| 1. |
- Arbajian, Elsa, et al.
(författare)
-
In-depth genetic analysis of sclerosing epithelioid fibrosarcoma reveals recurrent genomic alterations and potential treatment targets
- 2017
-
Ingår i: Clinical Cancer Research. - 1078-0432. ; 23:23, s. 7426-7434
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Sclerosing epithelioid fibrosarcoma (SEF) is a highly aggressive soft tissue sarcoma closely related to low-grade fibromyxoid sarcoma (LGFMS). Some tumors display morphological characteristics of both SEF and LGFMS, so called hybrid SEF/LGFMS. Despite the overlap of gene fusion variants between these two tumor types, SEF is much more aggressive. The present study aimed to further characterize SEF and hybrid SEF/LGFMS genetically in order to better understand the role of the characteristic fusion genes and possible additional genetic alterations in tumorigenesis.EXPERIMENTAL DESIGN: We performed whole exome sequencing, single nucleotide polymorphism (SNP) array analysis, RNA-sequencing (RNA-seq), global gene expression analyses and/or IHC on a series of 13 SEFs and 6 hybrid SEF/LGFMS. We also expressed the FUS-CREB3L2 and EWSR1-CREB3L1 fusion genes conditionally in a fibroblast cell line; these cells were subsequently analyzed by RNA-seq and expression of the CD24 protein was assessed by FACS analysis.RESULTS: The SNP array analysis detected a large number of structural aberrations in SEF and SEF/LGFMS, many of which were recurrent, notably DMD microdeletions. RNA-seq identified FUS-CREM and PAX5-CREB3L1 as alternative fusion genes in one SEF each. CD24 was strongly upregulated, presumably a direct target of the fusion proteins. This was further confirmed by the gene expression analysis and FACS analysis on Tet-On 3G cells expressing EWSR1-CREB3L1.CONCLUSIONS: While gene fusions are the primary tumorigenic events in both SEF and LGFMS, additional genomic changes explain the differences in aggressiveness and clinical outcome between the two types. CD24 and DMD constitute potential therapeutic targets.
|
|
| 2. |
- Askmyr, Maria, et al.
(författare)
-
Modeling chronic myeloid leukemia in immunodeficient mice reveals expansion of aberrant mast cells and accumulation of pre-B cells.
- 2014
-
Ingår i: Blood Cancer Journal. - : Springer Science and Business Media LLC. - 2044-5385. ; 4
-
Tidskriftsartikel (refereegranskat)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.
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
- Chapellier, Marion, et al.
(författare)
-
Arrayed molecular barcoding identifies TNFSF13 as a positive regulator of acute myeloid leukemia-initiating cells
- 2019
-
Ingår i: Haematologica. - : Ferrata Storti Foundation (Haematologica). - 1592-8721 .- 0390-6078. ; 104:10, s. 2006-2016
-
Tidskriftsartikel (refereegranskat)abstract
- Dysregulation of cytokines in the bone marrow microenvironment promotes acute myeloid leukemia cell growth. Due to the complexity and low throughput of in vivo stem-cell based assays, studying the role of cytokines in the bone marrow niche in a screening setting is challenging. Herein, we developed an ex vivo cytokine screen using 11 arrayed molecular barcodes, allowing for a competitive in vivo readout of leukemia-initiating capacity. With this approach, we assessed the effect of 114 murine cytokines on MLL-AF9 acute myeloid leukemia mouse cells and identified the tumor necrosis factor ligand superfamily member 13 (TNFSF13) as a positive regulator of leukemia-initiating cells. By using Tnfsf13-/- recipient mice, we confirmed that TNFSF13 supports leukemia-initiation also under physiological conditions. TNFSF13 was secreted by normal myeloid cells but not by leukemia mouse cells, suggesting that mature myeloid bone marrow cells support leukemia cells by secreting TNFSF13. TNFSF13 supported leukemia cell proliferation in an NF-κB-dependent manner by binding TNFRSF17 and suppressed apoptosis. Moreover, TNFSF13 supported the growth and survival of several human myeloid leukemia cell lines, demonstrating that our findings translate to human disease. Taken together, using arrayed molecular barcoding, we identified a previously unrecognized role of TNFSF13 as a positive regulator of acute myeloid leukemia-initiating cells. The arrayed barcoded screening methodology is not limited to cytokines and leukemia, but can be extended to other types of ex vivo screens, where a multiplexed in vivo read-out of stem cell functionality is needed.
|
|
| 7. |
- Chapellier, Marion, et al.
(författare)
-
Arrayed molecular barcoding of leukemic stem cells
- 2021
-
Ingår i: Leukemia Stem Cells. - New York, NY : Springer US. - 1940-6029 .- 1064-3745. ; 2185, s. 345-359
-
Bokkapitel (refereegranskat)abstract
- Functional screens on cancer cells using compound or protein libraries are usually performed in vitro. However, to assess the effects on leukemia stem cells (LSCs) in a screening setting, methodologies that allow for a high-throughput in vivo readout of leukemia-initiating activity are needed. One experimental approach to solve this issue is to genetically label, also referred to as “barcoding,” the leukemia cells in an arrayed format prior to exposing them to separate experimental conditions. The cells can then be pooled and injected into mice for competitive readout of leukemia-initiating activity. Here, we describe a procedure for combining lentiviral arrayed molecular barcoding of leukemia cells with next-generation sequencing, to enable screens on leukemia cells ex vivo followed by an in vivo competitive readout of LSC function. This methodology can also be applied to other model systems in which a competitive in vivo readout of cells is needed.
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
- Eriksson, Mia, et al.
