Recent Trends and Advancements in the Diagnosis and Management of Gastric Cancer

Role of N-Glycosylation in Gastrointestinal Cancers

Gastrointestinal cancers pose a significant global health challenge. N-glycosylation modulates various cellular processes, including key cancer-related mechanisms. Elucidating its involvement in the onset and advancement of these cancers can offer critical insights for enhancing diagnostic and therapeutic approaches. This review outlines the core process of protein N-glycosylation and highlights its contribution to the progression of gastrointestinal cancers, encompassing cell proliferation, survival, invasion, metastasis, and immune evasion, mainly through its impact on critical signaling pathways. Notably, aberrant N-glycosylation patterns have emerged as crucial biomarkers for the diagnosis and prognosis of various gastrointestinal cancers, providing the foundation for more personalized therapeutic approaches. Therapeutic strategies targeting N-glycosylation, such as glycosyltransferase inhibitors and glycoengineering, show significant promise in mitigating tumor aggressiveness and enhancing immune recognition. However, the clinical implementation of N-glycosylation biomarkers requires the standardization of glycosylation analysis techniques and solutions to challenges in sample processing and data interpretation. Future research efforts should concentrate on overcoming these obstacles to unlock the full potential of N-glycosylation in enhancing cancer management and advancing patient outcomes.

CRISPR/Cas13a Trans-Cleavage and Catalytic Hairpin Assembly Cascaded Signal Amplification Powered SERS Aptasensor for Ultrasensitive Detection of Gastric Cancer-Derived Exosomes

Cancer-derived exosomes carry a large number of specific molecular profiles from cancer cells and have emerged as ideal biomarkers for early cancer diagnosis. Accurate detection of ultralow-abundance exosomes in complex biological samples remains a great challenge. Herein, a novel SERS aptasensor powered by cascaded signal amplification of CRISPR/Cas13a trans-cleavage and catalytic hairpin assembly (CHA) was proposed for ultrasensitive detection of gastric cancer-derived exosomes, which included hairpin-structured recognition aptamers (MUC1-apt), cascaded signal amplification (i.e., CRISPR/Cas13a trans-cleavage and CHA), SERS tags, and silver nanorods (AgNRs) sensing chip. In the presence of SGC-7901 cell-derived exosomes, MUC1-apt specifically bound to MUC1 proteins highly expressed on exosomes via its contained MUC1 aptamer with its exposed RNA fragments activating the CRISPR/Cas13a trans-cleavage to cleave the uracil-modified hairpin reporter, and the cleavage products further triggered the downstream CHA reaction to form numerous duplexes, which can, in turn, capture a large number of SERS tags onto the AgNRs sensing chip to generate a significantly enhanced Raman signal. The proposed SERS aptasensor exhibits good performance on analysis of exosomes, i.e., rapid response within 60 min, single-particle sensitive detection from a 2 μL biological sample, good specificity in distinguishing SGC-7901 cell-derived exosomes against other exosomes, good uniformity, excellent repeatability, and satisfactory recoveries in human serum, and good universality to expand the detection of multiplex exosomes, which indicates that the SERS aptasensor provides a valuable reference for clinical diagnosis of early cancer.

Dapagliflozin suppressed gastric cancer growth via regulating OTUD5 mediated YAP1 deubiquitination

Gastric cancer (GC) is a common malignant disease that has a fifth highest incidence and fourth highest mortality worldwide. The Warburg effect is a common phenomenon observed in tumors, which suggests that tumor cells would enhance glucose uptake by overexpressing multiple glucose transporters. Sodium glucose transporter 2 (SGLT2) is one of glucose transporters which highly expressed in several cancers, but its role in gastric cancer is still unclear. Our research found that there was a high expression level of SGLT2 in gastric cancer tissues. We found that Dapagliflozin (a SGLT2 inhibitor) could suppress gastric cancer cell proliferation and migration in vitro and tumor growth in vivo. In present study, we revealed how dapagliflozin would suppress gastric cancer progression in a novel mechanism. We proved that dapagliflozin decreased the expression level of OTU deubiquitinase 5 (OTUD5), which further increased the ubiquitination and degradation of YAP1. Overexpression of OTUD5 in gastric cancer cells partly reversed the anti-tumor effect of dapagliflozin. Our findings revealed a novel mechanism by which dapagliflozin has an antitumor effect on gastric cancer and proposed a beneficial strategy for the application of dapagliflozin in gastric cancer patients.

