Molecular Alterations in Gastric Preneoplastic Lesions and Early Gastric Cancer

APOA1 mRNA and serum APOA1 protein as diagnostic and prognostic biomarkers in gastric cancer

Background

Gastric cancer (GC) remains a formidable challenge in oncology, ranking as a leading cause of cancer mortality globally. This underscores an urgent need for innovative prognostic markers that can revolutionize patient management and outcomes. Recent insights into cancer biology have spotlighted the profound influence of lipid metabolism alterations on tumorigenesis, tumor progression, and the tumor microenvironment. These alterations not only fuel cancer cell growth and proliferation but also play a strategic role in evading immune surveillance and promoting metastasis. The intricate web of lipid metabolism in cancer cells, characterized by deregulated uptake, synthesis, and oxidation of fatty acids (FAs), opens new avenues for targeted therapeutic interventions and prognostic evaluations. Specifically, this study zeroes in on apolipoprotein A-I (APOA1), a key player in lipid metabolism, to unearth its prognostic value in GC. By delving into the role of lipid metabolism-related genes, particularly APOA1, we aim to unveil their potential as groundbreaking biomarkers for GC prognosis. This endeavor not only aims to enhance our understanding of the molecular underpinnings of GC but also to spearhead the development of lipid metabolism-based strategies for improved diagnostic, prognostic, and therapeutic outcomes.

Methods

Transcriptomic and clinical data from GC patients and healthy individuals were sourced from The Cancer Genome Atlas (TCGA) database, a comprehensive project that molecularly characterizes over 20,000 primary cancer and matched normal samples across 33 cancer types. Significantly differentially expressed lipid metabolism-related genes were identified using the "limma" package in R. Prognostic genes were selected via univariate Cox regression analysis. Differential gene enrichment analysis was performed using Metascape (http://www.metascape.org). The Human Protein Atlas (HPA, https://www.proteinatlas.org) provided information on APOA1 protein expression in GC and healthy tissues. Immune cell infiltration was analyzed using the CIBERSORT algorithm (http://cibersort.stanford.edu).

Results

Significant differences in lipid metabolism-related gene expression were observed between GC and normal tissues, closely linked to FA metabolism, oxidoreductase activity, and sphingolipid metabolism. APOA1 emerged as a potential prognostic biomarker by intersecting prognostic and differentially expressed lipid metabolism genes. Immunohistochemical analysis confirmed APOA1 downregulation in GC. The receiver operating characteristic (ROC) analysis demonstrated its predictive value, with the area under the curve (AUC) being 0.64 [95% confidence interval (CI): 0.52-0.76]. APOA1 expression correlated with immune cell infiltrations. Clinical serum APOA1 results revealed lower levels in GC patients (1.38 vs. 1.26; P<0.05), associated with poor prognosis (hazard ratio =1.50; P<0.001) and clinical characteristics. ROC analysis of serum APOA1 demonstrated good diagnostic ability (AUC: 0.63, 95% CI: 0.61-0.65). Serum APOA1 levels significantly increased after treatment.

Conclusions

This study highlights lipid metabolism reprogramming in GC and identifies APOA1 as a potential diagnostic and prognostic biomarker, suggesting its clinical utility in managing GC.

[Identification of potential pathogenic genes of intestinal metaplasia based on transcriptomic sequencing and bioinformatics analysis]

OBJECTIVE

To explore the potential pathogenic genes of intestinal metaplasia.

METHODS

Twenty-one patients with intestinal metaplasia admitted to the Department of Gastroenterology at the Second Affiliated Hospital of Anhui University of Chinese Medicine from January, 2022 to June, 2022, and 21 healthy subjects undergoing gastroscopic examination during the same period were enrolled in this study. All the participants underwent gastroscopy and pathological examination, and gastric tissue samples were collected for transcriptome sequencing to screen for differentially expressed genes (DEGs). The biological functions of the DEGs were analyzed using bioinformatics analysis, and qRT-PCR was used to validate the results.

RESULTS

Transcriptomic sequencing identified a total of 1373 DEGs, including 827 upregulated and 546 downregulated ones. The top 6 upregulated genes (AGMAT, CCL25, FABP1, CDX1, SPINK4, and MUC2), ranked based on their significance and average expression level, were selected for validation, and qRT-PCR showed significant upregulation of their mRNAs in the gastric tissues of patients with intestinal metaplasia (P < 0.05).