(författare)
-
Agonistic targeting of TLR1/TLR2 induces p38 MAPK-dependent apoptosis and NFκB-dependent differentiation of AML cells
- 2017
-
Ingår i: Blood Advances. - : American Society of Hematology. - 2473-9529 .- 2473-9537. ; 1:23, s. 2046-2057
-
Tidskriftsartikel (refereegranskat)abstract
- Acute myeloid leukemia (AML) is associated with poor survival, and there is a strong need to identify disease vulnerabilities that might reveal new treatment opportunities. Here, we found that Toll-like receptor 1 (TLR1) and TLR2 are upregulated on primary AML CD34+CD38-cells relative to corresponding normal bone marrow cells. Activating the TLR1/TLR2 complex by the agonist Pam3CSK4 inMLL-AF9-driven human AML resulted in induction of apoptosis by p38 MAPK-dependent activation of Caspase 3 and myeloid differentiation in a NFκB-dependent manner. By using murineTrp53 -/- MLL-AF9AML cells, we demonstrate that p53 is dispensable for Pam3CSK4-induced apoptosis and differentiation. Moreover, murineAML1-ETO9a-driven AML cells also were forced into apoptosis and differentiation on TLR1/TLR2 activation, demonstrating that the antileukemic effects observed were not confined toMLL-rearranged AML. We further evaluated whether Pam3CSK4 would exhibit selective antileukemic effects. Ex vivo Pam3CSK4 treatment inhibited murine and human leukemia-initiating cells, whereas murine normal hematopoietic stem and progenitor cells (HSPCs) were relatively less affected. Consistent with these findings, primary human AML cells across several genetic subtypes of AML were more vulnerable for TLR1/TLR2 activation relative to normal human HSPCs. In theMLL-AF9AML mouse model, treatment with Pam3CSK4 provided proof of concept for in vivo therapeutic efficacy. Our results demonstrate that TLR1 and TLR2 are upregulated on primitive AML cells and that agonistic targeting of TLR1/TLR2 forces AML cells into apoptosis by p38 MAPK-dependent activation of Caspase 3, and differentiation by activating NFκB, thus revealing a new putative strategy for therapeutically targeting AML cells.
|
|
| 11. |
- Hansen, Nils, et al.
(författare)
-
SOCS2 is dispensable for BCR/ABL1-induced chronic myeloid leukemia-like disease and for normal hematopoietic stem cell function.
- 2013
-
Ingår i: Leukemia. - : Springer Science and Business Media LLC. - 1476-5551 .- 0887-6924. ; 27, s. 130-135
-
Tidskriftsartikel (refereegranskat)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.
|
|
| 12. |
- Hunaiti, Samar, et al.
(författare)
-
Secreted cystatins decrease proliferation and enhance apoptosis of human leukemic cells
- 2020
-
Ingår i: FEBS Open Bio. - : Wiley. - 2211-5463. ; 10:10, s. 2166-2181
-
Tidskriftsartikel (refereegranskat)abstract
- Cysteine proteases are implicated in proteolysis events favoring cancer cell growth, spread, and death by apoptosis. Herein, we have studied whether the net growth and survival of the leukemic cell lines Jurkat, U937, and HL-60 are affected by external addition of five proteins acting as natural cysteine protease inhibitors. None of the cystatins examined (A, C, D, and E/M) or chagasin showed consistent effects on Fas-induced apoptosis when evaluated at 1 µm. In contrast, when the intrinsic apoptosis pathway was activated by hydrogen peroxide, addition of cystatin D augmented caspase-3-like activity within all three cell lines. Flow cytometric analysis of U937 cells also showed increased numbers of annexin V-positive cells when hydrogen peroxide was used to initiate apoptosis and cells were cultured in the presence of cystatin D or C. Moreover, stimulation of hydrogen peroxide-induced apoptotic U937 cells with either cystatin C or D resulted in a dose-dependent decrease in the number of cells. Cell viability was also decreased when U937 cells were cultured in the presence of cystatin C or D (1–9 µm) only, demonstrating that these cystatins can reduce cell proliferation by themselves in addition to enhancing apoptosis induced by oxidative stress. These effects on U937 cells were paralleled by internalization of cystatins C and D, indicating these effects are caused by downregulation of intracellular proteolysis. External addition of cystatins C and D to HL-60 and Jurkat cells demonstrated similar degrees of cystatin D uptake and decreased viability as for U937 cells, indicating that these effects are general for leukemic cells.
|
|
| 13. |
- Hyrenius-Wittsten, Axel, et al.
(författare)
-
De novo activating mutations drive clonal evolution and enhance clonal fitness in KMT2A-rearranged leukemia
- 2018
-
Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 9:1
-
Tidskriftsartikel (refereegranskat)abstract
- Activating signaling mutations are common in acute leukemia with KMT2A (previously MLL) rearrangements (KMT2A-R). These mutations are often subclonal and their biological impact remains unclear. Using a retroviral acute myeloid mouse leukemia model, we demonstrate that FLT3 ITD, FLT3 N676K, and NRAS G12D accelerate KMT2A-MLLT3 leukemia onset. Further, also subclonal FLT3 N676K mutations accelerate disease, possibly by providing stimulatory factors. Herein, we show that one such factor, MIF, promotes survival of mouse KMT2A-MLLT3 leukemia initiating cells. We identify acquired de novo mutations in Braf, Cbl, Kras, and Ptpn11 in KMT2A-MLLT3 leukemia cells that favored clonal expansion. During clonal evolution, we observe serial genetic changes at the Kras G12D locus, consistent with a strong selective advantage of additional Kras G12D . KMT2A-MLLT3 leukemias with signaling mutations enforce Myc and Myb transcriptional modules. Our results provide new insight into the biology of KMT2A-R leukemia with subclonal signaling mutations and highlight the importance of activated signaling as a contributing driver.
|
|
| 14. |
|
|
| 15. |
- Järås, Marcus, et al.
