scholarly journals Luks-PV Induce HOXA9 Degradation Through Autophagy in MLL-rearranged Acute Myeloid Leukemia

2020 ◽  
Author(s):  
Ping Qiang ◽  
Chao Fang ◽  
Kaidi Song ◽  
Lan Shi ◽  
Yuanyuan Dai ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Over Expression ◽  
Autophagy Induction ◽  
Autophagy Pathway ◽  
Pharmacologic Inhibitors ◽  
Acute Myeloid

Abstract Background: Our previous studies have demonstrated that Luks-PV have good anti-leukemia ability effects and could possibly be a promising therapy for adult acute myeloid leukemia (AML). Aberrant over-expression of HOXA9 is a prominent feature of AML driven by multiple oncogenes, and therapeutic degrading of HOXA9 may be an effective treatment strategy in AML. This paper focused on the Luks-PV-regulating autophagy pathway, aiming to investigate the role of Luks-PV in mixed-lineage leukemia (MLL)-rearranged AML. Methods: The data of leukemia patients were downloaded from the gene expression profiling of TCGA datasets. Taking primary AML and THP-1 cells as the model system in vitro, Luks-PV-inhibited cell proliferation was determined by CCK‐8 and flow cytometry assays. The role of Luks-PV in autophagy regulation was analyzed using immunoblotting, transfection and immunofluorescence.Results: HOXA9 was over-expressed and associated with a poor prognosis in AML patients bearing MLL rearrangement. After the application of pharmacologic inhibitors of autophagy, Luks-PV induced cytotoxic autophagy in AML cells, as suggested by biochemical and microscopy results. HOXA9 molecules were detectable within autophagosomes after Luks-PV treatment, indicating that autophagy induction accounted for the degradation of HOXA9. Moreover, Luks-PV-induced HOXA9 downregulation inhibited AML cell proliferation, suggesting that HOXA9 could be degraded through Luks-PV-induced autophagy.Conclusion: Luks-PV suppresses AML cell proliferation by inducing HOXA9 degradation.

scholarly journals Knockdown of Long Noncoding RNA HOXA-AS2 Suppresses Chemoresistance of Acute Myeloid Leukemia via the miR-520c-3p/S100A4 Axis

2018 ◽  
Vol 51 (2) ◽  
pp. 886-896 ◽  
Author(s):  
Xiaoya Dong ◽  
Zhigang Fang ◽  
Mingxue Yu ◽  
Ling Zhang ◽  
Ruozhi Xiao ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Luciferase Reporter Assay ◽  
Luciferase Reporter ◽  
Reporter Assay ◽  
Online Programs ◽  
Acute Myeloid

Background/Aims: Among different molecular candidates, there is growing data to support that long noncoding RNAs (lncRNAs) play a significant role in acute myeloid leukemia (AML). HOXA-AS2 is significantly overexpressed in a variety of tumors and associated with anti-cancer drug resistance, however, little is known regarding the expression and function of HOXA-AS2 in the chemoresistance of AML. In this study, we aimed to determine the role and molecular mechanism of HOXA-AS2 in adriamycin-based chemotherapy resistance in AML cells. Methods: Quantitative real-time PCR was used to detect HOXA-AS2 expression in the BM samples and ADR cell lines, U/A and T/A cells. Furthermore, the effects of HOXA-AS2 silencing on cell proliferation and apoptosis were assessed in vitro by CCK8 and flow cytometry, and on tumor growth in vivo. Furthermore, bioinformatics online programs predicted and luciferase reporter assay were used to validate the association of HOXA-AS2 and miR-520c-3p in AML. Results: In this study, we showed that HOXA-AS2 is significantly upregulated in BM samples from AML patients after treatment with adriamycin-based chemotherapy and in U/A and T/A cells. Knockdown of HOXA-AS2 inhibited ADR cell proliferation in vitro and in vivo and promoted apoptosis. Bioinformatics online programs predicted that HOXA-AS2 sponge miR-520c-3p at 3’-UTR with complementary binding sites, which was validated using luciferase reporter assay and anti-Ago2 RIP assay. HOXA-AS2 could negatively regulate the expression of miR-520c-3p in ADR cells. S100A4 was predicted as a downstream target of miR-520c-3p, which was confirmed by luciferase reporter assay. Conclusion: Our results suggest that HOXA-AS2 plays an important role in the resistance of AML cells to adriamycin. Thus, HOXA-AS2 may represent a therapeutic target for overcoming resistance to adriamycin-based chemotherapy in AML.

