Search

Purpose: The lack of biomarkers that can distinguish aggressive from indolent prostate cancer has caused substantial overtreatment of clinically insignificant disease. Here, by genome-wide DNA methylome profiling, we sought to identify new biomarkers to improve the accuracy of prostate cancer diagnosis and prognosis., Experimental Design: Eight novel candidate markers, COL4A6, CYBA, TCAF1 (FAM115A), HLF, LINC01341 (LOC149134), LRRC4, PROM1, and RHCG, were selected from Illumina Infinium HumanMethylation450 BeadChip analysis of 21 tumor (T) and 21 non-malignant (NM) prostate specimens. Diagnostic potential was further investigated by methylation-specific qPCR analysis of 80 NM vs. 228 T tissue samples. Prognostic potential was assessed by Kaplan-Meier, uni- and multivariate Cox regression analysis in 203 Danish radical prostatectomy (RP) patients (cohort 1), and validated in an independent cohort of 286 RP patients from Switzerland and the U.S. (cohort 2)., Results: Hypermethylation of the 8 candidates was highly cancer-specific (area under the curves: 0.79-1.00). Furthermore, high methylation of the 2-gene panel RHCG-TCAF1 was predictive of biochemical recurrence (BCR) in cohort 1, independent of the established clinicopathological parameters Gleason score, pathological tumor stage, and pre-operative PSA (HR (95% confidence interval (CI)): 2.09 (1.26 - 3.46); P = 0.004), and this was successfully validated in cohort 2 (HR (95% CI): 1.81 (1.05 - 3.12); P = 0.032)., Conclusion: Methylation of the RHCG-TCAF1 panel adds significant independent prognostic value to established prognostic parameters for prostate cancer and thus may help to guide treatment decisions in the future. Further investigation in large independent cohorts is necessary before translation into clinical utility.

The past decade has shown mammalian genomes to be pervasively transcribed and identified thousands of noncoding (nc) transcripts. It is currently unclear to what extent these transcripts are of functional importance, as experimental functional evidence exists for only a small fraction. Here, we characterize the expression and evolutionary conservation properties of 12,115 known and novel nc transcripts, including structural RNAs, long nc RNAs (lncRNAs), antisense RNAs, EvoFold predictions, ultraconserved elements, and expressed nc regions. Expression levels are evaluated across 12 human tissues using a custom-designed microarray, supplemented with RNAseq. Conservation levels are evaluated at both the base level and at the syntenic level. We combine these measures with epigenetic mark annotations to identify subsets of novel nc transcripts that show characteristics similar to known functional ncRNAs. Few novel nc transcripts show both high expression and conservation levels. However, overall, we observe a positive correlation between expression and both conservation and epigenetic annotations, suggesting that a subset of the expressed transcripts are under purifying selection and likely functional. The identified subsets of expressed and conserved novel nc transcripts may form the basis for further functional characterization.

The local transcriptional response was studied in different locations of lungs from pigs experimentally infected with the respiratory pathogen Actinobacillus pleuropneumoniae serotype 5B, using porcine cDNA microarrays. This infection gives rise to well-demarcated infection loci in the lung, characterized by necrotic and haemorrhagic lesions. Lung tissue was sampled from necrotic areas, from visually unaffected areas and from areas bordering on necrotic areas. Expression pattern of these areas from infected pigs was compared to healthy lung tissue from un-infected pigs. Transcription of selected genes important in the innate defence response were further analysed by quantitative real-time reverse-transcriptase PCR. A clear correlation was observed between the number of differentially expressed genes as well as the magnitude of their induction and the sampling location in the infected lung, with the highest number of differentially expressed genes, and the most highly induced genes found in necrotic areas. Interestingly, a group of differentially regulated genes was represented in all three areas, comprising genes encoding cytokines, acute phase proteins, and factors related to regulation of apoptosis and the complement system. Interferon-γ was downregulated in both necrotic and bordering areas. Evidence of neutrophil recruitment was seen by the up-regulation of chemotactic factors for neutrophils. In conclusion, we found subsets of genes expressed at different levels in the three selected areas of the infected lung as compared to the control group. Thus it is demonstrated that an infection with clearly defined infected loci leads to a rapid disseminated intra-organ response in neighbouring seemingly unaffected tissue areas of the infected organ. Within the lung, we found a clear division of induced genes as, in unaffected areas a large part of differently expressed genes were involved in systemic reactions to infections, while differently expressed genes in necrotic areas were mainly concerned with homeostasis regulation.

Motivation: Single nucleotide polymorphisms (SNPs) analysis is an important means to study genetic variation. A fast and cost-efficient approach to identify large numbers of novel candidates is the SNP mining of large scale sequencing projects. The increasing availability of sequence trace data in public repositories makes it feasible to evaluate SNP predictions on the DNA chromatogram level. MAVIANT, a platform-independent Multipurpose Alignment VIewing and Annotation Tool, provides DNA chromatogram and alignment views and facilitates evaluation of predictions. In addition, it supports direct manual annotation, which is immediately accessible and can be easily shared with external collaborators., Results: Large-scale SNP mining of polymorphisms bases on porcine EST sequences yielded more than 7900 candidate SNPs in coding regions (cSNPs), which were annotated relative to the human genome. Non-synonymous SNPs were analyzed for their potential effect on the protein structure/function using the PolyPhen and SIFT prediction programs. Predicted SNPs and annotations are stored in a web-based database. Using MAVIANT SNPs can visually be verified based on the DNA sequencing traces. A subset of candidate SNPs was selected for experimental validation by resequencing and genotyping. This study provides a web-based DNA chromatogram and contig browser that facilitates the evaluation and selection of candidate SNPs, which can be applied as genetic markers for genome wide genetic studies., Availability: The stand-alone version of MAVIANT program for local use is freely available under GPL license terms at http://snp.agrsci.dk/maviant., Supplementary Information: Supplementary data are available at Bioinformatics online.

