Malignant rhabdoid tumors (MRTs) are rare lethal tumors of childhood that most commonly occur in the kidney and brain. MRTs are driven by SMARCB1 loss, but the molecular consequences of SMARCB1 loss ...in extra-cranial tumors have not been comprehensively described and genomic resources for analyses of extra-cranial MRT are limited. To provide such data, we used whole-genome sequencing, whole-genome bisulfite sequencing, whole transcriptome (RNA-seq) and microRNA sequencing (miRNA-seq), and histone modification profiling to characterize extra-cranial MRTs. Our analyses revealed gene expression and methylation subgroups and focused on dysregulated pathways, including those involved in neural crest development.
•Extra-cranial malignant rhabdoid tumors (MRTs) exhibit molecular heterogeneity•Evidence is presented for epigenetic reprogramming of HOX genes•MRTs exhibit dysregulated expression of genes involved in neural crest development•Dysregulation of oncogenes and tumor suppressor genes is reported
Chun et al. perform integrated molecular analyses of extra-cranial malignant rhabdoid tumors (MRTs) and show that, although SMARCB1 loss drives nearly all MRTs, there are two subgroups of MRTs that are associated with patient age and differentially expressed genes.
Ovarian cancer presents as an aggressive, advanced stage cancer with widespread metastases that depend primarily on multicellular spheroids in the peritoneal fluid. To identify new druggable pathways ...related to metastatic progression and spheroid formation, we integrated microRNA and mRNA sequencing data from 293 tumors from The Cancer Genome Atlas (TCGA) ovarian cancer cohort. We identified miR-509-3p as a clinically significant microRNA that is more abundant in patients with favorable survival in both the TCGA cohort (P = 2.3E-3), and, by in situ hybridization (ISH), in an independent cohort of 157 tumors (P < 1.0E-3). We found that miR-509-3p attenuated migration and disrupted multi-cellular spheroids in HEYA8, OVCAR8, SKOV3, OVCAR3, OVCAR4 and OVCAR5 cell lines. Consistent with disrupted spheroid formation, in TCGA data miR-509-3p's most strongly anti-correlated predicted targets were enriched in components of the extracellular matrix (ECM). We validated the Hippo pathway effector YAP1 as a direct miR-509-3p target. We showed that siRNA to YAP1 replicated 90% of miR-509-3p-mediated migration attenuation in OVCAR8, which contained high levels of YAP1 protein, but not in the other cell lines, in which levels of this protein were moderate to low. Our data suggest that the miR-509-3p/YAP1 axis may be a new druggable target in cancers with high YAP1, and we propose that therapeutically targeting the miR-509-3p/YAP1/ECM axis may disrupt early steps in multi-cellular spheroid formation, and so inhibit metastasis in epithelial ovarian cancer and potentially in other cancers.
RNA-Sequencing (RNA-seq) is now commonly used to reveal quantitative spatiotemporal snapshots of the transcriptome, the structures of transcripts (splice variants and fusions) and landscapes of ...expressed mutations. However, standard approaches for library construction typically require relatively high amounts of input RNA, are labor intensive, and are time consuming. METHODS: Here, we report the outcome of a systematic effort to optimize and streamline steps in strand-specific RNA-seq library construction. RESULTS: This work has resulted in the identification of an optimized messenger RNA isolation protocol, a potent reverse transcriptase for cDNA synthesis, and an efficient chemistry and a simplified formulation of library construction reagents. We also present an optimization of bead-based purification and size selection designed to maximize the recovery of cDNA fragments.
These developments have allowed us to assemble a rapid high throughput pipeline that produces high quality data from amounts of total RNA as low as 25 ng. While the focus of this study is on RNA-seq sample preparation, some of these developments are also relevant to other next-generation sequencing library types.
Many mutations that contribute to the pathogenesis of acute myeloid leukemia (AML) are undefined. The relationships between patterns of mutations and epigenetic phenotypes are not yet clear.
