A Novel Ferroptosis-Related Gene Risk Signature for Predicting Prognosis and Immunotherapy Response in Gastric Cancer.

BACKGROUND: Gastric cancer (GC) is the third leading cause of cancer death worldwide with complicated molecular and cellular heterogeneity. Iron metabolism and ferroptosis play crucial roles in the pathogenesis of GC. However, the prognostic role and immunotherapy biomarker potential of ferroptosis-related genes (FRGs) in GC still remains to be clarified. METHODS: We comprehensively analyzed the prognosis of different expression FRGs, based on gastric carcinoma patients in the TCGA cohort. The functional enrichment and immune microenvironment associated with these genes in gastric cancer were investigated. The prognostic model was constructed to clarify the relation between FRGs and the prognosis of GC. Meanwhile, the ceRNA network of FRGs in the prognostic model was performed to explore the regulatory mechanisms. RESULTS: Gastric carcinoma patients were classified into the A, B, and C FRGClusters with different features based on 19 prognostic ferroptosis-related differentially expressed genes in the TCGA database. To quantify the FRG characteristics of individual patients, FRGScore was constructed. And the research shows the GC patients with higher FRGScore had worse survival outcome. Moreover, thirteen prognostic ferroptosis-related differentially expressed genes (DEGs) were selected to construct a prognostic model for GC survival outcome with a superior accuracy in this research. And we also found that FRG RiskScore can be an independent biomarker for the prognosis of GC patients. Interestingly, GC patients with lower RiskScore had less immune dysfunction and were more likely to respond to immunotherapy according to TIDE value analysis. Finally, a ceRNA network based on FRGs in the prognostic model was analyzed to show the concrete regulation mechanisms. CONCLUSIONS: The ferroptosis-related gene risk signature has a superior potent in predicting GC prognosis and acts as the biomarkers for immunotherapy, which may provide a reference in clinic.

Identification of a Novel Ferroptosis-Related Gene Prediction Model for Clinical Prognosis and Immunotherapy of Colorectal Cancer.

BACKGROUND: Colorectal cancer (CRC) is the third most common malignancies worldwide. Ferroptosis is a programmed, iron-dependent cell death observed in cancer cells. However, the prognostic potential and immunotherapy biomarker potential of ferroptosis-related genes (FRGs) in CRC patients remains to be clarified. METHODS: At first, we comprehensively analysed the different expression and prognosis of related FRGs in CRC patients based on TCGA cohort. The relationship between functional enrichment of these genes and immune microenvironment in CRC was investigated using the TCGA database. Prognostic model was constructed to determine the association between FRGs and the prognosis of CRC. Relative verification was done based on the GEO database. Meanwhile, the ceRNA network of FRGs in the model was also performed to explore the regulatory mechanisms. RESULTS: Eight differentially expressed FRGs were associated with the prognosis of CRC patients. Patients from the TCGA database were classified into the A, B, and C FRG clusters with different features. And FRG scores were constructed to quantify the FRG pattern of individual patients with colorectal cancer. The CRC patients with higher FRG score showed worse survival outcomes, higher immune dysfunction, and lower response to immunotherapy. The prognostic model showed a high accuracy for predicting the OS of CRC. Finally, a ceRNA network was analysed to show the concrete regulation mechanisms of critical FRGs in CRC. CONCLUSIONS: The FRG risk score prognostic model based on 8 FRGs exhibit superior predictive performance, providing a novel prognostic model with a high accuracy for CRC patients. Moreover, FRG score can be the potential biomarker of the response of immunotherapy for CRC.

Comprehensive Analysis of N6-Methyladenosine-Related lncRNA Signature for Predicting Prognosis and Immune Cell Infiltration in Patients with Colorectal Cancer.

