Elucidating molecular mechanisms and therapeutic synergy: irreversible HER2-TKI plus T-Dxd for enhanced anti-HER2 treatment of gastric cancer

BACKGROUND

HER2-targeted therapies have improved the outcomes of HER2-positive gastric cancer (GC), yet resistance remains a challenge. We sought to explore the effects of reversible and irreversible HER2 tyrosine kinase inhibitors (TKIs) alone or in combination with the HER2-targeting antibody drug conjugate trastuzumab deruxtecan (T-Dxd).

METHODS

The effects of HER2-TKIs on HER2 and downstream signaling were evaluated via Western blotting. Proteasomal inhibitors and co-immunoprecipitation assays were performed to explore the role of proteasomal degradation in HER2 expression modulation, and immunofluorescence assays were employed to explore mechanisms of HER2 internalization. The synergistic potential of the irreversible HER2-TKI pyrotinib in combination with T-Dxd was validated using growth and viability assays in anti-HER2-positive GC cell cultures and tumor growth and immunohistochemical staining assays in a mouse xenograft model.

RESULTS

Our study revealed that reversible HER2-TKIs elevated HER2 protein levels, whereas irreversible HER2-TKIs decreased them. Pyrotinib triggered HER2 degradation within the proteasome by promoting ubiquitination and dissociation from HSP90. Furthermore, pyrotinib substantially induced HER2 internalization, which led to improved cellular uptake of T-Dxd. The increased T-Dxd uptake was accompanied by greater efficacy in suppressing the growth of GC cells and enhanced anti-tumor effects in an animal model.

CONCLUSION

In summary, our research reveals the molecular mechanisms of irreversible HER2-TKIs in regulating HER2 protein expression by promoting HER2 internalization. These findings advance our comprehension of targeted therapy for GC and provide a promising therapeutic combination strategy with enhanced efficacy against HER2-positive GC.

Exploring new frontiers: cell surface vimentin as an emerging marker for circulating tumor cells and a promising therapeutic target in advanced gastric Cancer

BACKGROUND

Circulating tumor cells (CTCs) hold immense promise in guiding treatment strategies for advanced gastric cancer (GC). However, their clinical impact has been limited due to challenges in identifying epithelial-mesenchymal transition (EMT)-CTCs using conventional methods.

METHODS

To bridge this knowledge gap, we established a detection platform for CTCs based on the distinctive biomarker cell surface vimentin (CSV). A prospective study involving 127 GC patients was conducted, comparing CTCs enumeration using both EpCAM and CSV. This approach enabled the detection of both regular and EMT-CTCs, providing a comprehensive analysis. Spiking assays and WES were employed to verify the reliability of this marker and technique. To explore the potential inducer of CSV+CTCs formation, a combination of Tandem Mass Tag (TMT) quantitative proteomics, m6A RNA immunoprecipitation-qPCR (MeRIP-qPCR), single-base elongation- and ligation-based qPCR amplification method (SELECT) and RNA sequencing (RNA-seq) were utilized to screen and confirm the potential target gene. Both in vitro and in vivo experiments were performed to explore the molecular mechanism of CSV expression regulation and its role in GC metastasis.

RESULTS

Our findings revealed the potential of CSV in predicting therapeutic responses and long-term prognosis for advanced GC patients. Additionally, compared to the conventional EpCAM-based CTCs detection method, the CSV-specific positive selection CTCs assay was significantly better for evaluating the therapeutic response and prognosis in advanced GC patients and successfully predicted disease progression 14.25 months earlier than radiology evaluation. Apart from its excellent role as a detection marker, CSV emerges as a promising therapeutic target for attenuating GC metastasis. It was found that fat mass and obesity associated protein (FTO) could act as a potential catalyst for CSV+CTCs formation, and its impact on the insulin-like growth factor-I receptor (IGF-IR) mRNA decay through m6A modification. The activation of IGF-I/IGF-IR signaling enhanced the translocation of vimentin from the cytoplasm to the cell surface through phosphorylation of vimentin at serine 39 (S39). In a GC mouse model, the simultaneous inhibition of CSV and blockade of the IGF-IR pathway yielded promising outcomes.

CONCLUSION

In summary, leveraging CSV as a universal CTCs marker represents a significant breakthrough in advancing personalized medicine for patients with advanced GC. This research not only paves the way for tailored therapeutic strategies but also underscores the pivotal role of CSV in enhancing GC management, opening new frontiers for precision medicine.

Bioinformatic Analysis and Experimental Validation of HMGA2-AS1 as a Prognostic Biomarker Associated with Immune Infiltration in Gastric Cancer

BACKGROUND

Natural antisense long noncoding RNAs (lncRNAs) have the ability to modulate the expression of their corresponding sense genes. Consequently, any dysregulation of these lncRNAs can contribute to the development of pathological processes. The ambiguity surrounding the role of HMGA2-AS1 in gastric cancer (GC) requires further investigation.

OBJECTIVE

The aim of this study was to examine the involvement of HMGA2-AS1 in GC.

METHODS

The Kaplan-Meier method, Cox regression analysis, gene set enrichment analysis (GSEA), and immune infiltration analysis were used in this study. These methods were used to evaluate the relationship between clinical characteristics and HMGA2-AS1 expression, prognostic factors, and the significant functional impact of HMGA2-AS1. HMGA2-AS1 levels in GC cell lines were validated using quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

In patients diagnosed with GC, a significant correlation was observed between high expression of HMGA2-AS1 and the T stage (p = 0.01). Furthermore, the high expression of HMGA2- AS1 was identified as a prognostic indicator for poorer OS (p = 0.004), PFS (p = 0.006), and DSS (p = 0.011). Furthermore, the expression of HMGA2-AS1 (p < 0.001) demonstrated an independent association with OS in patients with GC. The presence of a low expression phenotype of HMGA2-AS1 was associated with differential enrichment of various pathways, including the focal adhesion-PI3K-Akt-mTOR signaling pathway, focal adhesion, ECM glycoproteins, MET promoting cell motility, among others. Furthermore, the expression of HMGA2-AS1 exhibited correlations with B cells, CD56 bright cells, and TFH and Th17 cells. Furthermore, GC cell lines demonstrated significantly higher expression of HMGA2-AS1.

CONCLUSION

Elevated expression of HMGA2-AS1 in GC patients exhibited a significant correlation with unfavorable survival outcomes and increased immune infiltration. This suggests that HMGA2- AS1 holds promise as a potential prognostic biomarker and target for immunotherapy in GC.

Machine learning methods predict recurrence of pN3b gastric cancer after radical resection

Background

The incidence of stage pN3b gastric cancer (GC) is low, and the clinical prognosis is poor, with a high rate of postoperative recurrence. Machine learning (ML) methods can predict the recurrence of GC after surgery. However, the prognostic significance for pN3b remains unclear. Therefore, we aimed to predict the recurrence of pN3b through ML models.

Methods

This retrospective study included 336 patients with pN3b GC who underwent radical surgery. A 3-fold cross-validation was used to partition the participants into training and test cohorts. Linear combinations of new variable features were constructed using principal component analysis (PCA). Various ML algorithms, including random forest, support vector machine (SVM), logistic regression, multilayer perceptron (MLP), extreme gradient boosting (XGBoost), and Gaussian naive Bayes (GNB), were utilized to establish a recurrence prediction model. Model performance was evaluated using the receiver operating characteristic (ROC) curve and the area under the curve (AUC). Python was used for the analysis of ML algorithms.

Results

Nine principal components with a cumulative variance interpretation rate of 90.71% were identified. The output results of the test set showed that random forests had the highest AUC (0.927) for predicting overall recurrence with an accuracy rate of 80.5%. Random forests had the highest AUC (0.940) for predicting regional recurrence with an accuracy of 89.7%. For predicting distant recurrence, random forests had the highest AUC (0.896) with an accuracy of 84.3%. For peritoneal recurrence, random forests had the highest AUC (0.923) with an accuracy of 83.3%.

Conclusions

ML can personalize the prediction of postoperative recurrence in patients with GC with stage pN3b.

The long intergenic non-coding RNA LINC01140 modulates gastric cancer phenotypes and cancer cell lines aggressiveness

BACKGROUND

Long-intergenic non-protein coding gene 01140 (LINC01140) a long non-coding RNA is highly expressed in various cancers. However, its biological functions in gastric cancer progression is still unknown.

METHOD

To elucidate LINC01140 function, 70 GC tumor samples and 30 normal gastric tissues were collected. LINC01140 expression level were determined by qRT-PCR analysis and correlated with different clinico-pathological parameters. Then we tried to see the impact of LINC01140 on gastric cell line aggressiveness by knocking down the target gene and performing cell viability assay, migration assay and invasive capacity of the cell lines along with immunoblotting to check several protein levels.

RESULT

LINC01140 RNA is found to be positively correlated with FGF9 and significantly up regulated in GC tissues. LINC01140 knockdown inhibited the viability, migratory capacity and invasive capacity of AGS cells. LINC01140 targets miR-140-5p, while miR-140-5p targeted FGF9 to form lncRNA-miRNA-mRNA axis. The affect of miR-140-5p inhibition on gastric cancer cell aggressiveness were opposite to those of LINC01140 or FGF9 knockdown. Additionally, inhibition partially reversed the effects of LINC01140 knockdown on FGF9 protein levels, gastric cancer cell phenotypes.

CONCLUSION

LINC01140, miR-140-5p and FGF9 form a lncRNA-miRNA-mRNA axis that modulates the gastric cancer phenotypes and in turn affects gastric cancer cell aggressiveness.

Construction of a gene model related to the prognosis of patients with gastric cancer receiving immunotherapy and exploration of COX7A1 gene function

BACKGROUND

GC is a highly heterogeneous tumor with different responses to immunotherapy, and the positive response depends on the unique interaction between the tumor and the tumor microenvironment (TME). However, the currently available methods for prognostic prediction are not satisfactory. Therefore, this study aims to construct a novel model that integrates relevant gene sets to predict the clinical efficacy of immunotherapy and the prognosis of GC patients based on machine learning.

METHODS

Seven GC datasets were collected from the Gene Expression Omnibus (GEO) database, The Cancer Genome Atlas (TCGA) database and literature sources. Based on the immunotherapy cohort, we first obtained a list of immunotherapy related genes through differential expression analysis. Then, Cox regression analysis was applied to divide these genes with prognostic significancy into protective and risky types. Then, the Single Sample Gene Set Enrichment Analysis (ssGSEA) algorithm was used to score the two categories of gene sets separately, and the scores differences between the two gene sets were used as the basis for constructing the prognostic model. Subsequently, Weighted Correlation Network Analysis (WGCNA) and Cytoscape were applied to further screen the gene sets of the constructed model, and finally COX7A1 was selected for the exploration and prediction of the relationship between the clinical efficacy of immunotherapy for GC. The correlation between COX7A1 and immune cell infiltration, drug sensitivity scoring, and immunohistochemical staining were performed to initially understand the potential role of COX7A1 in the development and progression of GC. Finally, the differential expression of COX7A1 was verified in those GC patients receiving immunotherapy.