We ...analyzed the genomes of 200 clinically annotated adult cases of de novo AML, using either whole-genome sequencing (50 cases) or whole-exome sequencing (150 cases), along with RNA and microRNA sequencing and DNA-methylation analysis.
AML genomes have fewer mutations than most other adult cancers, with an average of only 13 mutations found in genes. Of these, an average of 5 are in genes that are recurrently mutated in AML. A total of 23 genes were significantly mutated, and another 237 were mutated in two or more samples. Nearly all samples had at least 1 nonsynonymous mutation in one of nine categories of genes that are almost certainly relevant for pathogenesis, including transcription-factor fusions (18% of cases), the gene encoding nucleophosmin (NPM1) (27%), tumor-suppressor genes (16%), DNA-methylation-related genes (44%), signaling genes (59%), chromatin-modifying genes (30%), myeloid transcription-factor genes (22%), cohesin-complex genes (13%), and spliceosome-complex genes (14%). Patterns of cooperation and mutual exclusivity suggested strong biologic relationships among several of the genes and categories.
We identified at least one potential driver mutation in nearly all AML samples and found that a complex interplay of genetic events contributes to AML pathogenesis in individual patients. The databases from this study are widely available to serve as a foundation for further investigations of AML pathogenesis, classification, and risk stratification. (Funded by the National Institutes of Health.).
The Genome of the Kinetoplastid Parasite, Leishmania major Ivens, Alasdair C.; Peacock, Christopher S.; Worthey, Elizabeth A. ...
Science (American Association for the Advancement of Science),
07/2005, Letnik:
309, Številka:
5733
Journal Article
Recenzirano
Odprti dostop
Leishmania species cause a spectrum of human diseases in tropical and subtropical regions of the world. We have sequenced the 36 chromosomes of the 32.8-megabase haploid genome of Leishmania major ...(Friedlin strain) and predict 911 RNA genes, 39 pseudogenes, and 8272 protein-coding genes, of which 36% can be ascribed a putative function. These include genes involved in host-pathogen interactions, such as proteolytic enzymes, and extensive machinery for synthesis of complex surface glycoconjugates. The organization of protein-coding genes into long, strand-specific, polycistronic clusters and lack of general transcription factors in the L. major, Trypanosoma brucei, and Trypanosoma cruzi (Tritryp) genomes suggest that the mechanisms regulating RNA polymerase II-directed transcription are distinct from those operating in other eukaryotes, although the trypanosomatids appear capable of chromatin remodeling. Abundant RNA-binding proteins are encoded in the Tritryp genomes, consistent with active posttranscriptional regulation of gene expression.
A physical map of the chicken genome Warren, Wesley C; Wallis, John W; Aerts, Jan ...
Nature,
12/2004, Letnik:
432, Številka:
7018
Journal Article
Recenzirano
Odprti dostop
Strategies for assembling large, complex genomes have evolved to include a combination of whole-genome shotgun sequencing and hierarchal map-assisted sequencing. Whole-genome maps of all types can ...aid genome assemblies, generally starting with low-resolution cytogenetic maps and ending with the highest resolution of sequence. Fingerprint clone maps are based upon complete restriction enzyme digests of clones representative of the target genome, and ultimately comprise a near-contiguous path of clones across the genome. Such clone-based maps are used to validate sequence assembly order, supply long-range linking information for assembled sequences, anchor sequences to the genetic map and provide templates for closing gaps. Fingerprint maps are also a critical resource for subsequent functional genomic studies, because they provide a redundant and ordered sampling of the genome with clones. In an accompanying paper we describe the draft genome sequence of the chicken, Gallus gallus, the first species sequenced that is both a model organism and a global food source. Here we present a clone-based physical map of the chicken genome at 20-fold coverage, containing 260 contigs of overlapping clones. This map represents approximately 91% of the chicken genome and enables identification of chicken clones aligned to positions in other sequenced genomes.
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