Poor Prognosis In Gastric Cancer Patients Research Articles

Downregulation of malic enzyme 3 facilitates progression of gastric carcinoma via regulating intracellular oxidative stress and hypoxia-inducible factor-1α stabilization.

Gastric cancer (GC) is one of the most malignant cancers worldwide. Metabolism disorder is a critical characteristic of malignant tumors related to tumor progression and metastasis. However, the expression and molecular mechanism of malic enzyme 3 (ME3) in GC are rarely reported. In this study, we aim to investigate the molecular mechanism of ME3 in the development of GC and to explore its potential value as a prognostic and therapeutic target in GC. ME3 mRNA and protein expression were evaluated in patients with GC using RT-qPCR, WB, and immunohistochemistry, as well as their correlation with clinicopathological indicators. The effect of ME3 on proliferation and metastasis was evaluated using Cell Counting Kit-8 (CCK-8), 5-ethynyl-20-deoxyuridine (EdU) assay, transwell assay, wound healing assay, and subcutaneous injection or tail vein injection of tumor cells in mice model. The effects of ME3 knockdown on the level of metabolites and hypoxia-inducible factor-1α (HIF-1α) protein were determined in GC cells. Oxidative phosphorylation was measured to evaluate adenosine triphosphate (ATP) production. ME3 was downregulated in human GC tissues (P < 0.001). The decreased ME3 mRNA expression was associated with younger age (P = 0.02), pathological staging (P = 0.049), and lymph node metastasis (P = 0.001), while low ME3 expression was associated with tumor size (P = 0.048), tumor invasion depth (P < 0.001), lymph node metastasis (P = 0.018), TNM staging (P < 0.001), and poor prognosis (OS, P = 0.0206; PFS P = 0.0453). ME3 knockdown promoted GC cell malignancy phenotypes. Moreover, α-ketoglutarate (α-KG) and NADPH/NADP+ ratios were reduced while malate was increased in the ME3 knockdown group under normoxia. When cells were incubated under hypoxia, the NADPH/NADP+ ratio and α-KG decreased while intracellular reactive oxygen species (ROS) increased significantly. The ME3 knockdown group exhibited an increase in ATP production and while ME3 overexpression group exhibited oppositely. We discovered that ME3 and HIF-1α expression were negatively correlated in GC cells and tissues, and proposed the hypothesis: downregulation of ME3 promotes GC progression via regulating intracellular oxidative stress and HIF-1α. We provide evidence that ME3 downregulation is associated with poor prognosis in GC patients and propose a hypothesis for the ME3 regulatory mechanism in GC progression. The present study is of great scientific significance and clinical value for exploring the prognostic and therapeutic targets of GC, evaluating and improving the clinical efficacy of patients, reducing recurrence and metastasis, and improving the prognosis and quality of life of patients.

Association of miR-338-3p with survival outcomes in gastric cancer patients who received peri-operative blood transfusion.

Perioperative blood transfusion (BT) is frequent in the treatment of gastric cancer (GC), but its effects on the prognosis of GC remains controversial. In this study, we aimed to further confirm the relationship of perioperative BT with GC overall survival and to evaluate the predictive value of microRNA-338-3p (miR-338-3p) for the prognosis of GC patients who received perioperative BT. Clinical data and serum samples were collected and analyzed from 246 patients with GC. Five-year follow-up survival information was assessed by Kaplan-Meier survival analysis. miR-338-3p relative expression was assessed by RT-qPCR, and its relationship with the prognosis of GC patients, who received perioperative BT, was evaluated using Kaplan-Meier curves and Cox regression analysis. GC patients received perioperative BT had poor 5year survival than those without BT. In patients received BT, miR-338-3p expression was higher in survival cases than died population and high miR-338-3p was independently associated with better overall survival prognosis. Perioperative BT is related with poor prognosis in GC patients and miR-338-3p may be a prognostic biomarker for GC patients received perioperative BT. BT in perioperative GC patients should be cautious, especially for those with low levels of miR-338-3p.