RESULTS

First, 47 protective genes and 408 risky genes were obtained, and the ssGSEA algorithm was applied for model construction, showing good prognostic discrimination ability. In addition, the patients with high model scores showed higher TMB and MSI levels, and lower tumor heterogeneity scores. Then, it is found that the COX7A1 expressions in GC tissues were significantly lower than those in their corresponding paracancerous tissues. Meanwhile, the patients with high COX7A1 expression showed higher probability of cancer invasion, worse clinical efficacy of immunotherapy, worse overall survival (OS) and worse disease-free survival (DFS).

CONCLUSIONS

The ssGSEA score we constructed can serve as a biomarker for GC patients and provide important guidance for individualized treatment. In addition, the COX7A1 gene can accurately distinguish the prognosis of GC patients and predict the clinical efficacy of immunotherapy for GC patients.

Characterization of gastric cancer-stimulated signaling pathways and function of CTGF in cancer-associated fibroblasts

BACKGROUND

Cancer-associated fibroblasts (CAFs) are key components of the tumor microenvironment (TME) that play an important role in cancer progression. Although the mechanism by which CAFs promote tumorigenesis has been well investigated, the underlying mechanism of CAFs activation by neighboring cancer cells remains elusive. In this study, we aim to investigate the signaling pathways involved in CAFs activation by gastric cancer cells (GC) and to provide insights into the therapeutic targeting of CAFs for overcoming GC.

METHODS

Alteration of receptor tyrosine kinase (RTK) activity in CAFs was analyzed using phospho-RTK array. The expression of CAFs effector genes was determined by RT-qPCR or ELISA. The migration and invasion of GC cells co-cultured with CAFs were examined by transwell migration/invasion assay.

RESULTS

We found that conditioned media (CM) from GC cells could activate multiple receptor tyrosine kinase signaling pathways, including ERK, AKT, and STAT3. Phospho-RTK array analysis showed that CM from GC cells activated PDGFR tyrosine phosphorylation, but only AKT activation was PDGFR-dependent. Furthermore, we found that connective tissue growth factor (CTGF), a member of the CCN family, was the most pronouncedly induced CAFs effector gene by GC cells. Knockdown of CTGF impaired the ability of CAFs to promote GC cell migration and invasion. Although the PDGFR-AKT pathway was pronouncedly activated in CAFs stimulated by GC cells, its pharmacological inhibition affected neither CTGF induction nor CAFs-induced GC cell migration. Unexpectedly, the knockdown of SRC and SRC-family kinase inhibitors, dasatinib and saracatinib, significantly impaired CTGF induction in activated CAFs and the migration of GC cells co-cultured with CAFs. SRC inhibitors restored the reduced expression of epithelial markers, E-cadherin and Zonula Occludens-1 (ZO-1), in GC cells co-cultured with CAFs, as well as CAFs-induced aggregate formation in a 3D tumor spheroid model.

CONCLUSIONS

This study provides a characterization of the signaling pathways and effector genes involved in CAFs activation, and strategies that could effectively inhibit it in the context of GC. Video Abstract.

Involvement of CXC chemokines (CXCL1-CXCL17) in gastric cancer: Prognosis and therapeutic molecules

Gastric cancer (GC) is the fifth-most prevalent and second-most deadly cancer worldwide. Due to the late onset of symptoms, GC is frequently treated at a mature stage. In order to improve the diagnostic and clinical decision-making processes, it is necessary to establish more specific and sensitive indicators valuable in the early detection of the disease whenever a cancer is asymptomatic. In this work, we gathered information about CXC chemokines and GC by using scientific search engines including Google Scholar, PubMed, SciFinder, and Web of Science. Researchers believe that GC chemokines, small proteins, class CXC chemokines, and chemokine receptors promote GC inflammation, initiation, and progression by facilitating angiogenesis, tumor transformation, invasion, survival, metastatic spread, host response safeguards, and inter-cell interaction. With our absolute best professionalism, the role of CXC chemokines and their respective receptors in GC diagnosis and prognosis has not been fully explained. This review article updates the general characteristics of CXC chemokines, their unique receptors, their function in the pathological process of GC, and their potential application as possible indicators for GC. Although there have only recently been a few studies focusing on the therapeutic efficacy of CXC chemokine inhibitors in GC, growing experimental evidence points to the inhibition of CXC chemokines as a promising targeted therapy. Therefore, further translational studies are warranted to determine whether specific antagonists or antibodies designed to target CXC chemokines alone or in combination with chemotherapy are useful for diagnosing advanced GC.

A methylation-related signature for predicting prognosis and sensitivity to first-line therapies in gastric cancer

Background

Methylation modification patterns play a crucial role in human cancer progression, especially in gastrointestinal cancers. We aimed to use methylation regulators to classify patients with gastric adenocarcinoma and build a model to predict prognosis, promoting the application of precision medicine.

Methods

We obtained RNA sequencing data and clinical data from The Cancer Genome Atlas (TCGA) database (n=335) and Gene Expression Omnibus (GEO) database (n=865). Unsupervised consensus clustering was used to identify subtypes of gastric adenocarcinoma. We performed functional enrichment analysis, immune infiltration analysis, drug sensitivity analysis, and molecular feature analysis to determine the clinical application for different subtypes. The univariate Cox regression analysis and the LASSO regression analysis were subsequently used to identify prognosis-related methylation regulators and construct a risk model.

Results

Through unsupervised consensus clustering, patients were divided into two subtypes (cluster A and cluster B) with different clinical outcomes. Cluster B included patients with a better prognosis outcome and who were more likely to respond to immunotherapy. We then successfully built a predictive model and found five methylation-related genes (CHAF1A, CPNE8, PHLDA3, SPARC, and EHF) potentially significant to the prognosis of patients. The 1-, 3-, and 5-year areas under the curve of the risk model were 0.712, 0.696, and 0.759, respectively. The risk score was an independent prognostic factor and had the highest concordance index among common clinical indicators. Meanwhile, the tumor microenvironment, sensitivity of chemotherapeutic drugs, molecular features, and oncogenic dedifferentiation differed significantly across the risk groups and subtypes.

Conclusions

We classified patients with gastric adenocarcinoma based on methylation regulators, which has positive implications for first-line clinical treatment. The prognostic model could predict the prognosis of patients and help to promote the development of precision medicine.

A novel prognostic and therapeutic target biomarker based on complement-related gene signature in gastric cancer

Background

Gastric cancer (GC) is one of the most prevalent cancer types that reduce human life expectancy. The current tumor-node-metastasis (TNM) staging system is inadequate in identifying higher or lower risk of GC patients because of tumor heterogeneity. Research shows that complement plays a dual role in the tumor development and progression of GC.

Methods

We downloaded GC data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). A complement-related risk signature was constructed through bioinformatics analysis. Subsequently, the predictive ability of this signature was validated with GSE84437 dataset, and a nomogram integrating risk score and common clinical factors was established. Besides, we evaluated the association of risk score with the immune and stromal cell infiltration in TCGA. Furthermore, immunotherapy response prediction and drug susceptibility analysis were conducted to access the ability of the risk signature in predicting the therapeutic effect.

Results

A complement-related gene (CRG) signature, based on six genes (SPLG, C9, ITIH1, ZFPM2, CD36, and SERPINE1), was established. In both the training and validation sets, the overall survival of GC patients in the high-risk group was lower than that of the low-risk group, and the nomogram to predict the 1-, 2-, and 3-year survival rates of GC patients was developed. In addition, CIBERSORT algorithm showed the high-risk patients had higher levels of immune cell infiltration than low-risk patients, and the ESTIMATE results implied that the high-risk group had more stromal component in tumor microenvironment. Besides, compared to the low-risk group, there were higher expressions of most immune checkpoint genes and HLA genes in the high-risk group, and the high-risk patients showed higher sensitivity to the chemotherapy and targeted drugs (axitinib, dasatinib, pazopanib, saracatinib, sunitinib and temsirolimus).

Conclusions

The novel CRG signature may act as a reliable, efficient tool for prognostic prediction and treatment guidance in future clinical practice.

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.

Development of a nomogram based on body composition analysis of quantitative computed tomography combined with clinical prognostic factors to predict disease-free survival after surgery and adjuvant chemotherapy in patients with gastric cancer

Background

Patients with gastric cancer (GC) have a high recurrence rate after surgery. To predict disease-free survival (DFS), we investigated the value of body composition changes (BCCs) measured by quantitative computed tomography (QCT) in assessing the prognosis of patients with GC undergoing resection combined with adjuvant chemotherapy and to construct a nomogram model in combination with clinical prognostic factors (CPFs).

Methods

A retrospective study of 60 patients with GC between February 2015 and June 2019 was conducted. Pre- and posttreatment CT images of patients was used to measure bone mineral density (BMD), subcutaneous fat area (SFA), visceral fat area (VFA), total fat area (TFA), paravertebral muscle area (PMA), and the rate of BCC was calculated. CPFs such as maximum tumor diameter (MTD), human epidermal growth factor receptor-2 (HER2), and Ki-67 were derived from postoperative pathological findings. Independent prognostic factors affecting DFS in GC were screened via univariate and multivariate Cox regression analysis. The Kaplan-Meier method and log-rank test were used to plot survival curves and compare the curves between groups, respectively. Receiver operating characteristic (ROC) curves, calibration curves, and decision curves to evaluate the efficacy of the nomogram.

Results

The results of multivariate Cox regression analysis showed that ΔBMD [hazard ratio (HR): 4.577; 95% confidence interval (CI): 1.483-14.132; P=0.008], ΔPMA (HR: 5.784; 95% CI: 1.251-26.740; P=0.025), HER2 (HR: 4.819; 95% CI: 2.201-10.549; P<0.001), and maximal tumor diameter (HR: 3.973; 95% CI: 1.893-8.337; P<0.001) were independent factors influencing DFS. ΔBMD, ΔSFA, ΔVFA, ΔTFA, and ΔPMA were -3.86%, -23.44%, -19.57%, -22.45%, and -5.94%, respectively. The prognostic model of BCCs combined with CPFs had the highest predictive performance. Decision curve analysis (DCA) indicated good clinical benefit for the prognostic nomogram. The concordance index of the prognostic nomogram was 0.814, and the area under the curve (AUC) of predicting 2- and 3-year DFS were 0.879 and 0.928, respectively. The calibration curve showed that the nomogram-predicted DFS aligned well with the actual DFS.

