Purpose We describe the outcome of the Biomarkers Consortium CSF Proteomics Project, a public-private partnership of government, academia, non-profit, and industry. The goal of this study was to evaluate a multiplexed mass spectrometry-based approach for the qualification of candidate Alzheimer’s Disease (AD) biomarkers using CSF samples from the AD Neuroimaging Initiative (ADNI). Experimental Design Reproducibility of sample processing, analytic variability, and ability to detect a variety of analytes of interest were thoroughly investigated. Multiple approaches to statistical analyses assessed whether panel analytes were associated with baseline pathology (MCI, AD) vs. Healthy Controls (CN) or associated with progression for MCI patients, and included: (i) univariate association analyses, (ii) univariate prediction models, (iii) exploratory multivariate analyses, and (iv) supervised multivariate analysis. Results A robust targeted mass spectrometry-based approach for the qualification of candidate AD biomarkers was developed. The results identified several peptides with potential diagnostic or predictive utility, with the most significant differences observed for the following peptides for differentiating (including peptides from Hemoglobin A (HBA), Hemoglobin B (HBB), and Superoxide dismutase (SODE)) or predicting (including peptides from Neuronal pentraxin-2 (NPTX2), Neurosecretory protein VGF (VGF), and Secretogranin-2 (SCG2)) progression vs. non-progression from mild cognitive impairment to AD. Conclusions and Clinical Relevance These data provide potential insights into the biology of CSF in AD and MCI progression and provide a novel tool for AD researchers and clinicians working to improve diagnostic accuracy, evaluation of treatment efficacy, and early diagnosis.

BackgroundDespite a typically good response to first-line combination chemotherapy, the prognosis for patients with advanced ovarian cancer remains poor because of acquired chemoresistance. The use of targeted therapies such as trastuzumab may potentially improve outcomes for patients with ovarian cancer. HER2 overexpression/amplification has been reported in ovarian cancer, but the exact percentage of HER2-positive tumors varies widely in the literature. In this study, HER2 gene status was evaluated in a large, multicentric series of 320 patients with advanced ovarian cancer, including 243 patients enrolled in a multicenter prospective clinical trial of paclitaxel/carboplatin-based chemotherapy.Methodology/Principal FindingsThe HER2 status of primary tumors and metastases was evaluated by both immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) analysis of paraffin-embedded tissue on conventional slides. The prognostic impact of HER2 expression was analyzed. HER2 gene was overexpressed and amplified in 6.6% of analyzed tumors. Despite frequent intratumoral heterogeneity, no statistically significant difference was detected between primary tumors and corresponding metastases.Conclusions/SignificanceOur results show that the decision algorithm usually used in breast cancer (IHC as a screening test, with equivocal results confirmed by FISH) is appropriate in ovarian cancer. In contrast to previous series, HER2-positive status did not influence outcome in the present study, possibly due to the fact that patients in our study received paclitaxel/carboplatin-based chemotherapy. This raises the question of whether HER2 status and paclitaxel sensitively are linked.

Impaired neuronal network function is a hallmark of neurodevelopmental and neurodegenerative disorders such as autism, schizophrenia, and Alzheimer’s disease and is typically studied using genetically modified cellular and animal models. Weak predictive capacity and poor translational value of these models urge for better human derived in vitro models. The implementation of human induced pluripotent stem cells (hiPSCs) allows studying pathologies in differentiated disease-relevant and patient-derived neuronal cells. However, the differentiation process and growth conditions of hiPSC-derived neurons are non-trivial. In order to study neuronal network formation and (mal)function in a fully humanized system, we have established an in vitro co-culture model of hiPSC-derived cortical neurons and human primary astrocytes that recapitulates neuronal network synchronization and connectivity within three to four weeks after final plating. Live cell calcium imaging, electrophysiology and high content image analyses revealed an increased maturation of network functionality and synchronicity over time for co-cultures compared to neuronal monocultures. The cells express GABAergic and glutamatergic markers and respond to inhibitors of both neurotransmitter pathways in a functional assay. The combination of this co-culture model with quantitative imaging of network morphofunction is amenable to high throughput screening for lead discovery and drug optimization for neurological diseases.

The liver is the central metabolic organ in the human body, and also plays an essential role in innate and adaptive immunity. While mouse models offer significant insights into immune-inflammatory liver disease, human immunology differs in important respects. It is not easy to address those differences experimentally. Therefore, to improve the understanding of human liver immunobiology and pathology, we have established precision-cut human liver slices to study innate immunity in human tissue. Human liver slices collected from resected livers could be maintained in ex vivo culture over a two-week period. Although an acute inflammatory response accompanied by signs of tissue repair was observed in liver tissue following slicing, the expression of many immune genes stabilized after day 4 and remained stable until day 15. Remarkably, histological evidence of pre-existing liver diseases was preserved in the slices for up to 7 days. Following 7 days of culture, exposure of liver slices to the toll-like receptor (TLR) ligands, TLR3 ligand Poly-I:C and TLR4 ligand LPS, resulted in a robust activation of acute inflammation and cytokine genes. Moreover, Poly-I:C treatment induced a marked antiviral response including increases of interferons IFNB, IL-28B and a group of interferon-stimulated genes. Therefore, precision-cut liver slices emerge as a valuable tool to study human innate immunity.