The BTK Inhibitor Ibrutinib Blocks SDF1/CXCR4 Mediated Migration of Acute Myeloid Leukemia Cells

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 915-915
Author(s):  
Stuart A Rushworth ◽  
Lyubov Zaitseva ◽  
Megan Y Murray ◽  
Matthew J Lawes ◽  
David J MacEwan ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
Lymphocytic Leukemia ◽  
Cell Trafficking ◽  
Acute Myeloid

Abstract Introduction Despite recent significant progress in the understanding of the biology of acute myeloid leukemia (AML) the clinical outcomes for the majority of patients diagnosed with AML presently remain poor. Consequently, there is an urgent need to identify pharmacological strategies in AML, which are not only effective but can be tolerated by the older, less well patient. Recently our group and others have shown that there is high Bruton’s Tyrosine Kinase (BTK) phosphorylation and RNA expression in AML. Moreover, our recent study described for the first time that ibrutinib and BTK-targeted RNA interference reduced factor-induced proliferation of both AML cell lines and primary AML blasts, as well as reducing AML blast adhesion to bone marrow stromal cells. Inhibition of BTK has been shown to regulate chronic lymphocytic leukemia, mantle cell lymphoma and multiple myeloma cell migration by inhibiting SDF1 (stromal derived factor 1) induced CXCR4 regulated cell trafficking. Here we report that in human AML ibrutinib in addition functions in a similar way to inhibit SDF1/CXCR4-mediated AML migration at concentrations achievable in vivo. Methods To investigate the role of BTK in regulating AML migration we used both pharmacological inhibitor ibrutinib and genetic knockdown using a lentivirus mediated BTK targeted miRNA in primary AML blasts and AML cell lines. We examined migration of AML blasts and AML cells to SDF-1 using Transwell permeable plates with 8.0µM pores. Western blotting was used to examine the role of SDF-1 in regulating BTK, AKT and MAPK activation in primary AML blasts. Results We initially examined the expression of CXCR4 in human AML cell lines and found that 4/4 cell lines were positive for CXCR4 expression. Next we examined the effects of ibrutinib on the migration of the AML cell lines U937, MV4-11, HL60 and THP-1 in response to SDF1. We found that ibrutinib can inhibit the migration of all AML cell lines tested. We tested the in-vitro activity of ibrutinib on SDF-1 induced migration in a spectrum of primary AML blasts from a wide age spectrum of adult patients and across a range of WHO AML subclasses and found that ibrutinib significantly inhibits primary AML blast migration (n=12). Next we found that ibrutinib can inhibit SDF-1 induced BTK phosphorylation and downstream MAPK and AKT signalling in primary AML blast. Finally to eliminate the problems associated with off target ibrutinib activity we evaluated migration of AML cells lines using genetic inhibition of BTK. The introduction of BTK-specific miRNA dramatically inhibited the expression of BTK in THP-1 and HL60 and reduced SDF1 mediated migration confirming that BTK is involved in regulating AML migration in response to SDF1. Conclusions These results reported here provide a molecular mechanistic rationale for clinically evaluating BTK inhibition in AML patients and suggests that in some AML patients the blasts count may initially rise in response to ibrutinib therapy, analgous to similar clinical observations in CLL. Disclosures No relevant conflicts of interest to declare.

scholarly journals Conditional MN1-TEL knock-in mice develop acute myeloid leukemia in conjunction with overexpression of HOXA9

Blood ◽  
2005 ◽  
Vol 106 (13) ◽  
pp. 4269-4277 ◽  
Author(s):  
Hiroyuki Kawagoe ◽  
Gerard C. Grosveld
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Chromosomal Translocation ◽  
Lymphoid Cells ◽  
Dependent Manner ◽  
Myeloproliferative Disease ◽  
Long Latency ◽  
Acute Myeloid

