Project description:We sought to illustrate molecular subtypes associated with clinical prognosis and to identify genetic aberrations for potential targeted therapeutics through comprehensive whole-genome analysis of 131 Chinese gastric cancer tissue specimens using whole-genome array CGH. We profiled 131 Chinese gastric cancer genomes using Agilent 244K array CGH technology. 70 samples Among them were further profiled by Affymetrix Hu133Plus2 arrays for mRNA expression.
Project description:To explore the spectrum of genetic aberrations of Chinese gastric cancer, 70 samples were further profiled by Affymetrix Hu133Plus2 arrays for mRNA expression 70 gastric cancer frozen tumor tissues were selected for RNA extraction and hybridization on Affymetrix microarrays. All these samples have been also profiled using Agilent 244K array CGH technology.
Project description:Purpose: To gain molecular insights of HBV integration that may contribute to HCC tumorigenesis, we performed whole transcriptome sequencing and whole genome copy number profiling of hepatocellular carcinoma (HCC) samples from 50 Chinese patients. Conclusions: This is the first report on the molecular basis of the MLL4 integration driving MLL4 over-expression. HBV-MLL4 integration occurred frequently in Chinese HCC patients, representing a unique molecular segment for HCC with HBV infection. We profiled 50 Chinese Hepatocellular Carcinoma patients and 14 adjacent tissues using Agilent 244K array CGH technology. 50 Tumor samples also did RNASeq profiling.
Project description:The mutation status of TP53 was analyzed by next generation sequencing using the Illumina TruSight Tumor (TST) 15 assay (Illumina) at the Molecular Pathology Center of the Jewish General Hospital (Montreal, QC, Canada). The CAP-compliant clinically validated TST15 assay was performed as per supplier's instruction with 10 ng DNA input. Libraries were sequenced on a MiSeq with a v3 flow cell (Illumina). Data was analyzed with a clinically validated pipeline (NextGene, SoftGenetics) and variants were annotated in Geneticist Assistant (SoftGenetics). The IARC TP53 database version R18 was consulted for the molecular interpretation of TP53 variants (www.p53.iarc.fr).
Project description:The tumorigenesis of small intestinal neuroendocrine tumors (NETs) is poorly understood. Recent studies have associated alternative polyadenylation with proliferation, cell transformation and cancer. Polyadenylation is the process in which the pre-mRNA is cleaved at a polyA site and a polyA tail is added. Genes with two or more polyA sites can undergo alternative polyadenylation. This produces two or more distinct mRNA isoforms with different 3M-bM-^@M-^Y untranslated regions. Additionally, alternative polyadenylation can also produce mRNAs containing different 3M-bM-^@M-^Y-terminal coding regions. Therefore, alternative polyadenylation alters both the repertoire and the expression level of proteins. Here we used high-throughput sequencing data to map polyA sites and characterize polyadenylation genome-wide in three small intestinal neuroendocrine tumors and a reference sample. In the tumors sixteen genes showed significant changes of alternative polyadenylation pattern, which lead to either the 3M-bM-^@M-^Y truncation of mRNA coding regions or 3M-bM-^@M-^Y untranslated regions. Among these, 11 genes had been previously associated with cancer, with 4 genes being known tumor suppressors: DCC, PDZD2, MAGI1 and DACT2. We validated the alternative polyadenylation in 3 out of 3 cases with Q-RT-PCR. Our findings suggest that changes of alternative polyadenylation pattern in these 16 genes could be involved in the tumorigenesis of small intestinal neuroendocrine tumors. Furthermore, they also point to alternative polyadenylation as a new target for both diagnostic and treatment of small intestinal neuroendocrine tumors. The identified genes with alternative polyadenylation specific to the small intestinal neuroendocrine tumors could be further tested as diagnostic markers and drug targets for disease prevention and treatment. PolyA-seq profiling of 3 human neuroendocrine tumors compared and pituitary using Direct RNA Sequencing from Helicos Biosciences Technology
Project description:Genome-wide methylation profiles were generated as part of a multi-omics characterization (SNP array, WES, RNA-seq, cDNA microarray) of a panel of gliomasphere cell lines and matched parental tumors. See https://www.ncbi.nlm.nih.gov/pubmed/27571888 about the GlioTeX panel. Methylation profiling data in this record come from tumour samples. SNP array (ArrayExpress E-MTAB-4804), cDNA microarray (ArrayExpress E-MTAB-4803), WES and RNAseq (European Genome-Phenome Archive EGAS00001001871) have been published before. In addition, for the current project we compare 450K methylation data to nanopore sequencing based methylation profiles. These sequencing data will be accessible via European Genome-Phenome Archive (EGAS00001002213). Please also refer to https://www.ebi.ac.uk/arrayexpress/experiments/E-MTAB-5795/files/E-MTAB05795.additional.1.zip for further information on the background of this multi-omics study.
