Our aim was to conduct a pilot case-control study of RNA expression profile using RNA sequencing of rectosigmoid mucosa of nine females with -diarrhea-predominant irritable bowel syndrome (IBS-D) with accelerated colonic transit and nine female healthy controls. Mucosal total RNA was isolated and purified, and next-generation pair-end sequencing was performed using Illumina TruSeq. Analysis was carried out using a targeted approach toward 12 genes previously associated with IBS and a hypothesis-generating approach. Of the 12 targeted genes tested, patients with IBS-D had decreased mRNA expression of TNFSF15 (fold change controls to IBS-D: 1.53, P = 0.01). Overall, up- and downregulated mRNA expressions of 21 genes ( P = 10−5 to 10−8; P values with false detection rates are shown) were potentially relevant to IBS-D including the following: neurotransmitters [ P2RY4 ( P = 0.001), vasoactive intestinal peptide ( VIP, P = 0.02)]; cytokines [ CCL20 ( P = 0.019)]; immune function [ C4BPA complement cascade ( P = 0.0187)]; interferon-related [ IFIT3 ( P = 0.016)]; mucosal repair and cell adhesion [trefoil protein ( TFF1, P = 0.012)], retinol binding protein [ RBP2 ( P = 0.017)]; fibronectin ( FN1, P = 0.009); and ion channel functions [guanylate cyclase ( GUCA2B, P = 0.017), PDZ domain-containing protein 3 ( PDZD3, P = 0.029)]. Ten genes associated with functions related to pathobiology of IBS-D were validated by RT-PCR. There was significant correlation in fold changes of the selected genes ( Rs = 0.73, P = 0.013). Up- or downregulation of P2RY4, GUC2AB, RBP2, FNI, and C4BPA genes were confirmed on RT-PCR, which also revealed upregulation of farnesoid X receptor ( FXR) and apical sodium-coupled bile acid transporter ( IBAT/ASBT). RNA-Seq and RT-PCR analysis of rectosigmoid mucosa in IBS-D show transcriptome changes that provide the rationale for validation studies to explore the role of mucosal factors in the pathobiology of IBS-D.
Mass Spectrometry Measurements of Prostate-Specific Antigen (PSA) Peptides Derived From Immune-Extracted PSA Provide a Potential Strategy for Harmonizing Immunoassay Differences
The study objectives were: to mine the complete exome to identify putative rare single nucleotide variants (SNVs) associated with irritable bowel syndrome (IBS)-diarrhea (IBS-D) phenotype, to assess genes that regulate bile acids in IBS-D, and to explore univariate associations of SNVs with symptom phenotype and quantitative traits in an independent IBS cohort. Using principal components analysis, we identified two groups of IBS-D ( n = 16) with increased fecal bile acids: rapid colonic transit or high bile acids synthesis. DNA was sequenced in depth, analyzing SNVs in bile acid genes ( ASBT, FXR, OSTα/β, FGF19, FGFR4, KLB, SHP, CYP7A1, LRH-1, and FABP6). Exome findings were compared with those of 50 similar ethnicity controls. We assessed univariate associations of each SNV with quantitative traits and a principal components analysis and associations between SNVs in KLB and FGFR4 and symptom phenotype in 405 IBS, 228 controls and colonic transit in 70 IBS-D, 71 IBS-constipation. Mining the complete exome did not reveal significant associations with IBS-D over controls. There were 54 SNVs in 10 of 11 bile acid-regulating genes, with no SNVs in FGF19; 15 nonsynonymous SNVs were identified in similar proportions of IBS-D and controls. Variations in KLB (rs1015450, downstream) and FGFR4 [rs434434 (intronic), rs1966265, and rs351855 (nonsynonymous)] were associated with colonic transit (rs1966265; P = 0.043), fecal bile acids (rs1015450; P = 0.064), and principal components analysis groups (all 3 FGFR4 SNVs; P < 0.05). In the 633-person cohort, FGFR4 rs434434 was associated with symptom phenotype ( P = 0.027) and rs1966265 with 24-h colonic transit ( P = 0.066). Thus exome sequencing identified additional variants in KLB and FGFR4 associated with bile acids or colonic transit in IBS-D.