The chromosomal translocation t(12; 22)(p13;q11) in human myeloid leukemia generates an MN1-TEL (meningioma 1-translocation-ETS-leukemia) fusion oncoprotein. This protein consists of N-terminal MN1 sequences, a transcriptional coactivator fused to C-terminal TEL sequences, an ETS (E26 transformation-specific) transcription factor. Enforced expression of MN1-TEL in multipotent hematopoietic progenitors in knock-in mice perturbed growth and differentiation of myeloid as well as lymphoid cells. Depending on obligatory secondary mutations, these mice developed T-cell lympholeukemia. Here we addressed the role of MN1-TEL in myeloid leukemogenesis using the same mouse model. Expression of MN1-TEL enhanced the growth of myeloid progenitors in an interleukin 3/stem cell factor (IL-3/SCF)–dependent manner in vitro whereas 10% of MN1-TEL–expressing mice developed altered myelopoiesis with severe anemia after long latency. Coexpression of MN1-TEL and IL-3, but not SCF, rapidly caused a fatal myeloproliferative disease rather than acute myeloid leukemia (AML). Because MN1-TEL+ AML patient cells overexpress HOXA9 (homeobox A9), we tested the effect of coexpression of MN1-TEL and HOXA9 in mice and found that 90% of MN1-TEL+/HOXA9+ mice developed AML much more rapidly than control HOXA9+ mice. Thus, the leukemogenic effect of MN1-TEL in our knock-in mice is pleiotropic, and the type of secondary mutation determines disease outcome.

scholarly journals Critical Role of Lama4 for Hematopoiesis Regeneration and Acute Myeloid Leukemia Progression

Blood ◽  
2021 ◽  
Author(s):  
Huan Cai ◽  
Makoto Kondo ◽  
Lakshmi Sandhow ◽  
Pingnan Xiao ◽  
Anne-Sofie Johansson ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Proliferation ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Critical Role ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Bm Niche ◽  
Acute Myeloid

Impairement of normal hmatopoiesis and leukemia progression are two well-linked processes during leukemia development and controlled by the bone marrow (BM) niche. Extracellular matrix proteins including laminin are important BM niche components. However, their role in hematopoiesis regeneration and leukemia is unknown. Laminin α4 (Lama4), a major receptor-binding chain of several laminins, is altered in BM niches in mice with acute myeloid leukemia (AML). So far, the impact of Lama4 on leukemia progression remains unknown. We here report that Lama4 deletion in mice resulted in impaired hematopoiesis regeneration following irradiation-induced stress, which is accompanied with altered BM niche composition and inflammation. Importantly, in a transplantation-induced MLL-AF9 AML mouse model, we demonstrate accelerated AML progression and relapse in Lama4-/-mice. Upon AML exposure, Lama4-/- mesenchymal stem cells (MSCs) exhibited dramatic molecular alterations including upregulation of inflammatory cytokines that favor AML growth. Lama4-/- MSCs displayed increased anti-oxidant activities and promoted AML stem cell proliferation and chemoresistance to cytarabine, which was accompanied by increased mitochondrial transfer from the MSCs to AML cells and reduced reactive oxygen species in AML cells in vitro. Similarly, we detected lower levels of reactive oxygen species in AML cells from Lama4-/- mice post-cytarabine treatment. Notably, LAMA4 inhibition or knockdown in human MSCs promoted human AML cell proliferation and chemoprotection. Together, our study for the first time demonstrates a critical role of Lama4 in impeding AML progression and chemoresistance. Targeting Lama4 signaling pathways may offer potential new therapeutic options for AML.

Role of Folylpolyglutamate Synthetase and Folylpolyglutamate Hydrolase in Methotrexate Accumulation and Polyglutamylation in Childhood Leukemia

Blood ◽  
1999 ◽  
Vol 93 (5) ◽  
pp. 1677-1683 ◽  
Author(s):  
Marianne G. Rots ◽  
Rob Pieters ◽  
Godefridus J. Peters ◽  
Paul Noordhuis ◽  
Christina H. van Zantwijk ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Multivariate Analysis ◽  
Myeloid Leukemia ◽  
Childhood Leukemia ◽  
Lymphoblastic Leukemia ◽  
Folylpolyglutamate Synthetase ◽  
Additional Role ◽  
Acute Myeloid

