Exploring Electron Transfer Mechanism in Synergistic Interactional Reduced Polyoxometalate-Based Cu(I)-Organic Framework for Photocatalytic Removal of U(VI).

Photocatalytic reduction of U(VI) is a promising method for removing uranium containing pollutants. However, using polyoxometalate-based metal-organic frameworks (POMOFs) for photoreduction of U(VI) is rare, and the relevant charge transfer pathway is also not yet clear. In this article, we demonstrate a highly efficient strategy and revealed a clearly electron transfer pathway for the photoreduction of U(VI) with 99% removal efficiency by using a novel POMOF, [Cu(4,4'-bipy)]5·{AsMo4VMo6VIV2VO40(VIVO)[VIVO(H2O)]}·2H2O (1), as catalyst. The POMOF catalyst was constructed by the connection of reduced {AsMo10V4} clusters and Cu(I)-MOF chains through Cu-O coordination bonds, which exhibits a broader and stronger light absorption capacity due to the presence of reduced {AsMo10V4} clusters. Significantly, the transition of electrons from Cu(I)-MOF to {AsMo10V4} clusters (Cu → Mo/V) greatly inhibits the recombination of photogenerated carriers, thereby advancing electron transfer. More importantly, the {AsMo10V4} clusters are not only adsorption sites but also catalytically active sites. This causes the fast transfer of photogenerated electrons from Mo/V to UO22+(Mo/V → O → U) via the surface oxygen atoms. The shorter electron transmission distance between catalytic active sites and UO22+ achieves faster and more effective electron transport. All in all, the highly effective photocatalytic removal of U(VI) using the POMOF as a catalyst is predominantly due to the synergistic interaction between Cu(I)-MOFs and reduced {AsMo10V4} clusters.

Effective oxygen activation on polyoxometalate-based hybrids for epoxidation of alkenes.

Two polyoxometalate-based hybrids, [M(btap)3(H2O)3(HPW12O40)]·xH2O (M-PW, M = Co/Mn, btap = 3,5-bis(1',2',4'-triazol-1'-yl)pyridine) were synthesized. Co-PW exhibited higher activity and selectivity towards olefin epoxidation than Mn-PW due to the synergistic effect between CoII and PW, in which the Co centers activate O2 to ˙O2- and further binding of free H+ from PW affords the active peroxyacid.

Rapid Oxidative Detoxification of Mustard Simulant by the Multisite Synergistic Catalytic Action of {PMoVI11MoVO40CuI8} Units.

Under hydrothermal and solvent-thermal conditions, we synthesized two novel polyoxometalate (POM)-based hybrids: [CuI4(Pz)2(H2O)8(PMoVI11MoVO40)]·3.5H2O (1, Pz = pyrazine) and [(C2H8N)5(HPMoVI9MoV3O40)]·DMF·4H2O (2). Single-crystal X-ray diffraction indicates that compound 1 is a three-dimensional structure consisting of Cu (I), {PMo12} anions, Pz, and water, where Cu (I) can be considered as Lewis acid sites. Furthermore, both compounds 1 and 2 possess favorable catalysis activity in catalyzing the conversion of chemical warfare agent simulant 2-chloroethylethyl sulfide (CEES) to nontoxic production of 2-chloroethylethyl sulfoxide (CEESO) under ambient temperature. Significantly, 1 could realize 98% conversion and 100% selectivity of CEES owing to the multisite synergy in the {PMoVI11MoVO40CuI8} units in which the tricoordinated Cu (I) could interact with S and O atoms from CEES and H2O2, respectively. This interaction not only decreases the distance of CEES from peroxomolybdenum species formed by H2O2 but also activates CEES.

Glucose transporter 3 (GLUT3) promotes lactylation modifications by regulating lactate dehydrogenase A (LDHA) in gastric cancer.