Conclusions

The prognostic nomogram combining BCCs and CPFs was able to reliably predict the DFS of patients with GC.

Circulating tumor cells in gastric cancer: developments and clinical applications

Circulating tumor cells (CTCs), which are shed from primary tumor or metastatic sites into the bloodstream and subsequently seed into distant tissues, are considered as the precursors of metastases. Gastric cancer (GC) is a highly heterogeneous malignant tumor. With regard to the diagnosis of GC, secondary pathological biopsy is difficult, while invasive examination is harmful to patients. In recent years, CTCs have made great progress in tumor diagnosis, prognosis prediction, efficacy detection and treatment guidance, but the research on the role of CTCs in GC remains limited. The following sections review the landmark studies demonstrating the technical approaches of CTCs monitoring in the field of GC. Moreover, we highlight the clinical application of CTCs numbers and phenotypes in monitoring the therapeutic efficacy and judging patient prognosis by sequential blood analyses.

Investigating the prognostic and predictive value of the type II cystatin genes in gastric cancer

BACKGROUND

Accumulating evidence indicates that type II cystatin (CST) genes play a pivotal role in several tumor pathological processes, thereby affecting all stages of tumorigenesis and tumor development. However, the prognostic and predictive value of type II CST genes in GC has not yet been investigated.

METHODS

The present study evaluated the expression and prognostic value of type II CST genes in GC by using The Cancer Genome Atlas (TCGA) database and the Kaplan-Meier plotter (KM plotter) online database. The type II CST genes related to the prognosis of GC were then screened out. We then validated the expression and prognostic value of these genes by immunohistochemistry. We also used Database for Annotation, Visualization, and Integrated Discovery (DAVID), Gene Multiple Association Network Integration Algorithm (GeneMANIA), Search Tool for the Retrieval of Interacting Genes/Proteins (STRING), nomogram, genome-wide co-expression analysis, and other bioinformatics tools to analyze the value of type II CST genes in GC and the underlying mechanism.

RESULTS

The data from the TCGA database and the KM plotter online database showed that high expression of CST2 and CST4 was associated with the overall survival (OS) of patients with GC. The immunohistochemical expression analysis showed that patients with high expression of CST4 in GC tissues have a shorter OS than those with low expression of CST4 (HR = 1.85,95%CI: 1.13-3.03, P = 0.015). Multivariate Cox regression analysis confirmed that the high expression level of CST4 was an independent prognostic risk factor for OS.

CONCLUSIONS

Our findings suggest that CST4 could serve as a tumor marker that affects the prognosis of GC and could be considered as a potential therapeutic target for GC.

Radiomics based on machine learning algorithms could predict prognosis and postoperative chemotherapy benefits of patients with gastric cancer: a retrospective cohort study

Background

Traditional clinical characteristics have certain limitations in evaluating cancer prognosis. The radiomics features provide information on tumor morphology, tissue texture, and hemodynamics, which can accurately reflect personalized predictions. This study investigated the clinical value of radiomics features on contrast-enhanced computed tomography (CT) images in predicting prognosis and postoperative chemotherapy benefits for patients with gastric cancer (GC).

Methods

For this study, 171 GC patients who underwent radical gastrectomy and pathology confirmation of the malignancy at the First Affiliated Hospital of Wenzhou Medical University were retrospectively enrolled. The general information, pathological characteristics, and postoperative chemotherapy information were collected. Patients were also monitored through telephone interviews or outpatient treatment. GC patients were randomly divided into the developing cohort (n=120) and validation cohort (n=51). The intra-tumor areas of interest inside the tumors were delineated, and 1,218 radiomics features were extracted. The optimal radiomics risk score (RRS) was constructed using 8 machine learning algorithms and 29 algorithm combinations. Furthermore, a radiomics nomogram that included clinicopathological characteristics was constructed and validated through univariate and multivariate Cox analyses.

Results

Eleven prognosis-related features were selected, and an RRS was constructed. Kaplan-Meier curve analysis showed that the RRS had a high prognostic ability in the developing and validation cohorts (log-rank P<0.01). The RRS was higher in patients with a larger tumor size (≥3 cm), higher Charlson score (≥2), and higher clinical stage (Stages III and IV) (all P<0.001). Furthermore, GC patients with a higher RRS significantly benefited from postoperative chemotherapy. The results of univariate and multivariate Cox regression analyses demonstrated that the RRS was an independent risk factor for overall survival (OS) and disease-free survival (DFS) (P<0.001). A visual nomogram was established based on the significant factors in multivariate Cox analysis (P<0.05). The C-index was 0.835 (0.793-0.877) for OS and 0.733 (0.677-0.789) for DFS in the developing cohort. The calibration curve also showed that the nomogram had good agreement.

Conclusions

A nomogram that combines the RRS and clinicopathological characteristics could serve as a novel noninvasive preoperative prediction model with the potential to accurately predict the prognosis and chemotherapy benefits of GC patients.

Microvesicles from bone marrow-derived mesenchymal stem cells promote Helicobacter pylori-associated gastric cancer progression by transferring thrombospondin-2

BACKGROUND

Our previous study found that bone marrow-derived mesenchymal stem cells (BMSCs) promote Helicobacter pylori (H pylori)-associated gastric cancer (GC) progression by secreting thrombospondin-2 (THBS2). Extracellular vesicles (EVs) are important carriers for intercellular communication, and EVs secreted by BMSCs have been shown to be closely related to tumor development. The aim of this study was to investigate whether BMSC-derived microvesicles (MVs, a main type of EV) play a role in H. pylori-associated GC by transferring THBS2.

METHODS

BMSCs and THBS2-deficient BMSCs were treated with or without the supernatant of H. pylori for 12 h at a multiplicity of infection of 50, and their EVs were collected. Then, the effects of BMSC-derived MVs and THBS2-deficient BMSC-derived MVs on the GC cell line MGC-803 were assessed by in vitro proliferation, migration, and invasion assays. In addition, a subcutaneous xenograft tumor model, a nude mouse intraperitoneal metastasis model, and a tail vein injection metastasis model were constructed to evaluate the effects of BMSC-derived MVs and THBS2-deficient BMSC-derived MVs on GC development and metastasis in vivo.

RESULTS

BMSC-derived MVs could be readily internalized by MGC-803 cells. BMSC-derived MVs after H. pylori treatment significantly promoted their proliferation, migration and invasion in vitro (all P < 0.05) and promoted tumor development and metastasis in a subcutaneous xenograft tumor model, a nude mouse intraperitoneal metastasis model, and a tail vein injection metastasis model in vivo (all P < 0.05). The protein expression of THBS2 was significantly upregulated after H. pylori treatment in BMSC-derived MVs (P < 0.05). Depletion of the THBS2 gene reduces the tumor-promoting ability of BMSC-MVs in an H. pylori infection microenvironment both in vitro and in vivo.

CONCLUSION

Overall, these findings indicate that MVs derived from BMSCs can promote H. pylori-associated GC development and metastasis by delivering the THBS2 protein. Video Abstract.

COL5A2 is a prognostic-related biomarker and correlated with immune infiltrates in gastric cancer based on transcriptomics and single-cell RNA sequencing

BACKGROUND

There is still a therapeutic challenge in treating gastric cancer (GC) due to its high incidence and poor prognosis. Collagen type V alpha 2 (COL5A2) is increased in various cancers, yet it remains unclear how it contributes to the prognosis and immunity of GC.

METHODS

The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets were used to download transcriptome profiling (TCGA-STAD; GSE84437), single-cell RNA sequencing (scRNA-seq) data (GSE167297) and clinical information. COL5A2 expression and its relationship with clinicopathological factors were analyzed. We conducted survival analysis and Cox regression analysis to evaluate the prognosis and independent factors of GC. Co-expressed analysis was also performed. To identify the underlying mechanism, we conducted analyses of differentially expressed genes (DEGs) and functional enrichment. The correlations between COL5A2 expression and immune cell infiltration levels and immune infiltrate gene marker sets were further explored. Additionally, we analyzed the association of COL5A2 expression with immunological checkpoint molecules. Furthermore, the relationship between COL5A2 expression and immunotherapy sensitivity was also investigated.

RESULTS

COL5A2 expression was elevated in GC. More than this, the scRNA-seq analysis revealed that COL5A2 expression had a spatial gradient. The upregulated COL5A2 was associated with worse overall survival. A significant correlation was found between COL5A2 overexpression and age, T classification and clinical stage in GC. COL5A2 was found to be an independent factor for the unfortunate outcome in Cox regression analysis. The co-expressed genes of COL5A2 were associated with tumor stage or poor survival. Enrichment analysis revealed that the DEGs were mainly associated with extracellular matrix (ECM)-related processes, PI3K-AKT signaling pathway, and focal adhesion. GSEA analyses revealed that COL5A2 was associated with tumor progression-related pathways. Meanwhile, COL5A2 expression was correlated with tumor-infiltrating immune cells. Moreover, immunophenoscore (IPS) analysis and PRJEB25780 cohorts showed that patients with low COL5A2 expression were highly sensitive to immunotherapy.

CONCLUSIONS

COL5A2 might act as a prognostic biomarker of GC prognosis and immune infiltration and may provide a therapeutic intervention strategy.

Nestin overexpression reduces the sensitivity of gastric cancer cells to trastuzumab

Background

Trastuzumab (TRA) shows significant efficacy in patients with human epidermal growth factor receptor 2 (HER2)-positive gastric cancer (GC). While TRA can help treat HER2-positive breast cancer, TRA resistance is a key clinical challenge. Nestin reportedly regulates the cellular redox homeostasis in lung cancer. This study aimed at identifying the functions of Nestin on the TRA sensitivity of HER2-positive GC cells.

Methods

Real-time polymerase chain reaction (PCR) and Western blotting (WB) were performed to explore the association between the mRNA and protein expression profiles, respectively, of Nestin and the Keap1-Nrf2 pathway. The influence of Nestin overexpression on the in vitro sensitivity of GC cells to TRA was explored by Cell Counting Kit-8 (CCK-8) assay, colony formation assay, reactive oxygen species (ROS) detection, and flow cytometry.

Results

TRA treatment caused Nestin downregulation in two HER2-positive GC cell lines (MKN45 and NCI-N87). Nestin overexpression reduced the sensitivity of GC cells to TRA. The expression and activity of Nrf2 and relevant downstream antioxidant genes were increased by Nestin overexpression. Nestin overexpression also significantly suppressed TRA-induced apoptosis and ROS generation. In vivo tumor growth experiment with female BALB/c nude mice indicated that Nestin upregulation restored the tumor growth rate which was inhibited by TRA treatment.