Abstract Inefficient polyglutamylation is a mechanism of resistance to methotrexate (MTX) in childhood T-lineage acute lymphoblastic leukemia (T-ALL) and in acute myeloid leukemia (AML) in comparison with childhood c/preB-ALL. We analyzed the profile of MTX polyglutamylation in childhood c/preB-ALL, T-ALL, and AML (n = 45, 15, and 14, respectively), the activity of the MTX-polyglutamate synthesizing enzyme folylpolyglutamate synthetase (FPGS) (n = 39, 11, and 19, respectively) and of the MTX-polyglutamate breakdown enzyme folylpolyglutamate hydrolase (FPGH) (n = 98, 25, and 34, respectively). MTX-Glu4-6 accumulation after 24 hours exposure to 1 μmol/L [3H]-MTX in vitro was lower in T-ALL (threefold) and AML (fourfold) compared with c/preB-ALL (P ≤ .001). The FPGS activity was twofold lower in T-ALL and AML than in c/preB-ALL samples (P < .01). FPGH activity was not different between c/preB-ALL and T-ALL, but threefold higher in AML (P < .001). FPGS, FPGH, and the ratio FPGS/FPGH were correlated with MTX-Glu4-6 accumulation (r = .49, r = −.34 and r = .61, respectively). Multivariate analysis showed that FPGS, but not FPGH, was an independent contributor for MTX-Glu1-6 accumulation, but not for MTX-Glu4-6 accumulation. In conclusion, low FPGS activity is associated with low accumulation of MTX-Glu4-6 in T-ALL and AML. For the group of AML as compared with the group of ALL, a high FPGH activity can play an additional role.

scholarly journals PAK1 Mediates Bone Marrow Stromal Cell-Induced Drug Resistance in Acute Myeloid Leukemia via ERK1/2 Signaling Pathway

2021 ◽  
Vol 9 ◽  
Author(s):  
Banban Li ◽  
Ruinan Jia ◽  
Wei Li ◽  
Ying Zhou ◽  
Dongmei Guo ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Cell Proliferation ◽  
Drug Resistance ◽  
Acute Myeloid Leukemia ◽  
Signaling Pathway ◽  
Myeloid Leukemia ◽  
Major Barrier ◽  
P21 Activated Kinase ◽  
Acute Myeloid

BackgroundChemoresistance is emerging as a major barrier to successful treatment in acute myeloid leukemia (AML), and bone marrow stromal cells (BMSCs) protect leukemia cells from chemotherapy eventually leading to recurrence. This study was designed to investigate the role of p21-activated kinase 1 (PAK1) in AML progression and chemosensitivity, highlighting the mechanism of stroma-mediated chemoresistance.MethodsThe GEPIA and TCGA datasets were used to analyze the relationship between PAK1 mRNA expression and various clinical parameters of AML patients. Cell proliferation and apoptosis were examined to evaluate the role of PAK1 on chemosensitivity in AML by silencing PAK1 with shRNA or small molecular inhibitor. Human BMSC (HS-5) was utilized to mimic the leukemia bone marrow microenvironment (BMM) in vitro, and co-culture model was established to investigate the role of PAK1 in BMSC-mediated drug resistance.Resultsp21-activated kinase 1 high expression was shown to be associated with shorter overall survival in AML patients. The silence of PAK1 could repress cell proliferation, promote apoptosis, and enhance the sensitivity of AML cells to chemotherapeutic agents. More importantly, BMSCs induced PAK1 up-regulation in AML cells, subsequently activating the ERK1/2 signaling pathway. The effect of BMSC-mediated apoptotic-resistance could be partly reversed by knock down of PAK1.Conclusionp21-activated kinase 1 is a potential prognostic predictor for AML patients. PAK1 may play a pivotal role in mediating BMM-induced drug resistance, representing a novel therapeutic target in AML.

scholarly journals "Identification of Mechanisms By Which Mesenchymal Stem/Stromal Cells Contribute to Acute Myeloid Leukemia"

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5194-5194
Author(s):  
Allolo Aldreiwish ◽  
Gauri Muradia ◽  
Remi Gagne ◽  
Marc Beal ◽  
Carole Yauk ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Stromal Cells ◽  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
In Silico Analysis ◽  
Leukemic Cells ◽  
Silico Analysis ◽  
Acute Myeloid