OBJECTIVES: Glucose transporter 3 (GLUT3) plays a major role in glycolysis and glucose metabolism in cancer cells. We aimed to investigate the correlation between GLUT3 and histone lactylation modification in the occurrence and progression of gastric cancer. MATERIALS AND METHODS: We initially used single-cell sequencing data to determine the expression levels of GLUT3 and lactate dehydrogenase A (LDHA) in primary tumor, tumor-adjacent normal, and metastasis tumor tissues. Immunohistochemistry analysis was conducted to measure GLUT3, LDHA, and L-lactyl levels in gastric normal and cancer tissues. Transwell and scratch assays were performed to evaluate the metastatic and invasive capacity of gastric cancer cell lines. Western blotting was used to measure L-lactyl and histone lactylation levels in gastric cancer cell lines. RESULTS: Single-cell sequencing data showed that GLUT3 expression was significantly increased in primary tumor and metastasis tumor tissues. In addition, GLUT3 expression was positively correlated with that of LDHA expression and lactylation-related pathways. Western blotting and immunohistochemistry analyses revealed that GLUT3 was highly expressed in gastric cancer tissues and cell lines. GLUT3 knockdown in gastric cancer cell lines inhibited their metastatic and invasive capacity to various degrees. Additionally, the levels of LDHA, L-lactyl, H3K9, H3K18, and H3K56 significantly decreased after GLUT3 knockdown, indicating that GLUT3 affects lactylation in gastric cancer cells. Moreover, LDHA overexpression in a GLUT3 knockdown cell line reversed the levels of lactylation and EMT-related markers, and the EMT functional phenotype induced by GLUT3 knockdown. The in vivo results were consistent with the in vitro results. CONCLUSIONS: This study suggests the important role of histone lactylation in the occurrence and progression of gastric cancer, and GLUT3 may be a new diagnostic marker and therapeutic target for gastric cancer.

Two 3D Two-Fold Interpenetrated Dia-Like Polyoxometalate-Based Metal-Organic Frameworks: Synthesis and Sulfide Selective Oxidation Activity.

Two new three-dimensional (3D) polyoxometalate-based metal-organic frameworks (POMOFs), [M2(btap)4(H2O)4(HPMo10VI Mo2VO40)] (M = Co (1) and Cd (2); btap = 3, 5-bis(1', 2', 4'-triazol-1'-yl)pyridine), have been synthesized under mild hydrothermal conditions and characterized in detail. Single-crystal X-ray diffraction (SXRD) analysis indicates that 1 and 2 are isostructural. In complexes 1 and 2, the metal ion is coordinated with the ligand to form two different left and right helical one-dimensional chains, which are alternately connected in a twisted form to build a two-fold interpenetrated three-dimensional structure, and the polyoxometalate is encapsulated into in the pores generated by the interpenetrating structure. It is noteworthy that 1 and 2, as recyclable catalysts, possess favorable heterogeneous catalytic activity and excellent sulfoxide selectivity in sulfide oxidation reactions, with H2O2 as an oxidant. By reason of the high dispersion of polyoxometalate with good intrinsic activity in the skeleton structure, the title complex has high activity. In addition, no obvious decrease of sulfoxide yield is observed after at least five cycles. These results indicate the excellent catalytic activity and sustainability of 1 and 2.

Neutrophil extracellular traps promote angiogenesis in gastric cancer.

Although antiangiogenic therapy has been used in gastric cancer, disease progression due to drug resistance remains common. Neutrophils play an important role in the occurrence and progression of cancer via neutrophil extracellular traps (NETs). However, few studies have investigated angiogenic regulation in gastric cancer. We aimed to determine the role of NETs in promoting angiogenesis in gastric cancer. Multiple immunohistochemical staining was used to analyze the spatial distribution of NETs and microvessels in patient tissue samples. A mouse subcutaneous tumor model was established to determine the effect of NETs on tumor growth, and changes in microvessel density were observed via immunohistochemical staining. We screened differentially expressed proteins in HUVECs stimulated by NETs via proteomics. Cell Counting Kit-8, EdU labeling, and tubule formation assays were used to verify the effect of NETs on HUVEC proliferation, migration, and tubule formation. Blocking NETs, which was related to decreased microvessel density, significantly inhibited tumor growth in the murine subcutaneous tumor model. Compared with those of the control group, tumor volume and mass among mice in the inhibition group decreased by 61.3% and 77.9%, respectively. The NET-DNA receptor CCDC25 was expressed in HUVECs, providing a platform for NETs to promote HUVEC proliferation, migration, and tubulation. In an in vitro rat aortic explant model, NETs induced HUVEC proliferation, survival, and chemotaxis, which were not significantly different from those observed in the VEGF stimulation group. Our results confirm that NETs promote angiogenesis in gastric cancer, providing a theoretical basis for identifying new anti-vascular therapeutic targets. Video Abstract.

Effect of NETs/COX-2 pathway on immune microenvironment and metastasis in gastric cancer.

