Project description:Acute myeloid leukemia (AML) is an aggressive cancer which causes the rapid proliferation of immature myeloid-lineage blood cells (myeloblasts) in the bone marrow. These leukemic cells receive trophic signals from the bone marrow micro-environment (BMM) in which they reside, that are essential to the initiation and maintenance of the disease. Because this is a complex and heterogeneous tissue, many aspects of this environment remain poorly characterised due to experimental hurdles. Here we performed single-cell RNA-sequencing of bone marrow aspirates from 10 AML patients across multiple key timepoints in disease progression (diagnosis, post-treatment, relapse).
Project description:About 5-10% newly diagnosed and about 20-30% of relapsed acute promyelocytic leukemia (APL) patients will have disease recurrence after receiving currently accepted standards of care. While there are reports of micro-environment mediated drug resistance (EM-DR) in AML, there is no data on the effect of malignant promyelocyte and stromal interaction on Arsenic trioxide (ATO) induced apoptosis. There are limited study available on the effect of leukemic cell interaction on stromal cells. We undertook a preliminary study to evaluate the changes induced by leukemic cells on stromal cells. In a gene expression profiling comparing HS-5 cells in co-culture with NB4 cells alone, 8456 genes were differentially regulated. On a preliminary analysis, we observed an up-regulation of various pathways such as adhesion, Cytokines, Wnt signalling in the stromal cells.
Project description:Acute myeloid leukemia (AML) cells release abundant exosomal miR-7977 that transfer into bone marrow (BM) mesenchymal stromal cells (MSCs). We have shown that exosomal miR-7977 was highly released from AML cells and was transferred into BM MSCs. It has been well known that a microRNA has multiple targets. In fact, miRDB predicted 633 targets. Based on these findings, control and miR-7977mimic were transferred into BM MSCs. Subsequently, alteration of transcriptome was analyzed to gain insight into the role of miR-7977 in bone marrow micro environment.
Project description:First-line treatment for pre-B acute lymphoblastic leukemia (pre-B ALL) typically encompasses a period of so-called induction therapy in which the patient is treated for 28 days with chemotherapy to induce a remission. A bone marrow sample is subsequently taken to determine the number of remaining leukemia cells, which are called minimal residual disease (MDR). MRD is a key prognostic factor, with higher MRD levels predicting worse outcome for patients. Induction therapy usually is able to drastically reduce the number of leukemic cells but chemoresistance, as first detected by higher MRD levels, remains a major clinical problem. MRD persists not only by leukemia cell-intrinsic mechanisms such as clonal selection and genetic changes, but also through protective interactions of the leukemia cells with the surrounding supporting stroma. This mechanism of drug resistance has been named environment-mediated drug resistance (EMDR) and is a general route through which MRD cells, regardless of underlying genetics of the leukemia cells, can persist after chemotherapy. The EMDR component contributing to the persistence of MRD leukemia cells can be studied in tissue culture models by treating leukemia cells with a non-lethal drug dose in the presence of stromal cell protection. Here we analysed the transcriptome of a PDX-derived human pre-B ALL cell line co-cultured with OP9 stromal cells as they developed drug insensitivity against the chemotherapeutic drug vincristine.
Project description:Drug resistance is vital for the poor prognosis of acute myeloid leukemia (AML) patients, but the underlying mechanism remains poorly understood. Given the unique microenvironment of bone marrow, we reasoned that drug resistance of AML might rely on distinct microenvironment-associated metabolic processes. Here, we identified SDH deficiency and over-cumulative succinate as typical features in AML, with a marked function in causing the resistance of AML cells to a wide range of anti-cancer therapies. Mechanistically, succinate promoted the accumulation of oncogenic proteins in a manner that precedes transcriptional activation. This function was mediated by succinate-triggered upregulation of UBC12 phosphorylation, which impaired its E2 function in cullins neddylation. Notably, decreasing succinate levels by fludarabine could effectively restore the drug sensitivity of SDH-deficient AML PDX. Together, we uncover a novel function of succinate in driving drug resistance by regulating p-UBC12/cullin activity, and indicate reshaping succinate metabolism as a promising treatment for SDH-deficient AML.
Project description:Drug resistance is vital for the poor prognosis of acute myeloid leukemia (AML) patients, but the underlying mechanism remains poorly understood. Given the unique microenvironment of bone marrow, we reasoned that drug resistance of AML might rely on distinct microenvironment-associated metabolic processes. Here, we identified SDH deficiency and over-cumulative succinate as typical features in AML, with a marked function in causing the resistance of AML cells to a wide range of anti-cancer therapies. Mechanistically, succinate promoted the accumulation of oncogenic proteins in a manner that precedes transcriptional activation. This function was mediated by succinate-triggered upregulation of UBC12 phosphorylation, which impaired its E2 function in cullins neddylation. Notably, decreasing succinate levels by fludarabine could effectively restore the drug sensitivity of SDH-deficient AML PDX. Together, we uncover a novel function of succinate in driving drug resistance by regulating p-UBC12/cullin activity, and indicate reshaping succinate metabolism as a promising treatment for SDH-deficient AML.
Project description:This data set consists of pediatric acute lymphoblastic leukemia (ALL) primary bone marrow biopsies from the BC Children's Hospital BioBank, pediatric ALL cell lines, non-cancer bone marrow biopsies, and few ALL PDX. All files are DIA and searched by Spectronaut with a spectral library.
