Project description:We want to obtain FLT3-ITD gene signature. To do so, we transduced CB CD34+ cells with mock or FLT3-ITD vectors and performed RNA sequencing (RNA-Seq). Two Groups: Group1: CB CD34+ cells transduced with mock vector; Group2: CB CD34+ cells transduced with FLT3-ITD vector;
Project description:We used whole genome microarray expression profiling as a discovery platform to identify genes regulated by FLT3-ITD activity. Viral particles with pMY-puro, pMY-puro-FLT3-ITD-1 or pMY-puro-FLT3-ITD-2, were generated using PLAT-gp packaging cells and infected to K562 cells. The vector-transduced cells were selected with 2µg/ml puromycin treatment.
Project description:FLT3 is the most frequently mutated gene in AML â up to 40% of AML harbor an activating mutation within FLT3 gene. Though AML is a relatively rare disease, such a high mutability rate, as observed with FLT3 gene, is striking. To elucidate the molecular background of this phenomenon, we have established nine unique FLT3/ITD - carrying 32D cell lines and a set of controls, and subjected them to whole genome expression analysis and 2DE LC/MS proteomics. Data obtained on this so far largest set of ITD mutants indicates that in comparison to the wild type FLT3 expressing 32D cells and transduction controls, FLT3/ITD positive cells exhibit less mature expression profiles resembling ST-HSC and MkEP/CMP/LMPP progenitors. We hypothesize that FLT3/ITD might contribute not only to the proliferative advantage of FLT3/ITD positive cells, but also to their reprogramming towards less differentiated stages, thus strengthening their malignant properties. This finding might explain the pronounced mutation rate of the aberrantly expressed FLT3 gene in AML, and, also, the inferior prognosis of FLT3/ITD positive AML patients. Moreover, the microarray data has revealed biological differences among individual ITD variants â a finding supporting the recent clinical data on the prognostic impact of the size of individual ITDs. Keywords: genetic modification Nine stable 32D cell lines harboring unique human FLT3/ITD mutants, two parental 32 cell lines, two 32D stable cell lines harboring cloning vector only, and two 32D cell lines stably expressing human wild type FLT3 were subjected to the microarray analysis.
Project description:mRNA expression regulated by FLT3/ITD and Cxcl12 were compared in the Ba/F3 cells expressing wild type FLT3 or FLT3/ITD and incubated with or without Cxcl12.
Project description:To investigate the effect of FLT3-ITD on gene expression, we have employed whole genomic microarray expression profiling using K562 cells
Project description:FLT3 is the most frequently mutated gene in AML – up to 40% of AML harbor an activating mutation within FLT3 gene. Though AML is a relatively rare disease, such a high mutability rate, as observed with FLT3 gene, is striking. To elucidate the molecular background of this phenomenon, we have established nine unique FLT3/ITD - carrying 32D cell lines and a set of controls, and subjected them to whole genome expression analysis and 2DE LC/MS proteomics. Data obtained on this so far largest set of ITD mutants indicates that in comparison to the wild type FLT3 expressing 32D cells and transduction controls, FLT3/ITD positive cells exhibit less mature expression profiles resembling ST-HSC and MkEP/CMP/LMPP progenitors. We hypothesize that FLT3/ITD might contribute not only to the proliferative advantage of FLT3/ITD positive cells, but also to their reprogramming towards less differentiated stages, thus strengthening their malignant properties. This finding might explain the pronounced mutation rate of the aberrantly expressed FLT3 gene in AML, and, also, the inferior prognosis of FLT3/ITD positive AML patients. Moreover, the microarray data has revealed biological differences among individual ITD variants – a finding supporting the recent clinical data on the prognostic impact of the size of individual ITDs. Keywords: genetic modification
Project description:ITD mutations in the FLT3 gene occur in the 30% of acute myeloid leukemia patients. The integration of ITD in the tyrosine kinase domain (TKD-ITD) of the FLT3 receptor has been shown to confer resistance to standard chemotherapy treatment. We applied state-of-the-art, high-sensitive, mass spectrometry (MS)-based (phospho)proteomics to investigate the molecular mechanisms underlying the sensitivity to cytarabine therapy in FLT3-ITD cells.