Acute myeloid leukemia (AML) is a blood malignancy resulting in abnormal hematopoiesis that is reported to be associated with alterations in the bone marrow microenvironment (BME). Current treatments for this heterogeneous disease, which target the leukemic cells but not the BME, are largely unsuccessful for the majority of AML subtypes. By better understanding the mechanisms by which the BME contributes to leukemogenesis, it may be possible to introduce more effective treatments for AML. Mesenchymal stem cells (MSCs) are an essential component of the BME that have been shown to support normal hematopoiesis. Therefore, MSCs may have several roles in the alteration of the BME, leukemogenesis, and AML relapse and can provide an excellent model for studying the BME in vitro. While some studies have characterized AML-derived MSCs (AML-MSCs), their exact role in the disease remains unclear. Our RNAseq analysis of AML-MSCs (n=30), and healthy donor MSCs (HD-MSCs) (n=8) identified that, among 7655 genes, 21 genes were significantly differentially expressed in AML-MSCs. Through in silico analysis of this gene set, genes of interest were identified as having the potential to directly alter the BME and affect AML pathogenesis through BMP/TGF-β pathways. Current work is focusing on investigation of the effects of selected genes with biological relevance on MSCs intrinsic and extrinsic functional properties. This study will improve our understanding of the role of MSCs in AML BME and help in the discovery of new therapeutic targets. Disclosures No relevant conflicts of interest to declare.

Toll-like Receptor 1 Is a Candidate Therapeutic Target in Acute Myeloid Leukemia

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5782-5782 ◽  
Author(s):  
Mia Eriksson ◽  
Pablo Peña ◽  
Marion Chapellier ◽  
Carl Högberg ◽  
Thoas Fioretos ◽  
...  
Keyword(s):  
Stem Cells ◽  
Acute Myeloid Leukemia ◽  
Cell Surface ◽  
Therapeutic Target ◽  
Myeloid Leukemia ◽  
Leukemic Cells ◽  
Toll Like Receptor ◽  
Acute Myeloid

Abstract Acute myeloid leukemia (AML) is a fatal disease that contains rare immature cells with self-renewal and leukemia-initiating capacity, known as leukemia stem cells (LSCs). Because current therapies are inefficient in eradicating LSCs, new therapies are warranted that efficiently target this cell population. One strategy being explored towards new therapies is identification of novel therapeutic targets on the cell surface of AML stem cells. To identify a cell surface protein upregulated on LSC, we used flow cytometry to measure the expression level of 13 cell surface proteins on immature leukemic cells from 18 AML patients and bone marrow cells from 7 healthy controls. We identified Toll-like receptor 1 (TLR1) as significantly upregulated in the immature CD34+CD38-compartment compared to corresponding normal cells that were almost devoid of TLR1 expression. These findings are consistent with elevated TLR1 mRNA levels observed in MDS patients (Wei et al, Leukemia, 2013). To evaluate the role of Tlr1 on immature leukemic cells, we performed shRNA-mediated inhibition of Tlr1 in MLL-AF9-expressing murine c-Kit+ leukemic cells. By using lentiviral vectors expressing the Tlr1-shRNAs along with a puromycin resistance gene, we identified two unique shRNAs that successfully suppressed the Tlr1 transcript and protein expression in comparison to a shRNA control. We next co-expressed the two Tlr1-shRNAs along with GFP in leukemia cells and monitored the percentage of GFP positive cells over time. Expression of the Tlr1-shRNAs resulted in strong depletion of the leukemic cells both in vitro and in vivo relative to the control shRNA. These findings suggest that TLR1 is important for the growth and survival of leukemic cells. To further address the role of Tlr1 on leukemic cells, we stimulated the leukemic cells with Pam3CSK4, a specific Tlr1/2 agonist. Pam3CSK4 alone was added to in vitro cultures of leukemic cells for three days, leading to increased survival and a slight increased number of leukemic cells. However, flow cytometric analysis revealed a differentiation shift of cells stimulated with Pam3CSK4 indicated by a decreased expression of the immature cell surface marker c-Kit and an increased expression of the myeloid linage marker Mac-1. To evaluate how Pam3CSK4 affects LSCs, we added Pam3CSK4 to ex vivo-cultures of leukemic cells for 3 days and then transplanted the cells into sublethally irradiated mice. Blood samples after two weeks showed a decreased leukemic burden in mice receiving Pam3CSK4-stimulated cells compared to controls. These findings suggest that enforced TLR1/TLR2-signaling causes differentiation of LSCs. In summary, this study demonstrates that TLR1 is upregulated on AML-stem cell enriched patient cells and that TLR1 expression is finely balanced to maintain LSCs. More specifically, our data suggest that the leukemic cells require Tlr1-expression for survival, but enhanced Tlr1/Tlr2-activation force the LSCs into differentiation. Hence, our study suggests that approaches aiming either for inhibition or enforced activation of TLR1 in AML should be explored further towards a potential new AML therapy. Collectively, we here identify TLR1 as a novel and promising candidate therapeutic target in AML. Disclosures No relevant conflicts of interest to declare.

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