Surrogate endpoints in phase III randomized trials of advanced gastroesophageal cancer: A systematic review and meta-analysis

Overall survival (OS) is the most meaningful endpoint in clinical trials. However, owing to their limitations, surrogate endpoints are commonly used and validation studies are required to assess their reliability. Analysis of phase III randomized controlled trials (RCTs) of advanced gastroesophageal cancer (AGC) with > 100 patients, correlation coefficients (r), and determination coefficients (R²) between OS and surrogates were evaluated through meta-analyses. Progression-free survival (PFS), time to progression (TTP), and objective response rate (ORR) were examined to determine their correlations with OS. Analysis of 65 phase III RCTs (29,766 subjects) showed a moderate correlation between PFS/TTP and OS (r = 0.77, R² = 0.59), while ORR correlation was low (r = 0.56, R² = 0.31). Excluding immunotherapy trials improved the PFS/TTP and OS correlations (r = 0.83, R² = 0.70). These findings suggest the potential use of PFS/TTP in AGC phase III investigations, disregarding the use of ORR as a surrogate endpoint.

[Screening of differentially expressed genes in gastric cancer based on GEO database and function and pathway enrichment analysis]

OBJECTIVE

To explore the core genes related to the diagnosis and prognosis of gastric cancer (GC) based on Gene Expression Omnibus (GEO) database and screen the molecular targets involved in the occurrence and development of GC.

METHODS

GC microarray data GSE118916, GSE54129 and GSE79973 were downloaded from GEO database, and the differentially expressed genes (DEGs) were screened. Enrichment analysis of the signaling pathways and molecular functions were preformed and protein-protein interaction networks (PPI) were constructed to identify the hub genes, whose expression levels and diagnostic and prognostic values were verifies based on gastric adenocarcinoma data from TCGA. The expression levels of these core genes were also detected in different GC cell lines using qRT- PCR.

RESULTS

Seventy-seven DEGs were identified, which encodes proteins located mainly in the extracellular matrix and basement membrane with activities of oxidoreductase and extracellular matrix receptor and ligand, involving the biological processes of digestion and hormone metabolism and the signaling pathways in retinol metabolism and gastric acid secretion. Nine hub genes were obtained, among which SPARC, TIMP1, THBS2, COL6A3 and THY1 were significantly up- regulated and TFF1, GKN1, TFF2 and PGC were significantly down-regulated in GC. The abnormal expressions of SPARC, TIMP1, THBS2, COL6A3, TFF2 and THY1 were significantly correlated with the survival time of GC patients. ROC curve analysis showed that aberrant expression of TIMP1 SPARC, THY1 and THBS2 had high diagnostic value for GC. High expressions of SPARC, TIMP1, THBS2 and COL6A3 were detected in GC tissues. In the GC cell lines, qRT- PCR revealed different expression patterns of these hub genes, but their expressions were largely consistent with those found in bioinformatics analyses.

CONCLUSION

SPARC, TIMP1, THBS2 and other DEGs are probably involved in GC occurrence and progression and may serve as potential candidate molecular markers for early diagnosis and prognostic evaluation of GC.

CA125 Kinetics as a Potential Biomarker for Peritoneal Metastasis Progression following Taxane-Plus-Ramucirumab Administration in Patients with Advanced Gastric Cancer

Currently, no established marker exists for predicting peritoneal metastasis progression during chemotherapy, although they are major interruptive factors in sequential chemotherapy in patients with advanced gastric cancer (AGC). This multicenter retrospective study was conducted from June 2015 to July 2019, analyzing 73 patients with AGC who underwent taxane-plus-ramucirumab (TAX/RAM) therapy and had their serum carbohydrate antigen 125 (CA125) concentrations measured. Of 31 patients with elevated CA125 levels above a cutoff of 35 U/mL, 25 (80.6%) had peritoneal metastasis. The CA125 concentrations before TAX/RAM treatment were associated with ascites burden. The overall survival was significantly shorter in the CA125-elevated group. CA125 kinetics, measured at a median of 28 days after chemotherapy, were associated with the ascites response (complete or partial response: -1.86%/day; stable disease: 0.28%/day; progressive disease: 2.33%/day). Progression-free survival in the CA125-increased group, defined by an increase of 0.0067%/day using receiver operating characteristic curve analysis, was significantly poorer among patients with peritoneal metastases. In conclusion, this study highlights that CA125 kinetics can serve as an early predictor for the progression of peritoneal metastasis during TAX/RAM treatment.

MFG-E8 promotes M2 polarization of macrophages and is associated with poor prognosis in patients with gastric cancer

Background

Milk Fat Globule-Epidermal Growth Factor 8 (MFG-E8) has been reported to play an oncogenic role in a variety of tumors. However, its involvement in gastric cancer (GC) development has not been described.

