Serum uric acid and risk of dementia in Parkinson's disease
PARKINSONISM & RELATED DISORDERS
Authors: Gonzalez-Aramburu, Isabel; Sanchez-Juan, Pascual; Sierra, Maria; Fernandez-Juan, Eduardo; Sanchez-Quintana, Coro; Berciano, Jose; Combarros, Onofre; Infante, Jon
Abstract
Objective: Low serum uric acid (UA) levels have been associated with a worse cognitive function later in life and also with a higher risk and faster progression of Parkinson's disease (PD). Here we studied whether serum UA levels and the genetic variants related to its variability are associated with the presence of dementia in a cohort of patients with PD. Methods: The study included 343 PD patients, which were examined for the presence of dementia according to the MDS Task Force criteria (level 1). The predominant PD phenotype and UPDRS-III and Hoehn-Yahr scales were recorded. Serum UA levels were determined in each participant. Genotyping of SLC2A9 rs734553, ABCG2 rs2231142, SLC17A1 rs1183201, SLC22A11 rs17300741, SLC22A12 rs505802, GCKR rs780094, PDZK1 rs12129861, LRRC16A + SCGN rs742132, and SLC16A9 rs12356193 was carried out by Taqman analysis. For each subject we calculated a cumulative genetic risk score (GRS), defined as the total number of risk alleles (range 2-15) associated to lower serum UA levels. Results: 72 out of 343 PD patients (21%) presented dementia. Serum UA levels were not different between PD patients with or without dementia. No significant association was detected between any single SNP and the risk of PD-dementia. When we analyzed the combined effect of the eight SNPs using the cumulative GRS no significant association between the number of risk alleles and the risk of PD was observed. Conclusions: Our data suggest that serum UA levels have not a significant impact on the risk of dementia in PD. (C) 2014 Elsevier Ltd. All rights reserved.
Proteogenomic Characterization of Patient-Derived Xenografts Highlights the Role of REST in Neuroendocrine Differentiation of Castration-Resistant Prostate Cancer
CLINICAL CANCER RESEARCH
Authors: Flores-Morales, Amilcar; Bergmann, Tobias B.; Lavallee, Charlotte; Batth, Tanveer S.; Lin, Dong; Lerdrup, Mads; Friis, Stine; Bartels, Anette; Kristensen, Gitte; Krzyzanowska, Agnieszka; Xue, Hui; Fazli, Ladan; Hansen, Klaus H.; Roder, Martin A.; Brasso, Klaus; Moreira, Jose M.; Bjartell, Anders; Wang, Yuzhuo; Olsen, Jesper, V; Collins, Colin C.; Iglesias-Gato, Diego
Abstract
Purpose: An increasing number of castration-resistant prostate cancer (CRPC) tumors exhibit neuroendocrine (NE) features. NE prostate cancer (NEPC) has poor prognosis, and its development is poorly understood. Experimental Design: We applied mass spectrometry-based proteomics to a unique set of 17 prostate cancer patient-derived xenografts (PDX) to characterize the effects of castration in vivo, and the proteome differences between NEPC and prostate adenocarcinomas. Genome-wide profiling of REST-occupied regions in prostate cancer cells was correlated to the expression changes in vivo to investigate the role of the transcriptional repressor REST in castration-induced NEPC differentiation. Results: An average of 4,881 proteins were identified and quantified from each PDX. Proteins related to neurogenesis, cell-cycle regulation, and DNA repair were found upregulated and elevated in NEPC, while the reduced levels of proteins involved in mitochondrial functions suggested a prevalent glycolytic metabolism of NEPC tumors. Integration of the REST chromatin bound regions with expression changes indicated a direct role of REST in regulating neuronal gene expression in prostate cancer cells. Mechanistically, depletion of REST led to cell-cycle arrest in G1, which could be rescued by p53 knockdown. Finally, the expression of the REST-regulated gene secretagogin (SCGN) correlated with an increased risk of suffering disease relapse after radical prostatectomy. Conclusions: This study presents the first deep characterization of the proteome of NEPC and suggests that concomitant inhibition of REST and the p53 pathway would promote NEPC. We also identify SCGN as a novel prognostic marker in prostate cancer.