Conclusions

Collectively, the inhibitory effect of Nestin on the TRA sensitivity of cells to TRA was confirmed in this study. These results imply that the antioxidant Nestin-Nrf2 axis may play a role in the mechanism underlying the resistance of GC cells to TRA.

Identification and validation of a novel prognostic model for gastric cancer based on m7G-related genes

Background

The role of N7-methyladenosine (m7G)-related genes in the progression and prognosis of gastric cancer (GC) remains unclear. This study aimed to explore prognostic biomarkers for GC based on m7G methylation regulators and to construct a prognostic risk model.

Methods

RNA sequencing profiles with corresponding clinicopathological information associated with GC of which the histological type was stomach adenocarcinoma (STAD) were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO), respectively. A total of 29 m7G regulators were extracted from previous studies. According to the expression similarity of m7G regulators, the GC samples obtained from TCGA were further classified into 2 clusters demonstrating different overall survival (OS) rates and genetic heterogeneity, and the differentially expressed genes (DEGs) between these 2 clusters were defined as m7G-related genes. Univariate regression analysis and regression analysis were then used to obtain the prognostic m7G-related genes. The samples in TCGA and Genotype-Tissue Expression (GTEx) were used to verify the differential expression and prognostic value of these m7G-related genes contained in the prognostic model. Subsequently, the risk score was combined with other prognostic factors to develop a nomogram. The predictive ability of the nomogram was evaluated by the standard receiver operating characteristic (ROC) curve. Gene set enrichment analysis (GSEA) was used to identify activation pathways in both groups. Finally, the association between the prognostic model and the immune characteristics of GC were appraised.

Results

A prognostic model consisting of 11 m7G-related genes was constructed. GC patients in the high-risk group were shown to have a poor prognosis and this result was further demonstrated in each group. The risk model can be applied for patients with different clinical features. The results of GSEA showed that cell adhesion, cell junction, and focal adhesion were highly enriched in the high-risk group. In addition, we found that the expression of programmed cell death ligand 1 (PD-L1) was significantly elevated in the low-risk group, whereas programmed cell death ligand 2 (PD-L2) and tumor necrosis factor receptor superfamily member 4 (TNFRSF4) were overexpressed in the high-risk group.

Conclusions

We successfully built and verified a m7G relevant prognostic model for predicting prognosis and providing a new train of thought for improving the treatment of GC.

Function of hsa_circ_0006646 as a competing endogenous RNA to promote progression in gastric cancer by regulating the miR-665-HMGB1 axis

Background

Mounting evidences indicate that circular RNAs (circRNAs) are a novel class of non-coding RNAs and play vital roles in the tumorigenesis and aggressiveness including gastric cancer (GC). Nevertheless, the precise functions and underlying mechanisms of circRNAs in GC remain largely unknown.

Methods

The Gene Expression Omnibus (GEO) data set GSE163416 was analyzed to screen the key circRNAs in GC. hsa_circ_0006646 was chosen for further study. GC tissues and matched adjacent normal gastric mucosal epithelial tissues were obtained from the Fourth Hospital of Hebei Medical University. The expressions of hsa_circ_0006646 was detected using quantitative real-time polymerase chain reaction (qRT-PCR). hsa_circ_0006646 was knocked down to identify its effects on GC cells. Bioinformatics algorithms were analyzed to predict the microRNA (miRNAs) potentially sponged by hsa_circ_0006646 and its target genes. Fluorescence in situ hybridization (FISH) was conducted to determine the subcellular location of hsa_circ_0006646 and the predicted miRNA. Then, qRT-PCR, luciferase reporter assay, radioimmunoprecipitation assay, Western blotting, and miRNA rescue experiments were used to confirm the hsa_circ_0006646-related regulatory axis in GC. Cell Counting Kit-8 (CCK-8), colony formation, wound healing, and Transwell experiments were performed to determine the effect of the hsa_circ_0006646-related regulatory axis on GC cells' malignant behaviors in vitro. The xenograft tumor mouse model was established to evaluate the effect of hsa_circ_0006646 in vivo.

Results

hsa_circ_0006646 exhibited a high expression in GC tissues as compared to corresponding adjacent normal gastric mucosal epithelial tissues and its high expression was positively correlated with TNM stage, lymph node invasion and poor prognosis (P<0.05). Knockdown of hsa_circ_0006646 suppressed the proliferation, colony formation, migration, and invasion in GC cells (all P<0.05). hsa_circ_0006646 upregulated high mobility group box 1 (HMGB1) by sponging miR-665 in GC cells (P<0.05). The hsa_circ_0006646-miR-665-HMGB1 axis promoted malignant behaviors and epithelial-mesenchymal transition (EMT) in GC cells by activating the Wnt/β-catenin pathway (P<0.05). The existence of hsa_circ_0006646-miR-665-HMGB1 axis was confirmed in GC specimens (P<0.05). Consequently, down-regulated hsa_circ_0006646 inhibited the progression and EMT of GC cells in vivo (P<0.05).

Conclusions

For the first time, we demonstrated that hsa_circ_0006646-miR-665-HMGB1 axis exerted its tumor-promoting effects in GC, which suggested that hsa_circ_0006646 could be potentially targeted for GC treatment.

Novel targets for gastric cancer: The tumor microenvironment (TME), N6-methyladenosine (m6A), pyroptosis, autophagy, ferroptosis and cuproptosis

Gastric cancer (GC) is a fatal illness, and its mortality rate is very high all over the world. At present, it is a serious health problem for any country. It is a multifactorial disease due to the rising drug resistance and the increasing global cancer burden, the treatment of GC still faces many obstacles and problems. In recent years, research on GC is being carried out continuously, and we hope to address the new targets of GC treatment through this review. At the same time, we also hope to discover new ways to fight GC and create more gospel for clinical patients. First, we discuss the descriptive tumor microenvironment (TME), N6-methyladenosine (m6A), pyroptosis, autophagy, ferroptosis, and cuproptosis. Finally, we expounded on the new or potential targets of GC treatment.

Development and validation of an inflammatory response-related gene and clinical factor-based signature for predicting prognosis in gastric cancer

Background

Gastric cancer (GC) is an aggressive disease that requires prognostic tools to aid in clinical management. The prognostic power of clinical features is unsatisfactory, which might be improved by combining mRNA-based signatures. Inflammatory response is widely associated with cancer development and treatment response. It is worth exploring the prognostic performance of inflammatory-related genes plus clinical factors in GC.

Methods

An 11-gene signature was trained using the least absolute shrinkage and selection operator (LASSO) based on the messenger RNA (mRNA) and overall survival (OS) data of The Cancer Genome Atlas-stomach adenocarcinoma (TCGA-STAD) cohort. A nomogram was established using the signature and clinical factors with a significant linkage with OS and was validated in 3 independent cohorts (GSE15419, GSE13861, and GSE66229) via calculating the area under the receiver operator characteristic curve (AUC). The association between the signature and immunotherapy efficacy was explored in the ERP107734 cohort.

Results

A high risk score was associated with shorter OS in both the training and the validation sets (the AUC for 1-, 3-, 5-year in TCGA-STAD cohort: 0.691, 0.644, and 0.707; GSE15459: 0.602, 0.602, and 0.650; GSE13861: 0.648, 0.611, and 0.647; GSE66229: 0.661, 0.630, and 0.610). Its prognostic power was improved by combining clinical factors including age, sex, and tumor stage (the AUC for 1-, 3-, 5-year in TCGA-STAD cohort: 0.759, 0.706, and 0.742; GSE15459: 0.773, 0.786, and 0.803; GSE13861: 0.749, 0.881, and 0.795; GSE66229: 0.773, 0.735, and 0.722). Moreover, a low-risk score was associated with a favorable response to pembrolizumab monotherapy in the advanced setting (AUC =0.755, P=0.010).

Conclusions

In GCs, the inflammatory response-related gene-based signature was related to immunotherapy efficacy, and its risk score plus clinical features yielded robust prognostic power. With prospective validation, this model may improve the management of GC by enabling risk stratification and the prediction of response to immunotherapy.

USP14-mediated deubiquitination of SIRT1 in macrophage promotes fatty acid oxidation amplification and M2 phenotype polarization

There is a trend of increasing young cases with gastric cancer globally. Sensitive early diagnosis methods and new therapeutic approaches are still the focus of clinical diagnosis and therapy of gastric cancer. USP14 plays an extensive role in tumor malignancy and fat metabolism regulation. However, researchers still have gaps in their knowledge of its substrates, which makes it difficult for deubiquitinases to become clinical targets. TAMs were isolated from tumor or polarized from primary THP1 cells by tumors cell lines under the control of IU1 and FAO inhibitor therapy. Cytokines controlled macrophages were compared to evaluate the capability to induce USP14 expression. Fatty acid uptake assay and OCR measurement were used to analyze macrophage metabolism. USP14 is found the correlation with tumor poor prognosis and poor immunophenotype in gastric cancer patients and mouse tumor models. Activation of USP14 determines elevated protein stability of SIRT1 and is required for activation of macrophage fatty acid oxidation and immunosuppressive phenotype. Although overexpression of USP14 is not sufficient to polarize macrophages to the M2 phenotype, inhibition of USP14 by IU1 in tumor-bearing mice disrupts the suppressive activity of cancer-promoting macrophages and effectively reshapes immune microenvironment characteristics. Our study provides evidence that a novel therapeutic strategy that targets to lipid metabolism of macrophages in tumors could be a potential option for emerging treatments for gastric cancer.

Comprehensive transcriptomic profiling and mutational landscape of primary gastric linitis plastica

BACKGROUND

Primary gastric linitis plastica (GLP) is a distinct phenotype of gastric cancer with poor survival. Comprehensive molecular profiles and putative therapeutic targets of GLP remain undetermined.

METHODS

We subjected 10 tumor-normal tissue pairs to whole exome sequencing (WES) and whole transcriptome sequencing (WTS). 10 tumor samples were all GLP which involves 100% of the gastric wall macroscopically. TCGA data were compared to generate the top mutated genes and the overexpressed genes in GLP.

RESULTS

Our results reveal that GLP has distinctive genomic and transcriptomic features, dysfunction in the Hippo pathway is likely to be a key step during GLP development. 6 genes were identified as significantly highly mutated genes in GLP, including AOX1, ANKRD36C, CPXM1, PTPN14, RPAP1, and DCDC1). MUC6, as a previously identified gastric cancer driver gene, has a high mutation rate (20%) in GLP. 20% of patients in our GLP cohort had CDH1 mutations, while none had RHOA mutations. GLP exhibits high immunodeficiency and low AMPK pathway activity. Our WTS results showed that 3 PI3K-AKT pathway-related genes (PIK3R2, AKT3, and IGF1) were significantly up-regulated in GLP. Two genes were identified using immunohistochemistry (IHC), IGF2BP3 and MUC16, which specifically expressed in diffuse-type-related gastric cancer cell lines, and its knockdown inhibits PI3K-AKT pathway activity.