KIAA1429 promotes gastric cancer progression by destabilizing RASD1 mRNA in an m6A-YTHDF2-dependent manner

BackgroundKIAA1429, a regulatory subunit of the N6-methyladenosine (m6A) methyltransferase complex, has been implicated in the progression of various cancers. However, the role of KIAA1429 in gastric cancer (GC) and its underlying mechanisms remain elusive. This study aimed to investigate the role of KIAA1429 in GC and to elucidate the underlying mechanisms.MethodsThe expression patterns and clinical relevance of KIAA1429 in GC were assessed using quantitative real-time PCR (qRT-PCR), Western blotting, immunohistochemistry (IHC), and bioinformatic analysis. In vitro and in vivo loss- and gain-of-function assays, m6A dot blot assays, methylated RNA immunoprecipitation sequencing (MeRIP-seq), RNA-seq, MeRIP-qPCR, dual luciferase reporter assays, RNA stability assays, RNA immunoprecipitation (RIP) assays, and RNA pull-down assays were performed to investigate the biological functions and underlying molecular mechanisms of KIAA1429 in GC.ResultsBoth the mRNA and protein expression of KIAA1429 were greater in GC tissues than in normal gastric tissues. High KIAA1429 expression correlated positively with poor prognosis in GC patients. KIAA1429 not only promoted GC cell proliferation, colony formation, G2/M cell cycle transition, migration, and invasion in vitro but also enhanced GC tumor growth and metastasis in vivo. Mechanistically, KIAA1429 increased the m6A level of RASD1 mRNA and enhanced its stability in an m6A-YTHDF2-dependent manner, thereby upregulating its expression. RASD1 knockdown partially rescued the KIAA1429 knockdown-induced impairment of pro‑oncogenic ability in GC cells. The expression levels of KIAA1429 and RASD1 were negatively correlated in GC tissues.ConclusionsKIAA1429 plays a pro‑oncogenic role in GC by downregulating RASD1 expression through destabilizing RASD1 mRNA in an m6A-YTHDF2-dependent manner. KIAA1429 may serve as a prognostic biomarker and therapeutic target for GC.

METTL5 promotes gastric cancer progression via sphingomyelin metabolism.

The treatment of gastric cancer (GC) has caused an enormous social burden worldwide. Accumulating studies have reported that N6-methyladenosine (m6A) is closely related to tumor progression. METTL5 is a m6A methyltransferase that plays a pivotal role in maintaining the metabolic stability of cells. However, its aberrant regulation in GC has not been fully elucidated. To excavate the role of METTL5 in the development of GC. METTL5 expression and clinicopathological characteristics were analyzed via The Cancer Genome Atlas dataset and further verified via immunohistochemistry, western blotting and real-time quantitative polymerase chain reaction in tissue microarrays and clinical samples. The tumor-promoting effect of METTL5 on HGC-27 and AGS cells was explored in vitro by Cell Counting Kit-8 assays, colony formation assays, scratch healing assays, transwell assays and flow cytometry. The tumor-promoting role of METTL5 in vivo was evaluated in a xenograft tumor model. The EpiQuik m6A RNA Methylation Quantification Kit was used for m6A quantification. Next, liquid chromatography-mass spectrometry was used to evaluate the association between METTL5 and sphingomyelin metabolism, which was confirmed by Enzyme-linked immunosorbent assay and rescue tests. In addition, we investigated whether METTL5 affects the sensitivity of GC cells to cisplatin via colony formation and transwell experiments. Our research revealed substantial upregulation of METTL5, which suggested a poor prognosis of GC patients. Increased METTL5 expression indicated distant lymph node metastasis, advanced cancer stage and pathological grade. An increased level of METTL5 correlated with a high degree of m6A methylation. METTL5 markedly promotes the proliferation, migration, and invasion of GC cells in vitro. METTL5 also promotes the growth of GC in animal models. METTL5 knockdown resulted in significant changes in sphingomyelin metabolism, which implies that METTL5 may impact the development of GC via sphingomyelin metabolism. In addition, high METTL5 expression led to cisplatin resistance. METTL5 was found to be an oncogenic driver of GC and may be a new target for therapy since it facilitates GC carcinogenesis through sphingomyelin metabolism and cisplatin resistance.

The prognostic implications and tumor-promoting functions of CHSY3 in gastric cancer.

Chondroitin sulfate synthase 3 (CHSY3) is an important enzyme that regulates glycosylation, but its role in tumors has not been determined. Here, we showed that high CHSY3 expression promotes proliferation in gastric cancer (GC) cells and is associated with poor prognosis in GC patients. We analyzed the immunohistochemistry data of 150 gastric cancer patients to determine the clinicopathological and survival significance of CHSY3. Immunofluorescence was used to detect the colocalization of CHSY3 with infiltrating immune cells. Additionally, CHSY3 was predominantly found in tumor tissues and showed higher abundance compared to matched adjacent tissues. High CHSY3 expression was associated with more advanced tumor stage, higher recurrence risk and worse survival. Immunohistochemistry and bioinformatic analysis revealed that CHSY3 expression was significantly positively correlated with tumor-associated macrophage (TAM) infiltration. Moreover, after knocking down CHSY3, the proliferation of cells was decreased, and the migration ability was reduced, as shown by scratch, monoclonal and transwell assays. In conclusion, this study revealed that CHSY3 has a tumor-promoting effect on GC, suggesting a novel therapeutic strategy against this disease.

