Project description:To examine Ikaros tumor suppressor mechanisms, we have utilized inducible RNAi to dynamically restore endogenous Ikaros expression in T-ALL driven by its knockdown. This causes rapid transcriptional repression of Notch1 and associated targets including Myc, even in leukemias harboring spontaneous activating Notch1 mutations (producing aberrant ICN1) similar to those found in 60% of human T-ALL. Ikaros restoration results in sustained regression of Notch1-wild type leukemias while endogenous or engineered ICN1 expression promotes rapid disease relapse, indicating that ICN1 functionally antagonizes Ikaros in T-ALL. RNA-seq was performed on T-ALL (Vav-tTA;TRE-GFP-shIkaros primary leukemia ALL65) cells isolated from three untreated and three 3-day Dox-treated mice. There were two sequencing runs of each RNA sample.
Project description:To examine Ikaros tumor suppressor mechanisms, we have utilized inducible RNAi to dynamically restore endogenous Ikaros expression in T-ALL driven by its knockdown. This causes rapid transcriptional repression of Notch1 and associated targets including Myc, even in leukemias harboring spontaneous activating Notch1 mutations (producing aberrant ICN1) similar to those found in 60% of human T-ALL. Ikaros restoration results in sustained regression of Notch1-wild type leukemias while endogenous or engineered ICN1 expression promotes rapid disease relapse, indicating that ICN1 functionally antagonizes Ikaros in T-ALL. Overall design: RNA-seq was performed on T-ALL (Vav-tTA;TRE-GFP-shIkaros primary leukemia ALL211) cells isolated from two untreated and two 3-day Dox-treated mice.
Project description:To examine Ikaros tumor suppressor mechanisms, we have utilized inducible RNAi to dynamically restore endogenous Ikaros expression in T-ALL driven by its knockdown. This causes rapid transcriptional repression of Notch1 and associated targets including Myc, even in leukemias harboring spontaneous activating Notch1 mutations (producing aberrant ICN1) similar to those found in 60% of human T-ALL. Ikaros restoration results in sustained regression of Notch1-wild type leukemias while endogenous or engineered ICN1 expression promotes rapid disease relapse, indicating that ICN1 functionally antagonizes Ikaros in T-ALL. RNA-seq was performed on T-ALL (Vav-tTA;TRE-GFP-shIkaros primary leukemia ALL211) cells isolated from two untreated and two 3-day Dox-treated mice.
Project description:To examine Ikaros tumor suppressor mechanisms, we have utilized inducible RNAi to dynamically restore endogenous Ikaros expression in T-ALL driven by its knockdown. This causes rapid transcriptional repression of Notch1 and associated targets including Myc, even in leukemias harboring spontaneous activating Notch1 mutations (producing aberrant ICN1) similar to those found in 60% of human T-ALL. Ikaros restoration results in sustained regression of Notch1-wild type leukemias while endogenous or engineered ICN1 expression promotes rapid disease relapse, indicating that ICN1 functionally antagonizes Ikaros in T-ALL. RNA-seq was performed on T-ALL (Vav-tTA;TRE-GFP-shIkaros primary leukemia ALL101) cells isolated from three untreated and three 3-day Dox-treated mice. There were two sequencing runs of each RNA sample.
Project description:To examine Ikaros tumor suppressor mechanisms, we have utilized inducible RNAi to dynamically restore endogenous Ikaros expression in T-ALL driven by its knockdown. This causes rapid transcriptional repression of Notch1 and associated targets including Myc, even in leukemias harboring spontaneous activating Notch1 mutations (producing aberrant ICN1) similar to those found in 60% of human T-ALL. Ikaros restoration results in sustained regression of Notch1-wild type leukemias while endogenous or engineered ICN1 expression promotes rapid disease relapse, indicating that ICN1 functionally antagonizes Ikaros in T-ALL. RNA-seq was performed on T-ALL (Vav-tTA;TRE-GFP-shIkaros primary leukemia ALL65) cells isolated from three untreated and three 3-day Dox-treated mice. There were two sequencing runs of each RNA sample.
Project description:To study the oncogenic role of the NRAS oncogene (NRAS(G12V)) in the context of acute myeloid leukemia (AML), we used a Vav promoter-tetracycline transactivator (Vav-tTA)-driven repressible TRE-NRAS(G12V) transgene system in Mll-AF9 knock-in mice developing AML. Conditional repression of NRAS(G12V) expression greatly reduced peripheral white blood cell (WBC) counts in leukemia recipient mice and induced apoptosis in the transplanted AML cells correlated with reduced Ras/Erk signaling. After marked decrease of AML blast cells, myeloproliferative disease (MPD)-like AML relapsed characterized by cells that did not express NRAS(G12V). In comparison with primary AML, the MPD-like AML showed significantly reduced aggressiveness, reduced myelosuppression, and a more differentiated phenotype. We conclude that, in AML induced by an Mll-AF9 transgene, NRAS(G12V) expression contributes to acute leukemia maintenance by suppressing apoptosis and reducing differentiation of leukemia cells. Moreover, NRAS(G12V) oncogene has a cell nonautonomous role in suppressing erythropoiesis that results in the MPD-like AML show significantly reduced ability to induce anemia. Our results imply that targeting NRAS or RAS oncogene-activated pathways is a good therapeutic strategy for AML and attenuating aggressiveness of relapsed AML.
Project description:Modulation of the amyloid-? (A?) trafficking pathway heralds a new therapeutic frontier for Alzheimer's disease (AD). As CD74 binds to the amyloid-? precursor protein (APP) and can suppresses A? processing, we investigated whether recombinant adeno-associated virus (AAV) delivery of CD74 could reduce A? production and affect disease outcomes. This idea was tested in a mouse AD model. Cotransduction of AAV-tetracycline-controlled transactivator (tTA) and AAV-tet-response element (TRE)-CD74 resulted in CD74 expression, reduced A? production in mouse neurons containing the human APP with familial AD-linked mutations. Stereotaxic injection of AAV-TRE-GFP or CD74 into the hippocampi of an AD mouse, defined as a TgCRND8 × calmodulin-dependent protein kinase II derived promoter-tTA double-transgenic, reduced A? loads and pyramidal neuronal A? accumulation in the hippocampus. Immunofluorescent studies showed that APP colocalization with Lamp1 was increased in CD74-expressing neurons. Moreover, Morris water maze tasks demonstrated that mice treated with AAV-TRE-CD74 showed improved learning and memory compared to AAV-TRE-GFP control animals. These results support the idea that CD74-induced alteration of A? processing could improve AD-associated memory deficits as shown in mouse models of human disease.