Antibody detection of translocations (ADOT) in Ewing Sarcoma
Ontology highlight
ABSTRACT: We developed a new approach called antibody detection of translocations (ADOT) which combines a transcriptional microarray-based approach with a novel antibody-based detection method to detect translocations in cancer. ADOT allows for the accurate and sensitive identification of translocations and provides exon-level information about the fusion transcript. ADOT can detect translocations in poor quality unprocessed total RNA. We demonstrate the feasibility of ADOT by examples in which both known and unknown Ewing sarcoma translocations are identified from cell lines, tumor xenografts, and FFPE primary tumors. These results demonstrate that ADOT may be an effective approach for translocation analysis in clinical specimens with significant RNA degradation and may offer a novel diagnostic tool for translocation-based cancers. We designed oligonucleotide probes for each possible exon-exon combination between potential fusion partners and printed the DNA oligonucleotides on custom-designed microarrays. Total RNA from tumor cells or tissues was hybridized on the array. Bound RNA was detected with the S9.6 monoclonal antibody that recognizes RNA-DNA duplexes in a sequence-independent fashion,and detected with Cy3-labeled anti-mouse IgG.
Project description:Olaparib is a widely used PARP inhibitor for the treatment of BRCA-mutated cancers. To comprehensively understand the drug's clinical impact, measuring its interactions with intended on- and off-targets is crucial. In this study, olaparib's on- and off-targets were profiled using photoaffinity labeling, a powerful, proteome-wide method for studying the direct interactions between a drug and its protein targets. A novel photoaffinity probe was designed and used in a proteomic screening to discover novel targets of olaparib in the human proteome. The probe, incorporating a pre-installed biotin group, bypasses the limitations of using a copper(I)-catalyzed click reaction in cell lysates for reporter group conjugation and revealed a broad range of olaparib interactors, including previously unreported proteins, in a quantitative mass spectrometry-based proteomic screening using HeLa whole cell lysate. The study contributes to our current understanding of the pharmacology of olaparib and provides a valuable tool for elucidating drug interactors within cell lysates, potentially guiding the development of more targeted therapeutics with fewer off-targets.
Project description:The aim of this study is to discover genes regulated by miR-204. Differential gene expression in HEK-293 cells transfected with miR-204-mimic compared to HEK-293 cells transfected with control oligo (HEK-293 control) was analyzed using the Agilent Human Whole Genome 4x44K gene expression array (Agilent Technologies, Santa Clara, CA). HEK-293 cells were transfected with either miR-204 or a control, and gene expression was analyzed using the Agilent Human Whole Genome 4x44K array. A dye-swap was performed.
Project description:The EwingM-bM-^@M-^Ys sarcoma protein EWS belongs to the TET family (FUS/TLS, EWS, TAF15) of RNA and DNA binding proteins, implicated in DNA transcription, pre-mRNA splicing and maintenance of genomic integrity. Translocations of these genes are characteristic of particular neoplasias, including EwingM-bM-^@M-^Ys sarcoma. To identify physiological RNA targets of EWS, we performed in vivo cross-linking and immunoprecipitation followed by high-throughput RNA sequencing (HITS-CLIP/CLIP-Seq) in HeLa cells. Sequencing identified EWS binding sites characterized by guanosine-rich motifs in nearly 9000 genes, with particular enrichment in exonic regions near 5M-bM-^@M-^Y splice sites. Exon 6 of