Background: Neutrophil extracellular traps (NETs) are crucial in the progression of several cancers. The formation of NETs is closely related to reactive oxygen species (ROS), and the granule proteins involved in nucleosome depolymerization under the action of ROS together with the loosened DNA compose the basic structure of NETs. This study aims to investigate the specific mechanisms of NETs promoting gastric cancer metastasis in order to perfect the existing immunotherapy strategies. Methods: In this study, the cells and tumor tissues of gastric cancer were detected by immunological experiments, real-time polymerase chain reaction and cytology experiments. Besides, bioinformatics analysis was used to analyze the correlation between cyclooxygenase-2 (COX-2) and the immune microenvironment of gastric cancer, as well as its effect on immunotherapy. Results: Examination of clinical specimens showed that NETs were deposited in tumor tissues of patients with gastric cancer and their expression was significantly correlated with tumor staging. Bioinformatics analysis showed that COX-2 was involved in gastric cancer progression and was associated with immune cell infiltration as well as immunotherapy. In vitro experiments, we demonstrated that NETs could activate COX-2 through Toll-like receptor 2 (TLR2) and thus enhance the metastatic ability of gastric cancer cells. In addition, in a liver metastasis model of nude mice we also demonstrated the critical role of NETs and COX-2 in the distant metastasis of gastric cancer. Conclusion: NETs can promote gastric cancer metastasis by initiating COX-2 through TLR2, and COX-2 may become a target for gastric cancer immunotherapy.

Identification of lactylation related model to predict prognostic, tumor infiltrating immunocytes and response of immunotherapy in gastric cancer.

Background: The epigenetic regulatory chemical lactate is a product of glycolysis. It can regulate gene expression through histone lactylation, thereby promoting tumor proliferation, metastasis, and immunosuppression. Methods: In this study, a lactylation-related model for gastric cancer (GC) was constructed, and its relationships to prognosis, immune cell infiltration, and immunotherapy were investigated. By contrasting normal tissues and tumor tissues, four lactylation-related pathways that were substantially expressed in GC tissues were found in the GSEA database. Six lactylation-related genes were screened for bioinformatic analysis. The GC data sets from the TCGA and GEO databases were downloaded and integrated to perform cluster analysis, and the lactylation related model was constructed by secondary clustering. Results: The fingding demonstrated that the lactylation score has a strong correlation with the overall survival rate from GC and the progression of GC. Mechanistic experiments showed that abundant immune cell infiltration (macrophages showed the highest degree of infiltration) and increased genetic instability are traits of high lactylation scores. Immune checkpoint inhibitors (ICIs) demonstrated a reduced response rate in GC with high lactylation scores. At the same time, tumors with high lactylation scores had high Tumor Immune Dysfunction and Exclusion scores, which means that they had a higher risk of immune evasion and dysfunction. Discussion: These findings indicate that the lactylation score can be used to predict the malignant progression and immune evasion of GC. This model also can guide the treatment response to ICIs of GC. The constructed model of the lactate gene is also expected to become a potential therapeutic target for GC and diagnostic marker.

Neutrophil extracellular traps participate in the development of cancer-associated thrombosis in patients with gastric cancer.

BACKGROUND: The development of venous thromboembolism (VTE) is associated with high mortality among gastric cancer (GC) patients. Neutrophil extracellular traps (NETs) have been reported to correlate with the prothrombotic state in some diseases, but are rarely reported in GC patients. AIM: To investigate the effect of NETs on the development of cancer-associated thrombosis in GC patients. METHODS: The levels of NETs in blood and tissue samples of patients were analyzed by ELISA, flow cytometry, and immunofluorescence staining. NET generation and hypercoagulation of platelets and endothelial cells (ECs) in vitro were observed by immunofluorescence staining. NET procoagulant activity (PCA) was determined by fibrin formation and thrombin-antithrombin complex (TAT) assays. Thrombosis in vivo was measured in a murine model induced by flow stenosis in the inferior vena cava (IVC). RESULTS: NETs were likely to form in blood and tissue samples of GC patients compared with healthy individuals. In vitro studies showed that GC cells and their conditioned medium, but not gastric mucosal epithelial cells, stimulated NET release from neutrophils. In addition, NETs induced a hypercoagulable state of platelets by upregulating the expression of phosphatidylserine and P-selectin on the cells. Furthermore, NETs stimulated the adhesion of normal platelets on glass surfaces. Similarly, NETs triggered the conversion of ECs to hypercoagulable phenotypes by downregulating the expression of their intercellular tight junctions but upregulating that of tissue factor. Treatment of normal platelets or ECs with NETs augmented the level of plasma fibrin formation and the TAT complex. In the models of IVC stenosis, tumor-bearing mice showed a stronger ability to form thrombi, and NETs abundantly accumulated in the thrombi of tumor-bearing mice compared with control mice. Notably, the combination of deoxyribonuclease I, activated protein C, and sivelestat markedly abolished the PCA of NETs. CONCLUSION: GC-induced NETs strongly increased the risk of VTE development both in vitro and in vivo. NETs are potential therapeutic targets in the prevention and treatment of VTE in GC patients.