SNHG15-mediated feedback loop interplays with HNRNPA1/SLC7A11/GPX4 pathway to promote gastric cancer progression.

Dysregulation of long noncoding RNA (lncRNA) expression plays a pivotal role in the initiation and progression of gastric cancer (GC). However, the regulation of lncRNA SNHG15 in GC has not been well studied. Mechanisms for ferroptosis by SNHG15 have not been revealed. Here, we aimed to explore SNHG15-mediated biological functions and underlying molecular mechanisms in GC. The novel SNHG15 was identified by analyzing RNA-sequencing (RNA-seq) data of GC tissues from our cohort and TCGA dataset, and further validated by qRT-PCR in GC cells and tissues. Gain- and loss-of-function assays were performed to examine the role of SNHG15 on GC both invitro and invivo. SNHG15 was highly expressed in GC. The enhanced SNHG15 was positively correlated with malignant stage and poor prognosis in GC patients. Gain- and loss-of-function studies showed that SNHG15 was required to affect GC cell growth, migration and invasion both invitro and invivo. Mechanistically, the oncogenic transcription factors E2F1 and MYC could bind to the SNHG15 promoter and enhance its expression. Meanwhile, SNHG15 increased E2F1 and MYC mRNA expression by sponging miR-24-3p. Notably, SNHG15 could also enhance the stability of SLC7A11 in the cytoplasm by competitively binding HNRNPA1. In addition, SNHG15 inhibited ferroptosis through an HNRNPA1-dependent regulation of SLC7A11/GPX4 axis. Our results support a novel model in which E2F1- and MYC-activated SNHG15 regulates ferroptosis via an HNRNPA1-dependent modulation of the SLC7A11/GPX4 axis, which serves as the critical effectors in GC progression, and provides a new therapeutic direction in the treatment of GC.

Cancer-associated fibroblasts promote gastric cancer cell proliferation by paracrine FGF2-driven ribosome biogenesis

The cancer-associated fibroblast (CAF)-derived secretome plays critical roles in tumor progression by remodelling tumor microenvironment. Tumorigenesis is accompanied by the transformation of normal fibroblasts (NF) into CAF, leading to significant changes in their secretome. This work aims to identify the differential components of secretome between NFs and CAFs and reveal their functions in gastric cancer (GC). Firstly, our molecular typing studies and immune infiltration analysis showed that CAF infiltration level was increased and showed a significant association with clinical characteristics and poor prognosis of GC patients. Secondly, RNA-seq analysis revealed that a total of 1531 genes showed significant expression changes between NF and CAF. According to the annotation of the Human Protein Atlas (HPA) database, 147 genes encode secreted proteins, including FGF2. Particularly, the cell co-culture and RNA sequencing studies confirmed that exogenous recombinant FGF2 protein treatment promoted GC cell proliferation by enhancing ribosome biogenesis. The rescue assay showed that CAF-secreted FGF2 protein promotes GC cell growth and proliferation in a FGFR1-dependent manner. Our finding provides evidence that targeting blockade of CAF-derived FGF2 protein might be a promising treatment for GC.

The RNA m6A reader IGF2BP3 regulates NFAT1/IRF1 axis-mediated anti-tumor activity in gastric cancer

N6-methyladenosine (m6A) and its associated reader protein insulin like growth factor 2 mRNA binding protein 3 (IGF2BP3) are involved in tumor initiation and progression via regulating RNA metabolism. This study aims to investigate the biological function and clinical significance of IGF2BP3 in gastric cancer (GC). The clinical significance of IGF2BP3 was evaluated using tumor related databases and clinical tissues. The biological role and molecular mechanism of IGF2BP3 in GC progression were investigated by multi-omics analysis including Ribosome sequence (Ribo-seq), RNA sequence (RNA-seq) and m6A sequence (m6A-seq) combined with gain- and loss- of function experiments. IGF2BP3 expression is significantly elevated in GC tissues and associated with poor prognosis of GC patients. Knockdown of IGF2BP3 significantly weakens the migration and clonogenic ability, promotes the apoptosis, inhibits translation, and suppresses in vitro growth and progression of GC cells. Mechanistically, IGF2BP3 regulates the mRNA stability and translation of the nuclear factor of activated T cells 1(NFAT1) in a m6A dependent manner. Then NFAT1 induced by IGF2BP3 acts as a transcription factor (TF) to negatively regulates the promoter activities of interferon regulatory factor 1 (IRF1) to inhibit its expression. Inhibition of IGF2BP3-induced expression of IRF1 activates interferon (IFN) signaling pathway and then exerts its anti-tumor effect. Elevated IGF2BP3 promotes in vivo and in vitro GC progression via regulation of NFAT1/IRF1 pathways. Targeted inhibition of IGF2BP3 might be a potential therapeutic approach for GC treatment.

