scholarly journals STAT5-dependent regulation of CDC25A by miR-16 controls proliferation and differentiation in FLT3-ITD acute myeloid leukemia

2019 ◽  
Author(s):  
Gabrielle Sueur ◽  
Alison Boutet ◽  
Mathilde Gotanègre ◽  
Véronique Mansat-De Mas ◽  
Arnaud Besson ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Mrna Levels ◽  
Monocytic Differentiation ◽  
Cell Proliferation And Differentiation ◽  
Flt3 Inhibitor ◽  
Proliferation And Differentiation ◽  
Cdc25a Phosphatase ◽  
Chip Analysis ◽  
Acute Myeloid

AbstractWe recently identified the CDC25A phosphatase as a key actor in proliferation and differentiation in acute myeloid leukemia which expresses the FLT3-ITD mutation. In this paper we demonstrate that CDC25A level is controlled by a complex STAT5/miR-16 transcription and translation pathway working downstream of this receptor. First, we established by CHIP analysis that STAT5 is directly involved in FLT3-ITD-dependent CDC25A gene transcription. In addition, we determined that miR-16 expression is repressed by FLT3-ITD activity, and that STAT5 participates in this repression. In accordance with these results, miR-16 expression was significantly reduced in a panel of AML primary samples carrying the FLT3-ITD mutation when compared with FLT3wt cells. The expression of a miR-16 mimic reduced CDC25A protein and mRNA levels, and RNA interference-mediated down modulation of miR-16 restored CDC25A expression in response to FLT3-ITD inhibition. Finally, decreasing miR-16 expression partially restored the proliferation of cells treated with the FLT3 inhibitor AC220, while the expression of miR-16 mimic stopped this proliferation and induced monocytic differentiation of AML cells. In summary, we identified a FLT3-ITD/STAT5/miR-16/CDC25A axis essential for AML cell proliferation and differentiation.

An Unusual Case Of Disseminated Histiocytic Sarcoma Preceded By Myeloid Sarcoma With Concomitant Acute Myeloid Leukemia

2020 ◽  
Vol 154 (Supplement_1) ◽  
pp. S107-S108
Author(s):  
A C Reddy ◽  
K S Reddy
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Lymphoblastic Leukemia ◽  
Neck Mass ◽  
Histiocytic Sarcoma ◽  
Myeloid Sarcoma ◽  
Monocytic Differentiation ◽  
Tissue Samples ◽  
Disseminated Disease ◽  
Acute Myeloid

Abstract Introduction/Objective Histiocytic sarcoma (HS) is rare (<1% of hematolymphoid neoplasms), and can present extranodally as disseminated disease. Immunophenotypically, the cells express CD163, CD68, lysozyme and CD45. HS often occurs as a secondary event following B-cell lymphomas, acute lymphoblastic leukemia or acute myeloid leukemia (AML) typically with monocytic differentiation retaining the same molecular/cytogenetic abnormalities as the primary tumor. Results Our patient, a 47 year old male was diagnosed with myeloid sarcoma (MS) following FNA of a new neck mass. A bone marrow biopsy revealed AML without monocytic differentiation. Flow cytometric findings of both marrow and neck mass were similar (positive for CD34, CD117, CD33, CD11b, CD13, CD15, CD64, CD7; negative for CD4, CD14, CD56). Karyotypic and FLT3 ITD mutation analysis were normal. CNS involvement was diagnosed 2 months later, while a marrow biopsy (status post therapy) confirmed resolution of AML. A hypermetabolic left perinephric mass noted by PET CT, when biopsied, showed large epithelioid polygonal cells with amphophilic cytoplasm and atypical vesicular nuclei (positive for CD68, PU.1; negative for LCA, CD163, CD34, CD4, pankeratin). A diagnosis of atypical epithelioid neoplasm suggestive of HS was rendered, although negativity for LCA and CD163 was unusual. No treatment was given for HS. A month later, the patient presented with a cheek mass diagnosed again as being suggestive of HS. His AML also relapsed. Next-generation sequencing (37 genes including BRAF) from both marrow and tissue samples detected the presence of a nonsense mutation in exon 7 of WT1 (p.Ser169). Conclusion Our case appears to be the first reported one of disseminated HS preceded by MS and concomitant AML, lacking monocytic differentiation. The findings overall support the hypothesis of origin as being from a common progenitor cell differentiating along both myeloid and histiocytic/other cell lineages at different time points.

