Hybrid Metabolic Activity-Related Prognostic Model and Its Effect on Tumor in Renal Cell Carcinoma.

Background: Tumor cells with a hybrid metabolic state, in which glycolysis and oxidative phosphorylation (OXPHOS) can be used, usually have a strong ability to adapt to different stress environments due to their metabolic plasticity. However, few studies on tumor cells with this phenotype have been conducted in the field of renal cell carcinoma (RCC). Methods: The metabolic pathway (glycolysis, OXPHOS) related gene sets were obtained from the Molecular Signatures Database (V7.5.1). The gene expression matrix, clinical information, and mutation data were obtained by Perl programming language (5.32.0) mining, the Cancer Genome Atlas and International Cancer Genome Consortium database. Gene Set Enrichment Analysis (GSEA) software (4.0.3) was utilised to analyse glycolysis-related gene sets. Analysis of survival, immune infiltration, mutation, etc. was performed using the R programming language (4.1.0). Results: Eight genes that are highly associated with glycolysis and OXHPOS were used to construct the cox proportional hazards model, and risk scores were calculated based on this to predict the prognosis of clear cell RCC patients and to classify patients into risk groups. Gene Ontology, the Kyoto Encyclopaedia of Genes and Genomes, and GSEA were analysed according to the differential genes to investigate the signal pathways related to the hybrid metabolic state. Immunoinfiltration analysis revealed that CD8+T cells, M2 macrophages, etc., had significant differences in infiltration. In addition, the analysis of mutation data showed significant differences in the number of mutations of PBRM1, SETD2, and BAP1 between groups. Cell experiments demonstrated that the DLD gene expression was abnormally high in various tumor cells and is associated with the strong migration ability of RCC. Conclusions: We successfully constructed a risk score system based on glycolysis and OXPHOS-related genes to predict the prognosis of RCC patients. Bioinformatics analysis and cell experiments also revealed the effect of the hybrid metabolic activity on the migration ability and immune activity of RCC and the possible therapeutic targets for patients.

Metformin Inhibits Abdominal Aortic Aneurysm Formation through the Activation of the AMPK/mTOR Signaling Pathway.

BACKGROUND AND OBJECTIVE: Epidemiological evidence suggests that the antidiabetic drug metformin (MET) can also inhibit abdominal aortic aneurysm (AAA) formation. However, the underlying protective mechanism remains unknown. It has been reported that phosphorylated AMP-activated protein kinase (AMPK) levels are significantly lower in AAA tissues than control aortic tissues. AMPK activation can inhibit the downstream signaling molecule called mechanistic target of rapamycin (mTOR), which has also been reported be upregulated in thoracic aneurysms. Thus, blocking mTOR signaling could attenuate AAA progression. MET is a known agonist of AMPK. Therefore, in this study, we investigated if MET could inhibit formation of AAA by activating the AMPK/mTOR signaling pathway. MATERIALS AND METHODS: The AAA animal model was induced by intraluminal porcine pancreatic elastase (PPE) perfusion in male Sprague Dawley rats. The rats were treated with MET or compound C (C.C), which is an AMPK inhibitor. AAA formation was monitored by serial ultrasound. Aortas were collected 4 weeks after surgery and subjected to immunohistochemistry, Western blot, and transmission electron microscopy analyses. RESULTS: MET treatment dramatically inhibited the formation of AAA 4 weeks after PPE perfusion. MET reduced the aortic diameter, downregulated both macrophage infiltration and matrix metalloproteinase expression, decreased neovascularization, and preserved the contractile phenotype of the aortic vascular smooth muscle cells. Furthermore, we detected an increase in autophagy after MET treatment. All of these effects were reversed by the AMPK inhibitor C.C. CONCLUSION: This study demonstrated that MET activates AMPK and suppresses AAA formation. Our study provides a novel mechanism for MET and suggests that MET could be potentially used as a therapeutic candidate for preventing AAA.

Alpinumisoflavone Exhibits Anticancer Activities in Glioblastoma Multiforme by Suppressing Glycolysis.

Glioblastoma multiforme (GBM, WHO grade IV astrocytoma) has become a public health burden worldwide. Alpinumisoflavone (AIF) is a flavonoid compound isolated from Derris eriocarpa. This study aims to examine the role of AIF in GBM. Our results showed that AIF could decrease the cell viability of both T98G and U373 GBM cell lines. AIF treatment also caused cell cycle arrest at G1/G0 phase along with upregulation of p27 and downregulation of cyclin D1. AIF could significantly induce apoptosis in GBM cells. Activation of caspase-9, disruption of mitochondrial membrane potential and loss of mitochondrial cytochrome C were also observed following AIF treatment. Inhibition of glycolysis by AIF was demonstrated by reducing glucose consumption and lactate output in GBM cells. Moreover, HK2 was identified as the molecular target responsible for the anticancer activities of AIF against GBM cells. The results showed that HK2 knockdown enhanced the anticancer activities of AIF whereas ectopic HK2 expression compromised its effect. Furthermore, the antineoplastic activities of AIF in vivo were also validated in xenograft murine model. Our results showed that AIF can exhibit anticancer activities in GBM by promoting apoptosis and inhibiting glycolysis via targeting HK2.