CONCLUSIONS

We provide the first integrative genomic and transcriptomic profiles of GLP, which may facilitate its diagnosis, prognosis, and treatment.

Efficacy and safety of camrelizumab plus chemotherapy versus chemotherapy alone in patients with untreated, HER2-negative, unresectable locally advanced, or metastatic gastric cancer or gastroesophageal junction cancer: a retrospective comparative cohort study

Background

Nivolumab combined with chemotherapy has been shown to improve prognosis in patients with untreated, human epidermal growth factor receptor 2 (HER2)-negative advanced gastric cancer (GC) and programmed death ligand-1 (PD-L1) combined positive score (CPS) ≥5. However, the available first-line treatment options for advanced GC are limited. Analysis of efficacy and safety of other programmed cell death protein 1 (PD-1) antibodies combined with chemotherapy may provide alternative treatment options.

Methods

This retrospective study included patients with untreated, HER2-negative, unresectable locally advanced, or metastatic GC or gastroesophageal junction (GEJ) cancer who received either camrelizumab combined with oxaliplatin plus S-1 (SOX)/capecitabine plus oxaliplatin (CapeOX) or SOX/CapOX alone between November 2020 and April 2022. The objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS) and safety were evaluated.

Results

This study included 49 patients in camrelizumab plus chemotherapy group and 54 in chemotherapy group. The baseline clinical characteristics beyond Epstein-Barr virus (EBV) status and PD-L1 CPS had no difference between combination group and chemotherapy group. ORR and DCR were significantly higher in combination therapy group than in chemotherapy group (59.18% vs. 38.89%, P=0.048; 83.67% vs. 62.96%, P=0.018). The median PFS in combination group was significantly longer than chemotherapy group [10.03 vs. 6.24 months, hazard ratio (HR) 0.603, 95% confidence interval (CI): 0.368-0.989, P=0.045]. The OS was not mature at the time of the OS analysis, with 40% patients died. Subgroup analyses showed that PFS was longer in patients with PD-L1 CPS ≥1 compared with CPS <1 and in patients with a neutrophil-lymphocyte ratio (NLR) <2.38 compared with ≥2.38. The most common grade 3-4 treatment-related adverse events (TRAEs) were granulocytopenia (57% in combination group vs. 54% in chemotherapy group), anemia (39% vs. 33%, respectively), and thrombocytopenia (39% vs. 33%, respectively). The proportion of reactive cutaneous capillary endothelial proliferation (RCCEP, 73% vs. 0%) was higher in combination group relative to chemotherapy group; all were grades 1-2.

Conclusions

Among patients treated with camrelizumab combined with chemotherapy, the clinical outcomes were superior to those patients treated with chemotherapy. However, these promising findings need to be confirmed in future clinical trials.

The clinical effect of conversion surgery for advanced gastric cancer patients with peritoneal metastasis

BACKGROUND

The prognosis of gastric cancer (GC) patients with peritoneal metastasis (PM) is extremely poor. We developed a new promising regimen combining intraperitoneal (i.p.) paclitaxel (PTX) with systemic PTX and S-1 chemotherapy for GC patients with PM. However, the value of conversion surgery (CS) for GC patients with PM remains unclear. This study aimed to clarify the clinical effect of CS from our updated previous report.

METHODS

We retrospectively analyzed 50 GC patients, divided into chemotherapy alone (CTx; n=15) and conversion surgery intervention (CSI; n=35) groups. In the CTx group, chemotherapy was continued in responders, while in the CSI group, surgery was performed in chemotherapy-responders. The primary endpoint was overall survival (OS) of the two groups. The secondary endpoint was the safety of CS.

RESULTS

In the CTx group, 9 of 15 patients (60%) responded to chemotherapy. In the CSI group, PM disappeared in 22 of 35 patients (62.9%), all of whom underwent CS. Post-operative complications occurred in 2 patients (9%) who underwent CS. There were no treatment-related deaths. Regarding OS, there was no significant difference between the two groups [P=0.14; 95% confidence interval (CI), 0.3016-1.197], nor between chemotherapy-responders in the two groups (P=0.059; 95% CI, 0.1473-1.039). However, four patients in the CSI group have survived more than 5 years after CS.

CONCLUSIONS

CS may be a promising treatment strategy for some GC patients with PM who have responded to chemotherapy.

Novel insight on predicting prognosis of gastric cancer based on inflammation

BACKGROUND

The tumor microenvironment (TME) and inflammation play vital roles in the development and progression of gastric cancer (GC). However, there are no inflammation-related models that can predict the prognosis and immunotherapy response of GC patients. We aimed to establish a prognostic model based on an inflammation-related gene (IRG) signature that can predict poor clinical outcomes in GC.

METHODS

We searched IRGs in The Cancer Genome Atlas (TCGA) database and identified genes differentially expressed in GC. The model was constructed using univariate Cox and least absolute shrinkage and selection operator (LASSO) regression analysis and validated using Gene Expression Omnibus (GEO) database. Receiver operating characteristic (ROC) curve, principal component analysis (PCA), and t-distribution stochastic neighbor embedding (t-SNE) analysis were performed to evaluate model performance. Independent prognostic factor, immune infiltration, cancer stemness, immunotherapy response analysis and gene set enrichment analysis (GSEA) were performed for functional evaluation.

RESULTS

An inflammation-related risk model was established based on 8 genes (F2, LBP, SERPINE1, ADAMTS12, FABP4, PROC, TNFSF18, and CYSLTR1). Risk score significantly correlated with poor outcomes and independently predicted prognosis. It was also associated with immune infiltration and reflected immunotherapy response.

CONCLUSIONS

We established and validated an inflammation-related prognostic model that predicts immune escape and patient prognosis in GC. Our model is expected to improve clinical outcomes by facilitating clinical decision making and the development of individualized treatments.

Identification of a five m6A-relevant mRNAs signature and risk score for the prognostication of gastric cancer

BACKGROUND

N6-methyladenosine (m6A) is the most abundant form of methylation modification in eukaryotic cell messenger RNA (mRNA). However, the role of m6A in gastric cancer (GC), which is one of the most common gastrointestinal malignancies, is unclear. In this study, m6A-relevant mRNA signatures and risk scores were determined to predict the prognosis of GC.

METHODS

The expression profiles and clinical information of 367 patients were downloaded from The Cancer Genome Atlas (TCGA). Cluster analysis and univariate Cox analysis were performed to identify the regulatory factors of RNA methylation associated with GC prognosis. A co-expression network was constructed using the WGCNA package in R. The correlations between module eigengenes and clinical traits were then calculated to identify the relevant modules. We used univariate Cox analysis to screen for genes that are significantly associated with prognosis in the module. We identified hub genes by least absolute shrinkage and selection operator (LASSO) and multivariate analysis and developed a Cox prognostic model. Finally, the hub gene expression values weighted by the coefficients from the LASSO regression were applied to generate a risk score for each patient, and receiver operating characteristic (ROC) and Kaplan-Meier curves were used to assess the prognostic capacity of the risk scores. The asporin (ASPN) gene in GC cell lines was verified via quantitative polymerase chain reaction (qPCR) and Western blot. Moreover, 5-ethynyl-2'-deoxyuridine (EdU) and transwell assays were applied to evaluate the effects of the proliferation, migration, and invasion abilities in GC cells after ASPN knockdown. Western blot verified the effects of ASPN on the phosphoinositide 3-kinase (PI3K)/serine/threonine kinase (AKT)/mechanistic target of rapamycin kinase (mTOR) pathway and epithelial-mesenchymal transition (EMT) pathway-related gene expression.

RESULTS

Our results indicated that AARD, ASPN, SLAMF9, MIR3117 and DUSP1 were hub genes affecting the prognosis of GC patients. Besides, we found that ASPN expression was upregulated in GC cells. The knockdown of ASPN expression suppressed GC cell proliferation, migration, and invasion by deactivating the PI3K/AKT/mTOR and EMT pathways, respectively.

CONCLUSIONS

Our findings indicated that ASPN participates in the biological process of GC as an oncogene and may be a promising biomarker in GC.

Perioperative lymphocyte-to-monocyte ratio changes plus CA199 in predicting the prognosis of patients with gastric cancer

Background

This study aimed to investigate the value of perioperative lymphocyte-to-monocyte ratio (LMR) changes in predicting postoperative survival among patients undergoing radical gastrectomy, and explore whether the combination of preoperative carbohydrate antigen 199 (CA199) and LMR changes would further improve the prognostic accuracy.

Methods

A total of 456 patients who underwent radical gastrectomy at the Affiliated Hospital of Nantong University were included as the training set, and 210 patients from the Nantong Tumor Hospital were enrolled as the validation set. The patients' peripheral complete blood counts, including lymphocytes, monocytes, and tumor marker CA199 level, were checked regularly in all patients 1 week before and after radical gastrectomy by two technicians who were blinded to their clinical characteristics. The LMR was calculated by dividing the lymphocyte count by the monocyte count in the peripheral blood. ^ΔLMR could be obtained by subtracting the preoperative LMR from the postoperative LMR. The serum CA199 level was determined through a latex immunoassay (Mitsubishi Chemical Ltd., Japan). The survival curve was drawn according to the Kaplan-Meier method, and variables with P<0.05 in univariate analyses were transferred to multivariate Cox regression analysis. A nomogram was constructed using the finalized separated prognostic factors of gastric cancer (GC). The main prognostic indicator was overall survival (OS).

Results

In the training and validation sets, the prognostic predictive ability of CA199 and ^ΔLMR (postoperative LMR minus preoperative LMR) was independently evaluated (both P<0.05). ^ΔLMR and CA199 were used to establish the ^ΔLMR-CA199 score. The results showed that the higher the ^ΔLMR-CA199 risk score, the worse the prognosis, especially in patients with advanced GC. Postoperative adjuvant chemotherapy improved the long-term prognosis of patients with a ^ΔLMR-CA199 score of 1 but had no significant effect on the survival rate of patients with 0 and 2 points.

Conclusions

^ΔLMR-CA199 can better predict the long-time survival of patients with GC. In addition, it can also predict the response of postoperative adjuvant chemotherapy in patients with GC.

A retrospective study of clinicopathological characteristics and prognostic factors of Krukenberg tumor with gastric origin

BACKGROUND

Krukenberg tumor (KT) of gastric origin has a poor prognosis. The present study of KTs are mainly case reports and clinical analysis with few samples. Therefore, it is urgent to explore the clinicopathologic characteristics of KTs through large sample studies. To improve the understanding of the clinical diagnosis and treatment of KT, this paper retrospectively analyzed 10 years of gastric cancer (GC) database data, including clinicopathological and prognostic features, aiming to provide a clinical reference for the diagnosis and treatment of the tumor.