scholarly journals ATM/G6PD-driven redox metabolism promotes FLT3 inhibitor resistance in acute myeloid leukemia

2016 ◽  
Vol 113 (43) ◽  
pp. E6669-E6678 ◽  
Author(s):  
Mark A. Gregory ◽  
Angelo D’Alessandro ◽  
Francesca Alvarez-Calderon ◽  
Jihye Kim ◽  
Travis Nemkov ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Mitochondrial Oxidative Stress ◽  
Flt3 Inhibitor ◽  
A Genome ◽  
Flt3 Inhibitors ◽  
Acute Myeloid

Activating mutations in FMS-like tyrosine kinase 3 (FLT3) are common in acute myeloid leukemia (AML) and drive leukemic cell growth and survival. Although FLT3 inhibitors have shown considerable promise for the treatment of AML, they ultimately fail to achieve long-term remissions as monotherapy. To identify genetic targets that can sensitize AML cells to killing by FLT3 inhibitors, we performed a genome-wide RNA interference (RNAi)-based screen that identified ATM (ataxia telangiectasia mutated) as being synthetic lethal with FLT3 inhibitor therapy. We found that inactivating ATM or its downstream effector glucose 6-phosphate dehydrogenase (G6PD) sensitizes AML cells to FLT3 inhibitor induced apoptosis. Examination of the cellular metabolome showed that FLT3 inhibition by itself causes profound alterations in central carbon metabolism, resulting in impaired production of the antioxidant factor glutathione, which was further impaired by ATM or G6PD inactivation. Moreover, FLT3 inhibition elicited severe mitochondrial oxidative stress that is causative in apoptosis and is exacerbated by ATM/G6PD inhibition. The use of an agent that intensifies mitochondrial oxidative stress in combination with a FLT3 inhibitor augmented elimination of AML cells in vitro and in vivo, revealing a therapeutic strategy for the improved treatment of FLT3 mutated AML.

scholarly journals An overview on the role of FLT3-tyrosine kinase receptor in acute myeloid leukemia: biology and treatment

2012 ◽  
Vol 6 (1) ◽  
pp. 8 ◽  
Author(s):  
Tiziana Grafone ◽  
Michela Palmisano ◽  
Chiara Nicci ◽  
Sergio Storti
Keyword(s):  
Acute Myeloid Leukemia ◽  
Tyrosine Kinase ◽  
Signaling Pathways ◽  
Myeloid Leukemia ◽  
Molecular Therapy ◽  
Tyrosine Kinase Receptor ◽  
Hematopoietic Stem ◽  
Downstream Signaling ◽  
Proliferation And Differentiation ◽  
Acute Myeloid

Hematopoiesis, the process by which the hematopoietic stem cells and progenitors differentiate into blood cells of various lineages, involves complex interactions of transcription factors that modulate the expression of downstream genes and mediate proliferation and differentiation signals. Despite the many controls that regulate hematopoiesis, mutations in the regulatory genes capable of promoting leukemogenesis may occur. The <em>FLT3</em> gene encodes a tyrosine kinase receptor that plays a key role in controlling survival, proliferation and differentiation of hematopoietic cells. Mutations in this gene are critical in causing a deregulation of the delicate balance between cell proliferation and differentiation. In this review, we provide an update on the structure, synthesis and activation of the FLT3 receptor and the subsequent activation of multiple downstream signaling pathways. We also review activating FLT3 mutations that are frequently identified in acute myeloid leukemia, cause activation of more complex downstream signaling pathways and promote leukemogenesis. Finally, FLT3 has emerged as an important target for molecular therapy. We, therefore, report on some recent therapies directed against it.

