This review discusses the applications of functionalized nanocarriers in the treatment of GC in recent years, including surface modifications with targeted markers, the combination of phototherapy, chemotherapy, and immunotherapy, along with their advantages and challenges. It also examines the future prospects of targeted nanomaterials in GC treatment. The review particularly focuses on the combined application of nanocarriers in multiple treatment modalities, such as phototherapy, chemotherapy, and immunotherapy, demonstrating their potential in multimodal treatments. Furthermore, it thoroughly explores the specific challenges that nanocarriers face in GC treatment, such as biocompatibility, drug release control, and clinical translation issues, while providing a systematic outlook on future developments. Additionally, this study emphasizes the potential value and feasibility of nanocarriers in clinical applications, contrasting with most reviews that focus on basic research. Through these innovations, we offer new perspectives and directions for the development of nanotechnology in the treatment of GC.

Risk of Esophageal and Gastric Cancer in Patients with Type 2 Diabetes Receiving Glucagon-like Peptide-1 Receptor Agonists (GLP-1 RAs): A National Analysis

INTRODUCTION

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are becoming more popular in managing type 2 diabetes mellitus (T2DM). Concerns linger over potential links to malignancies like pancreatic and thyroid cancers, requiring more research to clarify their safety profiles. Additionally, evidence suggests GLP-1 RAs may lower colorectal and pancreatic cancer risk, especially in obese and overweight individuals, indicating a protective effect beyond weight loss. Current studies leave a gap in comprehensively understanding cancer risks associated with GLP-1 RAs, which prompts further research to enhance our understanding of their overall safety.

METHODS

We queried the US Collaborative Network (63 health care organizations) of the TriNetX research database. Patients with T2DM were identified and divided into two cohorts: patients on GLP-1 RAs and patients not on GLP-1 RAs. We excluded tobacco use and alcohol use disorders, obese patients with a body mass index (BMI) of >25 kg/m2, and those with a family history of gastrointestinal malignancy, infectious mononucleosis, chronic gastritis, pernicious anemia, helicobacter pylori infection, or gastroesophageal reflux disease (GERD). We used a 1:1 propensity score matching (PSM) model using patients' baseline characteristics, medications, labs, and genetics. We compared the rate of gastric cancer and esophageal cancer at the seven-year mark.

RESULTS

A total of 2,748,431 patients with T2DM were identified. Of those, 6% (n = 167,077) were on a GLP-1 RA and 94% (n = 2,581,354) were not on a GLP-1 RA. After PSM, both cohorts included 146,277 patients. Patients with T2DM who were on a GLP-1 RA, compared to those who were not, had a statistically significant lower risk of both gastric cancer (0.05% vs. 0.13%, p < 0.0001) and esophageal cancer (0.04% vs. 0.13%, p < 0.0001) at the seven-year mark.

CONCLUSION

The use of GLP-1 RAs in patients with T2DM does not significantly increase the risk of gastric or esophageal cancer. This finding supports the continued use of GLP-1 analogues as a therapeutic option in managing T2DM, considering their well-established benefits and low risk of complications. Based on the study results, these medications may even have a protective effect against these malignancies.

Master Regulators of Causal Networks in Intestinal- and Diffuse-Type Gastric Cancer and the Relation to the RNA Virus Infection Pathway

Causal networks are important for understanding disease signaling alterations. To reveal the network pathways affected in the epithelial-mesenchymal transition (EMT) and cancer stem cells (CSCs), which are related to the poor prognosis of cancer, the molecular networks and gene expression in diffuse- and intestinal-type gastric cancer (GC) were analyzed. The network pathways in GC were analyzed using Ingenuity Pathway Analysis (IPA). The analysis of the probe sets in which the gene expression had significant differences between diffuse- and intestinal-type GC in RNA sequencing of the publicly available data identified 1099 causal networks in diffuse- and intestinal-type GC. Master regulators of the causal networks included lenvatinib, pyrotinib, histone deacetylase 1 (HDAC1), mir-196, and erb-b2 receptor tyrosine kinase 2 (ERBB2). The analysis of the HDAC1-interacting network identified the involvement of EMT regulation via the growth factors pathway, the coronavirus pathogenesis pathway, and vorinostat. The network had RNA-RNA interactions with microRNAs such as mir-10, mir-15, mir-17, mir-19, mir-21, mir-223, mir-25, mir-27, mir-29, and mir-34. The molecular networks revealed in the study may lead to identifying drug targets for GC.