Immunological and Mass Spectrometric Assays of SHBG: Consistent and Inconsistent Metabolic Associations in Healthy Men
Abstract Zebrafish ( Danio rerio ) is a popular vertebrate model organism largely deployed using outbred laboratory animals. The nonisogenic nature of the zebrafish as a model system offers the opportunity to understand natural variations and their effect in modulating phenotype. In an effort to better characterize the range of natural variation in this model system and to complement the zebrafish reference genome project, the whole genome sequence of a wild zebrafish at 39-fold genome coverage was determined. Comparative analysis with the zebrafish reference genome revealed approximately 5.2 million single nucleotide variations and over 1.6 million insertion–deletion variations. This dataset thus represents a new catalog of genetic variations in the zebrafish genome. Further analysis revealed selective enrichment for variations in genes involved in immune function and response to the environment, suggesting genome-level adaptations to environmental niches. We also show that human disease gene orthologs in the sequenced wild zebrafish genome show a lower ratio of nonsynonymous to synonymous single nucleotide variations.
Abstract 109: DNA methylation profiling associated with recurrence of prostate cancer
Abstract DNA methylation profiles could signify the risk of prostate cancer and predict the progression of cancer before the appearance of clinical symptoms. Specific CpG sites methylation of genes identified in our study could be used to improve the sensitivity and specificity for early diagnosis and to predict the risk of prostate cancer recurrence. To identify methylation changes associated with prostate cancer, we measured gene methylation using the Infinium Human Methylation27 bead chips. Tissue DNA isolation and bisulfite conversion was done using ZR Genomic DNA kit and EZ methylation kit. The methylation27 microarrays was used to analyze methylation of 27,578 CpG sites of 14,495 genes in 198 tumor tissues and 40 matched normal tissues. Methylation data was processed using the Genome Studio software, differentially methylated genes identified using one-way analysis of variance, and correction for multiple testing done using the false discovery rate q-value. To identify putative diagnostic and prognostic biomarkers we performed four subgroup comparisons: tumor vs. matched normal, recurrent tumors vs. non-recurrent tumors, clinical recurrence vs. biochemical recurrence, and systemic recurrence vs. local recurrence. Clinicopathological and molecular features including patient preoperative PSA levels, Gelason score, TNM stage, GPSM, recurrence type, were also evaluated for subgroup discrimination. Discriminative subgroup candidate methlyation markers were selected using a p value <0.05 and a mean difference between two contrast groups >0.05. Between the tumor and matched normal tissue samples, 164 CpG sites representing 147 genes were identified as significantly differentially methylated (p<9.99E-25, fold change>2.0). Between recurrent tumor and non-recurrent tumor tissues there were 78 CpG sites representing 75 genes that were significantly differentially methylated (p <0.002, fold change >1.5). Between clinically recurrent and biochemically recurrent tumors, 16 CpG sites representing 16 genes were significantly differentially methylated (p <0.05, fold change >1.5). Between systemic recurrent and local recurrent tumors there were 73 CpG sites representing 68 genes that were significantly differentially methylated (p <0.01, fold change >1.5) Our analysis revealed differential methylation of the genes, implicating their role in prostate cancer development and progression. We demonstrated that the hypermethylation of genes could be used as a sensitive molecular tool in detection of prostate tumorigenesis and prediction of tumor progression. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 109. doi:10.1158/1538-7445.AM2011-109
SAAP-RRBS: streamlined analysis and annotation pipeline for reduced representation bisulfite sequencing
Abstract Summary: Reduced representation bisulfite sequencing (RRBS) is a cost-effective approach for genome-wide methylation pattern profiling. Analyzing RRBS sequencing data is challenging and specialized alignment/mapping programs are needed. Although such programs have been developed, a comprehensive solution that provides researchers with good quality and analyzable data is still lacking. To address this need, we have developed a Streamlined Analysis and Annotation Pipeline for RRBS data (SAAP-RRBS) that integrates read quality assessment/clean-up, alignment, methylation data extraction, annotation, reporting and visualization. This package facilitates a rapid transition from sequencing reads to a fully annotated CpG methylation report to biological interpretation. Availability and implementation: SAAP-RRBS is freely available to non-commercial users at the web site http://ndc.mayo.edu/mayo/research/biostat/stand-alone-packages.cfm. Contact: baheti.saurabh@mayo.edu or sun.zhifu@mayo.edu Supplementary Information: Supplementary data are available at Bioinformatics online.