the Fas/CD95 receptor, which is alternatively spliced to generate isoforms with opposing activities in programmed cell death, was found as a prominent EWS CLIP target, as well as by chromatin-immunoprecipitation (ChIP) and functional analysis. Manipulation of EWS levels and mutation of EWS binding sites led to changes in alternative splicing consistent with EWS promoting exon 6 inclusion and leading to the synthesis of the pro-apoptotic Fas/CD95 isoform. Biochemical characterization of factors associated with FAS exon 6 are consistent with the notion that EWS binds to exonic sequences near the 5M-bM-^@M-^Y splice site and promotes the recruitment of U1snRNP, favoring also recognition of the upstream 3' splice site by U2AF and thus exon definition. Consistent with a role for EWS in the regulation of programmed cell death, cells depleted of EWS show decreased sensitivity to Fas-induced apoptosis. We discuss the potential implications of this novel function of EWS in EwingM-bM-^@M-^Ys sarcoma. CLIP-Seq analysis of EWS, with 2 biological replicates of EWS and one non-specific control
Project description:Background: Germinal center B-cell (GCB) lymphomas are common in children and adults. The prognosis strongly depends on age. Subgroups of GCB-lymphomas are characterized by chromosomal translocations affecting immunoglobulin (IG) loci leading to oncogene deregulation. Methods: Novel IG translocation partners were cloned within the network “Molecular Mechanisms in Malignant Lymphomas” (MMML) by long-distance inverse polymerase chain reaction. Mature aggressive B-cell lymphomas from the MMML as well as pediatric and adult lymphoma trials were analyzed by fluorescence in situ hybridization (FISH) and immunhistochemistry. Data from 438 MMML cases characterized by gene expression profiling were mined. Results: Cloning of unknown IG partners identified a t(6;14)(p25;q32) juxtaposing the IRF4 oncogene with the IGH-locus as novel recurrent aberration in GCB lymphoma. FISH analyses of 427 mature B-cell lymphomas for IRF4 translocations revealed 20 IG/IRF4 positive lymphomas (17 IGH/IRF4, 2 IGL/IRF4, 1 IGΚ/IRF4). IG/IRF4-positive lymphomas were predominantly GCB-type diffuse large B-cell lymphomas (DLBCL) or follicular lymphoma grade 3, shared overexpression of IRF4/MUM1 and BCL6 and lacked PRDM1/BLIMP1 expression and t(14;18)/BCL2 breaks. BCL6 aberrations were common. The gene expression profile of IG/IRF4-positive lymphomas was different from other subtypes of DLBCL and a classifier for IG/IRF4 positivity containing 27 genes allowed prediction of 3 additional MMML IG/IRF4-positive cases subsequently proven by FISH. IG/IRF4-positivity was associated with a favorable outcome likely due to significant enrichment of IG/IRF4-positive lymphomas in childhood and young adulthood. Conclusions: Our results suggest IRF4 translocations to be primary genetic alterations in a novel molecularly defined subset of GC-derived lymphomas predominantly affecting children. 271 diffuse large B-Cell lymphoma samples were hybridized to HGU133A Affymetrix GeneChips.
Project description:In this study we investigated to which extend aberrant c Myc activity plays a functional role in other aNHL and whether it is independent from MYC translocations. Based on a combined microarray analysis of human germinal centre (GC) B cells transfected with c Myc and 220 aNHLs cases, we developed a ‘c Myc index’. This data set contains expresssion profiles from Germinal center B-cells transfected with control or Myc expression vectors. The corresponding lymphoma gene expression profiles are included in the series with GEO accession GSE4475. Expression profiling of germinal center B-cells extracted from human tonsils with and without ectopic expression of Myc.