Methods

The cancer genome atlas (TCGA) and the gene expression omnibus database (GEO) databases were used to analyze the expression of MFG-E8 in GC. These findings were further validated using immunohistochemistry (IHC) and western blotting assay (WB). Kaplan-Meier method, univariate logistic regression, and Christopher Cox regression were used to study the relationship between MFG-E8 and clinical pathology. In addition, the potential signaling pathways involved in MFG-E8 and its potential correlation with levels of immune cell infiltration were investigated. Finally, the biological function of MFG-E8 in GC cells was revealed.

Results

MFG-E8 was highly expressed in GC patients and cells, and the high level of MFG-E8 was associated with poor overall survival (OS). KEGG analysis indicated that MFG-E8 may play an important role in the cAMP signaling pathway. The expression of MFG-E8 was positively correlated with the infiltration of M2 macrophages. The patients with high MFG-E8 were easy to develop chemotherapy resistance. Furthermore, the knockdown of MFG-E8 significantly inhibited the proliferation and invasion of GC cells.

Conclusion

MFG-E8 in GC may serve as a prognostic marker and a potential immunotherapy target for GC.

The role of lncRNA SNHG14 in gastric cancer: enhancing tumor cell proliferation and migration, and mechanisms of CDH2 expression

LncRNAs are a class of non-coding RNAs that play an important role in regulating gene expression. However, their specific molecular mechanisms in gastric carcinogenesis and metastasis need further exploration. TCGA data showed that the expression of MFGE8, which was closely related to survival, was significantly positively correlated with lncRNA SNHG14. And moreover, the results of high-throughput sequencing and qRT-PCR showed that lncRNA SNHG14 was significantly elevated in gastric cancer. Further, in vitro functional realization showed that lncRNA SNHG14 overexpression significantly increased gastric cancer's proliferation, invasion and migration. Animal experiments also showed that lncRNA SNHG14 overexpression promoted tumorigenesis and metastasis in vivo. Mechanistically, MFGE8 activates the expression of lncRNA SNHG14, which activates the cellular EMT by stabilizing CDH2. Our study suggests that lncRNA SNHG14 could be a potential target for gastric cancer therapy.

[Manganese-based nanoparticles for chemodynamic therapy of gastrointestinal cancer]

OBJECTIVE

To investigate the physicochemical features of glucose oxidase-loaded and manganese-based mesoporous silica nanoparticles (MSN@Mn-GOx) and its antitumor effect against gastrointestinal cancer.

METHODS

The morphology, particle size and Fenton-like properties of MSN@Mn-GOx nanoparticles were analyzed using transmission electron microscopy (TEM), dynamic light scattering (DLS), Zeta potential analysis, ultraviolet absorption spectroscopy, energy dispersive spectroscopy and X-ray photoelectron spectroscopy. A mouse model bearing human colon cancer HT-29 xenograft was established to examine the antitumor effect of MSN@Mn-GOx using MRI imaging. Reactive oxygen species (ROS) production assay, CCK-8 assay and EdU assay were used to evaluate the in vitro anti-tumor effect of the nanoparticles.

RESULTS

MSN@Mn-GOx nanoparticles were solid spheres with a diameter of about 100 nm and a Zeta potential of -35 mV. MSN@Mn-GOx had a higher H2O2 catalytic efficiency in glucose containing solution than in glucose-free solution, and showed a stronger Fenton-like properties at pH6.0 than at pH7.4 (P＜0.05). In the tumor-bearing mice, MSN@Mn-GOx treatment dose-dependently enhanced T1 imaging of the tumor (P＜0.01). Compared with the control group and MSN@Mn group, MSN@Mn-GOx induced a significantly higher level of ROS production and a stronger inhibitory effect on the proliferation of gastric and colon cancer cells (P＜0.05).

CONCLUSION

MSN@Mn-GOx nanoparticles have good chemodynamic properties and a strong anti-tumor effect and provide a potential therapeutic option for gastric cancer.

Development and validation of nomogram models to predict radiotherapy or chemotherapy benefit in stage III/IV gastric adenocarcinoma with surgery

Objectives

The advanced gastric adenocarcinoma (GAC) patients (stage III/IV) with surgery may have inconsistent prognoses due to different demographic and clinicopathological factors. In this retrospective study, we developed clinical prediction models for estimating the overall survival (OS) and cancer-specific survival (CSS) in advanced GAC patients with surgery.