CONCLUSION

AGMAT, CCL25, FABP1, CDX1, SPINK4, and MUC2 participate in the occurrence and development of intestinal metaplasia, and may serve as potential biomarkers for diagnosing intestinal metaplasia.

Revealing the pathogenesis of gastric intestinal metaplasia based on the mucosoid air-liquid interface

BACKGROUND

Gastric intestinal metaplasia (GIM) is an essential precancerous lesion. Although the reversal of GIM is challenging, it potentially brings a state-to-art strategy for gastric cancer therapeutics (GC). The lack of the appropriate in vitro model limits studies of GIM pathogenesis, which is the issue this work aims to address for further studies.

METHOD

The air-liquid interface (ALI) model was adopted for the long-term culture of GIM cells in the present work. This study conducted Immunofluorescence (IF), quantitative real-time polymerase chain reaction (qRT-PCR), transcriptomic sequencing, and mucoproteomic sequencing (MS) techniques to identify the pathways for differential expressed genes (DEGs) enrichment among different groups, furthermore, to verify novel biomarkers of GIM cells.

RESULT

Our study suggests that GIM-ALI model is analog to the innate GIM cells, which thus can be used for mucus collection and drug screening. We found genes MUC17, CDA, TRIM15, TBX3, FLVCR2, ONECUT2, ACY3, NMUR2, and MAL2 were highly expressed in GIM cells, while GLDN, SLC5A5, MAL, and MALAT1 showed down-regulated, which can be used as potential biomarkers for GIM cells. In parallel, these genes that highly expressed in GIM samples were mainly involved in cancer-related pathways, such as the MAPK signal pathway and oxidative phosphorylation signal pathway.

CONCLUSION

The ALI model is validated for the first time for the in vitro study of GIM. GIM-ALI model is a novel in vitro model that can mimic the tissue micro-environment in GIM patients and further provide an avenue for studying the characteristics of GIM mucus. Our study identified new markers of GIM as well as pathways associated with GIM, which provides outstanding insight for exploring GIM pathogenesis and potentially other related conditions.

GATA4 Forms a Positive Feedback Loop with CDX2 to Transactivate MUC2 in Bile Acids-Induced Gastric Intestinal Metaplasia

Background/Aims

Gastric intestinal metaplasia (GIM), a common precancerous lesion of gastric cancer, can be caused by bile acid reflux. GATA binding protein 4 (GATA4) is an intestinal transcription factor involved in the progression of gastric cancer. However, the expression and regulation of GATA4 in GIM has not been clarified.

Methods

The expression of GATA4 in bile acid-induced cell models and human specimens was examined. The transcriptional regulation of GATA4 was investigated by chromatin immunoprecipitation and luciferase reporter gene analysis. An animal model of duodenogastric reflux was used to confirm the regulation of GATA4 and its target genes by bile acids.

Results

GATA4 expression was elevated in bile acid-induced GIM and human specimens. GATA4 bound to the promoter of mucin 2 (MUC2) and stimulate its transcription. GATA4 and MUC2 expression was positively correlated in GIM tissues. Nuclear transcription factor-κB activation was required for the upregulation of GATA4 and MUC2 in bile acid-induced GIM cell models. GATA4 and caudal-related homeobox 2 (CDX2) reciprocally transactivated each other to drive the transcription of MUC2. In chenodeoxycholic acid-treated mice, MUC2, CDX2, GATA4, p50, and p65 expression levels were increased in the gastric mucosa.

Conclusions

GATA4 is upregulated and can form a positive feedback loop with CDX2 to transactivate MUC2 in GIM. NF-κB signaling is involved in the upregulation of GATA4 by chenodeoxycholic acid.

SALL4 in gastrointestinal tract cancers: upstream and downstream regulatory mechanisms

Effective therapeutic targets and early diagnosis are major challenges in the treatment of gastrointestinal tract (GIT) cancers. SALL4 is a well-known transcription factor that is involved in organogenesis during embryonic development. Previous studies have revealed that SALL4 regulates cell proliferation, survival, and migration and maintains stem cell function in mature cells. Additionally, SALL4 overexpression is associated with tumorigenesis. Despite its characterization as a biomarker in various cancers, the role of SALL4 in GIT cancers and the underlying mechanisms are unclear. We describe the functions of SALL4 in GIT cancers and discuss its upstream/downstream genes and pathways associated with each cancer. We also consider the possibility of targeting these genes or pathways as potential therapeutic options for GIT cancers.

