Project description:We mapped Sleeping Beauty (SB) and piggyBac (PB) insertions in primary human CD4+ T cells and compared their insertion profiles with those of the MLV retrovirus and the HIV lentivirus with respect to proximity to genes, TSSs, CpG islands, DNase I hypersensitive sites, repetitive elements, chromatin marks and transcriptional status of genes.
Project description:We mapped Sleeping Beauty (SB) and piggyBac (PB) insertions in primary human CD4+ T cells and compared their insertion profiles with those of the MLV retrovirus and the HIV lentivirus with respect to proximity to genes, TSSs, CpG islands, DNase I hypersensitive sites, repetitive elements, chromatin marks and transcriptional status of genes. Examination of two transposon systems in one cell type.
Project description:DNA transposon-based gene delivery vectors represent a promising new branch of randomly integrating vector development for gene therapy. For the side-by-side evaluation of the piggyBac and Sleeping Beauty systems - the only DNA transposons currently employed in clinical trials - during therapeutic intervention, we treated the mouse model of Tyrosinemia type I. with liver-targeted gene delivery using both transposon vectors. For genome-wide mapping of transposon insertion sites we developed a new Next Generation Sequencing procedure called Streptavidin-Based Enrichment Sequencing, which allowed us to identify approximately 1 million integration sites for both systems. We revealed that a high proportion of piggyBac integrations are clustered in hot regions and found that they are frequently recurring at the same genomic positions among treated animals, indicating that the genome-wide distribution of Sleeping Beauty-generated integrations is closer to random. We also revealed that the piggyBac transposase protein exhibits prolonged activity, which predicts the risk of oncogenesis by generating chromosomal double-strand breaks. Safety concerns associated with prolonged transpositional activity draw attention to the importance of squeezing the active state of the transposase enzymes into a narrower time window.
Project description:Single cell transposon insertion site profiles were generated from A375 xenograft tumors that had aquired BRAF inhibitor resistance in vivo as a consequence of Sleeping Beauty transposon mutagenesis.
Project description:Creating spontaneous yet genetically tractable human tumors from normal cells presents a fundamental challenge. Retroviruses and transposons have been separately used as somatic cell insertional mutagens to identify cancer drivers in model organisms. Here we combined these mutagenic elements to enable cancer gene discovery starting with normal human cells. Lentivirus was used to seed gain- and loss-of-function gene disruption elements which were further deployed by Sleeping Beauty transposons throughout the genome of human bone explant mesenchymal cells. De novo tumors rapidly generated in this context were high-grade sarcomas corresponding to the spectrum of myxofibrosarcoma and undifferentiated pleomorphic sarcoma, aggressive neoplasms with a predilection for older adults. Tumor insertion sites were genome-wide and enriched in regions of recurrent somatic copy number alteration found in multiple cancers, with a bias towards those of sarcomas. Novel driver genes which sustain somatic alterations in cancer patients were pinpointed. We identify the gene HDLBP, which codes for the RNA binding protein vigilin, as a candidate tumor suppressor deleted at 2q37.3 in greater than one in ten tumors across multiple tissues of origin. Hybrid viral-transposon systems will accelerate the functional annotation of cancer genomes by enabling insertional mutagenesis screens in higher eukaryotes that are not amenable to germline transgenesis. Lentivirus was used to seed gain- and loss-of-function gene disruption elements which were further deployed by Sleeping Beauty (SB) transposons throughout the genome of human bone explant mesenchymal cells. Genomic locations of LV (lentiviral backbone) and SB insertion sites were mapped by a pooled strategy utilizing linear amplification mediated PCR (LAM-PCR), followed by Illumina next generation sequencing of the product pool.
Project description:We generated an inducible DDdCas9VP192 activator cell line in H9 human embryonic stem cells using the Sleeping beauty transposition system. The guides targeting a LEUTX promoter and enhancers were introduced by PiggyBac transposition. Three sample types were generated: Promoter only, Promoter+Enhancer1, Promoter+Enhancer2. Cells were collected before and at 24 h, 48 h, and 72 h after doxycycline treatment, and subjected to STRT RNA-sequencing.
Project description:Exploiting the full potential of insertional mutagenesis screens with retroviruses and transposons requires methods for distinguishing clonal from subclonal insertion events within heterogeneous tumor cell populations. Current protocols, based on ligation mediated PCR, depend on endonuclease based fragmentation of genomic DNA, resulting in strong biases in amplification and sequencing due to a fixed product sizes of the amplicon. We have developed a method called shear-splink, which enables the semi-quantitative high-throughput sequence analysis of insertional mutations, enabling us to count the number of cells harboring a given integration, within a heterogeneous sample. The shear-splink method enriches for (sub)clonal integrations, thereby reducing the contribution of irrelevant passenger mutations normally hampering a reliable identification of common integration sites. Additionally, this improvement allows us to identify genetic interactions between affected genes, co-occurring mutations and to study acquired resistance mechanisms both in vivo and in vitro. Sequencing of retrovrial integration sites by LM-PCR. The associated manuscript describes a new method to quantitatively determine retrovrial integration sites using an improved ligation-mediated PCR approach and subsequent 454 pyrosequencing. [GSM562151 to GSM562159]: Sequence data from different mixtures of 2 different cell lines (called AE6 and BB12) which are processed without a restriction enzyme. These cell lines are derived from an MMTV induced mammary tumor, for which we amplify the MMTV integration sites using a ligation-mediated PCR setup. We mixed these 2 cell lines, both with a different integration spectrum, to determine whether our amplification and sequencing protocol is quantitative, meaning that the coverage per integration site is decreasing upon a further dilution of the sample. [GSM641935 to GSM641950]: Unique Sleeping beauty induced lymphoma specimens (spleen) obtained from a cohort of 16 wild-type mice with the 129P2/C57BL/6J mixed background. [GSM776576 to GSM776956]: The 379 submitted specimens are originating from 127 unique leukemia/lymphoma samples, processed using 3 different techniques in order to identify Sleeping Beauty integration sites. We compared restriction enzyme based LM-PCR (RE-splink) with shearing based LM-PCR (shear-splink) on 127 unique Sleeping Beauty (SB) induced leukemia's/lymphomas. All sequence data generated by the 454 sequencing platform are submitted to GEO, including the final output of our sequence analysis pipeline (in bed format; see Supplementary files linked below). Previous submissions contained similar sequence information (integration sites of viruses or transposons driving tumorigenesis) and are all part of the same manuscript.
Project description:Thymic lymphomas were generated by inducing Sleeping Beauty transposon mutagenesis at different stages of T-cell development. This dataset includes exon array results from 14 tumor samples from two different Sleeping Beauty models of T-ALL (7 Vav-SB and 7 CD4-SB samples).
Project description:To identify genes important for colorectal cancer (CRC) development and metastasis, we established a new metastatic mouse organoid model using Sleeping Beauty (SB) transposon mutagenesis. Intestinal organoids derived from mice carrying actively mobilizing SB transposons, an activating KrasG12D, and an inactivating ApcΔ716 allele, were transplanted to immunodeficient mice. Analysis of SB insertion sites in tumors identified numerous candidate cancer genes (CCGs) identified previously in intestinal SB screens performed in vivo, in addition to new CCGs, such as Atxn1. To provide functional validation, we knocked out Atxn1 in mouse tumor organoids carrying an activating KrasG12D, and an inactivating ApcΔ716 allele, and transplanted to mice. Tumor development was promoted when these gene were knocked out, demonstrating that these are potent tumor suppressors.