Project description:The Acute Myeloid Leukemia cell line HL-60 was rendered resistant to daunorubicin (DNR) or cytarabine (Ara-C) by continuous exposure to the drug up to concentrations of 30nM for DNR and 100nM for Ara-C. Transcriptomic analysis were then performed by RNA-Seq to compare the cell lines
Project description:Dormant chemotherapy-resistant leukemia cells can survive for an extended period before relapse. Nevertheless, the mechanisms underlying the development of chemoresistance in vivo remain unclear. Using intravital bone imaging, we characterized the behavior of murine acute myeloid leukemia (AML) cells (C1498) in the bone marrow before and after chemotherapy with cytarabine. Proliferative C1498 cells exhibited high motility in the bone marrow. Cytarabine treatment impaired the motility of residual C1498 cells. However, C1498 cells regained their migration potential after relapse. RNA sequencing revealed that cytarabine treatment promoted MRTF-SRF pathway activation. MRTF inhibition using CCG-203971 augmented the anti-tumor effects of chemotherapy in our AML mouse model, as well as suppressed the migration of chemoresistant C1498 cells. These results provide novel insight into the role of cell migration arrest on the development of chemoresistance in AML, as well as provide a strong rationale for the modulation of cellular motility as a therapeutic target for refractory AML.
Project description:Purpose: To investigate the transcriptome of primary pediatric acute myeloid leukemia to identify molecular signatures correlated with sensitivity to LV-10 mediated killing Method: RNA sequencing of polyA enriched pediatric acute myeloid leukemia bone marrow aspirates Results: pAML killing sensitivity is associated with the expression of a myeloid maturation signature, while resistant pAMLs expressed a more stem cell-like signature Conclusions: Pediatric acute myeloid leukemia samples have different sensitivities to killing by LV-10 in vitro and the transcriptomes of killing-sensitive and killing-resistant lines differ
Project description:We identified a transient increase in metabolites involved in glutamine metabolism in chemoresistant acute myeloid leukemia (AML) cells. To further investigate this, we evaluated the transcriptome of AML cells from bone marrow of vehicle-treated mice and mice treated with induction chemotherapy (doxorubicin+cytarabine) at 3 days (iCT group) and 10 days (relapse group) after completion of the chemotherapy.
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:Background: MicroRNAs are regulators of gene expression, mainly functioning by decreasing mRNA levels of their multiple targets. Deregulated microRNA expression has been shown for acute myeloid leukemia, a disease also characterized by altered gene expression associated with distinct genomic aberrations such as nucleophosmin (NPM1) mutations. To further illuminate the role of deregulated microRNA and gene expression in cytogenetically normal acute myeloid leukemia with NPM1 mutation, we performed an integrative analysis of microRNA and mRNA expression data sets. Design and Methods: Both microRNA and gene expression profiles were measured in a cohort of 43 adult acute myeloid leukemia patient samples (n=42 cytogenetically normal, n=1 del7q; median age 46 years [range 23-60]) of known NPM1 mutation status (n=23 mutated, n=20 wild-type) and data integratively analyzed. Putative microRNA-mRNA interactions were validated by quantitative RT-PCR, Western Blot and luciferase reporter assays. For selected microRNAs, sensitivity of microRNA-overexpressing cells to cytarabine treatment was tested by FACS viability and cell proliferation assays. Results: Our integrative approach of analyzing both microRNA and gene expression profiles in parallel resulted in a refined list of putative target genes affected by NPM1 mutation-associated microRNA deregulation. Of 177 putative microRNA - target mRNA interactions, we could identify and validate 77 novel candidates with known or potential implication in leukemogenesis, such as IRF2-miR-20a, KIT-miR-20a and MN1-miR-15a. Furthermore, our data showed that deregulated expression of tumor suppressor microRNAs such as miR-29a and miR-30c might contribute to the sensitivity to cytarabine, which is observed in NPM1-mutated acute myeloid leukemia. Conclusions: Overall, our observations highlight that integrative data analysis approaches can improve insights into leukemia biology, and lead to the identification of novel microRNA - target gene interactions of potential relevance for acute myeloid leukemia treatment. MicroRNA and gene expression profiles were measured in a cohort of 43 adult (42 cytogenetically normal and 1 del7q) acute myeloid leukemia patient samples of known NPM1 mutation status (n=23 mutated, n=20 wild-type). This submission represents the mRNA expression component of the study. The miRNA expression data will be deposited as supplementary information along with the accompanying manuscript.