(författare)
-
Adenoviral vectors for transient gene expression in human primitive hematopoietic cells: Applications and prospects.
- 2007
-
Ingår i: Experimental Hematology. - : Elsevier BV. - 1873-2399 .- 0301-472X. ; 35:3, s. 343-349
-
Forskningsöversikt (refereegranskat)abstract
- The proliferation and differentiation of primitive hematopoietic cells is tightly controlled by a number of signaling pathways. Transient blockage or enhancement of these signaling pathways may provide a new approach to manipulate the proliferation and differentiation of primitive hematopoietic cells. Adenoviral vectors have in recent years emerged as powerful tools for transient gene expression in human primitive hematopoietic cells. Important advantageous properties of adenoviral vectors include: feasible production of high-titer vector preparations, high efficiency in transducing both quiescent and actively dividing cells, high levels of transient gene expression, and a lack of mutagenic properties associated with integrating vectors. Progress in adenoviral fiber retargeting was recently demonstrated to enable high gene transfer efficiency into nondividing human CD34(+) cells and nonobese diabetic/severe combined immunodeficient mouse bone marrow repopulating cells (SRCs), via the ubiquitously expressed CD46 as a cellular receptor. Importantly, fiber-retargeted adenoviral vectors can be engineered to report gene expression in single living CD34(+) cells, thereby facilitating the isolation and characterization of SRCs and its downstream progenitors based on intrinsic signaling pathways. This review focuses on the current progress and the potential future applications of adenoviral gene transfer into human primitive hematopoietic cells and leukemic cells. (c) 2007 International Society for Experimental Hematology. Published by Elsevier Inc.
|
|
| 16. |
- Järås, Marcus
(författare)
-
CRISPR-terapi visar potential – möjligheter och utmaningar
- 2020
-
Ingår i: Lakartidningen. - 0023-7205. ; 117
-
Tidskriftsartikel (refereegranskat)abstract
- CRISPR är en revolutionerande teknik som möjliggör effektiv redigering av DNA.Kliniska studier med CRISPR-baserade terapier för blodsjukdomar och cancer pågår redan.Framtida tillämpningar av CRISPR kan förväntas bli breda men förutsätter etiska, juridiska och hälsoekonomiska överväganden.
|
|
| 17. |
- Järås, Marcus, et al.
(författare)
-
Csnk1a1 inhibition has p53-dependent therapeutic efficacy in acute myeloid leukemia
- 2014
-
Ingår i: Journal of Experimental Medicine. - : Rockefeller University Press. - 1540-9538 .- 0022-1007. ; 211:4, s. 605-612
-
Tidskriftsartikel (refereegranskat)abstract
- Despite extensive insights into the underlying genetics and biology of acute myeloid leukemia (AML), overall survival remains poor and new therapies are needed. We found that casein kinase 1 alpha (Csnk1a1), a serine-threonine kinase, is essential for AML cell survival in vivo. Normal hematopoietic stem and progenitor cells (HSPCs) were relatively less affected by shRNA-mediated knockdown of Csnk1a1. To identify downstream mediators of Csnk1a1 critical for leukemia cells, we performed an in vivo pooled shRNA screen and gene expression profiling. We found that Csnk1a1 knockdown results in decreased Rps6 phosphorylation, increased p53 activity, and myeloid differentiation. Consistent with these observations, p53-null leukemias were insensitive to Csnk1a1 knockdown. We further evaluated whether D4476, a casein kinase 1 inhibitor, would exhibit selective antileukemic effects. Treatment of leukemia stem cells (LSCs) with D4476 showed highly selective killing of LSCs over normal HSPCs. In summary, these findings demonstrate that Csnk1a1 inhibition causes reduced Rps6 phosphorylation and activation of p53, resulting in selective elimination of leukemia cells, revealing Csnk1a1 as a potential therapeutic target for the treatment of AML.
|
|
| 18. |
- Järås, Marcus
(författare)
-
Development of Adenoviral Vectors for Studying Hematopoietic Stem Cell Function
- 2006
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Hematopoietic stem cells (HSCs) are defined by their capacity to self-renew and differentiate into all hematopoietic cell lineages. Postnatally, HSCs reside predominantly in the bone marrow and are relatively rare, but important cells because of their therapeutic potential in bone marrow transplantation protocols and in their involvement in the origin of certain leukemias. To study how various genetic programs govern the regulation of HSCs, replication deficient viral vectors, including adenoviral vectors, have been utilized for gene transfer and expression in normal and malignant hematopoietic progenitor and stem cells. Adenoviral vectors allow high levels of transient transgene expression, however, adenoviral transduction of hematopoietic cells has been hampered by low expression of the coaxackie and adenovirus receptor (CAR), which is the primary target cell receptor for adenovirus serotype 5 (Ad5). With the aim to increase adenoviral gene transfer into hematopoietic cells, we modified the versatile Ad5 based AdEasy-1 vector system to Ad35 tropism by switching the shaft and knob domain of the fiber to that of the Ad35 species, which utilizes CD46 as a primary receptor for target cell anchoring. By using this fiber re-targeted system, termed AdEasy-1/F35, we demonstrated that primary chronic lymphocytic leukemia (CLL) and chronic myeloid leukemia (CML) patient cells could be efficiently transduced compared to conventional Ad5 vectors. Furthermore, we demonstrated that human candidate HSCs with NOD/SCID repopulating capacity from cord blood were efficiently transduced with the Ad35 tropism vectors. Moreover, in order to study the self-renewal process of HSCs, we utilized the Ad35 tropism vectors as reporters for monitoring human telomerase reverse transcriptase (hTERT) expression in human HSCs. Interestingly, increased hTERT expression was inversely correlated to the self-renewal capacity among primitive human hematopoietic cells and the hTERT reporter vector could be used to separate short-term from long-term repopulating human HSCs. In summary, we have developed a versatile adenoviral vector system with Ad35 tropism that can be used to transiently genetically modify normal and leukemic stem cells. This vector system can be used to study normal regulation of HSCs and has potential in the development of novel therapeutic approaches for malignant blood disorders.
|
|
| 19. |
- Järås, Marcus, et al.