Stool Protein Mass Spectrometry Identifies Biomarkers for Early Detection of Diffuse-type Gastric Cancer

There is a high unmet need for early detection approaches for diffuse gastric cancer (DGC). We examined whether the stool proteome of mouse models of gastric cancer (GC) and individuals with hereditary diffuse gastric cancer (HDGC) have utility as biomarkers for early detection. Proteomic mass spectrometry of the stool of a genetically engineered mouse model driven by oncogenic KrasG12D and loss of p53 and Cdh1 in gastric parietal cells [known as Triple Conditional (TCON) mice] identified differentially abundant proteins compared with littermate controls. Immunoblot assays validated a panel of proteins, including actinin alpha 4 (ACTN4), N-acylsphingosine amidohydrolase 2 (ASAH2), dipeptidyl peptidase 4 (DPP4), and valosin-containing protein (VCP), as enriched in TCON stool compared with littermate control stool. Immunofluorescence analysis of these proteins in TCON stomach sections revealed increased protein expression compared with littermate controls. Proteomic mass spectrometry of stool obtained from patients with HDGC with CDH1 mutations identified increased expression of ASAH2, DPP4, VCP, lactotransferrin (LTF), and tropomyosin-2 relative to stool from healthy sex- and age-matched donors. Chemical inhibition of ASAH2 using C6 urea ceramide was toxic to GC cell lines and GC patient-derived organoids. This toxicity was reversed by adding downstream products of the S1P synthesis pathway, which suggested a dependency on ASAH2 activity in GC. An exploratory analysis of the HDGC stool microbiome identified features that correlated with patient tumors. Herein, we provide evidence supporting the potential of analyzing stool biomarkers for the early detection of DGC. Prevention Relevance: This study highlights a novel panel of stool protein biomarkers that correlate with the presence of DGC and has potential use as early detection to improve clinical outcomes.

Inflammation-Related Gene ADH1A Regulates the Polarization of Macrophage M1 and Influences the Malignant Progression of Gastric Cancer

Background

Gastric cancer (GC) is a malignant tumor originating from the gastric mucosa epithelium, and there is a low survival rate of GC patients after treatment, with a poor prognostic outcome. The inflammatory response within the tumor microenvironment plays an important role in GC progression.

Methods

We downloaded GC-related datasets and inflammation-related genes from GEO, TCGA and MSigDB databases, performed differential analysis, protein-protein interaction analysis, immunoinfiltration analysis and Lasso analysis to screen inflammation-related hub genes affecting GC progression, and carried out qRT-PCR for validation. In order to explore the role of ADH1A, we constructed overexpressed plasmids, treated GC cells with cGMP/PKG pathway agonist 8-Br-cGMP, and tested cell functions with CCK8, EdU, Transwell, scratch assay and other experiments. On this basis, GC cells were co-cultured with monocyte THP-1 to explore the effect of ADH1A on the polarization of macrophages.

Results

ADH1A was significantly decreased in GC cells, and its expression trend was consistent with the results of bioinformatics analysis. Therefore, we chose ADH1A for subsequent functional validation. Overexpression of ADH1A in GC cells revealed ADH1A's role in inhibiting the activity, proliferation, migration and invasion of GC cells, promoting apoptosis and secretion of IL-6, IFN-γ, CCL5 and CSF2, and facilitating the transformation of macrophages to a pro-inflammatory M1 phenotype. ssGSEA results demonstrated the potential involvement of ADH1A in the cGMP/PKG signaling pathway, and significant changes in the expression of proteins related to the cGMP/PKG signaling pathway. The use of the cGMP/PKG signaling pathway agonist 8-Br-cGMP in ADH1A-overexpressing GC cells substantiated ADH1A's capacity to inhibit the cGMP/PKG signaling pathway, thereby suppressing the malignant progression of GC and promoting the transformation of macrophages to a pro-inflammatory M1 phenotype.

Conclusion

ADH1A is able to influence the malignant progression of GC and the transformation of macrophages to the pro-inflammatory M1 phenotype through the cGMP/PKG signaling pathway.

