1. |
- Askmyr, Maria, et al.
(author)
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Modeling chronic myeloid leukemia in immunodeficient mice reveals expansion of aberrant mast cells and accumulation of pre-B cells.
- 2014
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In: Blood Cancer Journal. - : Springer Science and Business Media LLC. - 2044-5385. ; 4
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Journal article (peer-reviewed)abstract
- Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm that, if not treated, will progress into blast crisis (BC) of either myeloid or B lymphoid phenotype. The BCR-ABL1 fusion gene, encoding a constitutively active tyrosine kinase, is thought to be sufficient to cause chronic phase (CP) CML, whereas additional genetic lesions are needed for progression into CML BC. To generate a humanized CML model, we retrovirally expressed BCR-ABL1 in the cord blood CD34(+) cells and transplanted these into NOD-SCID (non-obese diabetic/severe-combined immunodeficient) interleukin-2-receptor γ-deficient mice. In primary mice, BCR-ABL1 expression induced an inflammatory-like state in the bone marrow and spleen, and mast cells were the only myeloid lineage specifically expanded by BCR-ABL1. Upon secondary transplantation, the pronounced inflammatory phenotype was lost and mainly human mast cells and macrophages were found in the bone marrow. Moreover, a striking block at the pre-B-cell stage was observed in primary mice, resulting in an accumulation of pre-B cells. A similar block in B-cell differentiation could be confirmed in primary cells from CML patients. Hence, this humanized mouse model of CML reveals previously unexplored features of CP CML and should be useful for further studies to understand the disease pathogenesis of CML.
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2. |
- Askmyr, Maria, et al.
(author)
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Transgenic expression of human cytokines in immunodeficient mice does not facilitate myeloid expansion of BCR-ABL1 transduced human cord blood cells
- 2017
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In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 12:10
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Journal article (peer-reviewed)abstract
- Several attempts have been made to model chronic myeloid leukemia (CML) in a xenograft setting but expansion of human myeloid cells in immunodeficient mice has proven difficult to achieve. Lack of cross-reacting cytokines in the microenvironment of the mice has been proposed as a potential reason. In this study we have used NOD/SCID IL2–receptor gamma deficient mice expressing human SCF, IL-3 and GM-CSF (NSGS mice), that should be superior in supporting human, and particularly, myeloid cell engraftment, to expand BCR-ABL1 expressing human cells in order to model CML. NSGS mice transplanted with BCR-ABL1 expressing cells became anemic and had to be sacrificed due to illness, however, this was not accompanied by an expansion of human myeloid cells but rather we observed a massive expansion of human T-cells and macrophages/histiocytes. Importantly, control human cells without BCR-ABL1 expression elicited a similar reaction, although with a slight delay of disease induction, suggesting that while BCR-ABL1 contributes to the inflammatory reaction, the presence of normal human hematopoietic cells is detrimental for NSGS mice.
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3. |
- Hansen, Nils, et al.
(author)
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SOCS2 is dispensable for BCR/ABL1-induced chronic myeloid leukemia-like disease and for normal hematopoietic stem cell function.
- 2013
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In: Leukemia. - : Springer Science and Business Media LLC. - 1476-5551 .- 0887-6924. ; 27, s. 130-135
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Journal article (peer-reviewed)abstract
- Suppressor of cytokine signaling 2 (SOCS2) is known as a feedback inhibitor of cytokine signaling and is highly expressed in primary bone marrow (BM) cells from patients with chronic myeloid leukemia (CML). However, it has not been established whether SOCS2 is involved in CML, caused by the BCR/ABL1 fusion gene, or important for normal hematopoietic stem cell (HSC) function. In this study, we demonstrate that although Socs2 was found to be preferentially expressed in long-term HSCs, Socs2-deficient HSCs were indistinguishable from wild-type HSCs when challenged in competitive BM transplantation experiments. Furthermore, by using a retroviral BCR/ABL1-induced mouse model of CML, we demonstrate that SOCS2 is dispensable for the induction and propagation of the disease, suggesting that the SOCS2-mediated feedback regulation of the JAK/STAT pathway is deficient in BCR/ABL1-induced CML.Leukemia advance online publication, 24 July 2012; doi:10.1038/leu.2012.169.
