Project description:Notch1-IC, Notch2-IC or EBNA2 have been induced in a conditionally immortalized human B cell line (EREB2-5) in order to identify similar and unique target genes in B cells. CAT was used as a control. Experiment Overall Design: RNA was isolated at different time points after induction of Notch1-IC, Notch2-IC or EBNA2 in EREB2-5 cells. Three independent experiments were performed (except Notch1-IC at 3day).
Project description:Notch1-IC, Notch2-IC or EBNA2 have been induced in a conditionally immortalized human B cell line (EREB2-5) in order to identify similar and unique target genes in B cells. CAT was used as a control. Keywords: time course
Project description:To determine role of Notch signaling in AML leukemia initiating cells we used a conditional mouse knock-in model of Notch1-IC to induce Notch1-IC expression in MLL-AF9 transformed LGMP. WT and Notch1-IC+ LGMP were analyzed to determined genes controlled by Notch signaling.
Project description:Notch signaling plays essential roles in maintenance of muscle stem cell pool. We found that Notch2, but not Notch1 and Notch3, is expressed in fully differentiated myofibers. To study the specific role of Notch2 in adult myofibers, we generated muscle-specific Notch2-knockout mice. Here, we showed that muscle-specific Notch2 deficiency prevented muscle atrophy induced by hindlimb unloading and diabetes millitus. RNA sequencing analysis revealed that the loss of Notch2 gene in myofibers inhibited gene responses to unloading and diabetes. Especially, several FoxO-target genes and atrogenes were upregulated in wildtype muscles but not in Notch2-deficient muscles by unloading and diabetes. Thus, our characterization of muscle-specific Notch2-knockout mice indicates that Notch2 acts as a regulatory factor of skeletal muscle plasticity and could be a therapeutic target of muscle atrophy.
Project description:To determine role of Notch signaling in AML leukemia initiating cells we used a conditional mouse knock-in model of Notch1-IC to induce Notch1-IC expression in MLL-AF9 transformed LGMP. WT and Notch1-IC+ LGMP were analyzed to determined genes controlled by Notch signaling. 12 weeks old wt lethaly irradiated mice were transplanted with 50000 cKit+ MLL-AF9-IRES-YFP infected cells from MLL-AF9 EF1 wt/wt ROSAwt/CreERT2 or MLL-AF9 EF1 wt/lsl-N1-IC ROSAwt/CreERT2 mice + 250000 support wt total bone marrow cells. 4 weeks after transplant mice were injected 2 times with tamoxifen (0.2mg/g body weight) every other day. Mice were sacrificed and analyzed 6 days after last injection. LGMP were flow purified for RNA extraction and hybridization on Affymetrix microarrays.
Project description:Small cell lung cancer (SCLC) is a highly aggressive malignancy that lacks effective targeted therapies, in part due to frequent loss-of-function mutations in tumor suppressors and the absence of recurrent oncogenic drivers. Approximately 15% of SCLCs harbor inactivating mutations in NOTCH1 or NOTCH2, and most neuroendocrine-high SCLCs exhibit low NOTCH activity. Using CRISPR/Cas9 screening in primary cell lines derived from NOTCH1/2-isogenic SCLC genetically engineered mouse models, we identified TRIM28 as a synthetic lethal dependency in NOTCH2-inactivated SCLCs. Loss of TRIM28 in this context robustly induced expression of endogenous retroviruses, activated viral sensing pathways, and triggered a type I interferon response. Mechanistically, NOTCH2 inactivation increased reliance on TRIM28-mediated ERV silencing, creating a hyper-dependence on TRIM28 via the STING–MAVS–TBK1 axis. Notably, TRIM28 was essential for tumor growth only in the setting of NOTCH2 loss. These findings identify TRIM28 as a potential therapeutic target in NOTCH2-deficient or low-NOTCH2-expressing SCLC.
Project description:Small cell lung cancer (SCLC) is a highly aggressive malignancy that lacks effective targeted therapies, in part due to frequent loss-of-function mutations in tumor suppressors and the absence of recurrent oncogenic drivers. Approximately 15% of SCLCs harbor inactivating mutations in NOTCH1 or NOTCH2, and most neuroendocrine-high SCLCs exhibit low NOTCH activity. Using CRISPR/Cas9 screening in primary cell lines derived from NOTCH1/2-isogenic SCLC genetically engineered mouse models, we identified TRIM28 as a synthetic lethal dependency in NOTCH2-inactivated SCLCs. Loss of TRIM28 in this context robustly induced expression of endogenous retroviruses, activated viral sensing pathways, and triggered a type I interferon response. Mechanistically, NOTCH2 inactivation increased reliance on TRIM28-mediated ERV silencing, creating a hyper-dependence on TRIM28 via the STING–MAVS–TBK1 axis. Notably, TRIM28 was essential for tumor growth only in the setting of NOTCH2 loss. These findings identify TRIM28 as a potential therapeutic target in NOTCH2-deficient or low-NOTCH2-expressing SCLC.
Project description:Small cell lung cancer (SCLC) is a highly aggressive malignancy that lacks effective targeted therapies, in part due to frequent loss-of-function mutations in tumor suppressors and the absence of recurrent oncogenic drivers. Approximately 15% of SCLCs harbor inactivating mutations in NOTCH1 or NOTCH2, and most neuroendocrine-high SCLCs exhibit low NOTCH activity. Using CRISPR/Cas9 screening in primary cell lines derived from NOTCH1/2-isogenic SCLC genetically engineered mouse models, we identified TRIM28 as a synthetic lethal dependency in NOTCH2-inactivated SCLCs. Loss of TRIM28 in this context robustly induced expression of endogenous retroviruses, activated viral sensing pathways, and triggered a type I interferon response. Mechanistically, NOTCH2 inactivation increased reliance on TRIM28-mediated ERV silencing, creating a hyper-dependence on TRIM28 via the STING–MAVS–TBK1 axis. Notably, TRIM28 was essential for tumor growth only in the setting of NOTCH2 loss. These findings identify TRIM28 as a potential therapeutic target in NOTCH2-deficient or low-NOTCH2-expressing SCLC.
Project description:Next generation sequencing was used to identify Notch mutations in a large collection of diverse solid tumors. NOTCH1 and NOTCH2 rearrangements leading to constitutive receptor activation were confined to triple negative breast cancers (TNBC, 6 of 66 tumors). TNBC cell lines with NOTCH1 rearrangements associated with high levels of activated NOTCH1 (N1-ICD) were sensitive to the gamma-secretase inhibitor (GSI) MRK-003, both alone and in combination with pacitaxel, in vitro and in vivo, whereas cell lines with NOTCH2 rearrangements were resistant to GSI. Immunohistochemical staining of N1-ICD in TNBC xenografts correlated with responsiveness, and expression levels of the direct Notch target gene HES4 correlated with outcome in TNBC patients. Activating NOTCH1 point mutations were also identified in other solid tumors, including adenoid cystic carcinoma (ACC). Notably, ACC primary tumor xenografts with activating NOTCH1 mutations and high N1-ICD levels were sensitive to GSI, whereas N1-ICD low tumors without NOTCH1 mutations were resistant. Gene expression profiling for Notch-sensitive cancer cell lines using RNA-seq, each sample with triplicates