Project description:Aims and methods: astroblastoma is a rare glial brain tumor with singular morphology. Recurrent MN1-BEND2 fusions have been recently identified in most of pediatric cases. Adolescent and adult cases, however, remain molecularly poorly defined. Here, we performed clinical and molecular characterization of a retrospective cohort of 14 adult and one adolescent gliomas with astroblastic features. Results: strikingly, we found MN1 fusions a rare event in this age group (1/15). Using methylation profiling and targeted sequencing, most cases were reclassified as either pleomorphic xanthoastrocytomas (PXA) or high-grade glioma (HGG). PXA-like ABM show BRAF mutation (6/7 with V600E mutation and 1/7 with G466E mutation) and CD34 expression. Conversely, HGG-like ABM harbored specific mutations of diffuse midline glioma (2/5) or glioblastoma (3/5). These latter patients showed an unfavorable clinical course with significantly shorter overall survival (p = 0.027). MAPK pathway alterations (including FGFR fusion, BRAF and NF1 mutations) were present in 10 of 15 patients and overrepresented in the HGG group (3/5) compared to previously reported prevalence of these alterations in GBM and diffuse midline glioma. Conclusion: We suggest that astroblastoma comprises a variety of molecularly sharply defined entities. Adults’ astroblastomas harboring molecular features of PXA and HGG should be reclassified. CNS high-grade neuroepithelial tumors with MN1 alterations appears to be a truly pediatric entity and is uncommon in adult cases with a histology of astroblastoma. Astroblastic morphology in adults should thus prompt thorough molecular investigation aiming at a clear histomolecular diagnosis and identifying actionable drug targets, especially in MAPK pathway.
Project description:We have performed bioinformatic approaches to identify the level of enrichment between gene expression profiles characterizing MSI tumors and gene changes induced in vitro by the PARP-1 inhibitor Phenanthridinone and others using the Connectivity Map tool. In a first step, we have anyzed the expression of 300 colorectal cancers from the MECC study and generated a gene expression signature by microsatellite status. The criteria followed for selection of probe sets and detailed lists to be submitted subsequently to the Connectivity Map have been published previously by us in Clinical Cancer Research in 2009. In a second step, once we observed that deficiency in MRE11 exist among MSI tumors, our interest was focused on assessing if the homologous recombination pathway showed evidence of deregulation in MSI tumors. Therefore, we examined the expression levels of those genes integrated in the KEGG pathway hsa03440 using the previously generated gene expression data set. The dataset generated from our samples included a total of 300 colorectal fresh frozen tumors collected from the MECC study and were analyzed in two batches. The first batch was hybridized to the Affymetrix U133A chip and the second one to U133 Plus 2.0 (Supplementary Table S3). The final list of probe sets defining gene expression of MSI-H compared to MSS tumors was selected based on the strength of multiplicity adjusted P-values (cut-off P-value of < 0.001) and ratio of mean expression values across the two groups (cut-off Fold-change >1.3 and <0.7). It contained 442 upregulated and 480 downregulated probe sets. Then, MSI-H tumors present with changes in gene expression related to the homologous recombination pathway. Therefore, we examined the expression levels of those genes integrated in the KEGG pathway hsa03440 using the same data set. A total of 14 genes out of 30 were significantly differentially expressed in MSI-H compared to MSS tumors (Multiplicity adjusted Benjamini-Hochberg P-value<0.05). MRE11 and RAD50 probe sets showed a lower expression in MSI-H tumors and simultaneously other probe sets such as PARP-1 were significantly upregulated, probably secondary to the deficiency in the MRN complex proteins. This data provides evidence of significant differential expression of the homologous recombination pathway in MSI tumors.