Project description:Acute myeloid leukemia remodels the bone marrow non-hematopoietic microenvironment which disrupts niche archiecture and normal hematopoiesis The precise interactions underlying this process are not well understood We used microarrays to detail the global programme of gene expression underlying the interactions between healthy mesenchymal stroma cells and normal hematopoietic progenitors/stem cells (HSPCs) and AML
Project description:Interleukin-1β (IL-1β) drives hematopoietic stem cell (HSC) differentiation into the myeloid lineage, and enhanced IL-1β signaling plays a key role in hematological malignancies. However, little is known on the role of its endogenous regulatory cytokine, IL-1 receptor antagonist (IL-1rn), on both healthy and malignant hematopoiesis. Here, we show that inflammation through unbalanced IL-1rn is present in the experimental model of acute myeloid leukemia (AML) driven by the NRAS-G12D oncogene.
Project description:Antibody-based therapy for cancer is now one of the most successful and important strategies for treating patients with hematological malignancies. However, the lack of efficient tumor-associated antigens restricts the targeting therapy of myeloid leukemia. Analysis of the gene expression proï¬les of primary bone marrow samples from human acute myeloid leukemia (AML) patients or healthy donors was to identify and expand novel targets for the treatment of myeloid leukemias. we found that epithelial cell adhesion molecule (EpCAM) is overexpressed in patients with AML. we analyzed the gene expression proï¬les of bone marrow mononuclear cells from 2 human acute myeloid leukemia (AML) patients and 2 healthy donors using an oligonucleotide microarray, to identify up-regulated genes in AML samples comparing with healthy tissues.
Project description:<p>Acute Myeloid Leukemia (AML) commonly relapses after initial chemotherapy response. We assessed metabolic adaptations in chemoresistant cells in vivo before overt relapse, identifying altered branched-chain amino acid (BCAA) levels in patient-derived xenografts (PDX) and immunophenotypically identified leukemia stem cells from AML patients. Notably, this was associated with increased BCAA transporter expression with low BCAA catabolism. Restricting of BCAAs further reduced chemoresistant AML cells but relapse still occurred. Among the persisting cells we found an unexpected increase in protein production. This was accompanied by elevated translation of 2-oxoglutarate-and-iron-dependent oxygenase 1 (OGFOD1), a known ribosomal dioxygenase that adjusts the fidelity of tRNA anticodon pairing with coding mRNA1–3 and upregulates protein synthesis in AML driving disease aggressiveness. Inhibiting OGFOD1 impaired translation processing, decreased protein synthesis and improved animal survival even with chemoresistant AML through regulation of protein synthesis. Leukemic cells can therefore persist despite the stress of chemotherapy and nutrient deprivation through adaptive control of translation while sparing normal hematopoiesis. Targeting OGFOD1 may offer a distinctive, translation modifying means of reducing the chemopersisting cells that drive relapse.</p>
Project description:Acute myeloid leukemia (AML) is characterized by frequent relapse, which is driven by resistant leukemic stem or progenitor cells (LSCs). Here, we reported on a tumor-suppressive mechanism that can be harnessed to simultaneously clear LSCs and promote healthy hematopoiesis. Genetic deletion of the tumor necrosis factor (TNF) superfamily member lymphotoxin alpha (Lta) blocked cell death and accelerated leukemogenesis in murine AML models. Accordingly, exposure of leukemic cells to exogenous recombinant lymphotoxin alpha (LTα3) induced myeloid differentiation and, in part, cell death in AML progenitors. In syngeneic and patient-derived xenograft mouse models, exposure to recombinant LTα3 resulted in deep and durable remissions. LTα3 repressed leukemia by depleting tumor necrosis factor receptor (TNFR)-associated factor 2 (TRAF2) through activation of TNF receptors TNFR1 and TNFR2. In contrast with conventional therapies, LTα3 exerted only minimal toxicity on the healthy hematopoiesis but instead promoted hematopoietic progenitors. Leveraging this endogenous tumor-suppressive mechanism may decouple treatment efficacy on malignant cells from undesired bone marrow suppression.
Project description:we show that YBX1 is specifically required for maintaining myeloid leukemia cell survival but is dispensable for normal hematopoiesis. We found that expression of YBX1 is significantly upregulated in myeloid leukemia cells, and deletion of YBX1 significantly induces apoptosis, coupled with reduced proliferation and impaired leukemic capacity of primary human and mouse acute myeloid leukemia (AML) cells in vitro and in vivo. Loss of YBX1 does not obviously affect normal hematopoiesis. Mechanistically, YBX1 interacts with IGF2BPs and stabilizes m6A-tagged RNA. Moreover, YBX1 deficiency promotes mRNA decay in an m6A-dependent manner, which contributes to the defective survival due to YBX1 deletion. Thus, our findings uncover a selective and critical role of YBX1 in maintaining myeloid leukemia survival that might provide a rationale for the therapeutic targeting of YBX1 in myeloid leukemia.
Project description:we show that YBX1 is specifically required for maintaining myeloid leukemia cell survival but is dispensable for normal hematopoiesis. We found that expression of YBX1 is significantly upregulated in myeloid leukemia cells, and deletion of YBX1 significantly induces apoptosis, coupled with reduced proliferation and impaired leukemic capacity of primary human and mouse acute myeloid leukemia (AML) cells in vitro and in vivo. Loss of YBX1 does not obviously affect normal hematopoiesis. Mechanistically, YBX1 interacts with IGF2BPs and stabilizes m6A-tagged RNA. Moreover, YBX1 deficiency promotes mRNA decay in an m6A-dependent manner, which contributes to the defective survival due to YBX1 deletion. Thus, our findings uncover a selective and critical role of YBX1 in maintaining myeloid leukemia survival that might provide a rationale for the therapeutic targeting of YBX1 in myeloid leukemia.