Differential cytokine expression in gastric tissues highlights helicobacter pylori's role in gastritis

Helicobacter pylori (H. pylori), known for causing gastric inflammation, gastritis and gastric cancer, prompted our study to investigate the differential expression of cytokines in gastric tissues, which is crucial for understanding H. pylori infection and its potential progression to gastric cancer. Focusing on Il-1β, IL-6, IL-8, IL-12, IL-18, and TNF-α, we analysed gene and protein levels to differentiate between H. pylori-infected and non-infected gastritis. We utilised real-time quantitative polymerase chain reaction (RT-qPCR) for gene quantification, immunohistochemical staining, and ELISA for protein measurement. Gastric samples from patients with gastritis were divided into three groups: (1) non-gastritis (N-group) group, (2) gastritis without H. pylori infection (G-group), and (3) gastritis with H. pylori infection (GH-group), each consisting of 8 samples. Our findings revealed a statistically significant variation in cytokine expression. Generally, cytokine levels were higher in gastritis, but in H. pylori-infected gastritis, IL-1β, IL-6, and IL-8 levels were lower compared to H. pylori-independent gastritis, while IL-12, IL-18, and TNF-α levels were higher. This distinct cytokine expression pattern in H. pylori-infected gastritis underscores a unique inflammatory response, providing deeper insights into its pathogenesis.

Unique immunohistochemical profiles of MUC5AC, MUC6, P53, and Ki67 in gastric atypical hyperplasia and dysplasia

OBJECTIVES

Differentiating gastric atypical hyperplasia (AH) from dysplasia, including low-grade dysplasia (LGD) and high-grade dysplasia (HGD), poses significant challenges in small biopsies and specimens with technical artifacts. This study aims to establish objective diagnostic criteria for these conditions through combined morphologic and immunohistochemical (IHC) analyses.

METHODS

Between January 2018 and September 2020, a total of 123 gastric mucosa biopsy specimens were collected at Anyang Tumor Hospital. According to the WHO Classification of Digestive System Tumors (5th edition), specimens were categorized into three groups: AH (n=48), LGD (n=30), and HGD (n=45). Morphologic characteristics were assessed, and IHC staining for MUC5AC, MUC6, MUC2, CD10, P53, and Ki67 was performed, followed by statistical analysis.

RESULTS

Histologically, AH was predominantly marked by a pronounced inflammatory background (60.42%), intestinal metaplasia (64.58%), indistinct boundaries (83.33%), and a distinct maturation gradient (97.72%). AH nuclei were typically circular (97.92%), with a high nucleus-to-cytoplasm ratio (64.58%), prominent nucleoli (47.92%), and preserved polarity (89.58%). In contrast, LGD and HGD typically exhibited well-defined boundaries with an absent maturation gradient. LGD nuclei were rod-shaped (96.67%), with a low nucleus-to-cytoplasm ratio (96.67%) and preserved polarity (100%), whereas HGD demonstrated a loss of cellular polarity (77.78%). IHC findings revealed a consistent maturation gradient in AH, with polarized MUC5AC and MUC6 expression, significantly reduced in LGD (86.67%), and absent in HGD. P53 expression in HGD showed a predominant 'mutation-type pattern' (66.67%), contrasting with 'wild-type pattern' expression in AH and LGD (100%, 93.33%). Ki67 expression patterns varied from a 'pit neck pattern' in AH (95.83%) to a 'polarity pattern' in LGD (76.67%) and a 'diffuse pattern' in HGD (57.78%). The expression patterns of MUC5AC, MUC6, CD10, P53, and Ki67 varied significantly across the three groups (P<0.001).

CONCLUSIONS

The integration of histomorphological features and expression profiles of MUC5AC, MUC6, P53, and Ki67 is instrumental in diagnosing gastric atypical hyperplasia and dysplasia.