Several methods have been developed for amplification of RNA, making it possible to use cDNA microarrays for analysis of samples limited in amount of total RNA. The most widely used amplification protocol, the Eberwine method, amplifies RNA in a linear manner through in vitro transcription (IVT). However, when starting material is limited to nanogram amounts of total RNA, several rounds of amplification are necessary, making this method both expensive and labor-intensive. Amplification by PCR is robust and is able to amplify extremely limiting material. However, it is possible that the nonlinear nature of PCR could result in reduced reproducibility of the amplification compared with IVT. We have evaluated two methods that use a combination of PCR and IVT for amplification of nanogram amounts of total RNA. We have compared microarray results obtained by these methods with results obtained by two established methods: indirect labeling of 20 microg total RNA and Eberwine amplification of 1 microg total RNA. Starting from as little as 5 ng of total RNA, both methods yielded results in concordance with the Eberwine method.

The AMP-activated protein kinase (AMPK) plays a key role in the regulation of energy metabolism in eukaryotic cells acting as a metabolic sensor. In its activated form AMPK inhibits ATP consuming pathways and stimulates ATP generating pathways. A dominant mutation, denoted RN(-), in the porcine PRKAG3 gene, encoding the regulatory gamma3 subunit of AMPK, results in hyperaccumulation of glycogen in glycolytic skeletal muscle cells. To study the effects of this mutation on protein expression patterns in skeletal muscle, comparative proteome analysis of muscle samples from 12 animals (6 rn (+)/rn (+) and 6 RN(-)/rn (+)) was performed. The major finding of the proteome analysis was that the key enzyme in the synthesis of glycogen, UDP-glucose pyrophosphorylase, was significantly up-regulated in RN(-) carriers. This observation was subsequently supported by studies of enzyme activity and Northern blot analysis. Furthermore, the expression patterns of enzymes related to glycolysis and the citric acid cycle were also affected. Our data suggests that hyperaccumulation of glycogen mediated by the RN(-) mutation is due to an increased synthesis of glycogen.

Background: The gene infB encodes the prokaryotic translation initiation factor IF2, a central macromolecular component in the formation of the ribosomal 70S initiation complex. In Escherichia coli, infB encodes three forms of IF2: IF2alpha, IF2beta and IF2gamma. The expression of IF2beta and IF2gamma is a tandem translation from intact infB mRNA and not merely a translation of post-transcriptionally truncated mRNA. The molecular mechanism responsible for the ribosomal recognition of the two intracistronic translation initiation sites in E. coli infB is not well characterized., Results: We found three different forms of IF2 in Enterobacter cloacae, Klebsiella oxytoca, Salmonella enterica, Salmonella typhimurium, and two different forms in Proteus vulgaris. We identified the intracistronic translation initiation sites of the mRNA by isolation and N-terminal sequencing of the shorter isoforms of IF2 in S. enterica and S. typhimurium. A further search in the readily available public sequence databases revealed that infB from Yersinia pestis also contains an intracistronic in-frame initiation site used for the translation of IF2beta. The base composition in a part of the 5' end of the DNA coding strand of the enterobacterial infB gene shows a strong preference for adenine (A) over thymine (T) with a maximum ratio of A-to-T around the intracistronic initiation sites. We demonstrate that the mRNA has an open structure around the ribosomal binding region., Conclusion: Efficient intracistronic translation initiation of the infB gene is suggested to require an mRNA with this special base composition that results in an open, single-stranded structure at the ribosomal binding region.

A 453 bp fragment of infB, the gene encoding translation initiation factor 2, was sequenced and compared from 66 clinical isolates and type strains of Haemophilus species and related bacteria. Analysis of the partial infB sequences obtained suggested that the human isolates dependent on X and V factor, H. influenzae, H. haemolyticus, H. aegyptius and some cryptic genospecies of H. influenzae, were closely related to each other. H. parainfluenzae constituted a heterogeneous group within the boundaries of the genus, whereas H. aphrophilus/paraphrophilus and Actinobacillus actinomycetemcomitans were only remotely related to the type species of the genus Haemophilus H. parahaemolyticus and H. paraphrohaemolyticus took up an intermediary position and may not belong in the genus Haemophilus sensu stricto. Ambiguous results were obtained with seven isolates tentatively identified as H. segnis, which fell into two discrete clusters. The delineation of 'Haemophilus sensu stricto' as suggested by infB analysis supports previous results obtained by DNA hybridization, in contrast to the delineation inferred from 16S rRNA sequence comparison.

The sequence of infB, encoding the prokaryotic translation-initiation factor 2 (IF2), was determined in eight strains of Streptococcus agalactiae (group B streptococcus) and an alignment revealed limited intraspecies diversity within S. agalactiae. The amino acid sequence of IF2 from S. agalactiae and from related species were aligned and revealed an interspecies conserved central and C-terminal part, and an N-terminal part that is highly variable in length and amino acid sequence. The diversity and relationships in a collection of 58 genetically distinct strains of S. agalactiae were evaluated by comparing a partial sequence of infB. A total of six alleles were detected for the region of infB analysed. The alleles correlated with the separation of the same strains of S. agalactiae into major evolutionary lineages, as shown in previous work. The partial sequences of infB were furthermore used in phylogenetic analyses of species closely related to S. agalactiae, yielding an evolutionary tree which had a topology similar to a tree constructed using 16S rRNA sequences from the same species.