Project description:Genetic studies in T-cell acute lymphoblastic leukemia have uncovered a remarkable complexity of oncogenic and loss-of-function mutations. Amongst this plethora of genetic changes, NOTCH1 activating mutations stand out as the most frequently occurring genetic defect, identified in more than 50% of T-cell acute lymphoblastic leukemias, supporting an essential driver role for this gene in T-cell acute lymphoblastic leukemia oncogenesis. In this study, we aimed to establish a comprehensive compendium of the long non-coding RNA transcriptome under control of Notch signaling. For this purpose, we measured the transcriptional response of all protein coding genes and long non-coding RNAs upon pharmacological Notch inhibition in the human T-cell acute lymphoblastic leukemia cell line CUTLL1 using RNA-sequencing. Similar Notch dependent profiles were established for normal human CD34+ thymic T-cell progenitors exposed to Notch signaling activity in vivo. In addition, we generated long non-coding RNA expression profiles (array data) from GSI treated T-ALL cell lines, ex vivo isolated Notch active CD34+ and Notch inactive CD4+CD8+ thymocytes and from a primary cohort of 15 T-cell acute lymphoblastic leukemia patients with known NOTCH1 mutation status. Integration of these expression datasets with publically available Notch1 ChIP-sequencing data resulted in the identification of long non-coding RNAs directly regulated by Notch activity in normal and malignant T-cell context. Given the central role of Notch in T-cell acute lymphoblastic leukemia oncogenesis, these data pave the way towards development of novel therapeutic strategies that target hyperactive Notch1 signaling in human T-cell acute lymphoblastic leukemia. CD34+ cells of 2 healthy donors are cultured on a OP9-GFP or OP9-DLL1 feeder layer.
Project description:Genetic studies in T-cell acute lymphoblastic leukemia have uncovered a remarkable complexity of oncogenic and loss-of-function mutations. Amongst this plethora of genetic changes, NOTCH1 activating mutations stand out as the most frequently occurring genetic defect, identified in more than 50% of T-cell acute lymphoblastic leukemias, supporting an essential driver role for this gene in T-cell acute lymphoblastic leukemia oncogenesis. In this study, we aimed to establish a comprehensive compendium of the long non-coding RNA transcriptome under control of Notch signaling. For this purpose, we measured the transcriptional response of all protein coding genes and long non-coding RNAs upon pharmacological Notch inhibition in the human T-cell acute lymphoblastic leukemia cell line CUTLL1 using RNA-sequencing. Similar Notch dependent profiles were established for normal human CD34+ thymic T-cell progenitors exposed to Notch signaling activity in vivo. In addition, we generated long non-coding RNA expression profiles (array data) from GSI treated T-ALL cell lines, ex vivo isolated Notch active CD34+ and Notch inactive CD4+CD8+ thymocytes and from a primary cohort of 15 T-cell acute lymphoblastic leukemia patients with known NOTCH1 mutation status. Integration of these expression datasets with publically available Notch1 ChIP-sequencing data resulted in the identification of long non-coding RNAs directly regulated by Notch activity in normal and malignant T-cell context. Given the central role of Notch in T-cell acute lymphoblastic leukemia oncogenesis, these data pave the way towards development of novel therapeutic strategies that target hyperactive Notch1 signaling in human T-cell acute lymphoblastic leukemia. CD34+ cells of 4 healthy donors are cultured on a OP9-GFP or OP9-DLL1 feeder layer.
Project description:The T-cell leukemia homeobox 1 (TLX1, HOX11) transcription factor is critically involved in the multistep pathogenesis of T-cell acute lymphoblastic leukemia (T-ALL) and often cooperates with NOTCH1 activation during malignant T-cell transformation. However, the exact molecular mechanisms by which these T-cell specific oncogenes cooperate during transformation remain to be established. Here, we used an integrative genomics approach to show that the oncogenic properties of TLX1 are mediated by genome-wide interference with the ETS1 and RUNX1 transcription factors. Partial disruption of ETS1 and RUNX1 activity by ectopic TLX1 expression in immature thymocytes drives repression of T-cell specific super-enhancers and mediates an unexpected transcriptional antagonism with NOTCH1 signaling. These phenomena coordinately trigger a TLX1 driven pre-leukemic phenotype in human thymic precursor cells, which corresponds with the in vivo thymic regression observed in murine TLX1 tumor models, and creates a strong genetic pressure for acquiring activating NOTCH1 mutations as a prerequisite for full leukemic transformation. In conclusion, our results uncover a functional antagonism between cooperative oncogenes during the earliest phases of tumor development and provide novel insights in the multistep pathogenesis of TLX1 driven human leukemia. Gene expression was measured after TLX1 overexpression in human CD34+ T-cell progenitors cultured on an OP9-DLL1 feeder layer. Cells were collected after 72h of co-culture. This was performed for 2 independent thymus CD34+ donors.