The Value of CD64 Expression in Distinguishing Acute Myeloid Leukemia With Monocytic Differentiation From Other Subtypes of Acute Myeloid Leukemia: A Flow Cytometric Analysis of 64 Cases

2007 ◽  
Vol 131 (5) ◽  
pp. 748-754
Author(s):  
Cherie H. Dunphy ◽  
Wohzan Tang
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Flow Cytometric Analysis ◽  
World Health ◽  
Monocytic Differentiation ◽  
Flow Cytometric Immunophenotyping ◽  
Cd64 Expression ◽  
Flow Cytometric ◽  
Health Organization ◽  
Acute Myeloid

Abstract Context.—Flow cytometric immunophenotyping is a useful ancillary tool in the diagnosis and subclassification of acute myeloid leukemias (AMLs). A recent study concluded that CD64 is sensitive and specific for distinguishing AMLs with a monocytic component (ie, AML M4 and AML M5) from other AML subtypes. However, in that study, the intensity of CD64 was not well defined and the number of non-M4/non-M5 AMLs was small. Objective.—To evaluate the usefulness of CD64 by flow cytometric immunophenotyping in distinguishing AMLs with monocytic differentiation from other AML subtypes. Design.—Sixty-four AMLs subclassified based on the French-American-British and World Health Organization classifications on pretreatment bone marrows were retrieved from our files (7 M0s, 11 M1s, 17 M2s, 7 M3s, 9 M4s, 7 M5s, 4 M6s, and 2 M7s). A standard panel of markers, including CD2, CD3, CD5, CD7, CD10, CD11b, CD13, CD14, CD15, CD19, CD20, CD33, CD34, CD45, CD56, CD64, CD117, and HLA-DR, were analyzed by flow cytometric immunophenotyping in all AMLs (52 bone marrow samples; 12 peripheral blood samples). Results.—CD64 was expressed in AML subtypes M0 to M5 in varying intensities: heterogeneously expressed in 1 of 7 M0s; dimly expressed in 3 of 11 M1s; dimly and moderately expressed in 6 and 2 of 17 M2s, respectively; dimly and moderately expressed in 5 and 1 of 7 M3s, respectively; dimly expressed in 4 of 9 M4s; and heterogeneously, moderately, and strongly expressed in 1, 3, and 3 of 7 M5s, respectively. Conclusions.—Strong CD64 expression distinguishes AML M5; however, heterogeneous, dim, or moderate expression in itself does not distinguish M0 through M4 subtypes from M5 with dim to moderate CD64 expression. However, any CD64 expression associated with strong CD15 expression distinguishes AML M4 or M5, from other AML subtypes.

scholarly journals Is Hematopoietic Stem Cell Transplantation Required to Unleash the Full Potential of Immunotherapy in Acute Myeloid Leukemia?

2020 ◽  
Vol 9 (2) ◽  
pp. 554 ◽  
Author(s):  
Edward Abadir ◽  
Robin E. Gasiorowski ◽  
Pablo A. Silveira ◽  
Stephen Larsen ◽  
Georgina J. Clark
Keyword(s):  
Acute Myeloid Leukemia ◽  
Stem Cell ◽  
Stem Cell Transplantation ◽  
Cell Transplantation ◽  
Myeloid Leukemia ◽  
Hematologic Toxicity ◽  
Full Potential ◽  
Monocytic Differentiation ◽  
Hematopoietic Stem ◽  
Acute Myeloid