Comparative study on genomic and epigenomic profiles of retinoblastoma or tuberous sclerosis complex via nanopore sequencing and a joint screening framework

Recurrence and extraocular metastasis in advanced intraocular retinoblastoma (RB) are still major obstacles for successful treatment of Chinese children. Tuberous sclerosis complex (TSC) is a very rare, multisystemic genetic disorder characterized by hamartomatous growth. In this study, we aimed to compare genomic and epigenomic profiles with human RB or TSC using recently developed nanopore sequencing, and to identify disease-associated variations or genes. Peripheral blood samples were collected from either RB or RB/TSC patients plus their normal siblings, followed by nanopore sequencing and identification of disease-specific structural variations (SVs) and differentially methylated regions (DMRs) by a systematic biology strategy named as multiomics-based joint screening framework. In total, 316 RB- and 1295 TSC-unique SVs were identified, as well as 1072 RB- and 1114 TSC-associated DMRs, respectively. We eventually identified 6 key genes for RB for further functional validation. Knockdown of CDK19 with specific siRNAs significantly inhibited Y79 cellular proliferation and increased sensitivity to carboplatin, whereas downregulation of AHNAK2 promoted the cell growth as well as drug resistance. Those two genes might serve as potential diagnostic markers or therapeutic targets of RB. The systematic biology strategy combined with functional validation might be an effective approach for rare pediatric malignances with limited samples and challenging collection process.

Historical and Molecular Perspectives on the Presence of Helicobacter pylori in Latin America: A Niche to Improve Gastric Cancer Risk Assessment

Helicobacter pylori (H. pylori) is responsible for causing chronic gastritis, which can cause peptic ulcer and premalignant lesions such as atrophic gastritis, intestinal metaplasia, and dysplasia, with the risk of developing gastric cancer. Recent data describe that H. pylori colonizes the gastric mucosa of more than 50% of the world's population; however, this bacterium has been described as infecting the human population since its prehistory. This review focuses on the populations and subpopulations of H. pylori, differentiated by the polymorphisms present in their constitutive and virulence genes. These genes have spread and associated with different human populations, showing variability depending on their geographical distribution, and have evolved together with the human being. The predominant genotypes worldwide, Latin America and Chile, are described to understand the genetic diversity and pathogenicity of H. pylori in different populations and geographic regions. The high similarity in the sequence of virulence genes between H. pylori strains present in Peruvian and Spanish natives in Latin America suggests a European influence. The presence of cagA-positive strains and vacA s1 m1 allelic variants is observed with greater prevalence in Chilean patients with more severe gastrointestinal diseases and is associated with its geographical distribution. These findings highlight the importance of understanding the genetic diversity of H. pylori in different regions of the world for a more accurate assessment of the risk of associated diseases and their potential impact on health.

A comparison analysis of the somatic mutations in early-onset gastric cancer and traditional gastric cancer

BACKGROUND

Early onset gastric cancer (EOGC) has been on the rise in recent years and differs slightly in pathology from traditional gastric cancer (TGC). Somatic mutations have an essential role in the development of gastric cancer. We aimed to investigate these two types of gastric cancers at the level of somatic mutations and to further understanding of gastric cancer development.

METHODS

Somatic mutation, copy number variation (CNV), and clinical information were obtained from TCGA and UCSC Xena. Samples were divided into EOGC (< 50 years old, N = 28) and TGC (≥ 50 years old, N = 395) groups based on age. R packages "maftools" and "sigminer" were used to identify mutation signatures, while CNV information was processed using GISTIC2.0.

RESULTS

CDH1(21 %, P = 0.030) and ARID1A (28 %, P = 0.014) were more common in EOGC and TGC, respectively. The mutation frequency of ARID1A increased with age, while the opposite was true for CDH1. Sex, Lauren classifications, tumor mutation burden levels, mutation status of TP53, MUC6, NIPBL, KRAS, and copy number variation of the WOOX can affect the activity of the mutant signature.

CONCLUSIONS

Early-onset gastric cancer and traditional gastric cancer have distinct somatic mutation signatures, each with its own relatively specific high-frequency mutated genes, and the gene's mutation frequency correlates with age. Several clinical factors and genetic status affect the activity of some mutational features in gastric cancer in both groups.

The Importance of Th2 Immune Responses in Mediating the Progression of Gastritis-Associated Metaplasia to Gastric Cancer

Gastric cancer is one of the leading causes of cancer deaths worldwide, with chronic gastritis representing the main predisposing factor initiating the cascade of events leading to metaplasia and eventually progressing to cancer. A widely accepted classification distinguishes between autoimmune and environmental atrophic gastritis, mediated, respectively, by T cells promoting the destruction of the oxyntic mucosa, and chronic H. pylori infection, which has also been identified as the major risk factor for gastric cancer. The original dogma posits Th1 immunity as a main causal factor for developing gastritis and metaplasia. Recently, however, it has become evident that Th2 immune responses play a major role in the events causing chronic inflammation leading to tumorigenesis, and in this context, many different cell types and cytokines are involved. In particular, the activity of cytokines, such as IL-33 and IL-13, and cell types, such as mast cells, M2 macrophages and eosinophils, are intertwined in the process, promoting chronic gastritis-dependent and more diffuse metaplasia. Herein, we provide an overview of the critical events driving the pathology of this disease, focusing on the most recent findings regarding the importance of Th2 immunity in gastritis and gastric metaplasia.