METHODS

The clinicopathological characteristics, treatments, and survival data were collected and analyzed from 130 patients with KTs of GC. Clinicopathological data included clinical manifestations, laboratory findings, imaging reports, pathology and immunohistochemistry (IHC) reports. We collected treatment regimens information on whether they had undergone surgery and chemotherapy and performed survival follow-up. Univariate and multivariate analysis were used to investigate the risk factors of KTs with gastric origin.

RESULTS

The median age of the patients was 41 years. A total of 63.1% of patients had synchronous ovarian metastasis, 70.8% had bilateral ovarian metastasis, 68.5% had peritoneum metastasis, and 98.5% had pathologically poorly differentiated adenocarcinoma. The positive rate of human epidermal growth factor receptor 2 (HER-2) was 1.8%. The follow-up rate was 90.8%, and the median overall survival (mOS) of ovarian metastasis was 13.0 months. Univariate analysis showed statistically significant prognostic factors including menstrual status, size of the gastric lesions and ovarian metastases, number of lymph node metastasis, interval to ovarian metastasis, resection of gastric lesions, peritoneal metastasis, oophorectomy, chemotherapy after ovarian metastases, two-drug regimen chemotherapy, albumin, serum cancer antigen 125 (CA-125) levels, platelet count, D-dimer, fibrinogen, and high pretreatment platelet-to-lymphocyte ratio (PLR) and systemic immune-inflammation index (SII). Fibrinogen [hazard ration (HR) =0.483; 95% confidence interval (CI): 0.300-0.777; P=0.003], size of ovarian metastasis (HR =1.808; 95% CI: 1.178-2.776; P=0.007), chemotherapy after ovarian metastasis (HR =0.195; 95% CI: 0.101-0.379; P=0.000), peritoneal metastasis (HR =2.742; 95% CI: 1.606-4.682; P=0.000) and oophorectomy (HR =1.720; 95% CI: 1.066-2.778; P=0.026) were independent prognostic factors.

CONCLUSIONS

GC patients with KTs have some unique clinical features. Hypercoagulable states, peritoneal metastasis, and untimely chemotherapy and oophorectomy might be a worse predictor for KTs derived from gastric origin.

MicroRNA-19a-3p Acts as an Oncogene in Gastric Cancer and Exerts the Effect by Targeting SMOC2

MicroRNAs are reported to be involved in tumor development. This study aims to investigate the biological functions and molecular mechanisms of microRNA-19a-3p in gastric cancer cells. TCGA-based expression analysis and qRT-PCR assay illustrated that microRNA-19a-3p was overexpressed in gastric cancer. MTT and Transwell assays indicated that microRNA-19a-3p could strengthen the proliferation, migration, and invasion of gastric cancer cells. SMOC2 was bioinformatically predicted as the target of microRNA-19a-3p, followed by identified using a dual-luciferase assay. The effects of microRNA-19a-3p/SMOC2 regulatory axis on gastric cancer cells were examined by MTT and Transwell assays as well. Concludingly, this study demonstrated that microRNA-19a-3p could promote the aggressive cell phenotypes of gastric cancer cells by targeting SMOC2.

LRG1 mediated by ATF3 promotes growth and angiogenesis of gastric cancer by regulating the SRC/STAT3/VEGFA pathway

BACKGROUND

Increasing evidence indicates that leucine-rich-alpha-2-glycoprotein 1 (LRG1) is associated with multiple malignancies, but whether it participates in gastric cancer (GC) angiogenesis remains unclear.

METHODS

The expression levels of LRG1 were assessed in GC samples. Endothelial tube formation analysis, HUVEC migration assay, chorioallantoic membrane assay (CAM), and xenograft tumor model were used to investigate the effect of LRG1 on angiogenesis in gastric cancer. The involvement of activating transcription factor 3 (ATF3) was analyzed by chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assay. Western blot and enzyme-linked immunosorbent assay were performed to measure the SRC/STAT3/VEGFA pathway.

RESULTS

LRG1 was overexpressed in GC tissues and associated with cancer angiogenesis. In addition, LRG1 markedly promoted GC cell proliferation in vitro and in vivo. Moreover, overexpression of LRG1 could stimulate GC angiogenesis in vitro and in vivo. Then, we identified ATF3 promotes the transcription of LRG1 and is a positive regulator of angiogenesis. Additionally, LRG1 could activate VEGFA expression via the SRC/STAT3/ VEGFA pathway in GC cells, thus contributing to the angiogenesis of GC.

CONCLUSIONS

The present study suggests LRG1 plays a crucial role in the regulation of angiogenesis in GC and could be a potential therapeutic target for GC.

Long non-coding RNA (FALEC) promotes malignant behaviors of gastric cancer cells by regulating miR-203b/PIM3 axis

Background

Existing research shows that long non-coding RNAs (lncRNAs) have important regulatory effects in gastric cancer (GC). In recent years, focally amplified lncRNA on chromosome 1 (FALEC) has been repeatedly reported to have carcinogenic effects in thyroid carcinoma, colorectal cancer, and endometrial cancer, etc. While the role and mechanism of FALEC during GC tumorigenesis remains unclear.

Methods

The levels of FALEC, microRNA-203b (miR-203b), and Recombinant Pim-3 Oncogene (PIM3) were confirmed by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Cell autophagy, proliferation, apoptosis, migration, and invasion were estimated using western blot, transmission electron microscopy (TEM), cell counting kit-8 (CCK-8), flow cytometer, and Transwell assays. The interaction between miR-203b and FALEC or PIM3 was verified using a dual-luciferase reporter assay. Moreover, the involvement of miR-203b and PIM3 in the regulatory effects of FALEC on GC was determined with rescue experiments.

Results

The results showed that FALEC and PIM3 were highly expressed, while miR-203b was lowly expressed, in GC. FALEC knockdown repressed GC cell proliferation, migration, and invasion, and promoted apoptosis and autophagy in vitro. Meanwhile, FALEC knockdown prevented growth and induced GC autophagy in vivo. This shows that FALEC upregulated PIM3 by sponging miR-203b in GC cells. Besides, FALEC induced the malignant behaviors of GC cells by regulating the miR-203b/PIM3 axis.

Conclusions

The FALEC/miR-203b/PIM3 axis might be a promising therapeutic target for therapy in GC patients.

An artificial intelligence method to assess the tumor microenvironment with treatment outcomes for gastric cancer patients after gastrectomy

Background

The tumor microenvironment (TME) plays an important role in the occurrence and development of gastric cancer (GC) and is widely used to assess the treatment outcomes of GC patients. Immunohistochemistry (IHC) and gene sequencing are the main analysis methods for the TME but are limited due to the subjectivity of observers, the high cost of equipment and the need for professional analysts.

Methods

The ImmunoScore (IS) was developed in the TCGA cohort and validated in GEO cohorts. The Radiomic ImmunoScore (RIS) was developed in the TCGA cohort and validated in the Nanfang cohort. A nomogram was developed and validated in the Nanfang cohort based on RIS and clinical features.

Results

For IS, the area under the curves (AUCs) were 0.798 for 2-year overall survival (OS) and 0.873 for 4-year overall survival. For RIS, in the TCGA cohort, the AUCs distinguishing High-IS or Low-IS and predicting prognosis were 0.85 and 0.81, respectively; in the Nanfang cohort, the AUC predicting prognosis was 0.72. The nomogram performed better than the TNM staging system according to the ROC curve (all P < 0.01). Patients with TNM stage II and III in the High-nomogram group were more likely to benefit from adjuvant chemotherapy than Low-nomogram group patients.

Conclusions

The RIS and the nomogram can be used to assess the TME, prognosis and adjuvant chemotherapy benefit of GC patients after radical gastrectomy and are valuable additions to the current TNM staging system. High-nomogram GC patients may benefit more from adjuvant chemotherapy than Low-nomogram GC patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03298-7.

DNA methylation of RNA-binding protein for multiple splicing 2 functions as diagnosis biomarker in gastric cancer pathogenesis and its potential clinical significance

Higher methylation levels of RNA-binding protein for multiple splicing 2 (RBPMS2) was reported to be related with unfavorable outcome in gastric cancer (GC). However, molecular function and diagnostic significance of DNA methylation of RBPMS2 remains indistinct. Here we aimed to whether DNA methylation of RBPMS2 acts as a diagnosis biomarker in GC pathogenesis and its potential clinical significance. Western blot and immunochemistry assays were carried out to explore the level of RBPMS2. GC malignancy behaviors were determined by cell counting kit-8, Transwell, flow cytometry analysis and terminal-deoxynucleoitidyl transferase mediated nick end labeling staining. The inflammatory cell infiltration in xenograft model was observed by hematoxylin and eosin staining. CpG Islands was predicted by MethPrimer and the DNA methylation of RBPMS2 was evaluated by methylation-specific polymerase chain reaction. The results showed that RBPMS2 was downregulated in GC specimens. Poor survival rates were associated with low RBPMS2 expression. Overexpression of RBPMS2 inhibited GC growth while facilitated apoptosis in GC cells. In addition, level of DNA methylation of RBPMS2 in GC tissues was increased and DNA methylation of RBPMS2 was strongly associated with tumor invasion, Borrmann classification and TNM stage. We also observed that DNA methylation inhibitors counteracted the role of RBPMS2 in restraining GC development and tumorigenesis. To sum, our data demonstrated that DNA methylation of RBPMS2 was responsible for its downregulation in GC and promoted tumor progression, indicating DNA methylation of RBPMS2 might serve as a valuable potential parameter in GC pathogenesis.

Identification of lncRNAs based on different patterns of immune infiltration in gastric cancer

BACKGROUND

Gastric cancer is one of the most common malignant tumors in the world, which brings great challenges to people's life and health. The purpose of this study was to investigate immune related-lncRNAs and identify new biomarkers for the prognosis of gastric cancer (GC).

METHODS

We downloaded data from The Cancer Genome Atlas (TCGA) and used R software to determine the ESTIMATEScore, ImmuneScore, and StromalScore of each tumor sample. We performed prognostic analysis and identified the differentially expressed lnRNAs, which were then used to construct a prognostic model. Among the 44 hub genes in the competitive endogenous RNA (ceRNA) network, 3 differentially expressed genes were verified by qPCR.

RESULTS

Based on the degree of immune infiltration, cluster A had a higher ESTIMATEScore, ImmuneScore, and StromalScore and higher expression levels of PD-L1 (CD274) and CTLA4 than cluster B. Univariate Cox analysis was conducted for these differential lncRNAs, and 57 lncRNAs were found to have prognostic value (P<0.05). gene cluster A had a worse prognosis than gene cluster B (P=0.021). Then, a prognostic model was constructed. The low-risk group had a significantly higher survival rate. Finally, the qPCR results showed that the expression levels of BMPER, PRUNE2, and RBPMS2 were low in GC cell lines.