Hereditary Gastrointestinal Tumor Syndromes: When Risk Comes with Your Genes

Despite recent campaigns for screening and the latest advances in cancer therapy and molecular biology, gastrointestinal (GI) neoplasms remain among the most frequent and lethal human tumors. Most GI neoplasms are sporadic, but there are some well-known familial syndromes associated with a significant risk of developing both benign and malignant GI tumors. Although some of these entities were described more than a century ago based on clinical grounds, the increasing molecular information obtained with high-throughput techniques has shed light on the pathogenesis of several of them. The vast amount of information gained from next-generation sequencing has led to the identification of some high-risk genetic variants, although others remain to be discovered. The opportunity for genetic assessment and counseling in these families has dramatically changed the management of these syndromes, though it has also resulted in significant psychological distress for the affected patients, especially those with indeterminate variants. Herein, we aim to summarize the most relevant hereditary cancer syndromes involving the stomach and colon, with an emphasis on new molecular findings, novel entities, and recent changes in the management of these patients.

Molecular characterization of plasmacytoid urothelial carcinoma and the impact on treatment implications

Bladder cancer researchers and clinicians have increasingly viewed tumor biology through the lens of genomic and molecular alterations, drastically improving our knowledge of the underlying disease biology. This understanding has led to significant advances in treatment options that allow implementation of a personalized approach to cancer treatment. Large-scale genomic studies initially focused on the most common forms of bladder cancer. However, as genomic and molecular technologies become more widespread and are applied to less common variant histologies, we are gaining additional insight into the unique molecular and genomic characteristics driving the biology of variant histologies of bladder cancer. In this review, we summarize the current state of knowledge of molecular alterations underlying the distinct tumor biology of plasmacytoid urothelial carcinoma and how these alterations may impact treatment options.

Hereditary Cancer Syndromes: A Comprehensive Review with a Visual Tool

Hereditary cancer syndromes account for nearly 10% of cancers even though they are often underdiagnosed. Finding a pathogenic gene variant could have dramatic implications in terms of pharmacologic treatments, tailored preventive programs, and familiar cascade testing. However, diagnosing a hereditary cancer syndrome could be challenging because of a lack of validated testing criteria or because of their suboptimal performance. In addition, many clinicians are not sufficiently well trained to identify and select patients that could benefit from a genetic test. Herein, we searched the available literature to comprehensively review and categorize hereditary cancer syndromes affecting adults with the aim of helping clinicians in their daily clinical practice through a visual tool.

The Regulation of Cyclins and Cyclin-Dependent Kinases in the Development of Gastric Cancer

Gastric cancer predominantly occurs in adenocarcinoma form and is characterized by uncontrolled growth and metastases of gastric epithelial cells. The growth of gastric cells is regulated by the action of several major cell cycle regulators including Cyclins and Cyclin-dependent kinases (CDKs), which act sequentially to modulate the life cycle of a living cell. It has been reported that inadequate or over-activity of these molecules leads to disturbances in cell cycle dynamics, which consequently results in gastric cancer development. Manny studies have reported the key roles of Cyclins and CDKs in the development and progression of the disease in either in vitro cell culture studies or in vivo models. We aimed to compile the evidence of molecules acting as regulators of both Cyclins and CDKs, i.e., upstream regulators either activating or inhibiting Cyclins and CDKs. The review entails an introduction to gastric cancer, along with an overview of the involvement of cell cycle regulation and focused on the regulation of various Cyclins and CDKs in gastric cancer. It can act as an extensive resource for developing new hypotheses for future studies.

Signaling pathways and therapeutic interventions in gastric cancer

Gastric cancer (GC) ranks fifth in global cancer diagnosis and fourth in cancer-related death. Despite tremendous progress in diagnosis and therapeutic strategies and significant improvements in patient survival, the low malignancy stage is relatively asymptomatic and many GC cases are diagnosed at advanced stages, which leads to unsatisfactory prognosis and high recurrence rates. With the recent advances in genome analysis, biomarkers have been identified that have clinical importance for GC diagnosis, treatment, and prognosis. Modern molecular classifications have uncovered the vital roles that signaling pathways, including EGFR/HER2, p53, PI3K, immune checkpoint pathways, and cell adhesion signaling molecules, play in GC tumorigenesis, progression, metastasis, and therapeutic responsiveness. These biomarkers and molecular classifications open the way for more precise diagnoses and treatments for GC patients. Nevertheless, the relative significance, temporal activation, interaction with GC risk factors, and crosstalk between these signaling pathways in GC are not well understood. Here, we review the regulatory roles of signaling pathways in GC potential biomarkers, and therapeutic targets with an emphasis on recent discoveries. Current therapies, including signaling-based and immunotherapies exploited in the past decade, and the development of treatment for GC, particularly the challenges in developing precision medications, are discussed. These advances provide a direction for the integration of clinical, molecular, and genomic profiles to improve GC diagnosis and treatments.