BACKGROUND: Colorectal cancer (CRC) is the third most common tumor worldwide. Aberrant N6-methyladenosine (m6A) modification can influence the progress of the CRC. Additionally, long noncoding RNA (lncRNA) plays a critical role in CRC and has a close relationship with m6A modification. However, the prognostic potential of m6A-related lncRNAs in CRC patients still remains to be clarified. METHODS: We use "limma" R package, "glmnet" R package, and "survival" R package to screen m6A-related-lncRNAs with prognostic potential. Then, we comprehensively analysed and integrated the related lncRNAs in different TNM stages from TCGA database using the LASSO Cox regression. Meanwhile, the relationship between functional enrichment of m6A-related lncRNAs and immune microenvironment in CRC was also investigated using the TCGA database. A prognostic model was constructed and validated to determine the association between m6A-related lncRNAs in different TNM stages and the prognosis of CRC. RESULT: We demonstrated that three related m6A lncRNAs in different TNM stages were associated with the prognosis of CRC patients. Patients from the TCGA database were classified into the low-risk and the high-risk groups based on the expression of these lncRNAs. The patients in the low-risk group had longer overall survival than the patients in the high-risk group (P < 0.001). We further constructed and validated a prognostic nomogram based on these genes with a C-index of 0.80. The receiver operating characteristic curves confirmed the predictive capacity of the model. Meanwhile, we also found that the low-risk group has the correlation with the dendritic cell (DC). Finally, we discovered the relationship between the m6A regulators and the three lncRNAs. CONCLUSION: The prognostic model based on three m6A-related lncRNAs exhibits superior predictive performance, providing a novel prognostic model for the clinical evaluation of CRC patients.

Catheter ablation of premature ventricular complexes associated with false tendons: A case report.

BACKGROUND: False tendon is a common intraventricular anatomical variation. It refers to a fibroid or fibromuscular structure that exists in the ventricle besides the normal connection of papillary muscle and mitral or tricuspid valve. A large number of clinical studies have suggested that there is a significant correlation between false tendons and premature ventricular complexes. However, few studies have verified this correlation during radiofrequency catheter ablation of premature ventricular complexes. CASE SUMMARY: A 45-year-old male was admitted to receive radiofrequency ablation for symptomatic premature ventricular complexes. A three-dimensional model of the left ventricle was established by intracardiac echocardiography using the CartoSoundTM mapping system. In addition to the left anterior papillary muscle, the posterior papillary muscle was mapped. False tendons were found at the base of the interventricular septum, and the other end was connected to the left ventricular free wall near the apex. An irrigated touch force catheter was advanced into the left ventricle via the retrograde approach. The earliest activation site was marked at the interventricular septum attachment of the false tendons and was successfully ablated. CONCLUSION: This case verified that false tendons can cause premature ventricular complexes and may be cured by radiofrequency ablation guided by intracardiac echocardiography with the CartoSoundTM system.

Xuezhikang, extract of red yeast rice, improved abnormal hemorheology, suppressed caveolin-1 and increased eNOS expression in atherosclerotic rats.

BACKGROUND: Xuezhikang is the extract of red yeast rice, which has been widely used for the management of atherosclerotic disease, but the molecular basis of its antiatherosclerotic effects has not yet been fully identified. Here we investigated the changes of eNOS in vascular endothelia and RBCs, eNOS regulatory factor Caveolin-1 in endothelia, and hemorheological parameters in atherosclerotic rats to explore the protective effects of Xuezhikang. METHODOLOGY/PRINCIPAL FINDINGS: Wistar rats were divided into 4 groups (n = 12/group) group C, controls; group M, high-cholesterol diet (HCD) induced atherosclerotic models; group X, HCD+Xuezhikang; and group L, HCD +Lovastatin. In group X, Xuezhikang inhibited oxidative stress, down-regulated caveolin-1 in aorta wall (P<0.05), up-regulated eNOS expression in vascular endothelia and erythrocytes (P<0.05), increased NOx (nitrite and nitrate) in plasma and cGMP in erythrocyte plasma and aorta wall (P<0.05), increased erythrocyte deformation index (EDI), and decreased whole blood viscosity and plasma viscosity (P<0.05), with the improvement of arterial pathology. CONCLUSIONS/SIGNIFICANCE: Xuezhikang up-regulated eNOS expression in vascular endothelia and RBCs, increased plasma NOx and improved abnormal hemorheology in high cholesterol diet induced atherosclerotic rats. The elevated eNOS/NO and improved hemorheology may be beneficial to atherosclerotic disease.

[Effects of mixed-tocopherols and eicosapentaenoic acid on oxidized LDL-induced oxidative damage and inflammatory cytokine secretion in human umbilical vein endothelial cells].