(författare)
-
Expression of P190 and P210 BCR/ABL1 in normal human CD34(+) cells induces similar gene expression profiles and results in a STAT5-dependent expansion of the erythroid lineage
- 2009
-
Ingår i: Experimental Hematology. - : Elsevier BV. - 1873-2399 .- 0301-472X. ; 37:3, s. 367-375
-
Tidskriftsartikel (refereegranskat)abstract
- Objective. The P190 and P210 BCR/ABL1 fusion genes are mainly associated with different types of hematologic malignancies, but it is presently unclear whether they are functionally different following expression in primitive human hematopoietic cells. Materials and Methods. We investigated and systematically compared the effects of retroviral P190 BCR/ABL1 and P210 BCR/ABL1 expression on cell proliferation, differentiation, and global gene expression in human CD34(+) cells from cord blood. Results. Expression of either P190 BCR/ABL1 or P210 BCR/ABL1 resulted in expansion of erythroid cells and stimulated erythropoietin-independent burst-forming unit-erythroid colony formation. By using a lentiviral anti-signal transducer and activator of transcription 5 (STAT5) short-hairpin RNA, we found that both P190 BCR/ABL1- and P210 BCR/ABL1-induced erythroid cell expansion were STAT5-dependent. Under in vitro conditions favoring B-cell differentiation, neither P190 nor P210 BCR/ABL1-expressing cells formed detectable levels of CD19-positive cells. Gene expression profiling revealed that P190 BCR/ABL1 and P210 BCR/ABL1 induced almost identical gene expression profiles. Conclusions. Our data suggest that the early cellular and transcriptional effects of P190 BCR/ABL1 and P210 BCR/ABL1 expression are very similar when they are expressed in the same human progenitor cell population, and that STAT5 is an important regulator of BCR/ABL1-induced erythroid cell expansion. (C) 2009 ISEH - Society for Hematology and Stem Cells. Published by Elsevier Inc.
|
|
| 20. |
- Järås, Marcus, et al.
(författare)
-
Human short-term repopulating cells have enhanced telomerase reverse transcriptase expression.
- 2006
-
Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 108:3, s. 1084-1091
-
Tidskriftsartikel (refereegranskat)abstract
- Telomerase activity has been suggested to be critically involved in hematopoietic stem cell (HSC) self-renewal. However, it has been unclear whether human HSCs have telomerase activity and how telomerase activity is regulated within the HSC and progenitor pool. Here, we isolated living cord-blood (CB) CD34+ cells with up-regulated human telomerase reverse transcriptase (hTERT) expression by using an hTERT-reporting adenoviral vector encoding destabilized green fluorescent protein (dGFP) driven by the hTERT promoter, and functionally characterized them in comparison with control vector–transduced CD34+ cells expressing GFP. Following a 2-day serum-free transduction protocol, cells were sorted into a dGFP+ and a GFP+ fraction. Cell-cycle analysis revealed that the dGFP+ cells had a greater proportion of cells in S/G2/M phase compared with the GFP+ cells, (56% ± 1.8% vs 35% ± 4.3%; P < .001) and fewer cells in G0 phase (8.1% ± 3.0% vs 20% ± 4.7%; P < .01) However, the colony-forming and short-term nonobese diabetic/severe combined immunodeficient (NOD/SCID) B2m–/– mice bone marrow–repopulating capacities were similar between the dGFP+ and the GFP+ cells. Interestingly, the dGFP+ cells had a 6-fold lower repopulating capacity in NOD/SCID mice compared with the GFP+ cells and lacked secondary NOD/SCID B2m–/– mice bone marrow–repopulating capacity. Thus, up-regulation of hTERT expression within the CB HSC pool is accompanied by decreased self-renewal capacity.
|
|
| 21. |
- Järås, Marcus, et al.
(författare)
-
Isolation and killing of candidate chronic myeloid leukemia stem cells by antibody targeting of IL-1 receptor accessory protein.
