CircIQGAP1 regulates RCAN1 and RCAN2 through the mechanism of ceRNA and promotes the growth of malignant glioma.

Circular RNA (circRNA) is one of non-coding RNA with specific circular structure, which has been found to be involved in regulating a series of malignant biological behaviors in many malignant tumors. In this study, based on the IDH1 molecular typing of gliomas, we identified a significant downregulation of circRNA (circIQGAP1) expression in IDH1 mutant gliomas by high-throughput sequencing. In 79 tissue samples, we confirmed that circIQGAP1 expression was significantly downregulated in IDH1 mutant gliomas, and that low circIQGAP1 expression was positively associated with better prognosis. Knockdown of circIQGAP1 in glioma cell lines inhibited glioma cell malignancy and conversely overexpression of circIQGAP1 promoted glioma malignancy. circIQGAP1 regulated glioma cell migration, proliferation, invasion and apoptosis through miR-1256/RCAN1/Bax/Bcl-2/Caspase3 and miR-622/RCAN2/Bax/Bcl-2/Caspase3 axes. These results suggest that circIQGAP1 plays an important role in glioma development, promotes tumor growth, and is a potential therapeutic target for glioma.

Connecting METTL3 and intratumoural CD33+ MDSCs in predicting clinical outcome in cervical cancer.

BACKGROUND: Methyltransferase-like 3 (METTL3) is a member of the m6A methyltransferase family and acts as an oncogene in cancers. Recent studies suggest that host innate immunity is regulated by the enzymes controlling m6A epitranscriptomic changes. Here, we aim to explore the associations between the levels of METTL3 and CD33+ myeloid-derived suppressor cells (MDSCs) in tumour tissues and the survival of patients with cervical cancer (CC). METHODS: Specimens of paraffin embedded tumour from 197 CC patients were collected. The expression levels of METTL3 and CD33 were measured by immunohistochemical (IHC) staining. The clinical associations of the IHC variants were analysed by Pearson's or Spearman's chi-square tests. Overall survival (OS) and disease-free survival (DFS) were estimated by the Kaplan-Meier method and log-rank test. Hazard ratios (HRs) and independent significance were obtained via Cox proportional hazards models for multivariate analyses. METTL3 in CD33+ cells or CC-derived cells was knocked down by METTL3-specific siRNA, and MDSC induction in vitro was performed in a co-culture system in the presence of METTL3-siRNA and METTL3-knockdown-CC-derived cells compared with that of the corresponding controls. RESULTS: We found that tumour tissues displayed increased levels of METTL3 and CD33+ MDSCs compared with tumour-adjacent tissues from the same CC patients. Importantly, METTL3 expression was positively related to the density of CD33+ cells in tumour tissues (P = 0.011). We further found that the direct CD33+CD11b+HLA-DR- MDSC induction and tumour-derived MDSC induction in vitro were decreased in the absence of METTL3. The level of METTL3 in tumour microenvironments was significantly related to advanced tumour stage. The levels of METTL3 and CD33+ MDSCs in tumour tissues were notably associated with reduced DFS or OS. Cox model analysis revealed that the level of METTL3 in tumour cells was an independent factor for patient survival, specifically for DFS (HR = 3.157, P = 0.022) and OS (HR = 3.271, P = 0.012), while the CD33+ MDSC number was an independent predictor for DFS (HR: 3.958, P = 0.031). Interestingly, in patients with advanced-disease stages (II-IV), METTL3 in tumour cells was an independent factor for DFS (HR = 6.725, P = 0.010) and OS (HR = 5.140, P = 0.021), while CD33+ MDSC density was an independent factor for OS (HR = 8.802, P = 0.037). CONCLUSION: Our findings suggest that CD33+ MDSC expansion is linked to high levels of METTL3 and that METTL3 and CD33+ MDSCs are independent prognostic factors in CC.

Synthesis of a novel fluorescent probe based on 7-nitrobenzo-2-oxa-1,3-diazole skeleton for the rapid determination of vitamin B12 in pharmaceuticals.

A new fluorescent probe, 4-N,N-di(2-hydroxyethyl)imino-7-nitrobenzo-2-oxa-1,3-diazole (HINBD) was synthesized in a single step with reasonably good yield. The water-soluble HINBD emits strongly in the visible region (λex = 479 nm, λem = 545 nm) and is stable over a wide range of pH values. It was found that vitamin B12 (VB12 ) had the ability to quench the fluorescence of HINBD, and the quenched fluorescence intensity was proportional to the concentration of VB12 . A method for VB12 determination based on the quenching fluorescence of HINBD was thus established. Interference effects of various substances, including sugars, vitamins, amino acids, inorganic cations and some organic substances have been studied. Under optimal conditions, the linear range is 0.0-2.4 × 10(-5) mol/L. The determination limit is 8.3 × 10(-8) mol/L. The method was applied to measure VB12 in pharmaceutical preparations with satisfactory results.

Exogenous Iron Induces Mitochondrial Lipid Peroxidation, Lipofuscin Accumulation, and Ferroptosis in H9c2 Cardiomyocytes.