Identification of differentially expressed genes associated with the pathogenesis of gastric cancer by bioinformatics analysis

AIM

Gastric cancer (GC) is one of the most diagnosed cancers worldwide. GC is a heterogeneous disease whose pathogenesis has not been entirely understood. Besides, the GC prognosis for patients remains poor. Hence, finding reliable biomarkers and therapeutic targets for GC patients is urgently needed.

METHODS

GSE54129 and GSE26942 datasets were downloaded from Gene Expression Omnibus (GEO) database to detect differentially expressed genes (DEGs). Then, gene set enrichment analyses and protein-protein interactions were investigated. Afterward, ten hub genes were identified from the constructed network of DEGs. Then, the expression of hub genes in GC was validated. Performing survival analysis, the prognostic value of each hub gene in GC samples was investigated. Finally, the databases were used to predict microRNAs that could regulate the hub genes. Eventually, top miRNAs with more interactions with the list of hub genes were introduced.

RESULTS

In total, 203 overlapping DEGs were identified between both datasets. The main enriched KEGG pathway was "Protein digestion and absorption." The most significant identified GO terms included "primary alcohol metabolic process," "basal part of cell," and "extracellular matrix structural constituent conferring tensile strength." Identified hub modules were COL1A1, COL1A2, TIMP1, SPP1, COL5A2, THBS2, COL4A1, MUC6, CXCL8, and BGN. The overexpression of seven hub genes was associated with overall survival. Moreover, among the list of selected miRNAs, hsa-miR-27a-3, hsa-miR-941, hsa-miR-129-2-3p, and hsa-miR-1-3p, were introduced as top miRNAs targeting more than five hub genes.

CONCLUSIONS

The present study identified ten genes associated with GC, which may help discover novel prognostic and diagnostic biomarkers as well as therapeutic targets for GC. Our results may advance the understanding of GC occurrence and progression.

A unified DNA- and RNA-based NGS strategy for the analysis of multiple types of variants at the dual nucleic acid level in solid tumors

BACKGROUND

Targeted next-generation sequencing (NGS) is a powerful and suitable approach to comprehensively identify multiple types of variants in tumors. RNA-based NGS is increasingly playing an important role in precision oncology. Both parallel and sequential DNA- and RNA-based approaches are expensive, burdensome, and have long turnaround times, which can be impractical in clinical practice. A streamlined, unified DNA- and RNA-based NGS approach is urgently needed in clinical practice.

METHODS

A DNA/RNA co-hybrid capture sequencing (DRCC-Seq) approach was designed to capture pre-capture DNA and RNA libraries in a single tube and convert them into one NGS library. The performance of the DRCC-Seq approach was evaluated by a panel of reference standards and clinical samples.

RESULTS

The average depth, DNA data ratio, capture ratio, and target coverage 250 (×) of the DNA panel data had a negative correlation with an increase in the proportion of RNA probes. The SNVs, indels, fusions, and MSI status were not affected by the proportion of RNA probes, but the copy numbers of the target genes were higher than expected in the standard materials, and many unexpected gene amplifications were found using D:R (1:2) and D:R (1:4) probe panels. The optimal ratio of DNA and RNA probes in the combined probe panel was 1:1 using the DRCC-Seq approach. The DRCC-Seq approach was feasible and reliable for detecting multiple types of variants in reference standards and real-world clinical samples.

CONCLUSIONS

The DRCC-Seq approach is more cost-effective, with a shorter turnaround time and lower labor requirements than either parallel or sequential targeted DNA NGS and RNA NGS. It is feasible to identify multiple genetic variations at the DNA and RNA levels simultaneously in clinical practice.