- 2010
-
Ingår i: Proceedings of the National Academy of Sciences. - : Proceedings of the National Academy of Sciences. - 1091-6490 .- 0027-8424. ; 107:37, s. 16280-16285
-
Tidskriftsartikel (refereegranskat)abstract
- Chronic myeloid leukemia (CML) is genetically characterized by the Philadelphia (Ph) chromosome, formed through a reciprocal translocation between chromosomes 9 and 22 and giving rise to the constitutively active tyrosine kinase P210 BCR/ABL1. Therapeutic strategies aiming for a cure of CML will require full eradication of Ph chromosome-positive (Ph(+)) CML stem cells. Here we used gene-expression profiling to identify IL-1 receptor accessory protein (IL1RAP) as up-regulated in CML CD34(+) cells and also in cord blood CD34(+) cells as a consequence of retroviral BCR/ABL1 expression. To test whether IL1RAP expression distinguishes normal (Ph(-)) and leukemic (Ph(+)) cells within the CML CD34(+)CD38(-) cell compartment, we established a unique protocol for conducting FISH on small numbers of sorted cells. By using this method, we sorted cells directly into drops on slides to investigate their Ph-chromosome status. Interestingly, we found that the CML CD34(+)CD38(-)IL1RAP(+) cells were Ph(+), whereas CML CD34(+)CD38(-)IL1RAP(-) cells were almost exclusively Ph(-). By performing long-term culture-initiating cell assays on the two cell populations, we found that Ph(+) and Ph(-) candidate CML stem cells could be prospectively separated. In addition, by generating an anti-IL1RAP antibody, we provide proof of concept that IL1RAP can be used as a target on CML CD34(+)CD38(-) cells to induce antibody-dependent cell-mediated cytotoxicity. This study thus identifies IL1RAP as a unique cell surface biomarker distinguishing Ph(+) from Ph(-) candidate CML stem cells and opens up a previously unexplored avenue for therapy of CML.
|
|
| 22. |
- Landberg, Niklas, et al.
(författare)
-
CD36 defines primitive chronic myeloid leukemia cells less responsive to imatinib but vulnerable to antibody-based therapeutic targeting
- 2018
-
Ingår i: Haematologica. - : Ferrata Storti Foundation (Haematologica). - 0390-6078 .- 1592-8721. ; 103:3, s. 447-455
-
Tidskriftsartikel (refereegranskat)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.
|
|
| 23. |
|
|
| 24. |
- Mattebo, Alexander, et al.
(författare)
-
Yippee like 4 (Ypel4) is essential for normal mouse red blood cell membrane integrity
- 2021
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11:1
-
Tidskriftsartikel (refereegranskat)abstract
- The YPEL family genes are highly conserved across a diverse range of eukaryotic organisms and thus potentially involved in essential cellular processes. Ypel4, one of five YPEL family gene orthologs in mouse and human, is highly and specifically expressed in late terminal erythroid differentiation (TED). In this study, we investigated the role of Ypel4 in murine erythropoiesis, providing for the first time an in-depth description of a Ypel4-null phenotype in vivo. We demonstrated that the Ypel4-null mice displayed a secondary polycythemia with macro- and reticulocytosis. While lack of Ypel4 did not affect steady-state TED in the bone marrow or spleen, the anemia-recovering capacity of Ypel4-null cells was diminished. Furthermore, Ypel4-null red blood cells (RBC) were cleared from the circulation at an increased rate, demonstrating an intrinsic defect of RBCs. Scanning electron micrographs revealed an ovalocytic morphology of Ypel4-null RBCs and functional testing confirmed reduced deformability. Even though Band 3 protein levels were shown to be reduced in Ypel4-null RBC membranes, we could not find support for a physical interaction between YPEL4 and the Band 3 protein. In conclusion, our findings provide crucial insights into the role of Ypel4 in preserving normal red cell membrane integrity.
|
|
| 25. |
- Moura-Castro, Larissa H., et al.
(författare)
-
Sister chromatid cohesion defects are associated with chromosomal copy number heterogeneity in high hyperdiploid childhood acute lymphoblastic leukemia
- 2021
-
Ingår i: Genes Chromosomes and Cancer. - : Wiley. - 1045-2257 .- 1098-2264. ; 60:6, s. 410-417
-
Tidskriftsartikel (refereegranskat)abstract
- High hyperdiploid acute lymphoblastic leukemia (ALL) is one of the most common malignancies in children. The main driver event of this disease is a nonrandom aneuploidy consisting of gains of whole chromosomes but without overt evidence of chromosomal instability (CIN). Here, we investigated the frequency and severity of defective sister chromatid cohesion—a phenomenon related to CIN—in primary pediatric ALL. We found that a large proportion (86%) of hyperdiploid cases displayed aberrant cohesion, frequently severe, to compare with 49% of ETV6/RUNX1-positive ALL, which mostly displayed mild defects. In hyperdiploid ALL, cohesion defects were associated with increased chromosomal copy number heterogeneity, which could indicate increased CIN. Furthermore, cohesion defects correlated with RAD21 and NCAPG mRNA expression, suggesting a link to reduced cohesin and condensin levels in hyperdiploid ALL. Knockdown of RAD21 in an ALL cell line led to sister chromatid cohesion defects, aberrant mitoses, and increased heterogeneity in chromosomal copy numbers, similar to what was seen in primary hyperdiploid ALL. In summary, our study shows that aberrant sister chromatid cohesion is frequent but heterogeneous in pediatric high hyperdiploid ALL, ranging from mild to very severe defects, and possibly due to low cohesin or condensin levels. Cases with high levels of aberrant chromosome cohesion displayed increased chromosomal copy number heterogeneity, possibly indicative of increased CIN. These abnormalities may play a role in the clonal evolution of hyperdiploid pediatric ALL.
|
|
| 26. |
- Peña-Martínez, Pablo, et al.
