Project description:This quantitative protepomics study (TMT10 isobaric labeling) of the protein expression in the retina of Msi1/Msi2 double knockout mouse compared to floxed controls. The Msi1 and Msi2 genes were knocked out in photoreceptor cells using tamoxifen inducible Cre (Cre-ERT2) under the control of Pde6g promoter. Tamoxifen was administered by intrapertoneal injection for three consecutive day starting at postnatald day 30, and the retina was collected at postnatal day 51. Retinas from floxed animals lacking the Cre recombinase and treated with tamoxifen were used as controls. Five biological replicates for each knockout (three femailes, two males) and control (two femaes and three males) group were used.
Project description:MSI2, which is expressed predominantly in hematopoietic stem and progenitor cells (HSPCs), enforces HSPC expansion when overexpressed and is upregulated in myeloid leukemias indicating its regulated transcription is critical to balanced self-renewal and leukemia restraint. Despite this, little is understood of the factors that enforce appropriate physiological levels of MSI2 in the blood system. Here we define a promoter region that reports on endogenous expression of MSI2 and identify USF2 and PLAG1 as transcription factors whose promoter binding drives reporter activity. We show that these factors co-regulate, and are required for, efficient transactivation of endogenous MSI2. Coincident overexpression of USF2 and PLAG1 in primitive cord blood cells enhanced MSI2 transcription and yielded cellular phenotypes, including expansion of CD34+ cells in vitro, consistent with that achieved by direct MSI2 overexpression. Global ChIP-seq analyses confirm a preferential co-binding of PLAG1 and USF2 at the promoter of MSI2, as well as regulatory regions corresponding to genes with roles in HSPC homeostasis. PLAG1 and USF2 cooperation is thus an important contributor to stem cell-specific expression of MSI2 and represents novel HSPC-specific transcriptional circuitry.
Project description:We deleted SLC2A5 using CRISPR-Cas9 technology in human lung cancer cell A549. Control A549 cells and A549 cells with SLC2A5 knockout were transplanted in balb/c nude mice. Then RNA-seq was performed in control A549 and SLC2A5 ablation A549 Xenografts.
Project description:Understanding RBPs’ molecular functions as well as their cell-type specific activity requires identification of RBPs’ direct mRNA targets. However, efforts to identify RNA targets of RNA binding proteins in stem cells have been hindered by limited cell numbers. Here we adapted the HyperTRIBE method using an RBP fused to a Drosophila RNA editing enzyme (ADAR) to allow for global mapping of mRNA targets of the RBP MSI2 in rare mammalian adult stem cells. We applied this method to identify MSI2 RNA binding targets in mouse HSPCs (Lin- Sca1+ Kit+ or LSK cells) and mouse leukemic stem cells (LSCs). MSI2 fusion with the catalytic domain of the Hyperactive ADAR mutant (MSI2-ADA) or with the dead catalytic mutant (MSI2-DCD) were overexpressed for 48 hours in LSKs and LSCs, followed by RNA-seq. As ADAR converts A to I (G), the fusion leaves a "finger-print" where MSI2 binds. MSI2-DCD and empty vector controls were used to normalize the background editing. We show that despite comparable expression of the MSI2-ADA fusion protein and endogenous MSI2 in LSCs vs LSKs, MSI2 RNA binding activity (number of targets and editing frequency) in LSCs is significantly higher than that in LSKs. This elevated RNA binding activity is independent of abundancy of the target transcripts.
Project description:Interventions: experimental group :PD-1 Knockout Engineered T Cells
Primary outcome(s): Number of participants with Adverse Events and/or Dose Limiting Toxicities as a Measure of Safety and tolerability of dose of PD-1 Knockout T cells using Common Terminology Criteria for Adverse Events (CTCAE v4.0) in patients
Study Design: historical control
Project description:We demonstrate that Msi2 is the predominant form expressed in hematopoietic stem cells (HSC), and its knockdown leads to reduced engraftment and depletion of HSCs in vivo. Overexpression of Msi2 in a mouse model increases HSC cell cycle progression and cooperates with BCR-ABL1 to induce an aggressive leukemia. MSI2 is over-expressed in human myeloid leukemia, and expression levels directly correlate with decreased patient survival, thereby defining MSI2 expression as a novel prognostic marker in acute myeloid leukemia (AML). Depletion of MSI2 in human myeloid leukemia cells leads to decreased proliferation and apoptosis. These data implicate the MSI2 RNA binding protein in myeloid leukemogenesis and identify a novel potential target for therapy in AML.
Project description:We demonstrate that Msi2 is the predominant form expressed in hematopoietic stem cells (HSC), and its knockdown leads to reduced engraftment and depletion of HSCs in vivo. Overexpression of Msi2 in a mouse model increases HSC cell cycle progression and cooperates with BCR-ABL1 to induce an aggressive leukemia. MSI2 is over-expressed in human myeloid leukemia, and expression levels directly correlate with decreased patient survival, thereby defining MSI2 expression as a novel prognostic marker in acute myeloid leukemia (AML). Depletion of MSI2 in human myeloid leukemia cells leads to decreased proliferation and apoptosis. These data implicate the MSI2 RNA binding protein in myeloid leukemogenesis and identify a novel potential target for therapy in AML.
Project description:We demonstrate that Msi2 is the predominant form expressed in hematopoietic stem cells (HSC), and its knockdown leads to reduced engraftment and depletion of HSCs in vivo. Overexpression of Msi2 in a mouse model increases HSC cell cycle progression and cooperates with BCR-ABL1 to induce an aggressive leukemia. MSI2 is over-expressed in human myeloid leukemia, and expression levels directly correlate with decreased patient survival, thereby defining MSI2 expression as a novel prognostic marker in acute myeloid leukemia (AML). Depletion of MSI2 in human myeloid leukemia cells leads to decreased proliferation and apoptosis. These data implicate the MSI2 RNA binding protein in myeloid leukemogenesis and identify a novel potential target for therapy in AML.
Project description:The Musashi-2 (Msi2) RNA-binding protein maintains stem cell self-renewal and promotes oncogenesis by enhancing cell proliferation in hematopoietic and gastrointestinal tissues. However, it is unclear how Msi2 recognizes and regulates mRNA targets in vivo and whether Msi2 primarily controls cell growth in all cell types. Here we identified Msi2 targets with HITSCLIP and revealed that Msi2 primarily recognizes mRNA 3UTRs at sites enriched in multiple copies of UAG motifs in epithelial progenitor cells. RNA-seq and ribosome profiling demonstrated that Msi2 promotes targeted mRNA decay without affecting translation efficiency. Unexpectedly, the most prominent Msi2 targets identified are key regulators that govern cell motility with a high enrichment in focal adhesion and extracellular matrix-receptor interaction, in addition to regulators of cell growth and survival. Loss of Msi2 stimulates epithelial cellmigration, increases the number of focal adhesion and also compromises cell growth. These findings provide new insights into the molecular mechanisms of Msi2’s recognition and repression of targets and uncover a key function of Msi2 in restricting epithelial cell migration.