A Two-DNA Methylation Signature to Improve Prognosis Prediction of Clear Cell Renal Cell Carcinoma.

PURPOSE: Effective biomarkers and models are needed to improve the prognostic prospects of clear cell renal cell carcinoma (ccRCC). The purpose of this work was to identify DNA methylation biomarkers and to evaluate the utility of DNA methylation analysis for ccRCC prognosis. MATERIALS AND METHODS: An overview of genome-wide methylation of ccRCC tissues derived from The Cancer Genome Atlas (TCGA) database was download for analysis. DNA methylation signatures were identified using Cox regression methods. The potential clinical significance of methylation biomarkers acting as a novel prognostic markers was analyzed using the Kaplan-Meier method and receiver operating characteristic (ROC) curves. RESULTS: This study analyzed data for 215 patients with information on 23171 DNA methylation sites and identified a two-DNA methylation signature (cg18034859, cg24199834) with the help of a step-wise multivariable Cox regression model. The area under the curve of ROCs for the two-DNA methylation signature was 0.819. The study samples were stratified into low- and high-risk classifications based on an optimal threshold, and the two groups showed markedly different survival rates. Moreover, the two-DNA methylation marker was suitable for patients of varying ages, sex, stages (I and IV), and histologic grade (G2). CONCLUSION: The two-DNA methylation signature was deemed to be a potential novel prognostic biomarker of use in increasing the accuracy of predicting overall survival of ccRCC patients.

Associations of methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms with genetic susceptibility to rheumatoid arthritis: a meta-analysis.

The aim of our study was to conduct a meta-analysis to assess whether combined evidence shows associations between C677T and A1298C polymorphisms of methylenetetrahydrofolate reductase (MTHFR) and genetic susceptibility to rheumatoid arthritis (RA). A total of 11 articles involving 20 comparisons were included, containing 12 comparisons for the MTHFR C677T polymorphism and 8 comparisons for the MTHFR A1298C polymorphism. Significant evidence was detected for the association of RA susceptibility with the MTHFR C677T polymorphism T allele under allelic contrast and dominant model in Asians (T versus C, OR = 1.300, 95 % CI = 1.104-1.531, p = 0.002; TT + CT versus CC, OR = 1.495, 95 % CI = 1.187-1.882, p = 0.001). Significant association between RA susceptibility and the MTHFR A1298C polymorphism A allele under recessive model was found in the overall meta-analysis (AA versus AC + CC, OR = 1.281, 95 % CI = 1.048-1.565, p = 0.016). Our meta-analysis results demonstrate that the MTHFR C677T polymorphism is involved in the genetic susceptibility of RA in Asians, and the MTHFR A1298C polymorphism is associated with genetic susceptibility to RA in the overall population. Given the paucity of studies, especially in non-Asian populations, further studies with larger sample sizes are required to elucidate the role of MTHFR polymorphisms in the genetic basis of RA in different ethnic populations.

IGF2BP2 rs11705701 polymorphisms are associated with prediabetes in a Chinese population: A population-based case-control study.

Associations between insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) rs11705701, insulin receptor substrate 1 rs7578326, gastric inhibitory polypeptide receptor rs10423928 and transcription factor 7-like 2 rs12255372 gene polymorphisms with prediabetes and type 2 diabetes (T2D) have not been evaluated in the Han Chinese population. These four genetic variants were investigated for their associations with prediabetes and T2D among 490 unrelated patients with T2D, 471 patients with prediabetes and 575 healthy controls. Sequenom MassARRAY software was used to genotype the patients for these variants. The Generalized Multifactor Dimensionality Reduction method was used to analyze the gene-gene and gene-environment interactions. A breakdown analysis by gender revealed a significant association of IGF2BP2 rs11705701 with prediabetes under the dominant genetic model in females following application of the Bonferroni correction (odds ratio = 0.26; 95% confidence interval = 0.10-0.67; P=0.005). However, no significant associations were reported between any of the other three polymorphisms and T2D under any genetic models. Furthermore, there were no statistically significant gene-gene or gene-environment interactions when evaluated with the above association tests. The present case-control study reveals a significant association between IGF2BP2 rs11705701 and prediabetes in female patients.

Elevated DRD4 promoter methylation increases the risk of Alzheimer's disease in males.

Aberrant promoter methylation of multiple genes is associated with various diseases, including Alzheimer's disease (AD). The goal of the present study was to determine whether dopamine receptor D4 (DRD4) promoter methylation is associated with AD. In the current study, the methylation levels of the DRD4 promoter were measured in 46 AD patients and 61 controls using bisulfite pyrosequencing technology. The results of the present study demonstrated that DRD4 promoter methylation was significantly higher in AD patients than in controls. A further breakdown analysis by gender revealed that there was a significant association of DRD4 promoter methylation with AD in males (23 patients and 45 controls). In conclusion, the results of the present study demonstrated that elevated DRD4 promoter methylation was associated with AD risk in males.

OPRK1 promoter hypermethylation increases the risk of Alzheimer's disease.