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4. |
- Isern, A E, et al.
(author)
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Risk of recurrence following delayed large flap reconstruction after mastectomy for breast cancer.
- 2011
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In: British Journal of Surgery. - : Oxford University Press (OUP). - 1365-2168 .- 0007-1323. ; 98, s. 659-666
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Journal article (peer-reviewed)abstract
- BACKGROUND: The aim of this retrospective matched cohort study was to evaluate the rate of recurrence among women with delayed large flap breast reconstruction after mastectomy for breast cancer. The recurrence rate among women treated at a single hospital was compared with that in an individually matched control group of women with breast cancer who did not have reconstruction after mastectomy. METHODS: Between 1982 and 2001, 125 women with previous invasive breast carcinoma underwent delayed large flap breast reconstruction with pedicled musculocutaneous or microvascular flaps (a median of 32 months after mastectomy). They were matched individually with 182 women with breast cancer who had a mastectomy but did not undergo breast reconstruction. Matching criteria were year of diagnosis, age at diagnosis and treating hospital. Medical records were evaluated until October 2007. Histopathological specimens for all included women were re-evaluated. The endpoint was locoregional or distant breast cancer recurrence. The risk of recurrent disease was calculated using a Cox proportional hazards analysis, adjusted for established prognostic factors. RESULTS: Median follow-up for the entire cohort was 146 months. The reconstruction group had a 2·08 (95 per cent confidence interval 1·07 to 4·06) times higher risk of recurrent disease than the mastectomy only group. CONCLUSION: Women with breast cancer who had delayed reconstruction with a large flap in this study had a higher risk of recurrent disease than those with mastectomy alone. Copyright © 2011 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.
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5. |
- Landberg, Niklas, et al.
(author)
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CD36 defines primitive chronic myeloid leukemia cells less responsive to imatinib but vulnerable to antibody-based therapeutic targeting
- 2018
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In: Haematologica. - : Ferrata Storti Foundation (Haematologica). - 0390-6078 .- 1592-8721. ; 103:3, s. 447-455
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Journal article (peer-reviewed)abstract
- Tyrosine kinase inhibitors (TKIs) are highly effective for the treatment of chronic myeloid leukemia (CML), but very few patients are cured. The major drawbacks regarding TKIs are their low efficacy in eradicating the leukemic stem cells responsible for disease maintenance and relapse upon drug cessation. Herein, we performed ribonucleic acid sequencing of flow-sorted primitive (CD34+CD38low) and progenitor (CD34+CD38+) chronic phase CML cells, and identified transcriptional upregulation of 32 cell surface molecules relative to corresponding normal bone marrow cells. Focusing on novel markers with increased expression on primitive CML cells, we confirmed upregulation of the scavenger receptor CD36 and the leptin receptor by flow cytometry. We also delineate a subpopulation of primitive CML cells expressing CD36 that is less sensitive to imatinib treatment. Using CD36 targeting antibodies, we show that the CD36 positive cells can be targeted and killed by antibody-dependent cellular cytotoxicity. In summary, CD36 defines a subpopulation of primitive CML cells with decreased imatinib sensitivity that can be effectively targeted and killed using an anti-CD36 antibody.
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8. |
- Landberg, Niklas, et al.