(författare)
-
Interleukin 4 promotes phagocytosis of murine leukemia cells counteracted by CD47 upregulation
- 2022
-
Ingår i: Haematologica. - : Ferrata Storti Foundation (Haematologica). - 0390-6078 .- 1592-8721. ; 107:4, s. 816-824
-
Tidskriftsartikel (refereegranskat)abstract
- Cytokines are key regulators of tumor immune surveillance by controlling immune cell activity. Here, we investigated whether interleukin 4 (IL4) has antileukemic activity via immune-mediated mechanisms in an in vivo murine model of acute myeloid leukemia driven by the MLL-AF9 fusion gene. Although IL4 strongly inhibited leukemia development in immunocompetent mice, the effect was diminished in immune-deficient recipient mice, demonstrating that the antileukemic effect of IL4 in vivo is dependent on the host immune system. Using flow cytometric analysis and immunohistochemistry, we revealed that the antileukemic effect of IL4 coincided with an expansion of F4/80+ macrophages in the bone marrow and spleen. To elucidate whether this macrophage expansion was responsible for the antileukemic effect, we depleted macrophages in vivo with clodronate liposomes. Macrophage depletion eliminated the antileukemic effect of IL4, showing that macrophages mediated the IL4-induced killing of leukemia cells. In addition, IL4 enhanced murine macrophage-mediated phagocytosis of leukemia cells in vitro. Global transcriptomic analysis of macrophages revealed an enrichment of signatures associated with alternatively activated macrophages and increased phagocytosis upon IL4 stimulation. Notably, IL4 concurrently induced Stat6-dependent upregulation of CD47 on leukemia cells, which suppressed macrophage activity. Consistent with this finding, combining CD47 blockade with IL4 stimulation enhanced macrophage-mediated phagocytosis of leukemia cells. Thus, IL4 has two counteracting roles in regulating phagocytosis in mice; enhancing macrophage-mediated killing of leukemia cells, but also inducing CD47 expression that protects target cells from excessive phagocytosis. Taken together, our data suggest that combined strategies that activate macrophages and block CD47 have therapeutic potential in acute myeloid leukemia.
|
|
| 27. |
- Puram, Rishi V, et al.
(författare)
-
Core Circadian Clock Genes Regulate Leukemia Stem Cells in AML
- 2016
-
Ingår i: Cell. - : Elsevier BV. - 1097-4172 .- 0092-8674. ; 165:2, s. 16-303
-
Tidskriftsartikel (refereegranskat)abstract
- Leukemia stem cells (LSCs) have the capacity to self-renew and propagate disease upon serial transplantation in animal models, and elimination of this cell population is required for curative therapies. Here, we describe a series of pooled, in vivo RNAi screens to identify essential transcription factors (TFs) in a murine model of acute myeloid leukemia (AML) with genetically and phenotypically defined LSCs. These screens reveal the heterodimeric, circadian rhythm TFs Clock and Bmal1 as genes required for the growth of AML cells in vitro and in vivo. Disruption of canonical circadian pathway components produces anti-leukemic effects, including impaired proliferation, enhanced myeloid differentiation, and depletion of LSCs. We find that both normal and malignant hematopoietic cells harbor an intact clock with robust circadian oscillations, and genetic knockout models reveal a leukemia-specific dependence on the pathway. Our findings establish a role for the core circadian clock genes in AML.
|
|
| 28. |
- Ramakrishnan, Ramprasad, et al.
(författare)
-
CXCR4 Signaling Has a CXCL12-Independent Essential Role in Murine MLL-AF9-Driven Acute Myeloid Leukemia
- 2020
-
Ingår i: Cell Reports. - : Elsevier BV. - 2211-1247. ; 31:8
-
Tidskriftsartikel (refereegranskat)abstract
- Acute myeloid leukemia (AML) is defined by an accumulation of immature myeloid blasts in the bone marrow. To identify key dependencies of AML stem cells in vivo, here we use a CRISPR-Cas9 screen targeting cell surface genes in a syngeneic MLL-AF9 AML mouse model and show that CXCR4 is a top cell surface regulator of AML cell growth and survival. Deletion of Cxcr4 in AML cells eradicates leukemia cells in vivo without impairing their homing to the bone marrow. In contrast, the CXCR4 ligand CXCL12 is dispensable for leukemia development in recipient mice. Moreover, expression of mutated Cxcr4 variants reveals that CXCR4 signaling is essential for leukemia cells. Notably, loss of CXCR4 signaling in leukemia cells leads to oxidative stress and differentiation in vivo. Taken together, our results identify CXCR4 signaling as essential for AML stem cells by protecting them from differentiation independent of CXCL12 stimulation.
|
|
| 29. |
- Rodriguez-Zabala, Maria, et al.
(författare)
-
Combined GLUT1 and OXPHOS inhibition eliminates acute myeloid leukemia cells by restraining their metabolic plasticity
- 2023
-
Ingår i: Blood Advances. - 2473-9529. ; 7:18, s. 5382-5395
-
Tidskriftsartikel (refereegranskat)abstract
- Acute myeloid leukemia (AML) is initiated and propagated by leukemia stem cells (LSCs), a self-renewing population of leukemia cells responsible for therapy resistance. Hence, there is an urgent need to identify new therapeutic opportunities targeting LSCs. Here, we performed an in vivo CRISPR knockout screen to identify potential therapeutic targets by interrogating cell surface dependencies of LSCs. The facilitated glucose transporter type 1 (GLUT1) emerged as a critical in vivo metabolic dependency for LSCs in a murine MLL::AF9–driven model of AML. GLUT1 disruption by genetic ablation or pharmacological inhibition led to suppression of leukemia progression and improved survival of mice that received transplantation with LSCs. Metabolic profiling revealed that Glut1 inhibition suppressed glycolysis, decreased levels of tricarboxylic acid cycle intermediates and increased the levels of amino acids. This metabolic reprogramming was accompanied by an increase in autophagic activity and apoptosis. Moreover, Glut1 disruption caused transcriptional, morphological, and immunophenotypic changes, consistent with differentiation of AML cells. Notably, dual inhibition of GLUT1 and oxidative phosphorylation (OXPHOS) exhibited synergistic antileukemic effects in the majority of tested primary AML patient samples through restraining of their metabolic plasticity. In particular, RUNX1-mutated primary leukemia cells displayed striking sensitivity to the combination treatment compared with normal CD34+ bone marrow and cord blood cells. Collectively, our study reveals a GLUT1 dependency of murine LSCs in the bone marrow microenvironment and demonstrates that dual inhibition of GLUT1 and OXPHOS is a promising therapeutic approach for AML.
|
|
| 30. |
- Sandhow, Lakshmi, et al.