Immunoregulation and clinical significance of neutrophils/NETs-ANGPT2 in tumor microenvironment of gastric cancer.

Although significant progress has been made in the study of gastric cancer (GC), clinicians lack reliable protein markers for accurate diagnosis and tumor stratification. Neutrophil extracellular traps (NETs) are networks of extracellular fibers composed of DNA from neutrophils. We have previously reported that abundant NETs are deposited in GC, damaging human umbilical vein endothelial cells (HUVECs) and triggering the release of tissue factors, leading to a hypercoagulable state in GC. However, the specific effects of NETs on HUVECs are unclear. We aimed to explore the functional changes caused by NETs on HUVECs, providing evidence that NETs may fuel GC progression. Through quantitative proteomics, we identified 6182 differentially expressed proteins in NET-stimulated HUVECs by TMT. The reliability of the TMT technique was confirmed by parallel reaction monitoring (PRM) analysis of 17 differentially expressed proteins. Through bioinformatics analysis, we found that NETs upregulate ANGPT2 in HUVECs. We comprehensively analyzed the prognosis, biological function, immune response, and therapeutic value of ANGPT2 in GC. We found that overexpression of ANGPT2 in GC is associated with poor prognosis and potentially regulates multiple biological functions. At the same time, ANGPT2 also predicted immunotherapeutic and chemotherapeutic responses in GC. In conclusion, NETs promoted ANGPT2 overexpression in the GC microenvironment. In the future, the neutrophil/NETs-ANGPT2 axis may provide a new target for the treatment of GC.

Comprehensive Expression Profile Analysis of Neutrophil Extracellular Trap-Affected Genes in Gastric Cancer Cells and the Clinical Significance of lncRNA NEAT1-Related Signaling.

Background: Gastric cancer (GC) is the fifth most common malignant tumor and the third leading cause of cancer-related deaths worldwide. Neutrophil extracellular traps (NETs) can enhance the invasion of GC cells and are associated with poor prognosis in patients. However, its mechanism of action is not completely understood. Methods: The content of NETs in the peripheral blood of patients with GC was detected by enzyme-linked immunosorbent assay. GC AGS cells were treated with or without NETs for 24 h. High-throughput RNA sequencing was performed to screen differentially expressed long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and messenger RNAs (mRNAs). Real-time polymerase chain reaction (PCR) was used to verify gene expression. A competing endogenous RNA (ceRNA) regulatory network was constructed. Modules were screened using the molecular complex detection (MCODE) plug-in. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed using the genes in the network. The role and clinical significance of the lncRNA NEAT1-related signaling pathway were validated. Results: The content of NETs in the patients with GC was significantly higher than that in healthy controls and was also higher in patients with high-grade (stages III and IV) GC. NETs promoted the invasion of AGS cells. A total of 1,340 lncRNAs, 315 miRNAs, and 1,083 mRNAs were differentially expressed after NET treatment. The expression of five genes was validated using real-time PCR, which were in accordance with the RNA sequencing results. A ceRNA regulatory network was constructed with 1,239 lncRNAs, 310 miRNAs, and 1,009 mRNAs. Four genes (RAB3B, EPB41L4B, ABCB11, and CCDC88A) in the ceRNA network were associated with patient prognosis, with RAB3B being the most prominent and with signaling among the lncRNA NEAT1, the miRNA miR-3158-5p, and RAB3B. NEAT1 was upregulated in AGS cells after NET treatment. RNA interference of NEAT1 inhibited the invasion of AGS cells induced by NETs, inhibited miR-3158-5p expression, and promoted RAB3B expression. NEAT1 and RAB3B expression were positively correlated in patients with GC. Furthermore, RAB3B was upregulated and miR-3158-5p was downregulated in GC tissues compared with adjacent normal tissues, which was also associated with cancer stage. Conclusion: This study provides a comprehensive analysis of differentially expressed genes in NET-treated GC cells and validated the clinical significance of NEAT1-related signaling.