Quantitative Analysis on Molecular Characteristics Evolution of Gastric Cancer Progression and Prognosis

The dynamic changes of key biological characteristics from gastric low-grade intraepithelial neoplasia (LGIN) to high-grade intraepithelial neoplasia (HGIN) to early gastric cancer (EGC) are still unclear, which greatly affect the accurate diagnosis and treatment of EGC and prognosis evaluation of gastric cancer (GC). In this study, bioinformatics methods/tools are applied to quantitatively analyze molecular characteristics evolution of GC progression, and a prognosis model is constructed. This study finds that some dysregulated differentially expressed mRNAs (DEmRNAs) in the LGIN stage may continue to promote the occurrence and development of EGC. Among the LGIN, HGIN, and EGC stages, there are differences and relevance in the transcription expression patterns of DEmRNAs, and the activation related to immune cells is very different. The biological functions continuously changed during the progression from LGIN to HGIN to EGC. The COX model constructed based on the three EGC-related DEmRNAs has GC prognostic risk prediction ability. The evolution of biological characteristics during the development of EGC mined by the authors provides new insight into understanding the molecular mechanism of EGC occurrence and development. The three-gene prognostic risk model provides a new method for assisting GC clinical treatment decisions.

Key Roles of p53 Signaling Pathway-Related Factors GADD45B and SERPINE1 in the Occurrence and Development of Gastric Cancer

p53 can function as an independent and unfavorable prognosis biomarker in cancer patients. We tried to identify the key factors of the p53 signaling pathway involved in gastric cancer (GC) occurrence and development based on the genotype-tissue expression (GTEx) and the Cancer Genome Atlas (TCGA) screening. We downloaded gene expression data and clinical data of GC included in the GTEx and TCGA databases, followed by differential analysis. Then, the key factors in the p53 signaling pathway were identified, followed by an analysis of the correlation between key factors and the prognosis of GC patients. Human GC cell lines were selected for in vitro cell experiments to verify the effects of key prognostic factors on the proliferation, migration, invasion, and apoptosis of GC cells. We found 4,944 significantly differentially expressed genes (DEGs), of which 2,465 were upregulated and 2,479 downregulated in GC. Then, 27 DEGs were found to be involved in the p53 signaling pathway. GADD45B and SERPINE1 genes were prognostic high-risk genes. The regression coefficients of GADD45B and SERPINE1 were positive. GADD45B was poorly expressed, while SERPINE1 was highly expressed in GC tissues, highlighting their prognostic role in GC. The in vitro cell experiments confirmed that overexpression of GADD45B or silencing of SERPINE1 could inhibit the proliferation, migration, and invasion and augment the apoptosis of GC cells. Collectively, the p53 signaling pathway-related factors GADD45B and SERPINE1 may be key genes that participate in the development of GC.

The features of gastric epithelial reactive hyperplastic lesions under magnifying endoscopy combined with narrow-band imaging

BACKGROUND AND PURPOSE

Gastric reactive hyperplasia (RH) is a common benign lesion of the gastric mucosa that can be resolved by conservative treatment without endoscopic intervention. Some RH lesions are indistinguishable from low-grade intraepithelial neoplasia (LGIN) lesions of gastric mucosa under endoscopy. The aim of this study was to investigate the morphological features of RH lesions under magnifying endoscopy combined with narrow-band imaging (ME-NBI).

METHODS

A retrospective study of 653 patients with superficial suspicious lesions of gastric mucosa was performed. According to the pathological results of biopsies, the final included lesions were divided into the RH group (n = 88) and LGIN group (n = 138). We analysed the microvascular and microsurface patterns of these lesions under ME-NBI, extracted the most significant combination of endoscopic features of RH lesions, and evaluated their diagnostic performance.

RESULTS

ME-NBI characteristics that could distinguish RH lesions from LGIN lesions after univariate analysis were included in multivariate logistic regression. The results showed that ten characteristics, including intervening part (IP) length homogeneity, type III gastric pit pattern and homogeneity of marginal crypt epithelium (MCE), were statistically significant. Receiver operating characteristic (ROC) analysis showed that the triad of these features was the best combination for diagnosing RH lesions with an AUC of 0.886 (95% confidence interval; 0.842-0.929), the sensitivity of 85.5% and specificity of 79.5%.

CONCLUSIONS

The triad of IP length homogeneity, type III pit pattern and MCE homogeneity under ME-NBI helps endoscopists to identify gastric RH lesions, thereby avoiding unnecessary biopsy and repeat endoscopy due to misjudgment of neoplastic lesions.

Establishment of a novel lysosomal signature for the diagnosis of gastric cancer with in-vitro and in-situ validation

Background

Gastric cancer (GC) represents a malignancy with a multi-factorial combination of genetic, environmental, and microbial factors. Targeting lysosomes presents significant potential in the treatment of numerous diseases, while lysosome-related genetic markers for early GC detection have not yet been established, despite implementing this process by assembling artificial intelligence algorithms would greatly break through its value in translational medicine, particularly for immunotherapy.