(author)
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Primary cells in BCR/FGFR1-positive 8p11 myeloproliferative syndrome are sensitive to dovitinib, ponatinib, and dasatinib
- 2017
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In: European Journal of Haematology. - : Wiley. - 0902-4441 .- 1600-0609. ; 99:5, s. 442-448
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Journal article (peer-reviewed)abstract
- Objectives: Translocations involving the fibroblast growth factor receptor 1 (FGFR1) gene are associated with the 8p11 myeloproliferative syndrome (EMS), a rare neoplasm that following a usually short chronic phase progresses into acute myeloid or lymphoid leukemia. The treatment commonly involves chemotherapy and, if possible, allogeneic stem cell transplantation which is the only therapeutic option for long-term survival. Given the aggressive course of EMS, we here evaluated tyrosine kinase inhibitors as treatment options to delay disease progression. Methods: We described a new case of EMS and used chromosome analyses, PCR, and sequencing to investigate the underlying genetic aberrations. The sensitivity to several tyrosine kinase inhibitors was tested in vitro on the EMS cell line KG1 and on primary cells from the newly diagnosed EMS patient. Results: A translocation involving chromosomes 8 and 22 was detected, and a BCR/FGFR1 fusion gene was confirmed and characterized by sequencing. KG1 cells and primary EMS cells displayed distinct sensitivity to dovitinib, ponatinib, and dasatinib as compared to normal bone marrow control cells. Conclusions: These results suggest that treatment with tyrosine kinase inhibitors may be beneficial for patients with EMS during the search for a suitable stem cell donor and for those not eligible for transplantation.
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9. |
- Orsmark-Pietras, Christina, et al.
(author)
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Clinical and genomic characterization of patients diagnosed with the provisional entity acute myeloid leukemia with BCR-ABL1, a Swedish population-based study
- 2021
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In: Genes, Chromosomes and Cancer. - : Wiley-Liss Inc.. - 1045-2257 .- 1098-2264. ; 60:6, s. 426-433
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Journal article (peer-reviewed)abstract
- Acute myeloid leukemia (AML) with t(9;22)(q34;q11), also known as AML with BCR-ABL1, is a rare, provisional entity in the WHO 2016 classification and is considered a high-risk disease according to the European LeukemiaNet 2017 risk stratification. We here present a retrospective, population-based study of this disease entity from the Swedish Acute Leukemia Registry. By strict clinical inclusion criteria we aimed to identify genetic markers further distinguishing AML with t(9;22) as a separate entity. Twenty-five patients were identified and next-generation sequencing using a 54-gene panel was performed in 21 cases. Interestingly, no mutations were found in NPM1, FLT3, or DNMT3A, three frequently mutated genes in AML. Instead, RUNX1 was the most commonly mutated gene, with aberrations present in 38% of the cases compared to around 10% in de novo AML. Additional mutations were identified in genes involved in RNA splicing (SRSF2, SF3B1) and chromatin regulation (ASXL1, STAG2, BCOR, BCORL1). Less frequently, mutations were found in IDH2, NRAS, TET2, and TP53. The mutational landscape exhibited a similar pattern as recently described in patients with chronic myeloid leukemia (CML) in myeloid blast crisis (BC). Despite the concomitant presence of BCR-ABL1 and RUNX1 mutations in our cohort, both features of high-risk AML, the RUNX1-mutated cases showed a superior overall survival compared to RUNX1 wildtype cases. Our results suggest that the molecular characteristics of AML with t(9;22)/BCR-ABL1 and CML in myeloid BC are similar and do not support a distinction of the two disease entities based on their underlying molecular alterations.
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10. |
- Sandén, Carl, et al.
(author)
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Clonal competition within complex evolutionary hierarchies shapes AML over time
- 2020
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 11:1
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Journal article (peer-reviewed)abstract
- Clonal heterogeneity and evolution has major implications for disease progression and relapse in acute myeloid leukemia (AML). To model clonal dynamics in vivo, we serially transplanted 23 AML cases to immunodeficient mice and followed clonal composition for up to 15 months by whole-exome sequencing of 84 xenografts across two generations. We demonstrate vast changes in clonality that both progress and reverse over time, and define five patterns of clonal dynamics: Monoclonal, Stable, Loss, Expansion and Burst. We also show that subclonal expansion in vivo correlates with a more adverse prognosis. Furthermore, clonal expansion enabled detection of very rare clones with AML driver mutations that were undetectable by sequencing at diagnosis, demonstrating that the vast majority of AML cases harbor multiple clones already at diagnosis. Finally, the rise and fall of related clones enabled deconstruction of the complex evolutionary hierarchies of the clones that compete to shape AML over time.
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