Homeobox Protein BarH-like 1 Promotes Gastric Cancer Progression by Activating Coiled-Coil Domain-Containing Protein 178.

Coiled-coil domain-containing protein 178 (CCDC178) has been revealed to exert metastasis-promoting properties in hepatocellular carcinoma, whereas its function in gastric cancer (GC) has not been fully understood. We evaluated its role in GC and the molecular mechanism. The differentially expressed genes in datasets related to GC metastasis were intersected with survival-related genes in GC, followed by prognostic significance prediction. Loss- and gain-of-function assays were conducted to examine the involvement of CCDC178, Homeobox protein BarH-like 1 (BARX1), and the extracellular signal-regulated kinase (ERK) pathway in GC cell malignant phenotype and the polarization of tumor-associated macrophages (TAM). The corresponding functions were verified in the in vivo animal experiment. High CCDC178 expression predicted a poor prognosis for GC patients, and CCDC178 correlated significantly with macrophage infiltration in GC tissues. CCDC178 activated the ERK pathway in GC. Silencing of CCDC178 reduced the colony formation, migratory and invasive potential of GC cells, and the M2-like polarization of TAM, which was reversed by TBHQ (an ERK activator). BARX1 bound to the promoter region of CCDC178, thus inducing its transcriptional level. Silencing of BARX1 suppressed the M2-type polarization of TAM in vitro and in vivo, and CCDC178 mitigated the repressing role of BARX1 knockdown. BARX1 activates the transcription of CCDC178 to induce the ERK pathway, thereby supporting macrophage recruitment and M2-like polarization in GC.

Knockdown of TRIP13 inhibits gastric cancer stemness and cisplatin resistance by regulating FBXW7/ENO1 axis

Purpose: To explore the role of thyroid hormone receptor interactor 13 (TRIP13) in gastric cancer (GC) and the associated mechanism.&#x0D; Methods: TRIP13 expression in GC was found in The Cancer Genome Atlas (TCGA) database and siTRIP13 was transfected in GC cells in order to generate cell lines with low TRIP13 expression. Cell proliferation was determined by colony formation assay, while cell migration and invasion were evaluated by scratch test and Transwell assay, respectively. Sphere formation assay was used to assess cell stemness characteristics whereas half-inhibitory concentration (IC50) value was evaluated by Cell Counting Kit-8 (CCK8). F-box and WD repeat domain containing 7 (FBXW7) and enolase 1 (ENO1) expression were determined by western-blot assay.&#x0D; Results: TRIP13 was significantly expressed in GC based on TCGA database (p &lt; 0.001) and high expression predicted poor prognosis in GC patients (p &lt; 0.05). Based on the findings of the cell function assay, si-TRIP13 inhibited the proliferation, migration, invasion and stemness of GC cells (p &lt; 0.001) and decreased the IC50 value. Mechanically, knockdown of TRIP13 decreased ENO1 expression level by stabilizing FBXW7.&#x0D; Conclusion: TRIP13 functions as an oncogene in GC and stimulates growth and stemness via FBXW7/ENO1 pathway in GC. Thus, a potential therapeutic target for the treatment of gastric cancer is provided by this study.

BMP6 inhibits gastric cancer growth and predicts good prognosis.