Methods

To this end, this study, by utilizing the transcriptomic as well as single cell data and integrating 20 mainstream machine-learning (ML) algorithms. We optimized an AI-based predictor for GC diagnosis. Then, the reliability of the model was initially confirmed by the results of enrichment analyses currently in use. And the immunological implications of the genes comprising the predictor was explored and response of GC patients were evaluated to immunotherapy and chemotherapy. Further, we performed systematic laboratory work to evaluate the build-up of the central genes, both at the expression stage and at the functional aspect, by which we could also demonstrate the reliability of the model to guide cancer immunotherapy.

Results

Eight lysosomal-related genes were selected for predictive model construction based on the inclusion of RMSE as a reference standard and RF algorithm for ranking, namely ADRB2, KCNE2, MYO7A, IFI30, LAMP3, TPP1, HPS4, and NEU4. Taking into account accuracy, precision, recall, and F1 measurements, a preliminary determination of our study was carried out by means of applying the extra tree and random forest algorithms, incorporating the ROC-AUC value as a consideration, the Extra Tree model seems to be the optimal option with the AUC value of 0.92. The superiority of diagnostic signature is also reflected in the analysis of immune features.

Conclusion

In summary, this study is the first to integrate around 20 mainstream ML algorithms to construct an AI-based diagnostic predictor for gastric cancer based on lysosomal-related genes. This model will facilitate the accurate prediction of early gastric cancer incidence and the subsequent risk assessment or precise individualized immunotherapy, thus improving the survival prognosis of GC patients.

Dynamic variations of the gastric microbiota: Key therapeutic points in the reversal of Correa's cascade

Correa's cascade is a dynamic process in the development of intestinal-type gastric cancer (GC), and its pathological features, gastric microbiota and interactions between microorganisms and their hosts vary at different developmental stages. The characteristics of cells, tissues and gastric microbiota before or after key therapeutic points are critical for monitoring malignant transformation and early tumour reversal. This review summarises the pathological features of gastric mucosa, characteristics of gastric microbiota, specific microbial markers, microbe-microbe interactions and microbe-host interactions at different stages in Correa's cascade. The markers related to each Correa's cascade point were analysed in detail. We attempted to identify key therapeutic points for early cancer reversal and provide a novel approach to reduce the incidence of GC and improve precise treatment.

Short Telomere Lesions with Dysplastic Metaplasia Histology May Represent Precancerous Lesions of Helicobacter pylori-Positive Gastric Mucosa

Gastric cancers are strongly associated with Helicobacter pylori infection, with intestinal metaplasia characterizing the background mucosa in most cases. However, only a subset of intestinal metaplasia cases proceed to carcinogenesis, and the characteristics of high-risk intestinal metaplasia that link it with gastric cancer are still unclear. We examined telomere reduction in five gastrectomy specimens using fluorescence in situ hybridization, and identified areas with localized telomere loss (outside of cancerous lesions), which were designated as short telomere lesions (STLs). Histological analyses indicated that STLs were characteristic of intestinal metaplasia accompanied by nuclear enlargement but lacking structural atypia, which we termed dysplastic metaplasia (DM). A review of gastric biopsy specimens from 587 H. pylori-positive patients revealed 32 cases of DM, 13 of which were classified as high-grade based on the degree of nuclear enlargement. All high-grade DM cases exhibited a telomere volume reduced to less than 60% of that of lymphocytes, increased stemness, and telomerase reverse transcriptase (TERT) expression. Two patients (15%) exhibited low levels of p53 nuclear retention. After a 10-year follow-up, 7 (54%) of the high-grade DM cases had progressed to gastric cancer. These results suggest that DM is characterized by telomere shortening, TERT expression, and stem cell proliferation, and high-grade DM is a high-grade intestinal metaplasia that likely represents a precancerous lesion of gastric cancer. High-grade DM is expected to effectively prevent progression to gastric cancer in H. pylori-positive patients.