As a member of the opioid family, κ-opioid receptors play important role in cognitive and learning functions. The purpose of this study was to evaluate the association of OPRK1 promoter methylation with Alzheimer's disease (AD). OPRK1 DNA methylation levels of 48 cases and 58 well matched controls were measured using the bisulphite pyrosequencing technology. Our results showed that there was a significant correlation between three CpG sites on the OPRK1 promoter region (r>=0.715, p<0.001). Thus, the mean methylation value of the three CpG sites was used for the case-control comparison. And our results showed there was a significantly higher OPRK1 promoter methylation in AD cases than in controls (p=0.006, adjusted p=0.012). Subsequent luciferase reporter assay showed the CpGs containing fragment of OPRK1 promoter significantly increased the expression of reporter gene (Fold=2.248, p=0.0235). In summary, our results suggested that OPRK1 promoter hypermethylation might increase the risk of AD through its regulation on the gene expression of OPRK1.

Association between homocysteine and incidence of ischemic stroke in subjects with essential hypertension: a matched case-control study.

BACKGROUND: To assess the association between total plasma homocysteine (tHcy) and ischemic stroke (IS) in hypertensive subjects in a matched case-control study. METHODS: This is a 1:2 matched and population-based case-control study, all of the participants were recruited from the 60 communities in Shenzhen, China. Demographic and socioeconomic characteristics, medical records, lifestyle risk factors and other clinical characteristics were obtained from all of the subjects. The association between tHcy and incidence of IS was analyzed by using conditional logistic regression models. RESULTS: The median values of plasma tHcy were significantly higher in IS subjects than in non-IS subjects, especially in women. After adjusted for the confounding factors in Model 2, compared with the lowest quartile of tHcy, the odds ratios (ORs) and 95% CIs of the highest quartile of tHcy for IS were 0.83 (0.36-1.90) in men, 4.51 (1.29-15.7) in women and 1.31 (0.70-2.47) in the total subjects; the ORs and 95% CIs for IS per 5 µmol/L increase in homocysteine were 1.11 (0.99-1.22), 1.25 (1.03-1.58) and 1.15 (1.01-1.28) in men, women and total subjects, respectively. We observed significant associations in crude model, Model 1 and Model 2 in women for the comparison of tHcy ≥ 15 µmol/L versus < 15 µmol/L. Interaction analysis showed that the association of tHcy with IS was significant in women (p-interaction = 0.04). CONCLUSION: This matched case-control study indicates that tHcy may increase the susceptibility to IS in essential hypertension subjects, especially in women. Further large prospective cohort studies are needed to confirm our findings.

Elevation of peripheral BDNF promoter methylation links to the risk of Alzheimer's disease.

Brain derived neurotrophic factor (BDNF) has been known to play an important role in various mental disorders or diseases such as Alzheimer's disease (AD). The aim of our study was to assess whether BDNF promoter methylation in peripheral blood was able to predict the risk of AD. A total of 44 AD patients and 62 age- and gender-matched controls were recruited in the current case-control study. Using the bisulphite pyrosequencing technology, we evaluated four CpG sites in the promoter of the BDNF. Our results showed that BDNF methylation was significantly higher in AD cases than in the controls (CpG1: p = 10.021; CpG2: p = 0.002; CpG3: p = 0.007; CpG4: p = 0.005; average methylation: p = 0.004). In addition, BDNF promoter methylation was shown to be significantly correlated with the levels of alkaline phosphatase (ALP), glucose, Lp(a), ApoE and ApoA in males (ALP: r = -0.308, p = 0.042; glucose: r = -0.383, p = 0.010; Lp(a): r = 0.333, p = 0.027; ApoE: r = -0.345, p = 0.032;), ApoA levels in females (r = 0.362, p = 0.033), and C Reactive Protein (CRP) levels in both genders (males: r = -0.373, p = 0.016; females: r = -0.399, p = 0.021). Our work suggested that peripheral BDNF promoter methylation might be a diagnostic marker of AD risk, although its underlying function remains to be elaborated in the future.

The associations between VEGF gene polymorphisms and diabetic retinopathy susceptibility: a meta-analysis of 11 case-control studies.

AIMS. Published data on the associations of VEGF polymorphisms with diabetic retinopathy (DR) susceptibility are inconclusive. A systematic meta-analysis was undertaken to clarify this topic. METHODS. Data were collected from the following electronic databases: PubMed, Embase, OVID, Web of Science, Elsevier Science Direct, Excerpta Medica Database (EMBASE), and Cochrane Library with the last report up to January 10, 2014. ORs and 95% CIs were calculated for VEGF-2578C/A (rs699947), -1154G/A (rs1570360), -460T/C (rs833061), -634G>C (rs2010963), and +936C/T (rs3025039) in at least two published studies. Meta-analysis was performed in a fixed/random effect model by using the software STATA 12.0. RESULTS. A total of 11 studies fulfilling the inclusion criteria were included in this meta-analysis. A significant relationship between VEGF+936C/T (rs3025039) polymorphism and DR was found in a recessive model (OR = 3.19, 95% CI = 1.20-8.41, and P(z) = 0.01) in Asian and overall populations, while a significant association was also found between -460T/C (rs833061) polymorphism and DR risk under a recessive model (OR = 2.12, 95% CI = 1.12-4.01, and P(z) = 0.02). CONCLUSIONS. Our meta-analysis demonstrates that +936C/T (rs3025039) is likely to be associated with susceptibility to DR in Asian populations, and the recessive model of -460T/C (rs833061) is associated with elevated DR susceptibility.

