scholarly journals Changes in expression of WT1 during induced differentiation of the acute myeloid leukemia cell lines by treatment with 5-aza-2′-deoxycytidine and all-trans retinoic acid

2015 ◽  
Vol 11 (2) ◽  
pp. 1521-1526 ◽  
Author(s):  
LILI XIANG ◽  
JIAHE ZHOU ◽  
WEIYING GU ◽  
RONG WANG ◽  
JIANG WEI ◽  
...  
2019 ◽  
Vol 10 (12) ◽  
Author(s):  
Chi Huu Nguyen ◽  
Katharina Bauer ◽  
Hubert Hackl ◽  
Angela Schlerka ◽  
Elisabeth Koller ◽  
...  

AbstractEcotropic virus integration site 1 (EVI1), whose overexpression characterizes a particularly aggressive subtype of acute myeloid leukemia (AML), enhanced anti-leukemic activities of all-trans retinoic acid (atRA) in cell lines and patient samples. However, the drivers of leukemia formation, therapy resistance, and relapse are leukemic stem cells (LSCs), whose properties were hardly reflected in these experimental setups. The present study was designed to address the effects of, and interactions between, EVI1 and retinoids in AML LSCs. We report that Evi1 reduced the maturation of leukemic cells and promoted the abundance, quiescence, and activity of LSCs in an MLL-AF9-driven mouse model of AML. atRA further augmented these effects in an Evi1 dependent manner. EVI1 also strongly enhanced atRA regulated gene transcription in LSC enriched cells. One of their jointly regulated targets, Notch4, was an important mediator of their effects on leukemic stemness. In vitro exposure of leukemic cells to a pan-RAR antagonist caused effects opposite to those of atRA. In vivo antagonist treatment delayed leukemogenesis and reduced LSC abundance, quiescence, and activity in Evi1high AML. Key results were confirmed in human myeloid cell lines retaining some stem cell characteristics as well as in primary human AML samples. In summary, our study is the first to report the importance of EVI1 for key properties of AML LSCs. Furthermore, it shows that atRA enhances, and a pan-RAR antagonist counteracts, the effects of EVI1 on AML stemness, thus raising the possibility of using RAR antagonists in the therapy of EVI1high AML.


Cell Cycle ◽  
2015 ◽  
Vol 14 (16) ◽  
pp. 2578-2589 ◽  
Author(s):  
Gloria Manzotti ◽  
Sandra Parenti ◽  
Giovanna Ferrari-Amorotti ◽  
Angela Rachele Soliera ◽  
Sara Cattelani ◽  
...  

2005 ◽  
Vol 29 (6) ◽  
pp. 701-710 ◽  
Author(s):  
Yoshinobu Matsuo ◽  
Hans G. Drexler ◽  
Akira Harashima ◽  
Ayumi Okochi ◽  
Kensuke Kojima ◽  
...  

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1486-1486
Author(s):  
Lan Dan ◽  
Ana Gigina ◽  
Karl Welte ◽  
Julia Skokowa

Abstract Abstract 1486 Recently we demonstrated that nicotinamide phosphoribosyltransferase (NAMPT) is an essential enzyme mediating granulocyte colony-stimulating factor (G-CSF)-triggered granulopoiesis via activation of NAD+/sirtuins/C/EBPs signaling cascade. Nampt levels were significantly elevated in plasma and in myeloid cells of patients with severe congenital neutropenia (CN). CN is characterized by a “maturation arrest” of granulopoiesis on the promyelocytic stage of differentiation and by leukemogenic tansformation of hematopoiesis in ca. 20 % of patients. The mechanism of the leukemic transformation is still unclear. Previously, we reported elevated levels of activated oncogene ß-catenin in nuclei of myeloid progenitor cells of CN patients. The activity and nuclear translocation of ß-catenin is regulated by glycogen synthase kinase-3 ß (GSK3ß), which activates ß-catenin degradation complex. In the present study we found that in myeloid cells of CN patients GSK3ß was inhibited by phosphorylation on Ser9, as compared to healthy individuals. Therefore, we assume that GSK3ß-ß-catenin pathway could be involved in the leukemogenic transformation of hematopoiesis. Since, Nampt was also elevated in CN patients, we aimed to investigate the connection between hyperactivated Nampt and ß-catenin in leukemogenesis. The Nampt functions in hematopoiesis are dependent on the dose of Nampt and NAD+. Thus, in vitro stimulation of CD34+ cells with Nampt led to granulocytic differentiation via activation of sirtuin/C/EBP-dependent pathway. At the same time, inhibitors of NAMPT have been identified as therapeutical targets for some cancers including leukemia. This suggested that different mechanisms are operating downstream of NAMPT in the “normal” and leukemogenic myeloid cells. Screening of the different sirtuins in primary acute myeloid leukemia (AML) blasts revealed significant upregulation of SIRT2 mRNA and protein levels, as compared to CD34+ and CD33+ hematopoietic cells of healthy individuals. SIRT2 levels were also elevated in myeloid cells of CN patients treated with G-CSF. Specific inhibition of NAMPT (using 10 nMol of FK866) or SIRT2 (using 100nMol of AC93253) significantly reduced proliferation and induced apoptosis in human myeloid leukemia cell lines (NB4, HL60 and U937). We further tested if inhibition of Nampt or SIRT2 has an effect on GSK3ß/ß-catenin pathway. GSK3ß is known to be inhibited by Akt and treatment of the acute myeloid leukemia cell lines NB4 and HL60 with FK866 or AC93253 resulted in the activation of Akt via phosphorylation on Thr308 and Ser473 and inactivation of GSK-3ß via inhibition of phosphorylation on Ser9. Moreover, activated ß-catenin protein was almost completely disappeared from the nucleus of cells treated with FK866. Taken together, our results provide strong evidence that NAMPT and SIRT2 participate in leukemogenic transformation via inactivation of GSK3ß leading to nuclear accumulation of oncogenic ß-catenin. Disclosures: No relevant conflicts of interest to declare.


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