Methods

A retrospective analysis was conducted using the Surveillance, Epidemiology, and End Results (SEER) database. The total population from 2004 to 2015 was divided into four levels according to age, of which 179 were younger than 45 years old, 695 were 45-59 years old, 1064 were 60-74 years old, and 708 were older than 75 years old. There were 1,712 men and 934 women. Univariate and multivariate Cox regression analyses were performed to identify prognostic factors for OS and CSS. Nomograms were constructed to predict the 1-, 3-, and 5-year OS and CSS. The models' calibration and discrimination efficiency were validated. Discrimination and accuracy were evaluated using the consistency index, area under the receiver operating characteristic curve, and calibration plots; and clinical usefulness was assessed using decision curve analysis. Cross-validation was also conducted to evaluate the accuracy and stability of the models. Prognostic factors identified by Cox regression were analyzed using Kaplan-Meier survival analysis.

Results

A total of 2,646 patients were included in our OS study. Age, primary site, differentiation grade, AJCC 6th_TNM stage, chemotherapy, radiotherapy, and number of regional nodes examined were identified as prognostic factors for OS in advanced GAC patients with surgery (P < 0.05). A total of 2,369 patients were included in our CSS study. Age, primary site, differentiation grade, AJCC 6th_TNM stage, chemotherapy, radiotherapy, and number of regional nodes examined were identified as risk factors for CSS in these patients (P < 0.05). These factors were used to construct the nomogram to predict the 1-, 3-, and 5-year OS and CSS of advanced GAC patients with surgery. The consistency index and area under the receiver operating characteristic curve demonstrated that the models effectively differentiated between events and nonevents. The calibration plots for 1-, 3-, and 5-year OS and CSS probability showed good consistence between the predicted and the actual events. The decision curve analysis indicated that the nomogram had higher clinical predictive value and more significant net gain than AJCC 6th_TNM stage in predicting OS and CSS of advanced GAC patients with surgery. Cross-validation also revealed good accuracy and stability of the models.

Conclusion

The developed predictive models provided available prognostic estimates for advanced GAC patients with surgery. Our findings suggested that both OS and CSS can benefit from chemotherapy or radiotherapy in these patients.

Association between radiomics features of DCE-MRI and CD8+ and CD4+ TILs in advanced gastric cancer

Objective: The aim of this investigation was to explore the correlation between the levels of tumor-infiltrating CD8⁺ and CD4⁺ T cells and the quantitative pharmacokinetic parameters of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in patients with advanced gastric cancer. Methods: We retrospectively analyzed the data of 103 patients with histopathologically confirmed advanced gastric cancer (AGC). Three pharmacokinetic parameters, K_ep, K^trans, and V_e, and their radiomics characteristics were obtained by Omni Kinetics software. Immunohistochemical staining was used to determine CD4⁺ and CD8⁺ TILs. Statistical analysis was subsequently performed to assess the correlation between radiomics characteristics and CD4⁺ and CD8⁺ TIL density. Results: All patients included in this study were finally divided into either a CD8⁺ TILs low-density group (n = 51) (CD8⁺ TILs < 138) or a high-density group (n = 52) (CD8⁺ TILs ≥ 138), and a CD4⁺ TILs low-density group (n = 51) (CD4⁺ TILs < 87) or a high-density group (n = 52) (CD4⁺ TILs ≥ 87). ClusterShade and Skewness based on K_ep and Skewness based on K^trans both showed moderate negative correlation with CD8⁺ TIL levels (r = 0.630-0.349, p < 0.001), with ClusterShade based on K_ep having the highest negative correlation (r = -0.630, p < 0.001). Inertia-based K_ep showed a moderate positive correlation with the CD4⁺ TIL level (r = 0.549, p < 0.001), and the Correlation based on K_ep showed a moderate negative correlation with the CD4⁺ TIL level, which also had the highest correlation coefficient (r = -0.616, p < 0.001). The diagnostic efficacy of the above features was assessed by ROC curves. For CD8⁺ TILs, ClusterShade of K_ep had the highest mean area under the curve (AUC) (0.863). For CD4⁺ TILs, the Correlation of K_ep had the highest mean AUC (0.856). Conclusion: The radiomics features of DCE-MRI are associated with the expression of tumor-infiltrating CD8⁺ and CD4⁺ T cells in AGC, which have the potential to noninvasively evaluate the expression of CD8⁺ and CD4⁺ TILs in AGC patients.

FMO family may serve as novel marker and potential therapeutic target for the peritoneal metastasis in gastric cancer

Objective

To explore the relationship between flavin-containing monooxygenases (FMOs) and peritoneal metastasis (PM) in gastric cancer (GC).