Lipid peroxidation plays an important role in various pathologies and aging, at least partially mediated by ferroptosis. The role of mitochondrial lipid peroxidation during ferroptosis remains poorly understood. We show that supplementation of exogenous iron in the form of ferric ammonium citrate at submillimolar doses induces production of reactive oxygen species (ROS) and lipid peroxidation in mitochondria that precede ferroptosis in H9c2 cardiomyocytes. The mitochondria-targeted antioxidant SkQ1 and the redox mediator methylene blue, which inhibits the production of ROS in complex I of the mitochondrial electron transport chain, prevent both mitochondrial lipid peroxidation and ferroptosis. SkQ1 and methylene blue also prevented accumulation of lipofuscin observed after 24 h incubation of cardiomyocytes with ferric ammonium citrate. Using isolated cardiac mitochondria as an in vitro ferroptosis model, it was shown that rotenone (complex I inhibitor) in the presence of ferrous iron stimulates lipid peroxidation and lipofuscin accumulation. Our data indicate that ROS generated in complex I stimulate mitochondrial lipid peroxidation, lipofuscin accumulation, and ferroptosis induced by exogenous iron.

Anesthetic management of conjoined twins undergoing one-stage surgical separation: A single center experience.

OBJECTIVE: To summarize our experience in the anesthetic management of conjoined twins undergoing one-stage surgical separation. METHODOLOGY: Medical records of conjoined twins admitted to our hospital for treatment and considered for surgical separation from 1996 to present were retrospectively reviewed. Four cases of conjoined twins underwent one-stage surgical separation under general anesthesia. Preoperative evaluation was performed to determine the extent of anatomical conjunction and associated anomalies. Anesthesia was simultaneously induced in all conjoined twins. The intubation procedure was successfully performed with the head slightly rotated to each baby's side, followed by the administration of vecuronium. Anesthetic agents were administered according to the estimated weight of each baby. One case of conjoined twins underwent surgical separation with cardiopulmonary bypass due to shared hearts. Results : All conjoined twins were successfully separated. No significant respiratory or cardiac events occurred during surgery except for one twin, which died after separation because of complicated congenital heart disease. Conclusions : Accurate preoperative evaluation, respiratory and circulatory management, and close cooperation of the multidisciplinary team are important aspects of anesthetic management of conjoined twins surgery.

The cuproptosis-related signature associated with the tumor environment and prognosis of patients with glioma.

Background: Copper ions are essential for cellular physiology. Cuproptosis is a novel method of copper-dependent cell death, and the cuproptosis-based signature for glioma remains less studied. Methods: Several glioma datasets with clinicopathological information were collected from TCGA, GEO and CGGA. Robust Multichip Average (RMA) algorithm was used for background correction and normalization, cuproptosis-related genes (CRGs) were then collected. The TCGA-glioma cohort was clustered using ConsensusClusterPlus. Univariate Cox regression analysis and the Random Survival Forest model were performed on the differentially expressed genes to identify prognostic genes. The cuproptosis-signature was constructed by calculating CuproptosisScore using Multivariate Cox regression analysis. Differences in terms of genomic mutation, tumor microenvironment, and enrichment pathways were evaluated between high- or low-CuproptosisScore. Furthermore, drug response prediction was carried out utilizing pRRophetic. Results: Two subclusters based on CRGs were identified. Patients in cluster2 had better clinical outcomes. The cuproptosis-signature was constructed based on CuproptosisScore. Patients with higher CuproptosisScore had higher WHO grades and worse prognosis, while patients with lower grades were more likely to develop IDH mutations or MGMT methylation. Univariate and Multivariate Cox regression analysis demonstrated CuproptosisScore was an independent prognostic factor. The accuracy of the signature in prognostic prediction was further confirmed in 11 external validation datasets. In groups with high-CuproptosisScore, PIK3CA, MUC16, NF1, TTN, TP53, PTEN, and EGFR showed high mutation frequency. IDH1, TP53, ATRX, CIC, and FUBP1 demonstrated high mutation frequency in low-CuproptosisScore group. The level of immune infiltration increased as CuproptosisScore increased. SubMap analysis revealed patients with high-CuproptosisScore may respond to anti-PD-1 therapy. The IC50 values of Bexarotene, Bicalutamide, Bortezomib, and Cytarabine were lower in the high-CuproptosisScore group than those in the low-CuproptosisScore group. Finally, the importance of IGFBP2 in TCGA-glioma cohort was confirmed. Conclusion: The current study revealed the novel cuproptosis-based signature might help predict the prognosis, biological features, and appropriate treatment for patients with glioma.

FUT8-mediated aberrant N-glycosylation of B7H3 suppresses the immune response in triple-negative breast cancer.