Identification of Enhancer RNA CDK6-AS1 as a Potential Novel Prognostic Biomarker in Gastric Cancer.

Background: This study aimed to confirm the role of enhancer RNAs (eRNAs) in gastric cancer and their clinical utility. Methods: We used Cox survival and relevance analysis to identify the candidate eRNAs in gastric cancer and performed Gene Ontology and Reactome pathway enrichment to determine the potential functions of eRNAs. Correlation between eRNA, tumor-infiltrating immune cells, and drug sensitivity was then analyzed. Results: CDK6-AS1, a long non-coding RNA cyclin-dependent kinase 6, may serve as a poor potential prognostic biomarker candidate in gastric cancer with a positive correlation with its target gene CDK6. The low CDK6-AS1 expression group showed more frequent mutated driver genes than the high expression group. Moreover, CDK6-AS1 is involved in a key oncogenic pathway of the cell cycle and RNA transcription. CDK6-AS1 also shows dysregulations and associations with prognosis at the pan-cancer level. This eRNA may also be associated with immune cell infiltration and drug sensitivity. Conclusion: CDK6-AS1 may be a potential prognostic biomarker and chemotherapeutic drug sensitivity predictor in gastric cancer.

The Application Value of ceMDCT in the Diagnosis of Gastric Cancer Extramural Vascular Invasion and Its Influencing Factors.

OBJECTIVE: To investigate the value of enhanced multislice spiral CT (ceMDCT) in the diagnosis of extramural vascular invasion of gastric cancer and the influencing factors of extramural vascular invasion. There are different methods used in this paper. METHOD: 131 patients with primary gastric cancer treated in our hospital from January 2017 to May 2019 were selected. All patients underwent surgical resection and ceMDCT examination before operation. RESULT: There were 40 cases with extramural vascular invasion of gastric cancer by surgical pathological diagnosis. The kappa value of ceMDCT in diagnosing extramural vascular invasion of gastric cancer was 0.947, and the consistency was excellent. The diagnostic sensitivity, specificity, positive predictive value, and negative predictive value were 100.00%, 96.70%, 93.02%, and 100.00%, respectively. The proportions of T3-T4, tumour diameter ≥5.0 cm, and growth pattern of proximal nodular + diffuse type in patients with gastric cancer extramural vascular invasion were 92.50%, 85.00%, and 65.00%, respectively, which were significantly higher than those in patients without extramural vascular invasion (P < 0.05). The logistic regression analysis results showed that T3-T4, tumour diameter ≥5.0 cm, proximal nodular + diffuse growth pattern were the risk factors for extrahepatic vascular invasion in gastric cancer (OR = 3.751, 2.901, and 3.367, P < 0.05). CONCLUSION: ceMDCT has good application value in diagnosing gastric cancer extramural vascular invasion. The occurrence of gastric cancer extramural vascular invasion is affected by T staging, tumour diameter, and tumour growth pattern.

Fangchinoline exerts antitumour activity by suppressing the EGFR­PI3K/AKT signalling pathway in colon adenocarcinoma.

Fangchinoline (FAN), an alkaloid extracted from Stephania tetrandra, has a variety of biological and pharmacological activities, but evidence of its effects on colon adenocarcinoma (COAD) is limited. Therefore, the present study aimed to elucidate the molecular mechanisms by which FAN affects COAD. The cytotoxicity, viability and proliferation of DLD­1 and LoVo cells were assessed in the presence of FAN using MTT and colony formation assays. The effects of FAN on apoptosis and the cell cycle in COAD cells were analysed by flow cytometry, and the migration and invasion of these cells were assessed by wound healing and Transwell experiments. Furthermore, a network pharmacological analysis was conducted to investigate the target of FAN and the results were confirmed by western blotting. In addition, a xenograft model was established in nude mice, and ultrasound imaging was used to assess the preclinical therapeutic effects of FAN in vivo. To the best of our knowledge, the results of this study provided the first evidence that FAN inhibited cellular proliferation, stemness, migration, invasion, angiogenesis and epithelial­mesenchymal transition (EMT), and induced apoptosis and G1­phase cell cycle arrest. Network pharmacological analysis further confirmed that FAN prevented EMT through the epidermal growth factor receptor (EGFR)­phosphoinositide 3­kinase (PI3K)/AKT signalling pathway. Finally, FAN significantly repressed tumour growth and promoted apoptosis in xenografts. Thus, targeting EGFR with FAN may offer a novel therapeutic approach for COAD.