CONCLUSIONS

We identified a risk score of 19 lncRNAs as a prognostic marker of GC. There was a relationship between these 19 prognostic-related lncRNAs and the subtypes of infiltrating immune cells. An approach for predicting the prognosis of GC was therefore provided in this study.

A comprehensive update: gastrointestinal microflora, gastric cancer and gastric premalignant condition, and intervention by traditional Chinese medicine

With the recent upsurge of studies in the field of microbiology, we have learned more about the complexity of the gastrointestinal microecosystem. More than 30 genera and 1000 species of gastrointestinal microflora have been found. The structure of the normal microflora is relatively stable, and is in an interdependent and restricted dynamic equilibrium with the body. In recent years, studies have shown that there is a potential relationship between gastrointestinal microflora imbalance and gastric cancer (GC) and precancerous lesions. So, restoring the balance of gastrointestinal microflora is of great significance. Moreover, intervention in gastric premalignant condition (GPC), also known as precancerous lesion of gastric cancer (PLGC), has been the focus of current clinical studies. The holistic view of traditional Chinese medicine (TCM) is consistent with the microecology concept, and oral TCM can play a two-way regulatory role directly with the microflora in the digestive tract, restoring the homeostasis of gastrointestinal microflora to prevent canceration. However, large gaps in knowledge remain to be addressed. This review aims to provide new ideas and a reference for clinical practice.

Acacetin inhibits invasion, migration and TGF-β1-induced EMT of gastric cancer cells through the PI3K/Akt/Snail pathway

BACKGROUND

Epithelial-to-mesenchymal transition (EMT) is a pivotal cellular phenomenon involved in tumour metastasis and progression. In gastric cancer (GC), EMT is the main reason for recurrence and metastasis in postoperative patients. Acacetin exhibits various biological activities. However, the inhibitory effect of acacetin on EMT in GC is still unknown. Herein, we explored the possible mechanism of acacetin on EMT in GC in vitro and in vivo.

METHODS

In vitro, MKN45 and MGC803 cells were treated with acacetin, after which cell viability was detected by CCK-8 assays, cell migration and invasion were detected by using Transwell and wound healing assays, and protein expression was analysed by western blots and immunofluorescence staining. In vivo, a peritoneal metastasis model of MKN45 GC cells was used to investigate the effects of acacetin.

RESULTS

Acacetin inhibited the proliferation, invasion and migration of MKN45 and MGC803 human GC cells by regulating the expression of EMT-related proteins. In TGF-β1-induced EMT models, acacetin reversed the morphological changes from epithelial to mesenchymal cells, and invasion and migration were limited by regulating EMT. In addition, acacetin suppressed the activation of PI3K/Akt signalling and decreased the phosphorylation levels of TGF-β1-treated GC cells. The in vivo experiments demonstrated that acacetin delayed the development of peritoneal metastasis of GC in nude mice. Liver metastasis was restricted by altering the expression of EMT-related proteins.

CONCLUSION

Our study showed that the invasion, metastasis and TGF-β1-induced EMT of GC are inhibited by acacetin, and the mechanism may involve the suppression of the PI3K/Akt/Snail signalling pathway. Therefore, acacetin is a potential therapeutic reagent for the treatment of GC patients with recurrence and metastasis.

A novel robust nomogram based on preoperative hemoglobin and albumin levels and lymphocyte and platelet counts (HALP) for predicting lymph node metastasis of gastric cancer

BACKGROUND

Accurate assessment of lymph node status in gastric cancer (GC) patients can help to select appropriate treatment strategies for GC, but the diagnostic accuracy of conventional methods needs to be improved. The aim of this study was to investigate the predictive value of preoperative hemoglobin and albumin levels and lymphocyte and platelet counts (HALP) on lymph node status in GC patients and to construct a risk prediction model.

METHODS

This study retrospectively analyzed the clinicopathological characteristics of 349 patients with GC who underwent radical gastrectomy, among which 250 patients were recruited in the training cohort and 99 patients in the independent validation cohort. Significant risk factors in univariate analysis were further identified as independent variables in multivariate logistic regression analysis, which were then incorporated and presented in a nomogram. Receiver operating characteristic (ROC) curves, Calibration curve and decision curve analysis (DCA) curves were used to evaluate the discrimination, prediction accuracy and clinical effectiveness of the model.

RESULTS

Multifactorial logistic regression analysis showed that alcohol use (OR =2.203, P=0.036), Depth of invasion (OR =7.756, P<0.001), differentiation (OR =2.252, P=0.018), carcinoembryonic antigen (CEA) (OR =2.443, P=0.017), carbohydrate antigen 19-9 (CA199) (OR =2.715, P=0.008) and HALP (OR =2.276, P=0.032) were independent risk factors for lymph node metastasis (LNM) in GC. We used these factors to construct a nomogram for predicting LNM in GC patients, and the ROC curves showed good discrimination of the model with AUC values of 0.854 (training cohort) and 0.868 (validation cohort), respectively, and the calibration curves showed good predictive ability of the nomogram, in addition to the DCA curves results showed the clinical usefulness of the model.

CONCLUSIONS

In conclusion, we established a nomogram for predicting LNM in patients with GC.

Development and external validation of a prognostic nomogram for patients with gastric cancer after radical gastrectomy

Background

Gastric cancer (GC) is one of the most malignant diseases and threatens the health of individuals across the globe. Hitherto, the identification of prognosis risk stratification on GC has mainly depended on the TNM staging, but owing to its inaccuracy and incompleteness, the prognostic value it offers remains controversial in the current clinical setting. Thus, an effective prognostic model for GC after radical gastrectomy is still needed.

Methods

Patients with pathologically confirmed GC who underwent radical gastrectomy from 2 different centers were retrospectively enrolled into a training and the validation cohort, respectively. The least absolute shrinkage and selection operator (LASSO) algorithm was applied to select variables among multiple factors, including clinical characteristics, pathological parameters, and surgery- and treatment-related indicators. The multivariate Cox regression method was used to establish the model to predict 1-, 2-, and 3-year survival. Both internal and external validations of the nomogram were then completed in terms of discrimination, calibration, and clinical utility. Finally, prognostic risk stratification of GC was conducted with X-tile software.

Results

A total of 1,424 patients with GC were eligible in this study, including 1,010 in the training cohort and 414 in the validation cohort. Seven indicators were selected by LASSO to develop the nomogram, including the number of positive lymph nodes, tumor size, adjacent organ invasion, vascular invasion, the level of carbohydrate antigen 125 (CA 125), depth of invasion, and human epidermal growth factor receptor 2 (HER2) status. The nomogram demonstrated a robust predictive capacity with favorable accuracy, discrimination, and clinical utility both in the internal and external validations. Moreover, we divided the population into 3 risk groups of survival according to the cutoff points generated by X-tile, and in this way, the nomogram was further improved into a risk-stratified prognosis model.

Conclusions

We have developed a prognostic risk stratification nomogram for GC patients after radical gastrectomy with 7 available indicators that may guide clinical practice and help facilitate tailored decision-making, thus avoiding overtreatment or undertreatment and improving communication between clinicians and patients.

Elucidated tumorigenic role of MAML1 and TWIST1 in gastric cancer is associated with Helicobacter pylori infection

BACKGROUND

Epithelial-mesenchymal transition (EMT) has a fundamental role in tumor initiation, progression, and metastasis. Helicobacter pylori (HP) induces EMT and thus causes gastric cancer (GC) by deregulating multiple signaling pathways involved in EMT. TWIST1 and MAML1 have been confirmed to be critical inducers of EMT via diverse signaling pathways such as Notch signaling. This study aimed to investigate for the first time possible associations between TWIST1/MAML1 mRNA expression levels, HP infection, and clinicopathological characteristics in GC patients.

METHOD

TWIST1 and MAML1 mRNA expression levels were evaluated in tumoral and adjacent normal tissues in 73 GC patients using the quantitative reverse transcription PCR (RT-qPCR) method. PCR technique was also applied to examine the infection with HP in GC samples.

RESULTS

Upregulation of TWIST1 and MAML1 expression was observed in 35 (48%) and 34 (46.6%) of 73 tumor samples, respectively. Co-overexpression of these genes was found in 26 of 73 (35.6%) tumor samples; meanwhile, there was a significant positive correlation between MAML1 and TWIST1 mRNA expression levels (P < 0.001). MAML1 overexpression exhibited meaningful associations with advanced tumor stages (P = 0.006) and nodal metastases (P ˂ 0.001). 34 of 73 (46.6%) tumors tested positive for HP, and meanwhile, MAML1 expression was positively related with T (P = 0.05) and grade (P = 0.0001) in these HP-positive samples. Increased TWIST1 expression was correlated with patient sex (P = 0.035) and advanced tumor grade (P = 0.017) in HP-infected tumors. Furthermore, TWIST1 and MAML1 expression levels were inversely linked with histologic grade in HP-negative tumor samples (P = 0.021 and P = 0.048, respectively).

CONCLUSION

We propose TWIST1 and MAML1 as potential biomarkers of advanced-stage GC that determine the characteristics and aggressiveness of the disease. Based on accumulating evidence and our findings, they can be introduced as promising therapeutic targets to modify functional abnormalities in cells that promote GC progression. Moreover, HP may enhance GC growth and metastasis by disrupting TWIS1/MAML1 expression patterns and related pathways.

Clinical values and potential pathways of miR-183-5p in gastric cancer: a study based on integrational bioinformatics analysis

Background

The clinicopathological value and exploration of the potential molecular mechanism of microRNA-183-5p (miR-183-5p) have been investigated in various cancers. This study further explored the transcriptome profile regulated by miR-183-5p.

Methods

Messenger RNA (mRNA) expression data, miRNA expression, and clinical information of stomach adenocarcinoma (STAD) were downloaded from The Cancer Genome Atlas (TCGA) database. Differentially expressed genes (DEGs) that related to mir-189-5p expression and cancer proliferation were acquired using bioinformatics analysis. The biological functions of these genes were analyzed in terms of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Hub genes relating to gastric cancer (GC) signal pathway were explored. The results were validated by further experiments.

Results

A total of 308 genes were found to be regulated by miR-183-5p, and they were related to cancer and GC patients' survival outcome. The biological function of these genes was found to act mainly on biological processes and the involved signal pathways included neuroactive ligand-receptor interaction, cell adhesion molecules, and axon guidance. In addition, miR-183-5p was also shown to regulate the mTOR, Wnt, MAPK, and PI3K-Akt signaling pathways through the genes WNT2B, NGFR, and NTRK2.