Project description:Development of gene expression signatures for TLX1 overexpression in human thymus C34+ T-cell progenitors cultured on an OP9-DLL1 feeder layer
Project description:Umbilical cord blood (UCB) transplantation shows pro-angiogenic effect and contributes to symptom amelioration in animal models of cerebral infarction. OP9 is a stromal cell line used as feeder cells to promote hematoendothelial differentiation of embryonic stem cells. We co-cultured UCB 24hr with OP9 (i.e. OP9 preconditioning) and investigated its change in angiogenic properties and underlying mechanisms. Single cell RNA sequencing showed prominent phenotypic shift toward M2 in monocytic fraction of OP9 pre-conditioned UCB.
Project description:Gene expression analysis in Ebf1-/- lymphocyte progenitors complemented with EBF1wt or EBF1E271A and co-cultured with OP9-DL1 feeder cells.
Project description:Lineage-negative thymocytes were cultured on OP9-DL1 stromal cells for 16h in the presence of DMSO or the gamma secretase inhibitor MRK-003. DN3 cells cells were then sorted and their transcriptome analyzed.
Project description:To explore the molecular mechanisms underlying selective differentiation of MAIT-derived iPSCs into reMAITs, we conducted micro RNAs profiling based on microarrays. We sampled reMAITs during the time course of differentiation from iPSCs as well as mature MAITs isolated from cord blood (CB MAITs). As control, we used immature T cells differentiated from hematopoietic stem cells (HSCs). For each of reMAITs and the immature T cells, we selected four time points: Start, Early, Middle, and Late. MAITs isolated from CB were reprogrammed to iPSCs (PMID:23523177). The MAIT-derived iPSCs were cultured on OP9, and CD34+ CD43+ cells were isolated. These CD34+ CD43+ precursor cells were furthered cultured on OP9/DL1 for re-differentiation into MAITs. Based on the observation of the reported surface antigen profiles (PMID:23523177), reMAITs were harvested at four different time points: day 0 (Start), day 4 (Early), day 7-10 (Middle), and after day 30 (Late). For the immature T cells, CD34+ cells were isolated from CB using CD34 MicroBead Kit (Miltenyi Biotech). These CD34+ HSCs were cultured on OP9/DL1 for differentiation into T cell lineage as previously described (PMID:15494433). Based on the surface antigen profiles, the immature T cells were harvested at four different time points: CD34+ cells at day 0 (Start), CD4- CD8- double negative cells at day 21 (Early) and day 40 (Midlle), and CD4+ CD8+ double positive cells after day 50 (Late). Total RNA was extracted from each sample using RNeasy Kit (Quiagen). For micro RNA analysis, RNA was labeled with Cy3-pCp by ligation, and subjected to analysis using Human miRNA Microarray Release 19.0 8x60K (Agilent).
Project description:The pluripotency maintenance of pluripotent stem cells (PSCs) cultured in vitro requires the suitable microenvironment, which is commonly provided by the feeder layer. However, the preparation of feeder layer is time consuming and labor exhaustive. More importantly, the feeder cells treated with mitomycin or gamma-ray irradiation brings heterologous contamination to stem cells. The feeder-free PSC cultures are associated with high costs because of the requirement for additional supplements and special media. In this study, we characterize the pluripotency and metabolic status of bovine ESCs-F7 (classic bESCs lines, abbreviated as F7), which were cultured on methanol fixed mouse embryonic fibroblasts (MT-MEFs) or mitomycin C treated MEFs (1M-MEFs). MT-MEFs could be reused several times and were highly resistant to digestive enzymes. The relative expression levels of pluripotent markers were different between F7 cultured on MT-MEFs (marked as MT-F7) and those cultured on the 1M-MEFs (1M-F7). The long-term cultured MT-F7 cells formed embryoid bodies in vitro, showing the ability to differentiate into endodermal, ectodermal, and mesodermal germ layers like 1M-F7. RNA-sequencing analysis showed that the replacement of the feeder layer from 1M-MEFs to MT-MEFs lead to a novel steady transition of the F7, which included alteration of the expression patterns of genes that regulate pluripotency and metabolism. Further, the long-term cultured bovine expanded pluripotent stem cells (bEPSCs) on MT-MEFs (MT-bEPSCs) formed classical colonies, maintained pluripotency, and demonstrated elevated level of metabolic activity. In conclusion, this study demonstrated that methanol-fixed MEFs were efficient feeder layer that maintain the unique pluripotency and the distinctive metabolic characteristics of the bPSCs cultured in vitro.