(författare)
-
Skin mesenchymal niches maintain and protect AML-initiating stem cells
- 2023
-
Ingår i: Journal of Experimental Medicine. - 0022-1007 .- 1540-9538. ; 220:10
-
Tidskriftsartikel (refereegranskat)abstract
- Leukemia cutis or leukemic cell infiltration in skin is one of the common extramedullary manifestations of acute myeloid leukemia (AML) and signifies a poorer prognosis. However, its pathogenesis and maintenance remain understudied. Here, we report massive AML cell infiltration in the skin in a transplantation-induced MLL-AF9 AML mouse model. These AML cells could regenerate AML after transplantation. Prospective niche characterization revealed that skin harbored mesenchymal progenitor cells (MPCs) with a similar phenotype as BM mesenchymal stem cells. These skin MPCs protected AML-initiating stem cells (LSCs) from chemotherapy in vitro partially via mitochondrial transfer. Furthermore, Lama4 deletion in skin MPCs promoted AML LSC proliferation and chemoresistance. Importantly, more chemoresistant AML LSCs appeared to be retained in Lama4−/− mouse skin after cytarabine treatment. Our study reveals the characteristics and previously unrecognized roles of skin mesenchymal niches in maintaining and protecting AML LSCs during chemotherapy, meriting future exploration of their impact on AML relapse.
|
|
| 31. |
- von Palffy, Sofia, et al.
(författare)
-
A high-content cytokine screen identifies myostatin propeptide as a positive regulator of primitive chronic myeloid leukemia cells
- 2020
-
Ingår i: Haematologica. - : Ferrata Storti Foundation (Haematologica). - 0390-6078 .- 1592-8721. ; 105:8, s. 2095-2104
-
Tidskriftsartikel (refereegranskat)abstract
- Aberrantly expressed cytokines in the bone marrow (BM) niche are increasingly recognized as critical mediators of survival and expansion of leukemic stem cells. To identify regulators of primitive chronic myeloid leukemia (CML) cells, we performed a high-content cytokine screen using primary CD34+ CD38low chronic phase CML cells. Out of the 313 unique human cytokines evaluated, 11 were found to expand cell numbers ≥2-fold in a 7-day culture. Focusing on novel positive regulators of primitive CML cells, the myostatin antagonist myostatin propeptide gave the largest increase in cell expansion and was chosen for further studies. Herein, we demonstrate that myostatin propeptide expands primitive CML and normal BM cells, as shown by increased colony-forming capacity. For primary CML samples, retention of CD34-expression was also seen after culture. Furthermore, we show expression of MSTN by CML mesenchymal stromal cells, and that myostatin propeptide has a direct and instant effect on CML cells, independent of myostatin, by demonstrating binding of myostatin propeptide to the cell surface and increased phosphorylation of STAT5 and SMAD2/3. In summary, we identify myostatin propeptide as a novel positive regulator of primitive CML cells and corresponding normal hematopoietic cells.
|
|
| 32. |
- von Palffy, Sofia, et al.
(författare)
-
The complement receptor C3AR constitutes a novel therapeutic target in NPM1-mutated AML
- 2023
-
Ingår i: Blood Advances. - : American Society of Hematology. - 2473-9529 .- 2473-9537. ; 7:7, s. 1204-1218
-
Tidskriftsartikel (refereegranskat)abstract
- Mutated Nucleophosmin 1 (NPM1) is the most common genetic alteration in acute myeloid leukemia (AML), found in approximately 30% of cases. Although mutations in this gene are considered favorable according to current risk stratification guidelines, a large fraction of patients will suffer from relapse, demonstrating the urgent need for new treatment options. Therefore, we aimed to identify cell surface proteins specifically expressed on NPM1)-mutated AML cells, allowing for potential targeting with antibody-based therapies. Herein, we performed an arrayed flow cytometry-based screen directed to 362 cell surface markers. Comparing the cell surface expression on NPM1-mutated AML cells to primitive (CD34+ CD38-) normal bone marrow cells, we identified the complement receptor C3AR as specifically expressed in NPM1-mutated AML. By flow cytometry and single cell RNA-sequencing, we further show that normal hematopoietic stem and progenitor cells lack detectable C3AR gene and protein expression, making it particularly suitable as a target for antibody therapy. We also demonstrate that C3AR in combination with GPR56 distinguishes the leukemic stem cells (LSCs) in NPM1-mutated AML from the normal hematopoietic stem cells, defining the LSC population, as shown by transplantation into immunodeficient mice. Mechanistically, stimulation of C3AR-expressing cells with C3a, the ligand of C3AR, leads to activation of ERK1/2 and increased survival of AML cells, suggesting that this is an important signaling axis in this subtype of AML. Finally, we show that antibodies directed against C3AR efficiently elicit NK cell-mediated killing of primary AML cells ex vivo, highlighting C3AR as a candidate therapeutic target in NPM1-mutated AML.
|
|
| 33. |
- Vu, Ly P., et al.