Conclusions

The miRNA miR-183-5p participates in the tumorigenesis and development of GC via certain signaling pathways, in particular the nerve- and immunity-related genes.

Comprehensive bioinformatics analyses identified Homeobox B9 as a potential prognostic biomarker and therapeutic target for gastric cancer

Background

The Homeobox B (HOXB) family promotes tumor progression, but the mechanism of its action in gastric cancer (GC) is unclear. We sought to identify the HOXB family members that are critical to the prognosis of GC patients.

Methods

The Oncomine, Gene Expression Profiling Interactive Analysis (GEPIA), cBioPortal, UALCAN, Kaplan-Meier plotter, and the GeneMANIA databases were used to analyze the messenger RNA (mRNA) expression levels, prognostic value, and gene-gene interaction network of the HOXB9 family members in GC. The expression of HOXB9 in GC and its relationship with various clinicopathological parameters and the prognosis of patients were verified by immunohistochemistry.

Results

The expression of HOXB3, HOXB5, HOXB6, HOXB7, HOXB9, and HOXB13 mRNA was significantly upregulated in GC. There was a significant correlation between the upregulation of HOXB3, HOXB5, and HOXB9 mRNA and a low overall survival (OS) rate. The high expression of HOXB7, HOXB9, and HOXB13 mRNA was closely correlated to tumor grade and stage. HOXB9 was the HOXB family member most closely related to the occurrence and development of GC. A further analysis showed that HOXB9 might be involved in deoxyribonucleic acid repair and division regulation. A validation study showed that the advanced cancer group had a higher level of HOXB9 expression than the early cancer group. The high expression of HOXB9 in gastric tissue plays an important role in the survival and prognosis of GC patients.

Conclusions

HOXB family members have different degrees of abnormal expression in GC. High HOXB9 expression in GC tissues was significantly correlated with a worse prognosis. Thus, HOXB9 is a potential novel biomarker and therapeutic target for GC.

Combination of the ratio between metastatic and harvested lymph nodes and negative lymph node count as a prognostic indicator in advanced gastric cancer: a retrospective cohort study

Background

The aim of our study was to examine the impact of the combination of the ratio between metastatic and harvested lymph nodes (RML) and negative lymph node (NLN) count on overall survival (OS) in patients with advanced gastric cancer (GC).

Methods

The clinicopathological data of 2,952 advanced GC patients who received curative resection between 1994 and 2015 were collected. They were divided into four groups according to the RML: 0, 0-0.1, 0.1-0.4, and >0.4. We distinguished survival differences through Kaplan-Meier analysis among the subgroups to investigate the impacts of the RML on OS in advanced GC patients. OS was examined according to clinicopathological variables. Spearman's correlation coefficient was used to assess the relationships between the RML and metastatic lymph node (MLN) count and NLN count.

Results

A total of 1,182 patients were enrolled into the study. The median follow-up time was 39 months (interquartile range 20 to 68 months). The 5-year OS rate of all 1,182 GC patients was 54.4%. Kaplan-Meier survival analysis showed that the median OS declined significantly with increasing RML (5-year survival rate 81.2% vs. 69.1% vs. 42.8% vs. 13.1%, P<0.001). As the NLN count increased, the survival rate of GC patients increased (5-year survival rate 12.8% vs. 25.2% vs. 60.2%, P<0.05). The RML, not NLN count, was identified as an independent factor for OS (P<0.001) through multivariate analysis. Spearman correlation analysis suggested that the RML was positively correlated with the number of MLNs (ρ=0.973, P<0.001) and inversely associated with the NLN count (ρ=-0.513, P<0.001).

Conclusions

The RML is an independent prognostic predictor of OS in advanced GC patients, and the NLN count may serve as a supplementary strategy for the present tumor-node-metastasis (TNM) classification to further improve the prognostic prediction efficiency. The combination of the RML and NLN count should be an important predictor for current clinical applications.

MiR-200a-3p promotes gastric cancer progression by targeting DLC-1

Gastric cancer (GC) is one of the most common malignancies, ranking the third highest mortality rate worldwide. Due to the insidious symptoms and difficulty in early detection, patients with GS were mostly in the middle and late stages when they were diagnosed. Although ontogenetic or tumor-suppressive effects of miRNA-200a-3p have been demonstrated, the exact mechanism underlying GC is not clear. Therefore, the expression, effect, and mechanism of miRNA-200a-3p in GC progression were systematically investigated in this study. qRT-PCR, Western blotting, and immunohistochemical staining were applied to investigate the miRNA-200a-3p and deleted in liver cancer 1 (DLC-1) expression. Cell viability, proliferation, apoptosis, migration, and invasion capabilities of GC cells were assessed using cell counting kit-8 (CCK-8) colorimetry, EdU integration, flow cytometry, wound healing, and the transwell assay. The relationship between miRNA-200a-3p and tumor growth was investigated by tumor xenograft assay in vivo. A dual-luciferase reporter assay was estimated to verify the connection between miR-200-3p and DLC-1. The results showed that miRNA-200a-3p expression was significantly increased in both GC tissues and cells. Furthermore, via DLC-1, miRNA-200a-3p promotes tumor growth and development. miRNA-200a-3p, by targeting DLC-1, can function as an oncogene in GC cells. Collectively, our findings indicated that the miRNA-200a-3p/DLC axis might provide a theological basis for potential improvements in GC treatment strategies.

Transcription factor KLF15 inhibits the proliferation and migration of gastric cancer cells via regulating the TFAP2A-AS1/NISCH axis

BACKGROUND

Recently, overwhelming evidence supports that long noncoding RNAs (lncRNAs) play crucial roles in the occurrence and progression of tumors. However, the role and mechanism of lncRNA TFAP2A-AS1 in human gastric cancer (GC) remains unclear. Thus, the biological role and regulatory mechanisms of TFAP2A-AS1 in GC were explored.

METHODS

Quantitative real-time PCR (qPCR) was applied to detect gene expression. Western blot was used to measure protein expression. Cell proliferation and migration were determined by functional assays. Fluorescence in situ hybridization (FISH) assays were performed to determine the subcellular distribution of TFAP2A-AS1 in GC. Mechanism investigations were conducted to explore the downstream genes of TFAP2A-AS1 and the upstream transcription factor of TFAP2A-AS1 in GC cells.

RESULTS

TFAP2A-AS1 inhibits the proliferation and migration of GC cells. In the downstream regulation mechanism, miR-3657 was verified as the downstream gene of TFAP2A-AS1 and NISCH as the target of miR-3657. NISCH also suppresses cell proliferation and migration in GC. In the upstream regulation mechanism, transcription factor KLF15 positively mediates TFAP2A-AS1 to suppress GC cell proliferation and migration.

CONCLUSION

KLF15-mediated TFAP2A-AS1 hampers cell proliferation and migration in GC via miR-3657/NISCH axis.

Human telomerase reverse transcriptase (hTERT) synergistic with Sp1 upregulate Gli1 expression and increase gastric cancer invasion and metastasis

Abnormal expression of human telomerase reverse transcriptase (hTERT) has been widely identified in tumors, but the relevant mechanism is not well known. This study aims to investigate the role and mechanism of hTERT in gastric cancer metastasis. Gastric cancer and adjacent non-tumor tissues were collected and the expression levels of hTERT and Gli1 were detected by immunohistochemistry. The results demonstrated that hTERT and Gli1 expression levels in gastric cancer tissue were significantly higher than adjacent non-tumor tissues. Western blot and quantitative real-time PCR were used to an identified expression of the related protein in BGC-823 and SGC-7901 cells. The interactions between hTERT and Sp1 were tested by co-immunoprecipitation experiments. Chromatin immunoprecipitation was performed to confirm that Sp1 and hTERT could bind to the Gli1 promoter. Chromatin reimmunoprecipitation assay further demonstrated that both hTERT and Sp1 bind to the Sp1 site of the Gli1 promoter. Moreover, the hTERT, Sp1, and Gli1 were upregulate was verified in human gastric cancer tissues. These results showed that the expression levels of hTERT in GC tissues were strongly closed to the depth of invasion, lymph node metastasis, TNM (tumor, node, metastasis) stage, and distant metastasis. By combining Sp1 and Gli1 promoter, hTERT upregulated Gli1 expression and promoted invasion and metastasis of GC cells. Overall, these data provide a new molecular mechanism of hTERT to promotes gastric cancer progression. Targeting the hTERT/Sp1/Gli1 axis may represent a new therapeutic strategy.

Value of multiphase contrast-enhanced CT with three-dimensional reconstruction in detecting depth of infiltration, lymph node metastasis, and extramural vascular invasion of gastric cancer

Background

Multiphase contrast-enhanced computed tomography (CECT) can reveal the location, morphology, size, and enhancement pattern of gastric cancer (GC), whereas the three-dimensional reconstruction (3DR) technique can better display the relationships of the lesions with surrounding structures, the feeding vessels, and lymph node metastasis. Here, we investigated the value of multi-phase CECT with 3DR in detecting depth of infiltration, lymph node metastasis, and extramural vascular invasion (EMVI) of GC.

Methods

The clinical and imaging data of 132 GC patients admitted to the Chongqing Hospital of Traditional Chinese Medicine and the Third Affiliated Hospital of Chongqing Medical University during the period from January 2012 to October 2019 were collected. All patients received plain and multiphase contrast-enhanced CT scans. The agreement between the results of preoperative CT evaluation and the surgical/pathological findings was compared.

Results

(I) CT findings of GC of 3 differentiation levels: on the multiphase CECT, the peak enhancement percentage was highest in the portal venous phase. The CT values significantly differed among the arterial, portal venous, and equilibrium phases (P<0.05); the differences in the arterial, portal venous, and equilibrium phases were statistically significant among the well-, moderately, and poorly differentiated groups (all P<0.05); finally, the difference in the equilibrium phase was statistically significant between the well- and moderately differentiated groups (P<0.05). (II) Preoperative CT and postoperative pathology had good consistency in T staging (Kappa =0.667). (III) The Kappa values between the preoperative CT-diagnosed lymph node metastasis and postoperative pathologically showing an increasing consistency with the increase of CT enhancement differences. (IV) Preoperative CT and postoperative pathology had good consistency in N staging (Kappa =0.779). (V) Preoperative CT in displaying arterial supply to the stomach. The rate of positive EMVI was 32.6% (43/132) on preoperative CT. The positive EMVI diagnosed by preoperative CT was correlated with tumor size, growth pattern, tissue differentiation degree, T stage, and N stage (all P<0.05).

Conclusions

Multiphase CECT combined with 3DR has high diagnostic performance in detecting the depth of infiltration, lymph node metastasis, and EMVI of GC.