Most patients with triple negative breast cancer (TNBC) do not respond to anti-PD1/PDL1 immunotherapy, indicating the necessity to explore immune checkpoint targets. B7H3 is a highly glycosylated protein. However, the mechanisms of B7H3 glycosylation regulation and whether the sugar moiety contributes to immunosuppression are unclear. Here, we identify aberrant B7H3 glycosylation and show that N-glycosylation of B7H3 at NXT motif sites is responsible for its protein stability and immunosuppression in TNBC tumors. The fucosyltransferase FUT8 catalyzes B7H3 core fucosylation at N-glycans to maintain its high expression. Knockdown of FUT8 rescues glycosylated B7H3-mediated immunosuppressive function in TNBC cells. Abnormal B7H3 glycosylation mediated by FUT8 overexpression can be physiologically important and clinically relevant in patients with TNBC. Notably, the combination of core fucosylation inhibitor 2F-Fuc and anti-PDL1 results in enhanced therapeutic efficacy in B7H3-positive TNBC tumors. These findings suggest that targeting the FUT8-B7H3 axis might be a promising strategy for improving anti-tumor immune responses in patients with TNBC.

Hypoxia Induces Mitochondrial Defect That Promotes T Cell Exhaustion in Tumor Microenvironment Through MYC-Regulated Pathways.

T cell exhaustion is an obstacle to immunotherapy for solid tumors. An understanding of the mechanism by which T cells develop this phenotype in solid tumors is needed. Here, hypoxia, a feature of the tumor microenvironment, causes T cell exhaustion (TExh) by inducing a mitochondrial defect. Upon exposure to hypoxia, activated T cells with a TExh phenotype are characterized by mitochondrial fragmentation, decreased ATP production, and decreased mitochondrial oxidative phosphorylation activity. The TExh phenotype is correlated with the downregulation of the mitochondrial fusion protein mitofusin 1 (MFN1) and upregulation of miR-24. Overexpression of miR-24 alters the transcription of many metabolism-related genes including its target genes MYC and fibroblast growth factor 11 (FGF11). Downregulation of MYC and FGF11 induces TExh differentiation, reduced ATP production and a loss of the mitochondrial mass in T cell receptor (TCR)-stimulated T cells. In addition, we determined that MYC regulates the transcription of FGF11 and MFN1. In nasopharyngeal carcinoma (NPC) tissues, the T cells exhibit an increased frequency of exhaustion and loss of mitochondrial mass. In addition, inhibition of miR-24 signaling decreases NPC xenograft growth in nude mice. Our findings reveal a mechanism for T cell exhaustion in the tumor environment and provide potential strategies that target mitochondrial metabolism for cancer immunotherapy.

Sphingosine 1 phosphate receptor-1 (S1P1) promotes tumor-associated regulatory T cell expansion: leading to poor survival in bladder cancer.

Regulatory T cells (Tregs) represent an important contributor to cancer immune escape, but the molecular mechanism responsible for Treg expansion in tumors is heterogeneous and unclear. Here, we investigated the role of S1P1, a receptor of the bioactive lipid sphingosine 1-phosphate (S1P), in regulating the crosstalk between tumor cells and tumor-associated Tregs in bladder cancer (BC). We found that the frequency of CD4+Foxp3+ Tregs was increased in circulating and tumor-infiltrating lymphocytes from BC patients. S1P1 expression was upregulated in BC tissues compared with tumor-adjacent tissues and was positively correlated with the density of tumor-infiltrated Foxp3+ Tregs. Both S1P1 and Treg predicted poor overall survival in BC patients. The in vitro data paralleled the in vivo data and suggested that the activation or overexpression of S1P1 in BC cells promoted the generation of BC-induced (i)Tregs from CD4+CD25-cells, and the generation of these cells was reversed by treatment with anti-IL-10 or anti-TGF-ß. Moreover, S1P1 promoted Treg migration mediated by BC cells. Mechanistically, S1P1 activated the TGF-ß signaling pathway, leading to the secretion of TGF-ß and IL-10 from BC cells. In total, our findings suggest that S1P1 induces tumor-derived Treg expansion in a cell-specific manner and serves as a potent prognostic biomarker and therapeutic target in BC.

Salinity of animal manure and potential risk of secondary soil salinization through successive manure application.

To enhance animal productivity and maximize economic returns, mineral salts are routinely added to animal feed worldwide. Salinity and ionic composition of animal manure from intensive poultry and livestock farms in Guangdong province were investigated. Field experiments were conducted for six successive crops of Brassica Parachinensis to evaluate the possibility of secondary soil salinization by successive application of chicken manure (CM) and pigeon manure (PM) to a garden soil. The concentration of total soluble salts (TSS), which were mainly composed of sulfate and chloride of potassium and sodium, averaged 49.0, 20.6 and 60.3 g.kg(- 1) in chicken, pig and pigeon manure, respectively. After three crops, successive application of CM and PM increased soil concentrations of TSS, Na(+), K(+), Mg(2+), SO(4)(2-), and Cl(-) with application rate, resulting in a rise in soil salinity from low to medium levels and a slight reduction in soil pH. After heavy rains during the last three crops, soil TSS was reduced considerably and pH showed a slight increase. Concentrations of Cl(-) and Mg(2+) increased and Ca(2+) decreased at the end of the experiment, all leading to changes in the ionic composition of soil salinity. Manure with higher ion concentrations appeared to play a more important role in affecting ionic composition of soil salinity. The results further suggest that even in a region with abundant rainfall like Guangzhou, there is still potential risk for secondary soil salinization when high rates of CM and PM are applied.