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Urtasun R.,Mount Sinai School of Medicine | Urtasun R.,Center for Translational Research | Cubero F.J.,Mount Sinai School of Medicine | Cubero F.J.,RWTH Aachen | Nieto N.,Mount Sinai School of Medicine
Alcoholism: Clinical and Experimental Research | Year: 2012

Background: Induction of reactive oxygen species (ROS) is a central mechanism in alcohol hepatotoxicity. Krüppel-like factor 6 (KLF6), a transcription factor and a tumor-suppressor gene, is an early-responsive gene to injury; however, the effect of ROS and alcohol on KLF6 induction is unknown. The aim of this study is to investigate the contribution of 2 sources of ROS, cytochrome P450 2E1 (CYP2E1), NAD(P)H quinone oxidoreductase (NQO1), and alcohol on the modulation of KLF6Full expression, splicing to KLF6_V1 and KLF6_V2, and the effect on TNFα, a downstream target. Methods and Results: Endogenous ROS production in CYP2E1-expressing HepG2 cells induced mRNA and protein expression of KLF6Full and its splice variants compared to control cells. Incubation with pro-oxidants such as arachidonic acid (AA), β-naphtoflavone, and H2O2 further enhanced KLF6Full and its splice variants. The AA effects on KLF6Full and its splice forms were blocked by vitamin E-which prevents lipid peroxidation-and by diallylsulfide-a CYP2E1 inhibitor. Menadione and paraquat, 2 pro-oxidants metabolized via NQO1, induced KLF6Full mRNA in a thiol-dependent manner. Antioxidants and an NQO1 inhibitor suppressed the menadione-dependent increase in KLF6Full and its splice variants mRNA. Furthermore, primary hepatocytes and livers from chronic alcohol-fed rats, with elevated lipid peroxidation, H2O2 and CYP2E1 but with low GSH, showed a ~2-fold increase in KLF6Full mRNA compared to controls. Inhibition of p38 phosphorylation further up-regulated the CYP2E1 and the AA effects on KLF6Full mRNA, whereas inhibition JNK and ERK1/2 phosphorylation decreased both. KLF6_V1 but not KLF6Full ablation markedly increased TNFα levels in macrophages; thus, TNFα emerges as a downstream target of KLF6_V1. Conclusions: The novel effect of ROS on modulating KLF6Full expression and its splice variants could play a relevant role in liver injury and in TNFα regulation. © 2012 by the Research Society on Alcoholism. Source

Sharma. A.,U.S. National Institute on Aging | Berga-Bolanos. R.,Center for Translational Research | Sen J.M.,U.S. National Institute on Aging | Alberola-Ila J.,Oklahoma Medical Research Foundation
PLoS ONE | Year: 2014

Natural killer T (NKT) cells are a component of innate and adaptive immune systems implicated in immune, autoimmune responses and in the control of obesity and cancer. NKT cells develop from common CD4+ CD8+ double positive (DP) thymocyte precursors after the rearrangement and expression of T cell receptor (TCR) Vα14-Jα18 gene. Temporal regulation and late appearance of Vα14-Jα18 rearrangement in immature DP thymocytes has been demonstrated. However, the precise control of lifetime of DP thymocytes in vivo that enables distal rearrangements remains incompletely defined. Here we demonstrate that T cell factor (TCF)-1, encoded by the Tcf7 gene, is critical for the extended lifetime of DP thymocytes. TCF-1-deficient DP thymocytes fail to undergo TCR Vα14-Jα18 rearrangement and produce significantly fewer NKT cells. Ectopic expression of Bcl-xL permits Va14-Ja18 rearrangement and rescues NKT cell development. We report that TCF-1 regulates expression of RORγt, which regulates DP thymocyte survival by controlling expression of Bcl-xL. We posit that TCF-1 along with its cofactors controls the lifetime of DP thymocytes in vivo. Source

Baker J.N.,St Jude Childrens Research Hospital | Levine D.R.,St Jude Childrens Research Hospital | Hinds P.S.,Center for Translational Research | Weaver M.S.,St Jude Childrens Research Hospital | And 10 more authors.
Journal of Pediatrics | Year: 2015