Gastric cancer (GC) is a common tumors in the digestive tract, and effective treatment methods are still lacking. Bone morphogenetic protein 6 (BMP6) is closely related to the occurrence and development of various tumors, but its relevance to GC is still unclear. The aim of the study was to explore the relationship between BMP6 and the occurrence and development of GC. In this study, we investigated the relationship between BMP6 and the prognosis of GC patients using bioinformatics technology and clinical tissue samples. We also explored the connection between BMP6 and the biological behavior of GC cells through molecular biology experiments and relevant in vivo animal experiments. Finally, we examined the mechanisms by which BMP6 inhibits the onset and progression of GC. Through analysis of The Cancer Genomics Atlas (TCGA) database, we observed that BMP6 is expressed at low levels in GC, and its low expression is associated with a poor prognosis in GC patients. Cell experiments demonstrated that BMP6 expression can influence the proliferation of GC cells both in vitro and in vivo. Furthermore, we discovered that BMP6 is linked to the nuclear factor-κB (NF-κB) pathway, and subsequent experiments confirmed that BMP6 can inhibit the biological activity of GC cells by activating the NF-κB pathway. Our findings suggest that BMP6 is a potential prognostic biomarker in GC and can regulate the biological activity of GC cells through the NF-κB pathway. BMP6 may serve as a promising therapeutic target for GC, and our study introduces novel ideas for the prevention and treatment of this disease.

High expression of TRIP13 is associated with tumor progression in H. pylori infection induced gastric cancer

Background/objectiveH. pylori is a recognized bacterial carcinogen in the world to cause gastric cancer (GC). However, the molecular mechanism of H. pylori infection-induced GC is not completely clear. Thus, there is an urgent need to reveal the precise mechanisms regulating cancer development due to H. pylori infection. MethodsGEO microarray databases and TCGA databases were extracted for the analysis of different expression genes (DEGs). Then, Kaplan-Meier Plotter was used for prognostic analysis. Functional enrichment analysis of TRIP13 was performed by metascape database and TIMER database. Specific role of TRIP13 in GC with H. pylori infection was confirmed by CCK8, cell cycle analysis and WB. ResultsA total 10 DEGs were substantially elevated in GC and H. pylori+ tissues and might be associated with H. pylori infection in GC and only the highly expressed TRIP13 was statistically associated with poor prognosis in GC patients. Meanwhile, TRIP13 were upregulated in both CagA-transfected epithelial cells and GC cells. And TRIP13 deficiency inhibited cell proliferation and arrested the cell cycle at the G1 phase. ConclusionOur study suggested that high expression of TRIP13 can promote the proliferation, cell cycle in GC cells, which could be used as a biomarker for H. pylori infection GC.

Pumilio1 regulates NPM3/NPM1 axis to promote PD-L1-mediated immune escape in gastric cancer

Abnormal regulation of RNA binding proteins (RBPs) plays an essential role in tumorigenesis and progression, but their functions and mechanisms remain largely elusive. Previously, we reported that Pumilio 1 (PUM1), a RBP, could regulate glycolysis metabolism and promote the progression of gastric cancer (GC). However, the role of PUM1 in tumor immune regulation remains largely elusive. In this study, we report that PUM1 induces immune escape through posttranscriptional regulation of PD-L1 in GC. We used multiplexed immunohistochemistry to analyze the correlation between PUM1 expression and immune microenvironment in GC. The effect of PUM1 deficiency on tumor killing of T cells was examined in vitro and in vivo. The molecular mechanism of PUM1 was evaluated via RNA immunoprecipitation, chromatin immunoprecipitation, Western blot, co-immunoprecipitation, and RNA stability assays. Clinically, elevated PUM1 expression is associated with high-expression of PD-L1, lack of CD8+ T cell infiltration and poor prognosis in GC patients. PUM1 positively regulates PD-L1 expression and PUM1 reduction enhances T cell killing of tumors. Mechanistically, PUM1 directly binds to nucleophosmin/nucleoplasmin 3 (NPM3) mRNA and stabilizes NPM3. NPM3 interacts with NPM1 to promote NPM1 translocation into the nucleus and increase the transcription of PD-L1. PUM1 inhibits the anti-tumor activity of T cells through the PUM1/NPM3/PD-L1 axis. In summary, this study reveals the critical post-transcriptional effect of PUM1 in the modulation of PD-L1-dependent GC immune escape, thus provides a novel indicator and potential therapeutic target for cancer immunotherapy.

CircFNTA promotes tumorigenesis and progression of gastric cancer via miR-604/miR-647/SCN8A axis.