Project description:Retinaldehyde dehydrogenases convert retinal into all-trans retinoic acid (ATRA), thereby regulating cell differentiation and cancer stem cell proliferation. Chemical tools and methods are valuable commodities to study aldehyde dehydrogenase (ALDH) activity in human cells. Here, we describe the design, synthesis and application of LEI-945, a first-in-class activity-based probe modeled on retinal that reports on individual ALDHs in cancer cells. Comparative chemical proteomics with LEI-945 explained the ability of various breast cancer cell lines to produce ATRA via retinaldehyde dehydrogenases isozymes, whereas the ALDEFLUORTM assay could not. Competitive chemical proteomics using LEI-945 revealed that the ALDH inhibitor NCT-505 inhibited both ALDH1A1 and ALDH1A3 in MDA-MB-468 breast cancer cells inducing a cell cycle arrest in the G1 phase as well as cell death through necrosis. Our results show that LEI-945 holds promise to guide the discovery of ALDH-based therapeutics
Project description:Laminopathies are caused by mutations in components of the nuclear envelope (NE). While most NE components are widely expressed, laminopathies affect only a subset of tissues. However, the understanding of the molecular mechanisms that explain this phenomenon is still elusive. Here we have performed a genome wide DamID analysis in adult C. elegans nematodes comparing the DNA association profile of two components of the NE, Lamin/LMN-1 and Emerin/EMR-1. Although both proteins were associated to silent DNA, EMR-1 showed a predominant role in the anchoring of muscle and neuronal promoters to the nuclear periphery. Deletion of either EMR-1 or LEM-2, another integral NE protein, caused local changes in nuclear architecture with both increased and decreased LMN-1 association. Comparison of Dam::LMN-1 and Dam::EMR-1 DNA assotiation in wild type strains and Dam::LMN-1 DNA association in wild type, lem-2(tm1582) and emr-1(gk119) mutant backgrounds.
Project description:Unprecedented bacterial targets are urgently needed for the development of novel antibiotics to overcome the current resistance crisis. Challenges include the limited uptake of compounds as well as prioritizing proteins for their druggability and functional relevance. Especially, the wealth of uncharacterized proteins represents an untapped source for novel targets. However, tools to decipher their function are largely lacking. We here utilize the systematic mining of pyridoxal phosphate dependent enzymes (PLP DEs) in bacteria to focus on a target class, which is known to bind ligands, accesses PLP via active transport from the media and is involved in crucial metabolic processes. For this, we systematically exploited the chemical space of the pyridoxal (PL) scaffold and obtained eight PL probes bearing modifications at various ring positions. These probes were subsequently tested for phosphorylation by cognate kinases and labelling of PLP DEs in clinically relevant Gram-positive (Staphylococcus aureus) as well as Gram-negative (Escherichia coli and Pseudomonas aeruginosa) strains. Overall, the coverage of this diverse set of probes along with refined labelling conditions not only exceeded the performance of a previous probe generation, it also provided a detailed map of binding preferences of certain structural motifs. Although originally conducted in mutant cells devoid of PLP de novo biosynthesis, we here demonstrate efficient PLP DE labelling also in a wild type strain. Overall, the profiling revealed several putative PLP DEs with unknown function, of which we exemplarily characterized five via in-depth enzymatic assays. Finally, we screened a panel of putative PLP binders for antibiotic activity and unravelled the targets of hit molecules via competitive profiling with our probes. Here, an uncharacterized enzyme, essential for bacterial growth, was assigned as PLP dependent cysteine desulfurase and confirmed to be inhibited by the marketed drug phenelzine. Our approach provides a basis for deciphering novel PLP DEs as essential antibiotic targets along with corresponding ways to decipher small molecule inhibitors.
Project description:HeLa cell line was trasfected by a EWS siRNA oligo causing knock-down of EWS or a siRNA scrambled oligo Three biological replicates were labeled in direct and dye-swap microarray experiments and hybridized onto an Agilent custom splicing-sensitive microarray platform.
Project description:nCounter miRNA Expression Assay data for all profiled miRQC samples prepared by the miRQC Consortium. In this study, we systematically compared 12 commercially available miRNA expression platforms by measuring an identical set of standardized positive and negative control samples, including human universal reference RNA, human brain RNA and titrations thereof, human serum samples, and synthetic spikes from miRNA family members with varying homology. We developed novel and robust quality metrics to objectively assess platform performance of very different technologies such as small RNA sequencing, RT-qPCR and (microarray) hybridization. We assessed reproducibility, sensitivity, accuracy, specificity, and concordance of differential expression. miRQC Consortium multi-platform comparision. *This represents the NanoString component only