OBJECTIVE: To observe the influence of either alone or combined mixed-tocopherols combined with eicosapentaenoic acid (EPA) and α-Tocopherol use on oxidized LDL (oxLDL) induced 8-hydroxy-2'-deoxyguanosine (8-OHDG) and interleukin-6 (IL-6) secretion by human umbilical vein endothelial cells (HUVECs) and to explore the potential mechanism. METHOD: Cultured HUVECs in vitro were incubated with oxLDL, oxLDL + α-tocopherol, oxLDL + mixed-tocopherols, oxLDL + EPA, oxLDL + α-tocopherol + EPA, oxLDL + mixed-tocopherols + EPA for 24 hours, respectively. Secretion of 8-OHDG and IL-6 were detected by cell enzyme linked immunosorbent assay (ELISA). The expressions of superoxide dismutase (SOD), protein kinase C-δ (PKC-δ), phosphorylated PKC-δ (p-PKC-δ) were analyzed by Western blot. RESULTS: 8-OHDG and IL-6 secretion of HUVECs was significantly increased significantly after incubated with oxLDL for 24 hours which could be significantly attenuated in the presence of tocopherols and EPA (alone or in combination, all P < 0.05) while the strongest inhibition effects were seen with combined use of mixed-tocopherols and EPA. Moreover, combination of mixed-tocopherols and EPA could also significantly increase SOD activity and decrease PKC activity (all P < 0.05). However, the protein expression of SOD and PKC-was similar among groups. CONCLUSION: Combined mixed-tocopherols + EPA use enhanced the inhibiting effects on the secretion of 8-OHDG and IL-6 in oxLDL stimulated HUVECs which might be linked with increased SOD activity and reduced p-PKC activity.

[Effects of n-3 polyunsaturated fatty acids on hemorheology and coagulation in atherosclerotic rats].

OBJECTIVE: To investigate the effect of n-3 polyunsaturated fatty acids (n-3PUFAs) on the hemorheology and coagulation function of high-fat induced atherosclerotic rats and understand the underlying mechanism. METHODS: Twenty-four Wistar rats were assigned randomly into 3 groups: normal control, model and n-3PUFAs treatment (n = 8 in each). The rats in model and treatment groups were injected with a single dose of vitamin D(3) (600,000 U/kg) and fed with a high-fat diet. Basic chow was provided for normal control group. After a 6-week high-fat diet, the rats in treatment group were treated with n-3PUFAs at 250 mg×kg(-1)×d(-1) by gastric tube. The serum lipid, aortal morphological changes, hemorheology, coagulation, nitric oxide (NO), total antioxidant capacity (T-AOC) and malonaldehyde (MDA) were detected after a 6-week n-3PUFAs diet. RESULTS: Compared with control group, model group rat total cholesterol (TC), low density cholesterol (LDL-C), plasma viscosity, whole blood viscosity, fibrinogen (FIB) and MDA concentrations were higher (all P < 0.05), but activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), erythrocyte deformation index(DI), plasma NO and T-AOC were lower (all P < 0.05). Compared with model group, n-3PUFAs could reduce blood lipid levels, inhibit atherosclerotic plaque formation, decrease plasma viscosity [(1.58 ± 0.23) mPa·s vs (1.81 ± 0.16) mPa·s], whole blood viscosity [(4.76 ± 0.42) mPa·s vs (5.47 ± 0.41) mPa·s, (4.24 ± 0.32) mPa·s vs (4.91 ± 0.39) mPa·s, (4.04 ± 0.29) mPa·s vs (4.58 ± 0.33) mPa·s] and FIB [(2.45 ± 0.12)g/L vs (2.65 ± 0.13) g/L], lower MDA content [(10.1 ± 0.7) µmol/ml vs (11.2 ± 0.6) µmol/ml], prolong APTT, PT and TT [(29.04 ± 0.49)s vs (26.46 ± 0.25) s, (13.86 ± 0.55) s vs (10.71 ± 0.34) s, (23.05 ± 0.24) s vs (20.90 ± 0.68) s], increase erythrocyte DI (0.35 ± 0.01 vs 0.31 ± 0.02), plasma NO [(3.9 ± 0.7) nmol/ml vs (2.8 ± 0.7) nmol/ml] and T-AOC levels [(8.0 ± 0.6) U/ml vs (6.7 ± 0.6) U/ml]of atherosclerotic rats (all P < 0.05). CONCLUSION: n-3PUFAs may improve hemorheology and coagulation of atherosclerotic rats, reduce oxidative stress, improve endothelial function and inhibit atherosclerotic plaque formation.