Objective To synthesize the perspectives of a broad range of pediatric palliative care (PPC) clinicians and parents, to formulate a consensus on prioritization of the PPC research agenda. Study design A 4-round modified Delphi online survey was administered to PPC experts and to parents of children who had received PPC. In round 1, research priorities were generated spontaneously. Rounds 2 and 3 then served as convergence rounds to synthesize priorities. In round 4, participants were asked to rank the research priorities that had reached at least 80% consensus. Results A total of 3093 concepts were spontaneously generated by 170 experts and 72 parents in round 1 (65.8% response rate [RR]). These concepts were thematically organized into 78 priorities and recirculated for round 2 ratings (n = 130; 53.7% RR). Round 3 achieved response stability, with 31 consensus priorities oscillating within 10% of the mode (n = 98; 75.4% RR). Round 4 resulted in consensus recognition of 20 research priorities, which were thematically grouped as decision making, care coordination, symptom management, quality improvement, and education. Conclusions This modified Delphi survey used professional and parental consensus to identify preeminent PPC research priorities. Attentiveness to these priorities may help direct resources and efforts toward building a formative evidence base. Investigating PPC implementation approaches and outcomes can help improve the quality of care services for children and families. © 2015 Elsevier Inc. Source

Li Y.,Rush University Medical Center | Melnikov A.A.,U.S. Biomarkers Inc | Levenson V.,U.S. Biomarkers Inc | Levenson V.,Center for Translational Research | And 4 more authors.
BMC Cancer | Year: 2015

Background: DNA methylation regulates gene expression, through the inhibition/activation of gene transcription of methylated/unmethylated genes. Hence, DNA methylation profiling can capture pivotal features of gene expression in cancer tissues from patients at the time of diagnosis. In this work, we analyzed a breast cancer case series, to identify DNA methylation determinants of metastatic versus non-metastatic tumors. Methods: CpG-island methylation was evaluated on a 56-gene cancer-specific biomarker microarray in metastatic versus non-metastatic breast cancers in a multi-institutional case series of 123 breast cancer patients. Global statistical modeling and unsupervised hierarchical clustering were applied to identify a multi-gene binary classifier with high sensitivity and specificity. Network analysis was utilized to quantify the connectivity of the identified genes. Results: Seven genes (BRCA1, DAPK1, MSH2, CDKN2A, PGR, PRKCDBP, RANKL) were found informative for prognosis of metastatic diffusion and were used to calculate classifier accuracy versus the entire data-set. Individual-gene performances showed sensitivities of 63-79 %, 53-84 % specificities, positive predictive values of 59-83 % and negative predictive values of 63-80 %. When modelled together, these seven genes reached a sensitivity of 93 %, 100 % specificity, a positive predictive value of 100 % and a negative predictive value of 93 %, with high statistical power. Unsupervised hierarchical clustering independently confirmed these findings, in close agreement with the accuracy measurements. Network analyses indicated tight interrelationship between the identified genes, suggesting this to be a functionally-coordinated module, linked to breast cancer progression. Conclusions: Our findings identify CpG-island methylation profiles with deep impact on clinical outcome, paving the way for use as novel prognostic assays in clinical settings. © 2015 Li et al.; licensee BioMed Central. Source

Marino N.,U.S. National Cancer Institute | Marshall J.-C.,U.S. National Cancer Institute | Marshall J.-C.,Center for Translational Research | Collins J.W.,U.S. National Cancer Institute | And 4 more authors.
Cancer Research | Year: 2013

Nm23-H1 has been identified as a metastasis suppressor gene, but its protein interactions have yet to be understood with any mechanistic clarity. In this study, we evaluated the proteomic spectrum of interactions made by Nm23-H1 in 4T1 murine breast cancer cells derived from tissue culture, primary mammary tumors, and pulmonary metastases. By this approach, we identified the actin-severing protein Gelsolin as binding partner for Nm23-H1, verifying their interaction by coimmunoprecipitation in 4T1 cells as well as in human MCF7, MDA-MB-231T, and MDA-MB-435 breast cancer cells. In Gelsolin-transfected cells, coexpression of Nm23-H1 abrogated the actin-severing activity of Gelsolin. Conversely, actin severing by Gelsolin was abrogated by RNA interference- mediated silencing of endogenous Nm23-H1. Tumor cell motility was negatively affected in parallel with Gelsolin activity, suggesting that Nm23-H1 binding inactivated the actin-depolymerizing function of Gelsolin to inhibit cell motility. Using indirect immunoflourescence to monitor complexes formed by Gelsolin and Nm23-H1 in living cells, we observed their colocalization in a perinuclear cytoplasmic compartment that was associated with the presence of disrupted actin stress fibers. In vivo analyses revealed that Gelsolin overexpression increased the metastasis of orthotopically implanted 4T1 or tail vein-injected MDA-MB-231T cells (P = 0.001 and 0.04, respectively), along with the proportion of mice with diffuse liver metastases, an effect ablated by coexpression of Nm23-H1. We observed no variation in proliferation among lung metastases. Our findings suggest a new actin-based mechanism that can suppress tumor metastasis. © 2013 American Association for Cancer Research. Source

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