Α-eleostearic acid inhibits growth and induces apoptosis in breast cancer cells via HER2/HER3 signaling.

α-eleostearic acid (α-ESA) has been shown to possess antitumor activity in cancer cells. However, the underlying mechanism(s) remain largely unknown. The present study was designed to investigate the antitumor effect of α-ESA in breast cancer cells showing different expression levels of the human epidermal growth factor receptor 2 (HER2). α-ESA inhibited cell growth and induced apoptosis in the SKBR3 and T47D breast cancer cell lines. The mechanism by which cell growth was inhibited involved G0/G1 and G2/M cell cycle phase arrest. The MTT assay showed that SKBR3 cells are more sensitive to α-ESA compared to T47D cells. Western blot analysis revealed that α-ESA treatment not only reduced HER2/HER3 protein expression, but also increased the level of phosphorylated phosphatase and tensin homolog protein (PTEN), which led to decreased levels of phosphorylated Akt. Inactive Akt further reduced phosphorylation of glycogen synthase kinase-3ß (GSK-3ß) and B-cell lymphoma 2 (Bcl-2)­associated death promoter (BAD) proteins. Furthermore, the level of the anti-apoptotic protein Bcl-2 was found to be reduced following α-ESA treatment. Notably, nuclear factor κB (NF-κB) was activated by α-ESA treatment. Data of the present study showed that the antitumor activity of α-ESA is at least partly mediated by reduction of the HER2/HER3 heterodimer protein level, activation of the Akt/BAD/Bcl-2 apoptotic pathway and inhibition of the Akt/GSK-3ß survival pathway in the two breast cancer cell lines investigated in this study. Therefore, α-ESA may be considered a beneficial dietary factor for the prevention and treatment of invasive breast cancer in cells overexpressing HER2.

Glutamic acid decarboxylase epitope protects against autoimmune diabetes through activation of Th2 immune response and induction of possible regulatory mechanism.

Oral tolerance mediated by autoantigens has been applied successfully as a potential therapeutic strategy for preventing and treating autoimmune diseases. We previously showed cholera toxin B subunit (CTB) is an efficient mucosal carrier molecule for induction of systemic T cell tolerance to linked insulin antigens. In this study, we used an oral antigen consisting of a fusion protein composed of CTB and triple copies of glutamic acid decarboxylase 65 (GAD65) peptides 531-545 (3p531) to test its in vivo effect and investigate the mechanism of immune tolerance. Non-obese diabetic mice fed microgram quantities of the CTB-3p531 fusion protein showed a prominent reduction in pancreatic islet inflammation and a delay in the development of diabetes. Increased anti-GAD65 IgG1, serum IgA and unchanged IgG2a antibodies titers; together with an increase of IL-4, IL-10 production and a decrease of IFN-gamma production suggested possible activation of GAD65-specific Th2 immune responses. Adoptive transfer of splenocytes indicated oral administration of CTB-3p531 fusion protein generated potent regulatory cells that can suppress diabetogenic T cells. This study demonstrates the CTB-3p531 fusion protein protects against autoimmune diabetes by generation of regulatory T cells and induction of immunological tolerance.

A novel dual PI3Kalpha/mTOR inhibitor PI-103 with high antitumor activity in non-small cell lung cancer cells.

PI-103, the first synthetic multitargeted compound which simultaneously inhibits PI3Kalpha and mammalian target of rapamycin (mTOR) shows high antitumor activity in glioma xenografts. In the present study, clear antitumor activity was observed with PI-103 treatment in two gefitinib-resistant non-small cell lung cancer (NSCLC) cell lines, A549 and H460, by simultaneously inhibiting p70s6k phosporylation and Akt phosphorylation in response to mTOR inhibition. In addition, H460 cells with activating mutations of PIK3CA were more sensitive to PI-103 than A549 cells with wild-type PIK3CA. PI-103 was found to inhibit growth by causing G0-G1 arrest in A549 and H460 cells. Western blotting showed that PI-103 induced down-regulation of cyclin D1 and E1 and simultaneously up-regulated p21 and p27, associated with arrest in the G0-G1 phase of the cell cycle. Furthermore, p53, the tumor suppressor which transcriptionally regulates p21, was also upregulated with PI-103 treatment. Collectively, our results suggest that multitargeted intervention is the most effective tumor therapy, and the cooperative blockade of PI3Kalpha and mTOR with PI-103 shows promise for treating gefitinib-resistant NSCLC.