(författare)
-
Functional screen of MSI2 interactors identifies an essential role for SYNCRIP in myeloid leukemia stem cells
- 2017
-
Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 49:6, s. 866-875
-
Tidskriftsartikel (refereegranskat)abstract
- The identity of the RNA-binding proteins (RBPs) that govern cancer stem cells remains poorly characterized. The MSI2 RBP is a central regulator of translation of cancer stem cell programs. Through proteomic analysis of the MSI2-interacting RBP network and functional shRNA screening, we identified 24 genes required for in vivo leukemia. Syncrip was the most differentially required gene between normal and myeloid leukemia cells. SYNCRIP depletion increased apoptosis and differentiation while delaying leukemogenesis. Gene expression profiling of SYNCRIP-depleted cells demonstrated a loss of the MLL and HOXA9 leukemia stem cell program. SYNCRIP and MSI2 interact indirectly though shared mRNA targets. SYNCRIP maintains HOXA9 translation, and MSI2 or HOXA9 overexpression rescued the effects of SYNCRIP depletion. Altogether, our data identify SYNCRIP as a new RBP that controls the myeloid leukemia stem cell program. We propose that targeting these RBP complexes might provide a novel therapeutic strategy in leukemia.
|
|
| 34. |
- Ågerstam, Helena, et al.
(författare)
-
Antibodies targeting human IL1RAP (IL1R3) show therapeutic effects in xenograft models of acute myeloid leukemia.
- 2015
-
Ingår i: Proceedings of the National Academy of Sciences. - : Proceedings of the National Academy of Sciences. - 1091-6490 .- 0027-8424. ; 112:34, s. 10786-10791
-
Tidskriftsartikel (refereegranskat)abstract
- Acute myeloid leukemia (AML) is associated with a poor survival rate, and there is an urgent need for novel and more efficient therapies, ideally targeting AML stem cells that are essential for maintaining the disease. The interleukin 1 receptor accessory protein (IL1RAP; IL1R3) is expressed on candidate leukemic stem cells in the majority of AML patients, but not on normal hematopoietic stem cells. We show here that monoclonal antibodies targeting IL1RAP have strong antileukemic effects in xenograft models of human AML. We demonstrate that effector-cell-mediated killing is essential for the observed therapeutic effects and that natural killer cells constitute a critical human effector cell type. Because IL-1 signaling is important for the growth of AML cells, we generated an IL1RAP-targeting antibody capable of blocking IL-1 signaling and show that this antibody suppresses the proliferation of primary human AML cells. Hence, IL1RAP can be efficiently targeted with an anti-IL1RAP antibody capable of both achieving antibody-dependent cellular cytotoxicity and blocking of IL-1 signaling as modes of action. Collectively, these results provide important evidence in support of IL1RAP as a target for antibody-based treatment of AML.
|
|
| 35. |
- Ågerstam, Helena, et al.
(författare)
-
IL1RAP antibodies block IL-1-induced expansion of candidate CML stem cells and mediate cell killing in xenograft models.
- 2016
-
Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 128:23, s. 2683-2693
-
Tidskriftsartikel (refereegranskat)abstract
- Chronic myeloid leukemia (CML) is currently treated with tyrosine kinase inhibitors, but these do not effectively eliminate the CML stem cells. As a consequence, CML stem cells persist and cause relapse in most patients upon drug discontinuation. Furthermore, no effective therapy exists for the advanced stages of the disease. Interleukin-1 receptor accessory protein (IL1RAP; IL1R3) is a coreceptor of interleukin-1 receptor type 1 and has been found upregulated on CML stem cells. Here, we show that primitive (CD34(+)CD38(-)) CML cells, in contrast to corresponding normal cells, express a functional interleukin-1 (IL-1) receptor complex and respond with NF-κB activation and marked proliferation in response to IL-1. IL1RAP antibodies that inhibit IL-1 signaling could block these effects. In vivo administration of IL1RAP antibodies in mice transplanted with chronic and blast phase CML cells resulted in therapeutic effects mediated by murine effector cells. These results provide novel insights into the role of IL1RAP in CML and a strong rationale for the development of an IL1RAP antibody therapy to target residual CML stem cells.
|
|
| 36. |
- Ågerstam, Helena, et al.
(författare)
-
Modeling the human 8p11-myeloproliferative syndrome in immunodeficient mice
- 2010
-
Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 116:12, s. 2103-2111
-
Tidskriftsartikel (refereegranskat)abstract
- The 8p11 myeloproliferative syndrome (EMS), also referred to as stem cell leukemia/lymphoma, is a chronic myeloproliferative disorder that rapidly progresses into acute leukemia. Molecularly, EMS is characterized by fusion of various partner genes to the FGFR1 gene, resulting in constitutive activation of the tyrosine kinases in FGFR1. To date, no previous study has addressed the functional consequences of ectopic FGFR1 expression in the potentially most relevant cellular context, that of normal primary human hematopoietic cells. Herein, we report that expression of ZMYM2/FGFR1 (previously known as ZNF198/FGFR1) or BCR/FGFR1 in normal human CD34(+) cells from umbilicalcord blood leads to increased cellular proliferation and differentiation toward the erythroid lineage in vitro. In immunodeficient mice, expression of ZMYM2/FGFR1 or BCR/FGFR1 in human cells induces several features of human EMS, including expansion of several myeloid cell lineages and accumulation of blasts in bone marrow. Moreover, bone marrow fibrosis together with increased extramedullary hematopoiesis is observed. This study suggests that FGFR1 fusion oncogenes, by themselves, are capable of initiating an EMS-like disorder, and provides the first humanized model of a myeloproliferative disorder transforming into acute leukemia in mice. The established in vivo EMS model should provide a valuable tool for future studies of this disorder. (Blood. 2010;116(12):2103-2111)
|
|