Materials and methods

TIMER 2.0 was used to perform pan-cancer analysis and assess the correlation between the expression of FMOs and cancers. A dataset from The Cancer Genome Atlas (TCGA) was used to analyze the correlation between FMOs and clinicopathological features of GC. PM is well established as the most common mode of metastasis in GC. To further analyze the correlation between FMOs and PM of GC, a dataset was obtained from the National Center for Biotechnology Information Gene Expression Omnibus (GEO) database. The results were validated by immunohistochemistry. The relationship between FMOs and PM of GC was explored, and a novel PM risk signature was constructed by least absolute shrinkage and selection operator (LASSO) regression analysis. The regression model's validity was tested by multisampling. A nomogram was established based on the model for predicting PM in GC patients. The mechanism of FMOs in GC patients presenting with PM was assessed by conducting Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses in TCGA and GEO datasets. Finally, the potential relationship between FMOs and immunotherapy was analyzed.

Results

The pan-cancer analysis in TCGA and GEO datasets showed that FMO1 was upregulated, while FMO2 and FMO4 were downregulated in GC. Moreover, FMO1 and FMO2 correlated positively with the T and N stage of GC in the TCGA dataset. FMO1 and FMO2 expression was a risk factor for GC (hazard ratio: 1.112 and 1.185). The overexpression of FMO1 was significantly correlated with worse disease-free-survival (DFS) and overall survival (OS). However, no relationship was found between FMO2 expression in GC and DFS and OS. PM was highly prevalent among GC patients and typically associated with a worse prognosis. FMO1 was highly expressed in GC with PM. FMO1 and FMO2 were positively correlated with PM in GC. We identified a 12-gene panel for predicting the PM risk signature by LASSO (Area Under Curve (AUC) = 0.948, 95%CI: 0.896-1.000). A 10-gene panel for PM prediction was identified (AUC = 0.932, 95%CI: 0.874-0.990), comprising FMO1 and FMO2. To establish a model for clinical application, a 7-gene panel was established (AUC = 0.927, 95% CI: 0.877-0.977) and successfully validated by multisampling. (AUC = 0.892, 95% CI: 0.878-0.906). GO and KEGG analyses suggest that FMO1 and FMO2 regulate the extracellular matrix and cell adhesion. FMO1 and FMO2 were positively correlated with the immune score of GC, and their expression was associated with the infiltration of immune cells.

Conclusion

PM in GC is strongly correlated with FMOs. Overall, FMO1 and FMO2 have huge prospects for application as novel diagnostic and therapeutic targets.

[Overexpression of miR-431-5p impairs mitochondrial function and induces apoptosis in gastric cancer cells via the Bax/Bcl-2/caspase3 pathway]

OBJECTIVE

To investigate the expression of microRNA miR-431-5p in gastric cancer (GC) tissues and its effects on apoptosis and mitochondrial function in GC cells.

METHODS

The expression level of miR-431-5p in 50 clinical samples of GC tissues and paired adjacent tissues was detected using real-time fluorescence quantitative PCR, and its correlation with the clinicopathological features of the patients was analyzed. A cultured human GC cell line (MKN-45 cells) were transfected with a miR-431-5p mimic or a negative control sequence, and the cell proliferation, apoptosis, mitochondrial number, mitochondrial potential, mitochondrial permeability transition pore (mPTP), reactive oxygen species (ROS) production and adenosine triphosphate (ATP) content were detected using CCK-8 assay, flow cytometry, fluorescent probe label, or ATP detection kit. The changes in the expression levels of the apoptotic proteins in the cells were detected with Western blotting.

RESULTS

The expression level of miR-431-5p was significantly lower in GC tissues than in the adjacent tissues (P < 0.001) and was significantly correlated with tumor differentiation (P=0.0227), T stage (P=0.0184), N stage (P=0.0005), TNM stage (P=0.0414) and vascular invasion (P=0.0107). In MKN-45 cells, overexpression of miR-431-5p obviously inhibited cell proliferation and induced cell apoptosis, causing also mitochondrial function impairment as shown by reduced mitochondrial number, lowered mitochondrial potential, increased mPTP opening, increased ROS production and reduced ATP content. Overexpression of miR-431-5p significantly downregulated the expression of Bcl-2 and increased the expressions of pro-apoptotic proteins p53, Bcl-2 and cleaved caspase-3 protein.

CONCLUSION

The expression of miR-431-5p is down-regulated in GC, which results in mitochondrial function impairment and promotes cell apoptosis by activating the Bax/Bcl-2/caspase3 signaling pathway, suggesting the potential role of miR-431-5p in targeted therapy for GC.