Project description:Whole exome sequencing (the SureSelectXT Mouse All Exon Kit) was done on leukemias from NP23-NHD13 double transgenic mice with strain background designated “C57Bl6-NIH”.
Project description:Mutations in the isocitrate dehydrogenase 1 (IDH1) and IDH2 genes are frequently observed in a wide variety of hematologic malignancies, including myeloid and T-cell leukemias. In this study, we generated Idh2R140Q transgenic mice to examine the role of the Idh2R140Q mutation in leukemia. No leukemia developed in Idh2R140Q transgenic mice, suggesting a need for additional genetic events for leukemia development. Since myeloid cells from NUP98-HOXD13 fusion (NHD13) transgenic mice frequently acquire somatic Idh mutations when they transform to AML, we generated Idh2R140Q/NHD13 double transgenic mice. Idh2R140Q/NHD13 transgenic mice developed an immature T cell leukemia with an immunophenotype similar to double-negative 1 (DN1) or DN2 thymocytes. Idh2R140Q/NHD13 leukemic cells were enriched for an early thymic precursor transcriptional signature, and the gene expression profile for Idh2R140Q/NHD13 DN1/DN2 T-ALL closely matched that of human early/immature T cell precursor (EITP) ALL. Moreover, recurrent mutations found in EITP ALL patients, including KRAS, PTPN11, JAK3, SH2B3, and EZH2 were also found in Idh2R140Q/NHD13 DN1/DN2 T-ALL. In vitro treatment of Idh2R140Q/NHD13 thymocytes with enasidenib, a selective inhibitor of mutant IDH2, led to a marked decrease in leukemic cell proliferation. These findings demonstrate that Idh2R140Q/NHD13 mice can serve as a useful in vivo model for the study of EITP ALL development and therapy. We used gene expression arrays to compare the global gene expression profiles between Idh2R140Q/NHD13 DN1/DN2 T-ALL, non-DN1/DN2 cortical T-ALL (CD4+CD8+) and wild-type thymus.
Project description:Loss of function TET2 mutations are frequently seen in myelodysplastic syndrome (MDS) patients. Previous studies have demonstrated that TET2 deficiency enhances maintenance of MDS hematopoietic stem and progenitor cells (HSPCs). Nonetheless, the pathogenic role of TET2 in MDS progression remains elusive. Here, we demonstrate Tet2 knockout (KO) markedly accelerated malignant transformation in Nup98-HoxD13 (NHD13) transgenic mice and promotes leukemogenesis of HoxA9 transduction/transplant mice. Consistently, low TET2 level cooperating with high HOXA9 level predicts poor outcome of MDS patients. Notably, Tet2 KO conferred a clonal advantage to the HSPCs of NHD13 mice. Whole-exome sequencing revealed that Tet2 KO facilitates accumulation of mutations at genes associated with leukemogenesis, including Arih2, whose loss of function promotes MDS cells proliferation. Using 5-hydroxymethylcytosine immunoprecipitation coupled with high-throughput sequencing analysis, we found while Tet2 deletion decreased overall 5hmC levels, it also increased 5hmC distribution at certain mutation loci such as Arih2. Vitamin C treatment, which mimics Tet2/Tet3 restoration, blocked disease progression in Tet2-deficient NHD13 mice. Collectively, our findings demonstrate that TET2 activity governs occurrence of secondary mutations in MDS HSPCs, providing a rationale for enhancing TETs function to block MDS-malignant transformation.
2022-10-12 | GSE213591 | GEO
Project description:Whole exome sequencing of leukemias from MCM2 transgenic mice
Project description:Loss of function TET2 mutations are frequently seen in myelodysplastic syndrome (MDS) patients. Previous studies have demonstrated that TET2 deficiency enhances maintenance of MDS hematopoietic stem and progenitor cells (HSPCs). Nonetheless, the pathogenic role of TET2 in MDS progression remains elusive. Here, we demonstrate Tet2 knockout (KO) markedly accelerated malignant transformation in Nup98-HoxD13 (NHD13) transgenic mice and promotes leukemogenesis of HoxA9 transduction/transplant mice. Consistently, low TET2 level cooperating with high HOXA9 level predicts poor outcome of MDS patients. Notably, Tet2 KO conferred a clonal advantage to the HSPCs of NHD13 mice. Whole-exome sequencing revealed that Tet2 KO facilitates accumulation of mutations at genes associated with leukemogenesis, including Arih2, whose loss of function promotes MDS cells proliferation. Using 5-hydroxymethylcytosine immunoprecipitation coupled with high-throughput sequencing analysis, we found while Tet2 deletion decreased overall 5hmC levels, it also increased 5hmC distribution at certain mutation loci such as Arih2. Vitamin C treatment, which mimics Tet2/Tet3 restoration, blocked disease progression in Tet2-deficient NHD13 mice. Collectively, our findings demonstrate that TET2 activity governs occurrence of secondary mutations in MDS HSPCs, providing a rationale for enhancing TETs function to block MDS-malignant transformation.
Project description:We analyzed the genome wide localization of H3K4me3, H3K27me3 and the NUP98-PHF23 (with V5 tag) fusion protein which binds H3K4me3 via its PHD finger, using ChIP-seq. Results correlated with gene expression profiles. NUP98-PHF23 bound only 1.6% of H3K4me3 marks including Hoxa/b + Meis1. Assess H3K4me3 and H3K27me3 histone marks, and correlate these marks with chromatin binding of the NP23 fusion protein using lymphoblast and myeloblast cell lines derived from NP23 leukemias.
Project description:We examined the patterns of gene expression of mouse thymic leukemias extracted from Mb1-CreDPB mice by RNA sequencing (RNA-seq). Our goal was to integrate RNA-seq data with whole-exome sequencing (WES) to determined secondary driver mutations of leukemogenesis in the absence of Spi-B and PU.1,
Project description:NUP98-PHF23 is oncogenic and results in a Hoxa/b + Meis1 overexpression in NP23 leukemias and in premalignant (clinically healthy) hematopoietic tissues.