Global Methylation Profiling for Risk Prediction of Prostate Cancer
Azadirachta indica(common name: neem) leaves have been found to possess immunomodulatory, anti-inflammatory and anti-carcinogenic properties. The present study evaluates anti-angiogenic potential of ethanol extract of neem leaves (EENL) in human umbilical vein endothelial cells (HUVECs). Treatment of HUVECs with EENL inhibited VEGF induced angiogenic responsein vitroandin vivo. Thein vitroproliferation, invasion and migration of HUVECs were suppressed with EENL. Nuclear fragmentation and abnormally small mitochondria with dilated cristae were observed in EENL treated HUVECs by transmission electron microscopy. Genome-wide mRNA expression profiling after treatment with EENL revealed differentially regulated genes. Expression changes of the genes were validated by quantitative real-time polymerase chain reaction. Additionally, increase in the expression of HMOX1, ATF3 and EGR1 proteins were determined by immunoblotting. Analysis of the compounds in the EENL by mass spectrometry suggests the presence of nimbolide, 2′,3′-dehydrosalannol, 6-desacetyl nimbinene and nimolinone. We further confirmed antiproliferative activity of nimbolide and 2′,3′-dehydrosalannol in HUVECs. Our results suggest that EENL by regulating the genes involved in cellular development and cell death functions could control cell proliferation, attenuate the stimulatory effects of VEGF and exert antiangiogenic effects. EENL treatment could have a potential therapeutic role during cancer progression.
Candidate Serum Biomarkers for Prostate Adenocarcinoma Identified by mRNA Differences in Prostate Tissue and Verified with Protein Measurements in Tissue and Blood
Abstract BACKGROUND Improved tests are needed for detection and management of prostate cancer. We hypothesized that differential gene expression in prostate tissue could help identify candidate blood biomarkers for prostate cancer and that blood from men with advanced prostate disease could be used to verify the biomarkers presence in circulation. METHODS We identified candidate markers using mRNA expression patterns from laser-capture microdissected prostate tissue and confirmed tissue expression using immunohistochemistry (IHC) for the subset of candidates having commercial antisera. We analyzed tissue extracts with tandem mass spectrometry (MS/MS) and measured blood concentrations using immunoassays and MS/MS of trypsin-digested, immunoextracted peptides. RESULTS We selected 35 novel candidate prostate adenocarcinoma biomarkers. For all 13 markers having commercial antisera for IHC, tissue expression was confirmed; 6 showed statistical discrimination between nondiseased and malignant tissue, and only 5 were detected in tissue extracts by MS/MS. Sixteen of the 35 candidate markers were successfully assayed in blood. Four of 8 biomarkers measured by ELISA and 3 of 10 measured by targeted MS showed statistically significant increases in blood concentrations of advanced prostate cancer cases, compared with controls. CONCLUSIONS Seven novel biomarkers identified by gene expression profiles in prostate tissue were shown to have statistically significant increased concentrations in blood from men with advanced prostate adenocarcinoma compared with controls: apolipoprotein C1, asporin, cartilage oligomeric matrix protein, chemokine (C-X-C motif) ligand 11 (CXCL11), CXCL9, coagulation factor V, and proprotein convertase subtilisin/kexin 6.