SNP arrays offer the opportunity to get a genome-wide view on copy number alterations and are increasingly used in oncology. DNA from formalin-fixed paraffin-embedded material (FFPE) is partially degraded which limits the application of those technologies for retrospective studies. We present the use of Affymetrix GeneChip SNP6.0 for identification of copy number alterations in fresh frozen (FF) and matched FFPE samples. Fifteen pairs of adenocarcinomas with both frozen and FFPE embedded material were analyzed. We present an optimization of the sample preparation and show the importance of correcting the measured intensities for fragment length and GC-content when using FFPE samples. The absence of GC content correction results in a chromosome specific "wave pattern" which may lead to the misclassification of genomic regions as being altered. The highest concordance between FFPE and matched FF were found in samples with the highest call rates. Nineteen of the 23 high level amplifications (83%) seen using FF samples were also detected in the corresponding FFPE material. For limiting the rate of "false positive" alterations, we have chosen a conservative False Discovery Rate (FDR). We observed better results using SNP probes than CNV probes for copy number analysis of FFPE material. This is the first report on the detection of copy number alterations in FFPE samples using Affymetrix GeneChip SNP6.0.

Ultra-deep sequencing (UDS) of amplicons is a major application for next-generation sequencing technologies, even more so for the 454 Genome Sequencer FLX. Especially for this application, errors that might be introduced during any of the sample processing or data analysis steps should be avoided or at least recognized, as they might lead to aberrant sequence variant calling. Since 454 pyrosequencing relies on PCR-driven target amplification, it is key to differentiate errors introduced during the amplification step from genuine minority variants. Thereto, optimal primer design is imperative because primer selection, primer dimer formation, and nonspecific binding may all affect the quality and outcome of amplicon-based deep sequencing. Also, other intrinsic PCR characteristics including amplification drift and the formation of secondary structures may influence sequencing data quality. We illustrate these phenomena using real life case studies and propose experimental and analytical evidence-based solutions for effective practice. Furthermore, because accuracy of the DNA polymerase is vital for reliable UDS results, a comparative analysis of error profiles from seven different DNA polymerases was performed and experimentally assessed in parallel by 454 sequencing. Finally, intra and interrun variability evaluation of the 454 sequencing protocol revealed highly reproducible results in amplicon-based UDS.

During epithelial-mesenchymal transition (EMT), epithelial cells are converted into isolated motile and invasive mesenchymal cells. In model systems, EMT is induced most often by the activation of tyrosine kinase receptors through signaling pathways involving translational and post-translational regulation. In this study, we have used the NBT-II bladder carcinoma cell system to investigate in vitro Fibroblast Growth Factor-1 (FGF-1)-induced EMT. Transcriptome analyses were performed on NBT-II cells stimulated for 2, 6, 24, and 48 h with FGF-1. As some phenotypic changes occurred around 6 h post-stimulation, a supervised analysis was designed to identify transcript variations across defined time-periods. Our results clearly indicate that immediately after FGF-1 stimulation a set of genes assigned to transcriptional regulation (e.g., jun-B and v-ets) and to EMT induction (e.g., Notch 1) is transiently up-regulated. A set of genes involved in proteolytic systems (e.g., MMP-13 and uPAR) is immediately up-regulated but subsequently maintained throughout FGF-1 stimulation. Then follows a second wave of gene expression that includes a strong but transient up-regulation of ephrin B1 and arginase I. Finally, a third group of genes is stably modulated over 48 h which consists primarily of down-regulated genes specifically associated with the EMT-based loss of the epithelial phenotype and maintenance of the mesenchymal and invasive phenotype of carcinoma cells. Using genome-wide oligoarray technology, we have identified novel expressions of immediate, immediate-early and later EMT biomarkers that are specifically activated downstream of the FGF/FGFR pathway and which might be significant prognostic factors for tumor progression of carcinoma.

The role of adjuvant chemotherapy in patients with stage IB non-small-cell lung cancer (NSCLC) is controversial. Identifying patient subgroups with the greatest risk of relapse and, consequently, most likely to benefit from adjuvant treatment thus remains an important clinical challenge. Here, we hypothesized that recurrent patterns of genomic amplifications and deletions in lung tumors could be integrated with gene expression information to establish a robust predictor of clinical outcome in stage IB NSCLC. Using high-resolution microarrays, we generated tandem DNA copy number and gene expression profiles for 85 stage IB lung adenocarcinomas/large cell carcinomas. We identified specific copy number alterations linked to relapse-free survival and selected genes within these regions exhibiting copy number-driven expression to construct a novel integrated signature (IS) capable of predicting clinical outcome in this series (P = 0.02). Importantly, the IS also significantly predicted clinical outcome in two other independent stage I NSCLC cohorts (P = 0.003 and P = 0.025), showing its robustness. In contrast, a more conventional molecular predictor based solely on gene expression, while capable of predicting outcome in the initial series, failed to significantly predict outcome in the two independent data sets. Our results suggest that recurrent copy number alterations, when combined with gene expression information, can be successfully used to create robust predictors of clinical outcome in early-stage NSCLC. The utility of the IS in identifying early-stage NSCLC patients as candidates for adjuvant treatment should be further evaluated in a clinical trial. [Cancer Res 2009;69(3):1055-62]