MUC1 Expressions and Its Prognostic Values in US Gastric Cancer Patients

This study aims to evaluate the prognostic value of MUC expression in US GC patients. A total of 70 tumor specimens were collected from GC patients who underwent surgery or endoscopic resection between 2013 and 2019 at a tertiary referral center in the US. MUC expression status including MUC1, MUC2, MUC5AC, and MUC6 was evaluated by immunohistochemical staining. The positive rates of MUC1, MUC2, MUC5AC, and MUC6 were 71.4%, 78.6%, 74.3%, and 33.3%, respectively. Patients with positive MUC1 expression had a significantly higher rate of aggressive pathologic features including diffuse-type cancer (42.0% vs. 0%; p < 0.001), advanced GC (80.0% vs. 30.0%, p < 0.001), lymph node metastasis (62.0% vs. 20.0%; p = 0.001), and distant metastasis (32.0% vs. 5.0%; p = 0.017) compared with those with negative MUC1 expression. However, the differences in the pathologic features were not observed according to MUC2, MUC5AC, and MUC6 expression status. In early gastric cancer (EGC), patients with a high level of MUC1 expression showed a higher rate of lymphovascular invasion (71.4% vs. 21.4%; p = 0.026) and EGC meeting non-curative resection (85.7% vs. 42.9%; p = 0.061) than those with negative MUC1. In US GC patients, MUC1 expression is associated with aggressive pathological features, and might be a useful prognostic marker.

Understanding the Clinical Significance of MUC5AC in Biliary Tract Cancers

Biliary tract cancers (BTC) arise from biliary epithelium and include cholangiocarcinomas or CCA (including intrahepatic (ICC) and extrahepatic (ECC)) and gallbladder cancers (GBC). They often have poor outcomes owing to limited treatment options, advanced presentations, frequent recurrence, and poor response to available systemic therapy. Mucin 5AC (MUC5AC) is rarely expressed in normal biliary epithelium, but can be upregulated in tissues of benign biliary disease, premalignant conditions (e.g., biliary intraepithelial neoplasia), and BTCs. This mucin's numerous glycoforms can be divided into less-glycosylated immature and heavily-glycosylated mature forms. Reported MUC5AC tissue expression in BTC varies widely, with some associations based on cancer location (e.g., perihilar vs. peripheral ICC). Study methods were variable regarding cancer subtypes, expression positivity thresholds, and MUC5AC glycoforms. MUC5AC can be detected in serum of BTC patients at high concentrations. The hesitancy in developing MUC5AC into a clinically useful biomarker in BTC management is due to variable evidence on the diagnostic and prognostic value. Concrete conclusions on tissue MUC5AC are difficult, but serum detection might be relevant for diagnosis and is associated with poor prognosis. Future studies are needed to further the understanding of the potential clinical value of MUC5AC in BTC, especially regarding predictive and therapeutic value.

A Sweet Warning: Mucin-Type O-Glycans in Cancer

Glycosylation is a common post-translational modification process of proteins. Mucin-type O-glycosylation is an O-glycosylation that starts from protein serine/threonine residues. Normally, it is involved in the normal development and differentiation of cells and tissues, abnormal glycosylation can lead to a variety of diseases, especially cancer. This paper reviews the normal biosynthesis of mucin-type O-glycans and their role in the maintenance of body health, followed by the mechanisms of abnormal mucin-type O-glycosylation in the development of diseases, especially tumors, including the effects of Tn, STn, T antigen, and different glycosyltransferases, with special emphasis on their role in the development of gastric cancer. Finally, tumor immunotherapy targeting mucin-type O-glycans was discussed.

Inflammation and Gastric Cancer

Gastric cancer remains a major killer globally, although its incidence has declined over the past century. It is the fifth most common cancer and the third most common reason for cancer-related deaths worldwide. Gastric cancer is the outcome of a complex interaction between environmental, host genetic, and microbial factors. There is significant evidence supporting the association between chronic inflammation and the onset of cancer. This association is particularly robust for gastrointestinal cancers in which microbial pathogens are responsible for the chronic inflammation that can be a triggering factor for the onset of those cancers. Helicobacter pylori is the most prominent example since it is the most widespread infection, affecting nearly half of the world’s population. It is well-known to be responsible for inducing chronic gastric inflammation progressing to atrophy, metaplasia, dysplasia, and eventually, gastric cancer. This review provides an overview of the association of the factors playing a role in chronic inflammation; the bacterial characteristics which are responsible for the colonization, persistence in the stomach, and triggering of inflammation; the microbiome involved in the chronic inflammation process; and the host factors that have a role in determining whether gastritis progresses to gastric cancer. Understanding these interconnections may improve our ability to prevent gastric cancer development and enhance our understanding of existing cases.