Project description:The identification of subtype-specific translocations has revolutionized diagnostics of sarcoma and provided new insight into oncogenesis. We used RNA-Seq to investigate samples diagnosed as small round cell tumors of bone, possibly Ewing sarcoma, but lacking the canonical EWSR1-ETS translocation. A new fusion was observed between the BCL6 co-repressor (BCOR) and the testis specific cyclin B3 (CCNB3) genes on chromosome X. RNA-Seq results were confirmed by RT-PCR and cloning the tumor-specific genomic translocation breakpoints. 24 BCOR-CCNB3-positive tumors were identified among a series of 594 sarcomas. Gene profiling experiments indicate that BCOR-CCNB3-positive cases are biologically distinct from other sarcomas, particularly EwingM-bM-^@M-^Ys sarcoma. Finally, we show that CCNB3 immunohistochemistry is a powerful diagnostic marker for this group of sarcoma and that over-expression of BCOR-CCNB3 or of a truncated CCNB3 activates S-phase in NIH3T3 cells. Thus the intrachromosomal X fusion described here represents a new subtype of bone sarcoma caused by a novel gene fusion mechanism. Comparison of expression profiles of 10 BCOR-CCNB3 samples (plus 4 EWS-FLI1 Ewing sarcomas samples as control) with publicly available profiles of other tumor types.
Project description:The identification of subtype-specific translocations has revolutionized diagnostics of sarcoma and provided new insight into oncogenesis. We used RNA-Seq to investigate samples diagnosed as small round cell tumors of bone, possibly Ewing sarcoma, but lacking the canonical EWSR1-ETS translocation. A new fusion was observed between the BCL6 co-repressor (BCOR) and the testis specific cyclin B3 (CCNB3) genes on chromosome X. RNA-Seq results were confirmed by RT-PCR and cloning the tumor-specific genomic translocation breakpoints. 24 BCOR-CCNB3-positive tumors were identified among a series of 594 sarcomas. Gene profiling experiments indicate that BCOR-CCNB3-positive cases are biologically distinct from other sarcomas, particularly Ewing’s sarcoma. Finally, we show that CCNB3 immunohistochemistry is a powerful diagnostic marker for this group of sarcoma and that over-expression of BCOR-CCNB3 or of a truncated CCNB3 activates S-phase in NIH3T3 cells. Thus the intrachromosomal X fusion described here represents a new subtype of bone sarcoma caused by a novel gene fusion mechanism.
Project description:In this study, we characterize the fusion protein produced by the EPC1-PHF1 translocation in Low Grade Endometrial Stromal Sarcoma (LG-ESS) and Ossifying FibroMyxoid Tumors (OFMT). We express the fusion protein and necessary controls in K562 Cells. The fusion protein assembles a mega-complex harboring both NuA4/TIP60 and PRC2 subunits and enzymatic activities and leads to mislocalization of chromatin marks in the genome, linked to aberrant gene expression.
Project description:In this study, we characterize the fusion protein produced by the EPC1-PHF1 translocation in Low Grade Endometrial Stromal Sarcoma (LG-ESS) and Ossifying FibroMyxoid Tumors (OFMT). We express the fusion protein and necessary controls in K562 Cells. The fusion protein assembles a mega-complex harboring both NuA4/TIP60 and PRC2 subunits and enzymatic activities and leads to mislocalization of chromatin marks in the genome, linked to aberrant gene expression.
Project description:In this study, we characterize the fusion protein produced by the EPC1-PHF1 translocation in Low Grade Endometrial Stromal Sarcoma (LG-ESS) and Ossifying FibroMyxoid Tumors (OFMT). We express the fusion protein and necessary controls in K562 Cells. The fusion protein assembles a mega-complex harboring both NuA4/TIP60 and PRC2 subunits and enzymatic activities and leads to mislocalization of chromatin marks in the genome, linked to aberrant gene expression.
Project description:The concept of Ewing family of tumors (EFT), characterized by FET-ETS fusions, has been recently challenged by the description of Ewing-like tumors with different gene fusions. Here we investigate the similarities and differences of FET-ETS, BCOR-CCNB3, CIC-DUX4 and EWSR1-NFATc2 tumors samples with a number of other sarcomas. Unsupervised clustering of gene expression profiles fully discriminates these four molecular entities. Specific gene signatures and pathways were further validated in model cell lines. While a clear inflammatory signature characterizes EWSR1-NFATc2 tumors, BCOR-CCNB3 and CIC-DUX4 exhibit high expression of homeobox and ETS protein families, respectively. We strongly suggest that abnormalities of chromatin remodeling may gather CIC-DUX4 and BCOR-CCNB3 tumors with rhabdoid tumors and synovial sarcomas.
Project description:The concept of Ewing family of tumors (EFT), characterized by FET-ETS fusions, has been recently challenged by the description of Ewing-like tumors with different gene fusions. Here we investigate the similarities and differences of FET-ETS, BCOR-CCNB3, CIC-DUX4 and EWSR1-NFATc2 tumors samples with a number of other sarcomas. Unsupervised clustering of gene expression profiles fully discriminates these four molecular entities. Specific gene signatures and pathways were further validated in model cell lines. While a clear inflammatory signature characterizes EWSR1-NFATc2 tumors, BCOR-CCNB3 and CIC-DUX4 exhibit high expression of homeobox and ETS protein families, respectively. We strongly suggest that abnormalities of chromatin remodeling may gather CIC-DUX4 and BCOR-CCNB3 tumors with rhabdoid tumors and synovial sarcomas. This dataset conains 14 CIC-DUX4 and 7 EWSR1-NFATc2 tumor samples as well as Human mesenchymal cell line expressing EWSR1-NFATc2 (duplicates) or mock treated (duplicates) and IB120 CIC-DUX4 cell line expressing an shRNA directed against CIC-DUX4 (4 replicates) or mock treated (duplicates).
Project description:Sarcoma represents a highly heterogeneous group of tumors. We report here the first unbiased and systematic search for gene fusions and analysis of transcriptomic profiles in 100 monomorphic sarcomas cases using RNA-sequencing profiling. Fusion genes were detected in two thirds of samples. Similarly to fusion genes such as PAX3/7-FOXO1, EWSR1/FUS-ETS, SS18-SSX, BRD3/4-NUTM1 or EWSR1/FUS/TAF15-NR4A3 characterizing well-defined entities, we show that all sarcomas displaying CIC fusions- whatever their fusion partner (being DUX4, NUTM1 or FOXO4) - form a transcriptionally homogeneous group of tumors. Likewise, tumors with either a BCOR fusion (with CCNB3, MAML3 or ZC3H7B partners) or with a BCOR internal duplication form a single biological entity. We also found that EML4-ALK fusions also characterize a homogeneous infantile fibrosarcoma subgroup. In contrast, fusions like VGLL2-NCOA2/CITED2, TMP3/TRP-NTRK1 or ETV6-NTRK3 are observed in more heterogeneous tumors. Finally, we also describe a new group of bone sarcomas characterized by EWSR1- or FUS-TFCP2 fusions.
Project description:Ewings Sarcoma (ES) belongs to the group of bone cancers defined by the existence of a certain EWS-ETS fusion gene. In this study we use the model cell line CADO-ES1 (EWSR1-ERG fusion gene) to characterize the genomic structure in respect to CNV and fusion gene events.
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.