Gastric cancer (GC) is a major contributor to cancer-related deaths and is characterized by high heterogeneity in epidemiology and histopathology worldwide. Increasing evidence indicates that circular RNAs (circRNAs) play multifaceted roles in cellular processes in human cancers. Here, we demonstrated that circFNTA high expression increases the proliferation, metastasis, and epithelial-mesenchymal transition process and tumorigenicity of GC cells. First, we found that circFNTA was upregulated in GC cells and tissues, and the high circFNTA levels were positively associated with the poor prognosis in GC patients. Using luciferase reporter and RNA-pull down assays, we elucidated that circFNTA sponged two microRNAs, miR-604 and miR-647. In addition, the proliferation and metastatic ability of GC cell reduction caused by silencing circFNTA was hindered by inhibitors of miR-604 and miR-647. Moreover, SCN8A was predicted by miRDB as a common target gene of miR-604 and miR-647, which was then verified by the luciferase reporter assay. Knockdown of circFNTA causes messenger RNA and protein levels in SCN8A to be downregulated in GC cells. However, this effect was overturned by cotransfection miR-604 and miR-647. Also, we identified that SCN8A was downregulated in GC tissues, which was positively correlated with circFNTA expression. In rescue experiments, the attenuated cell proliferation and metastatic ability caused by circFNTA knockdown was reversed by miR-604 and miR-647 inhibitors and SCN8A overexpression. Collectively, our findings suggest an oncogenic role of circFNTA in GC progression and elucidate that circFNTA exerts its function by modulating the miR-604/miR-647/SCN8A axis.

Expression and Clinical Significance of PIEZO2 in Gastric Cancer.

The aim of this research was to investigate the expression of PIEZO2 and its potential clinical significance in gastric cancer (GC). In this study, we detected the protein expression levels of PIEZO2 in GC tissues and adjacent normal tissues by immunohistochemistry (IHC) and analysed the relationship between the protein expression levels of PIEZO2 and clinicopathological parameters of GC patients. Gene Expression Profiling Interactive Analysis (GEPIA) and Kaplan-Meier Plotter were used to verify the diagnostic and prognostic values of PIEZO2. Proteins interacting with PIEZO2 were predicted using the SRING database. Our results showed that the protein expression levels of PIEZO2 in GC tissues were lower than those in adjacent normal tissues (all P < 0.05), and the protein expression level of PIEZO2 was correlated with lymph node metastasis and TNM stage of GC patients (all P < 0.05). Aberrant overexpression of PIEZO2 was associated with poor prognosis of GC patients. Proteins such as VR1, TRPV1, LHFPL5, STOM, TRPA1 and STOML3 had obvious interactions with PIEZO2 (P = 0.00213). In summary, our current study identified PIEZO2 as a promising target for early diagnosis and as a potential prognostic biomarker in GC patients.

B7-H3 and CD47 co-expression in gastric cancer is a predictor of poor prognosis and potential targets for future dual-targeting immunotherapy.

Gastric cancer (GC) is one of the most prevalent types of cancer worldwide. B7-H3, an immune checkpoint molecule with promising potential, has been found to be overexpressed in various cancers. CD47 is an anti-phagocytic molecule that interacts with the signal regulatory protein alpha (SIRPα) to affect phagocytes. The relationship between the expression of B7-H3 and CD47, two potential therapeutic targets found in tumor cells, remains unknown. In this study, our objective is to investigate the clinical significance of co-expression of B7-H3 and CD47, as well as the potential therapeutic value of combination therapy in GC. We utilized immunohistochemistry (IHC) to assess the expression of B7-H3, CD47, CD68, CD86 and CD163 in tissue microarrays obtained from 268 GC patients who underwent surgeries. Western blotting was employed to assess the protein level of B7-H3 and CD47 in GC tissues. The co-localization of B7-H3/CD47 and CD68 in GC tissues was determined using multiplex immunohistochemistry (m-IHC). We further verified the relationship between B7-H3/CD47 and macrophage infiltration via flow cytometry. To estimate the clinical outcomes of patients from different subgroups, we employed the Kaplan-Meier curve and the Cox model. Among the 268 GC cases, a total of 180 cases exhibited positive expression of B7-H3, while 122 cases showed positive expression of CD47. In fresh GC clinical tissues, B7-H3 and CD47 protein level was also higher in tumor tissue than in adjacent normal tissue. Remarkably, 91 cases demonstrated co-expression of B7-H3 and CD47. We observed a significant correlation between B7-H3 expression and tumor stage (P = 0.001), differentiation (P = 0.045), and depth (P = 0.003). Additionally, there was a significant association between B7-H3 and CD47 expression (P = 0.018). The percentage of B7-H3 and CD47 double positive cells in fresh GC tumor tissues were elevated compared with control adjacent tissues regardless of CD45- or CD45+ cells (P = 0.0029, P = 0.0012). Patients with high B7-H3 or CD47 expression had significantly lower overall survival (OS) rates compared to those with low expression levels (P = 0.0176 or P = 0.0042). Surprisingly, patients with combined high expression of B7-H3 and CD47 exhibited a considerably worse prognosis than others (P = 0.0007). Univariate analysis revealed that cases with high expression of B7-H3, CD47, or both had significantly higher hazard ratios (HR) than cases with low expression of these markers. Furthermore, the results of multivariate analysis indicated that B7-H3/CD47 co-expression and CD47 expression alone are independent prognostic factors for overall survival. Moreover, significant correlations were observed between B7-H3 and CD68 expression, CD47 and CD68 expression, as well as B7-H3/CD47 co-expression and CD68 expression in GC patients (P < 0.001, P = 0.003, and P < 0.001). Flow cytometry test showed that the percentage of CD68-positive cells but not CD86-positive cells among B7-H3-positive or CD47-positive immune cells in GC tumor tissue was elevated significantly compared with adjacent tissue. Our findings demonstrated a correlation between B7-H3 expression and CD47 expression in GC patient tissues. Co-expression of B7-H3 and CD47 can serve as an indicator of poor prognosis in GC patients. In GC tumor tissue, but not adjacent tissue, B7-H3 and CD47 expression was accompanied with macrophage infiltration.