Project description:Transcriptional profiling of murine bone marrow c-kit+, Sca-1+ lineage neative (KSL) cells from p21CDKN1a-/- and p21+/+ overexpressing Flt3/ITD. The goal was to determine the effect on global gene expression by loss of p21 in Flt3/ITD transformed KSL cells Internal tandem duplication (ITD) mutations in the Flt3 gene (Flt3-ITD) are associated with poor prognosis in patients with acute myeloid leukemia (AML). Few inhibitors of Flt3-ITD are effective against Flt3-ITD+ AML due to the development of drug-resistance. In this study, we demonstrate that Flt3-ITD activates a novel pathway involving p21Cdkn1a (p21) and pre-B cell leukemia transcription factor 1 (Pbx1) that attenuates Flt3-ITD cell proliferation and is involved in the development drug resistance. Flt3-ITD up-regulated p21 expression in mouse bone marrow c-kit+-Sca-1+-Lin- (KSL) cells and in Ba/F3 cells. Loss of p21 expression enhanced growth factor-independent proliferation and sensitivity to cytarabine as a consequence of enriching the S+G2/M phase population concomitant with a significant increase in the expression of Pbx1, but not Evi-1, in Flt3-ITD+ cells. This enhancement of cell proliferation by loss of p21 was partially abrogated when Pbx1 expression was silenced in Flt3-ITD+ primary bone marrow colony-forming cells (CFCs) and Ba/F3 cells. Antagonizing Flt3-ITD using AC220, a selective inhibitor of Flt3-ITD, decreased the expression of p21, coincident with the up-regulation of Pbx1 mRNA and a rapid decline in the number of viable Flt3-ITD+ Ba/F3 cells, however the cells eventually became refractory to AC220. Overexpressing p21 in Flt3-ITD+ Ba/F3 cells delayed the emergence of cells refractory to AC220, whereas silencing p21 accelerated their development. These data demonstrate that Flt3-ITD is capable of inhibiting the proliferation of Flt3-ITD+ cells through the p21/Pbx1 axis and that antagonizing Flt3-ITD contributes to the subsequent development of cells refractory to Flt3-ITD inhibitor by disrupting p21 expression.
Project description:Transcriptional profiling of murine bone marrow c-kit+, Sca-1+ lineage neative (KSL) cells from p21CDKN1a-/- and p21+/+ overexpressing Flt3/ITD. The goal was to determine the effect on global gene expression by loss of p21 in Flt3/ITD transformed KSL cells Internal tandem duplication (ITD) mutations in the Flt3 gene (Flt3-ITD) are associated with poor prognosis in patients with acute myeloid leukemia (AML). Few inhibitors of Flt3-ITD are effective against Flt3-ITD+ AML due to the development of drug-resistance. In this study, we demonstrate that Flt3-ITD activates a novel pathway involving p21Cdkn1a (p21) and pre-B cell leukemia transcription factor 1 (Pbx1) that attenuates Flt3-ITD cell proliferation and is involved in the development drug resistance. Flt3-ITD up-regulated p21 expression in mouse bone marrow c-kit+-Sca-1+-Lin- (KSL) cells and in Ba/F3 cells. Loss of p21 expression enhanced growth factor-independent proliferation and sensitivity to cytarabine as a consequence of enriching the S+G2/M phase population concomitant with a significant increase in the expression of Pbx1, but not Evi-1, in Flt3-ITD+ cells. This enhancement of cell proliferation by loss of p21 was partially abrogated when Pbx1 expression was silenced in Flt3-ITD+ primary bone marrow colony-forming cells (CFCs) and Ba/F3 cells. Antagonizing Flt3-ITD using AC220, a selective inhibitor of Flt3-ITD, decreased the expression of p21, coincident with the up-regulation of Pbx1 mRNA and a rapid decline in the number of viable Flt3-ITD+ Ba/F3 cells, however the cells eventually became refractory to AC220. Overexpressing p21 in Flt3-ITD+ Ba/F3 cells delayed the emergence of cells refractory to AC220, whereas silencing p21 accelerated their development. These data demonstrate that Flt3-ITD is capable of inhibiting the proliferation of Flt3-ITD+ cells through the p21/Pbx1 axis and that antagonizing Flt3-ITD contributes to the subsequent development of cells refractory to Flt3-ITD inhibitor by disrupting p21 expression. biological replicates: 3 KSL cell replicates overexpressing ITD-Flt3 from p21+/+ and p21-/- cells, 1 KSL cell replicate from p21+/+ and p21-/- cells
Project description:Examination of gene expression patterns in lineage negative FLT3-ITD– and pMIG-transduced BM cells via microarray study. We performed a global mRNA profiling analysis of murine Lin– FLT3-ITD+ cells compared to empty-vector controls, purified 48h after transduction. We examined association patterns of FLT3-ITD and pMIG cells and identified a specific gene expression signature associated with FLT3-ITD signalling.