Project description:The whole genome DASL HT assay was used in combination with the HumanHT-12 v4 BeadChip for screening normal and tumour tissue in a retrospective 28 sample cohort of small bowel adenocarcinoma patients. Non-normalized and average normalized (background subtracted) data Comparing differences in gene expression in a matched normal tumour cohort of 28 small bowel adenocarcinoma patients.
Project description:Elucidating the role of gut microbiota in physiological and pathological processes has recently emerged as a key research aim in life sciences. In this respect, metaproteomics (the study of the whole protein complement of a microbial community) can provide a unique contribution by revealing which functions are actually being expressed by specific microbial taxa. However, its wide application to gut microbiota research has been hindered by challenges in data analysis, especially related to the choice of the proper sequence databases for protein identification. Here we present a systematic investigation of variables concerning database construction and annotation, and evaluate their impact on human and mouse gut metaproteomic results. We found that both publicly available and experimental metagenomic databases lead to the identification of unique peptide assortments, suggesting parallel database searches as a mean to gain more complete information. Taxonomic and functional results were revealed to be strongly database-dependent, especially when dealing with mouse samples. As a striking example, in mouse the Firmicutes/Bacteroidetes ratio varied up to 10-fold depending on the database used. Finally, we provide recommendations regarding metagenomic sequence processing aimed at maximizing gut metaproteome characterization, and contribute to identify an optimized pipeline for metaproteomic data analysis.
Project description:The whole genome DASL HT assay was used in combination with the HumanHT-12 v4 BeadChip for screening normal and tumour tissue in a retrospective 28 sample cohort of small bowel adenocarcinoma patients. Non-normalized and average normalized (background subtracted) data
Project description:The Formalin-Fixed Paraffin-Embedded (FFPE) samples on selected breast cancer subtypes (ER+/Her2-, ER+/Her2+, ER-/Her2+, and ER-/Her2-) and their paired fresh fine needle aspirated biopsies (FNA) were investigated. The cases represented different subtypes of breast cancers based on their clinical receptors ER (E) and Her2 (H) status to demonstrate the ability of gene profiles to differentiate these tumors. Compared to FNA specimens, FFPE samples yielded relatively more degraded RNA, and 80% of the samples deemed suitable for cDNA-mediated annealing, selection, extension and ligation (DASL) assay. It is able to demonstrate that gene profiles from FFPE microarrays were reproducible and correlated well with the corresponding gene profiles from FNA microarrays. The gene profiles from both FNA and FFPE could differentiate the four breast cancer subtypes, and the expression levels of corresponding gene set were consistent with qRT-PCR and correlated to the clinical outcomes on published microarray data. It supports the use of FFPE specimens to develop a prognostic tool for breast cancers which can obviate the need for fresh specimens. 25 FFPE specimens were processed for whole genome DASL assays using Illumina Human-Ref8 version 3 BeadChips. Invasive ductal carcinoma (IDC)-type subtypes ER+/Her2-, ER+/Her2+, ER-/Her2+, and ER-/Her2- (ER: estrogen receptor, HER2: human epidermal growth factor receptor 2) were analyzed.
Project description:Genome-scale DNA methylation was analyzed in a cohort of paragangliomas to identify DNA methylation changes. Bisulfite converted DNA from 22 fresh frozen paragangliomas and 2 normal adrenal medulla samples were hybridized to Illumina HumanMethylation450 BeadChips.
Project description:Genome-scale DNA methylation was analyzed in a large cohort of pheochromocytomas and paragangliomas (PCC/PGL). Consensus clustering identified 3 stable clusters significantly associated with expression subgroups, gene mutations, and clinical parameters. Bisulfite-converted DNA from 145 fresh frozen PCC/PGL and 3 normal adrenal medulla samples were hybridized to Illumina Infinium 27k Human Methylation BeadChips.
Project description:Unluckily, FFPE archival methods lead to partial RNA degradation, limiting the amount of derivable information. This study aims to evaluate if the DASL gene expression assay, designed to generate reproducible data from degraded RNAs, is a reliable method to apply on RNA from FFPE tissues. In order to do that, we analyzed 20 FFPE breast cancer samples and 20 FF (Fresh Frozen) matched samples with the Illumina Whole Genome DASL platform for a genome-wide expression profiling.
Project description:Triple negative breast tumours from archived formalin fixed paraffin embeded samples of the National Cancer Institute of Mexico were analyzed for differential gene expressión. Transcriptomic analysis of the 12 tumor samples was done with the FFPE-designed WG-DASL HT assay (Illumina) according to manufacturer’s instructions. This assay measures 29,285 annotated transcripts derived from the RefSeq database corresponding to 20,727 unique genes. Briefly, 200ng of total RNA were reverse-transcribed into biotinylated cDNA, which was then primer-extended with the Assay Specific Oligos. The cDNA was then amplified with universal primers and hybridized to Illumina Human WG DASL HT Expression BeadChip arrays. The Illumina Genome Studio V2010.2 was used to obtain the signal values (AVG-Signal), with no normalization and no background subtraction.The performance of hybridizations was evaluated by assessing the presence of outliers and the noise-to-signal ratios by calculating the ratio of centiles P95/P05 prior to normalisation for each sample. We defined outliers as samples with P95/P05 ratio <9.5. All samples were found to show a correct noise-to-signal ratio (P95/P05>9.6). For differential gene expression analysis, the public dataset GSE32124, which includes 33 fresh frozen tissue samples, generated on the Illumina HumanHT-12 v4.0 beadChip, and which contains 99.98% of the 29,285 probes of the Human WG DASL HT BeadChip was used as normal breast tissue control.
Project description:Diffuse large B-cell lymphoma (DLBCL) exhibits heterogeneous clinical outcomes even in tumors of the same stage and with similar pathological characteristics. A substantial number of patients with DLBCL still fail to be cured despite recent improvements in therapy. In this study, we used formalin fixed paraffin embedded (FFPE) tumor samples for microarray gene expression profiling to develop robust prognostic profiles for DLBCL. We performed a retrospective microarray gene expression profiling study of FFPE from a cohort of DLBCL patients using the whole genome cDNA mediated Annealing, Selection and Ligation (WG-DASL) assay. After removing poor-quality samples, data from 164 patients were used for statistical analyses to develop and validate a prognostic gene expression signature using a gradient lasso and leave-one-out cross-validation process.