From monoclonal antibodies (mAbs) to Chimeric Antigen Receptor (CAR) T cells, immunotherapies have enhanced the efficacy of treatments against B cell malignancies. The same has not been true for Acute Myeloid Leukemia (AML). Hematologic toxicity has limited the potential of modern immunotherapies for AML at preclinical and clinical levels. Gemtuzumab Ozogamicin has demonstrated hematologic toxicity, but the challenge of preserving normal hematopoiesis has become more apparent with the development of increasingly potent immunotherapies. To date, no single surface molecule has been identified that is able to differentiate AML from Hematopoietic Stem and Progenitor Cells (HSPC). Attempts have been made to spare hematopoiesis by targeting molecules expressed only on later myeloid progenitors as well as AML or using toxins that selectively kill AML over HSPC. Other strategies include targeting aberrantly expressed lymphoid molecules or only targeting monocyte-associated proteins in AML with monocytic differentiation. Recently, some groups have accepted that stem cell transplantation is required to access potent AML immunotherapy and envision it as a rescue to avoid severe hematologic toxicity. Whether it will ever be possible to differentiate AML from HSPC using surface molecules is unclear. Unless true specific AML surface targets are discovered, stem cell transplantation could be required to harness the true potential of immunotherapy in AML.

Abstract 804: Antitumor activity of the potent and novel FLT3 inhibitor HM43239 in acute myeloid leukemia

2018 ◽  
Author(s):  
Miyoung Lee ◽  
Young Eun Ha ◽  
Mi Jin Moon ◽  
Joo-Yun Byun ◽  
HyunKyung Yu ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Antitumor Activity ◽  
Myeloid Leukemia ◽  
Flt3 Inhibitor ◽  
Acute Myeloid

Abstract 1293: HM43239, a novel FLT3 inhibitor in overcoming resistance for acute myeloid leukemia

2019 ◽  
Author(s):  
JiSook Kim ◽  
InHwan Bae ◽  
JaeYul Choi ◽  
MinJeong Kim ◽  
JooYun Byun ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Flt3 Inhibitor ◽  
Acute Myeloid

scholarly journals STAT5-dependent regulation of CDC25A by miR-16 controls proliferation and differentiation in FLT3-ITD acute myeloid leukemia

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Gabrielle Sueur ◽  
Alison Boutet ◽  
Mathilde Gotanègre ◽  
Véronique Mansat-De Mas ◽  
Arnaud Besson ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Proliferation And Differentiation ◽  
Acute Myeloid

Monocytic Maturation Induced by FLT3 Inhibitor Therapy of Acute Myeloid Leukemia: Morphologic and Immunophenotypic Characteristics

2019 ◽  
Vol 51 (5) ◽  
pp. 478-483
Author(s):  
Cade D Arries ◽  
Sophia L Yohe
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Tyrosine Kinase ◽  
Cell Population ◽  
Myeloid Leukemia ◽  
Inhibitor Therapy ◽  
Molecular Abnormalities ◽  
Flt3 Inhibitor ◽  
Flt3 Inhibitors ◽  
Acute Myeloid

Abstract Background FMS-like tyrosine kinase-3 (FLT3-ITD) mutations are some of the most common mutations in acute myeloid leukemia (AML), and patient outcomes have improved since the advent of tyrosine kinase inhibitors. First, granulocytic differentiation was described in FLT3-positive AML treated with FLT3 inhibitors, and more recently, monocytic differentiation was reported. Methods Two patients with myelomonocytic cells in their bone marrow were identified during routine follow-up after AML treatment that included FLT3 inhibitors. The bone marrow study was done as standard of care. Results Both patients had FLT3-ITD+ AML and showed an atypical maturing monocytic cell population and a decrease in the leukemic blast cell population after FLT3 inhibitor therapy. Concurrent genetic testing revealed persistent genetic abnormalities. Conclusions These cases illustrate monocytic maturation in FLT3+ AML after FLT3 inhibitor treatment. It is critical for pathologists and clinicians to be aware of the differentiation phenomenon, as these patients have persistent molecular abnormalities despite response to treatment and normalization of blast counts.

Sign in / Sign up

Export Citation Format

Share Document