Project description:Transcriptional profiling of early-onset sporadic rectal adenocarcinoma, comparing Wnt- and Wnt+ rectal tumor. Goal was to determine differentially expressed genes between them based on global gene expression.
Project description:Copy number profiling of early-onset sporadic rectal adenocarcinoma, comparing Wnt- and Wnt+ rectal tumor. Goal was to determine differentially altered genes between them based on global copy no.
Project description:Gene fusions (GFs) represent a distinct class of structural variants identified consistently in cancer genomes across multiple cancer types. Several GFs exhibit gain of oncogenic function, and thus, have been the focus for development of efficient targeted therapies. Here, we present a comprehensive landscape of GFs in early-onset sporadic rectal cancer (EOSRC), a poorly studied colorectal cancer (CRC) subtype prevalent in developing countries from the transcriptome analysis of 37 EOSRC samples. Gene Ontology analysis revealed enrichment of unique biological process terms associated with 5’- and 3’- fusion partner genes. An extensive network analysis highlighted several promiscuous genes participating in GF formation. Further, an in-depth evaluation revealed significant association of these promiscuous genes with chromosome fragile sites.
Project description:Sporadic early onset colorectal carcinoma (EOCRC) is a growing problem that remains poorly understood. Clinical specificities and mechanisms of tumorigenesis might be relevant to both diagnosis and treatment. In this prospective study, clinicopathological features, genomic and gene expression profiles of sporadic EOCRC were compared to other well defined groups of CRC.
Project description:Sporadic early onset colorectal carcinoma (EOCRC) is a growing problem that remains poorly understood. Clinical specificities and mechanisms of tumorigenesis might be relevant to both diagnosis and treatment. In this prospective study, clinicopathological features, genomic and gene expression profiles of sporadic EOCRC were compared to other well defined groups of CRC. Seventy selected patients were divided into 4 groups according to age (< 45 or > 60 years) and mismatch repair status. Mutations of key genes involved in colorectal carcinogenesis (P53, KRAS, BRAF, PIK3CA) were detected and the methylator phenotype (CIMP) established. Gene expression profiles (GEP) were obtained using pangenomic Affymetrix GeneChip.
Project description:Non-familial Alzheimer’s disease (AD) occurring before 65 years of age is commonly referred to as early-onset Alzheimer’s disease (EOAD) and constitutes ~5-6% of all Alzheimer’s disease (AD) cases. While EOAD exhibits the same clinicopathological changes such as amyloid plaques, neurofibrillary tangles (NFTs), brain atrophy, and cognitive decline as observed in the more prevalent late-onset AD (LOAD), EOAD patients tend to have more severe cognitive deficits, including visuospatial, language, and motor dysfunction. Patient-derived induced pluripotent stem cells (iPSCs) have been used to model and study penetrative, familial AD (FAD) mutations in APP, PSEN1, and PSEN2, but have been seldom used for sporadic forms of AD that display more heterogeneous disease manifestation. In this study, we sought to characterize iPSC-derived neurons from EOAD patients via RNA-sequencing. A modest difference in expression profiles between EOAD patients and non-demented control subjects resulted in a limited number of differentially expressed genes (DEGs). Based on this analysis, we provide evidence that iPSC-derived neuron model systems, likely due to the loss of EOAD-associated epigenetic signatures during the iPSC reprogramming, are not an ideal model system to study sporadic AD.
Project description:Alzheimer’s disease (AD) is the most common neurodegenerative dementia. Around 10% of cases present an age of onset before 65 years-old, which in turn can be divided in monogenic or familial AD (FAD) and sporadic early-onset AD (EOAD). Mutations in PSEN1, PSEN2 and APP genes have been linked with FAD. The aim of our study was to describe the brain whole-genome RNA expression profile of the posterior cingulate area in EOAD and FAD caused by PSEN1 mutations (FAD-PSEN1). 14 patients (7 EOAD and 7 FAD-PSEN1) and 7 neurologically healthy controls were selected and samples were hybridized in a Human Gene 1.1 microarray from Affymetrix. When comparing controls with EOAD and controls with FAD-PSEN1, we found 3183 and 3351 differentially expressed genes (DEG) respectively (FDR corrected p<0.05). However, any DEG was found in the comparison of the two groups of patients. Microarrays were validated through quantitative-PCR of 17 DEG. In silico analysis of the DEG revealed an alteration in biological pathways related to calcium-signaling, axon guidance and long-term potentiation (LTP), among others, in both groups of patients. These pathways are mainly related with cell signalling cascades, synaptic plasticity and learning and memory processes. In conclusion, the altered biological final pathways in EOAD and FAD-PSEN1 are highly coincident. Also, the findings are in line with those previously reported for late-onset AD (LOAD, onset >65 years-old), which implies that the consequences of the disease at the molecular level are similar in the final stages of the disease. 21 Samples were analyzed: 7 controls, 7 Early-onset Alzheimer's disease (AD) patients and 7 early-onset AD genetically determined by a mutation in PSEN1 gene.