CircHIPK3 contributes to cisplatin resistance in gastric cancer by blocking autophagy-dependent ferroptosis.

Cisplatin is the first-line chemotherapy for gastric cancer (GC). However, its efficacy is dampened by the development of chemoresistance, which leads to poor prognosis in GC patients. Recently, evidence has revealed that circular RNAs(circRNAs) and dysregulation of autophagy-dependent ferroptosis play critical roles in cancer chemoresistance. Herein, for the first time we report that circHIPK3 has a vital role in GC cisplatin resistance. CircHIPK3 regulated cisplatin resistance by targeting autophagy and ferroptosis. In brief, knockdown circHIPK3 decreased GC cell cisplatin resistance by enhancing ferroptosis via the miR-508-3p/Bcl-2/beclin1/SLC7A11 axis. Taken together, our results demonstrate that ferroptosis is a promising strategy to ameliorate cisplatin resistance. Importantly, serum exosomal circHIPK3 could also be a noninvasive indicator to evaluate cisplatin resistance in GC.

LINC00665 activating Wnt3a/β-catenin signaling by bond with YBX1 promotes gastric cancer proliferation and metastasis.

Long noncoding RNAs (lncRNAs) play a key role in human cancer development; nevertheless, the effect of lncRNA LINC00665 on the progression of gastric cancer (GC) still unclear. In this study, we found that LINC00665 expression is upregulated in GC than normal gastric mucosa tissues and higher LINC00665 expression is associated with a poor prognosis in GC patients. Downregulated LINC00665 inhibited GC cells proliferation, invasion, and migration in vitro. Pulmonary metastasis animal models showed that downregulated LINC00665 could reduce the lung metastasis of GC in vivo. Tumor organoids were generated from human malignant GC tissues, downregulated LINC00665 could inhibit the growth of the organoids of GC tissues. Mechanistically, downregulated LINC00665 could inhibit GC cells EMT. RNA pulldown, RIP, and RIP-seq studies found that LINC00665 can bind to the transcription factor YBX1 and form a positive feed-forward loop. The luciferase reporter and CHIP results showed that YBX1 could regulate the transcriptional activity of Wnt3a, and downregulation of LINC00665 could block the activation of Wnt/β-catenin signaling. In conclusion, our results identified a feedback loop between LINC00665 and YBX1 that activates Wnt/β-catenin signaling, and it may be a potential therapeutic approach to suppress GC progression.

GADD45B regulates the carcinogenesis process of chronic atrophic gastritis and the metabolic pathways of gastric cancer.