Downregulated long noncoding RNA LINC00313 inhibits the epithelial-mesenchymal transition, invasion, and migration of thyroid cancer cells through inhibiting the methylation of ALX4.

Thyroid cancer represents one of the prevalent endocrine cancer with relatively high incidence rate around the world, accompanied by unchanged fatality rate. We probe into the specific role of LINC00313 in mediation of cellular processes of thyroid cancer including proliferation, migration, and invasion through the methylation of aristaless-like homeobox 4 (ALX4). Thyroid cancer-related long noncoding RNAs (lncRNAs) and genes were analyzed by microarray-based analysis. The antitumor effect of LINC00313 was examined with the gain- and loss-of-function experiments. In addition, the binding of LINC00313 and the promoter region of ALX4, and the interaction of LINC00313 with methylation-related proteins were detected. Later, xenograft tumors in nude mice were induced expecting to dig out the modulatory function of LINC00313 in tumor growth of thyroid carcinoma. The microarray-based analysis manifested that LINC00313 was overexpressed, whereas ALX4 was downregulated in thyroid cancer, the results of which were also verified in thyroid cancer tissues. Besides, our results demonstrated that LINC00313 bound to the ALX4 promoter region, and LINC00313 recruited DNMT1 and DNMT3B proteins to promote the methylation of ALX4 promoter region, thus suppressing the ALX4 expression. Finally, the downregulation of LINC00313 and upregulation of ALX4 repressed the AKT/mTOR signaling axis, thus inhibiting proliferative, migratory, invasive abilities as well as epithelial-to-mesenchymal transition (EMT) of thyroid cancer cells. Collectively, downregulated LINC00313 suppresses cell proliferation, migration, as well as invasion of thyroid cancer by inhibiting the methylation of ALX4 and increasing its expression by inactivation of the AKT/mTOR signaling pathway.

Uric acid in aortic dissection: A meta-analysis.

BACKGROUND: Studies on the serum uric acid levels in patients with aortic dissection have yielded conflicting results. OBJECTIVE: To compare the difference in serum uric acid (SUA) levels between aortic dissection patients and controls by meta-analysis. METHODS: Electronic literature search was conducted in PubMed, Embase, CKNI, CBM, Wanfang, and VIP databases until January 31, 2018. All observational studies that investigated SUA levels in aortic dissection patients and controls were included. Weighted mean difference (WMD) with 95% confidence intervals (CI) was used to summarize the difference in SUA levels between aortic dissection and control group. RESULTS: A total of seven case-control studies involving 1197 patients and 1193 controls were included. Pooled analysis showed that SUA levels were significantly higher in aortic dissection patients compared with those in the controls (WMD 58.22 µmol/L; 95% CI 26.71-89.73) in a random effect model. No significant difference (WMD 9.94 µmol/L; 95% CI -17.89-37.76) was observed in SUA levels between Stanford type A and Stanford type B aortic dissection. CONCLUSIONS: This meta-analysis provides evidence that SUA levels are significantly higher among patients with aortic dissection than those in controls. Elevated SUA levels may contribute to the pathogenesis of aortic dissection. Further large clinical studies to investigate whether SUA levels are an independently risk factor for aortic dissection are warranted.

Cardiac troponin and adverse outcomes in atrial fibrillation: A meta-analysis.

BACKGROUND: The prognostic value of cardiac troponin elevation in atrial fibrillation (AF) is unclear. OBJECTIVE: To investigate the association of cardiac troponin elevation with adverse outcomes in AF by conducting a meta-analysis. METHODS: We systematically searched the PubMed and Embase databases until April 2017 for studies assessing the association of cardiac troponin-T (cTnT) or troponin-I (cTnI) elevation with adverse outcomes in AF. The outcome measures were all-cause mortality and major adverse cardiac events (MACEs: death, stroke, myocardial infarction, pulmonary embolism, major bleeding, or revascularization). RESULTS: Six studies involving 22,697 AF patients were identified. Meta-analysis showed that AF with elevated cardiac troponin was independently associated with increased risk of all-cause mortality (HR 2.04; 95% CI 1.56-2.67) and MACEs (HR 1.93; 95% CI 1.61-2.30). Furthermore, the prognostic value of cardiac troponin elevation was consistently found irrespective of method determination, type of troponin measured, sample size, and study quality subgroup. CONCLUSIONS: AF with cardiac troponin elevation was independently associated with increased risk of all-cause mortality and MACEs. Therefore, determination of troponin should be considered for risk stratification in AF.