Gastric cancer continues to be a significant global healthcare challenge, and its burden remains substantial. The development of gastric cancer (GC) is closely linked to chronic atrophic gastritis (CAG), yet there is a scarcity of research exploring the underlying mechanisms of CAG-induced carcinogenesis. In this study, we conducted a comprehensive investigation into the oncogenes involved in CAG using both bulk transcriptome and single-cell transcriptome data. Our approach employed hdWGCNA to identify pathogenic genes specific to CAG, with non-atrophic gastritis (NAG) serving as the control group. Additionally, we compared CAG with GC, using normal gastric tissue as the control group in the single-cell transcriptome analysis. By intersecting the identified pathogenic genes, we pinpointed key network molecules through protein interaction network analysis. To further refine the gene selection, we applied LASSO, SVM-RFE, and RF techniques, which resulted in a set of cancer-related genes (CRGs) associated with CAG. To identify CRGs potentially linked to gastric cancer progression, we performed a univariate COX regression analysis on the gene set. Subsequently, we explored the relationship between CRGs and immune infiltration, drug sensitivity, and clinical characteristics in gastric cancer patients. We employed GSVA to investigate how CRGs regulated signaling pathways in gastric cancer cells, while an analysis of cell communication shed light on the impact of CRGs on signal transmission within the gastric cancer tumor microenvironment. Lastly, we analyzed changes in metabolic pathways throughout the progression of gastric cancer. Using hdWGCNA, we have identified a total of 143 pathogenic genes that were shared by CAG and GC. To further investigate the underlying mechanisms, we conducted protein interaction network analysis and employed machine learning screening techniques. As a result, we have identified 15 oncogenes that are specifically associated with chronic atrophic gastritis. By performing ROC reanalysis and prognostic analysis, we have determined that GADD45B is the most significant gene involved in the carcinogenesis of CAG. Immunohistochemical staining and differential analysis have revealed that GADD45B expression was low in GC tissues while high in normal gastric tissues. Moreover, based on prognostic analysis, high expression of GADD45B has been correlated with poor prognosis in GC patients. Additionally, an analysis of immune infiltration has shown a relationship between GADD45B and the infiltration of various immune cells. By correlating GADD45B with clinical characteristics, we have found that it primarily affects the depth of invasion in GC. Through cell communication analysis, we have discovered that the CD99 signaling pathway network and the CDH signaling pathway network are the main communication pathways that significantly alter the microenvironment of gastric tissue during the development of chronic atrophic gastritis. Specifically, GADD45B-low GC cells were predominantly involved in the network communication of the CDH signaling pathway, while GADD45B-high GC cells played a crucial role in both signaling pathways. Furthermore, we have identified several metabolic pathways, including D-Glutamine and D-glutamate metabolism and N-Glycan biosynthesis, among others, that played important roles in the occurrence and progression of GC, in addition to the six other metabolic pathways. In summary, our study highlighted the discovery of 143 pathogenic genes shared by CAG and GC, with a specific focus on 15 oncogenes associated with CAG. We have identified GADD45B as the most important gene in the carcinogenesis of CAG, which exhibited differential expression in GC tissues compared to normal gastric tissues. Moreover, GADD45B expression was correlated with patient prognosis and is associated with immune cell infiltration. Our findings also emphasized the impact of the CD99 and CDH signaling pathway networks on the microenvironment of gastric tissue during the development of CAG. Additionally, we have identified key metabolic pathways involved in GC progression. GADD45B, an oncogene implicated in chronic atrophic gastritis, played a critical role in GC development. Decreased expression of GADD45B was associated with the onset of GC. Moreover, GADD45B expression levels were closely tied to poor prognosis in GC patients, influencing the infiltration patterns of various cells within the tumor microenvironment, as well as impacting the metabolic pathways involved in GC progression.

C-type lectin receptor Dectin-1 blockade on tumour-associated macrophages improves anti-PD-1 efficacy in gastric cancer

BackgroundThis study aimed to investigate the expression and clinical significance of Dendritic cell-associated C-type lectin-1 (Dectin-1) in gastric cancer (GC), and to explore the mechanism of Dectin-1 regulating tumour-associated macrophage (TAM)-mediated immune evasion in GC.MethodsThe association of Dectin-1+ cells with clinical outcomes was inspected by immunohistochemistry on tumour microarrays. Flow cytometry and RNA sequencing were applied to detect characteristics of T cells, phenotypic and transcriptional features of Dectin-1+ TAMs. The effect of Dectin-1 blockade was evaluated using an in vitro intervention experiment based on fresh GC tissues.ResultsHigh infiltration of intratumoral Dectin-1+ cells predicted poor prognosis in GC patients. Dectin-1+ cells were mainly composed of TAMs, and the accumulation of Dectin-1+ TAMs was associated with T-cell dysfunction. Notably, Dectin-1+ TAMs exhibited an immunosuppressive phenotype. Furthermore, blockade of Dectin-1 could reprogramme Dectin-1+ TAMs and reactivate anti-tumour effects of T cells, as well as enhanced PD-1 inhibitor-mediated cytotoxicity of CD8+ T cells against tumour cells.ConclusionsDectin-1 could affect T-cell anti-tumour immune response by regulating the immunosuppressive function of TAMs, leading to poor prognosis and immune evasion in GC patients. Blockade of Dectin-1 can be used alone or in combination with current therapeutic strategies in GC.