scholarly journals Identification and targeting of novel CDK9 complexes in acute myeloid leukemia

Blood ◽  
2019 ◽  
Vol 133 (11) ◽  
pp. 1171-1185 ◽  
Author(s):  
Elspeth M. Beauchamp ◽  
Sameem M. Abedin ◽  
Sara G. Radecki ◽  
Mariafausta Fischietti ◽  
Ahmet Dirim Arslan ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Messenger Rna ◽  
Myeloid Leukemia ◽  
Mammalian Target Of Rapamycin ◽  
Mrna Translation ◽  
Mtor Signaling ◽  
Signaling Activation ◽  
Acute Myeloid

Abstract Aberrant activation of mTOR signaling in acute myeloid leukemia (AML) results in a survival advantage that promotes the malignant phenotype. To improve our understanding of factors that contribute to mammalian target of rapamycin (mTOR) signaling activation and identify novel therapeutic targets, we searched for unique interactors of mTOR complexes through proteomics analyses. We identify cyclin dependent kinase 9 (CDK9) as a novel binding partner of the mTOR complex scaffold protein, mLST8. Our studies demonstrate that CDK9 is present in distinct mTOR-like (CTOR) complexes in the cytoplasm and nucleus. In the nucleus, CDK9 binds to RAPTOR and mLST8, forming CTORC1, to promote transcription of genes important for leukemogenesis. In the cytoplasm, CDK9 binds to RICTOR, SIN1, and mLST8, forming CTORC2, and controls messenger RNA (mRNA) translation through phosphorylation of LARP1 and rpS6. Pharmacological targeting of CTORC complexes results in suppression of growth of primitive human AML progenitors in vitro and elicits strong antileukemic responses in AML xenografts in vivo.

scholarly journals Bone mesenchymal stem cell-derived exosomal microRNA-7-5p inhibits progression of acute myeloid leukemia by targeting OSBPL11

2022 ◽  
Vol 20 (1) ◽  
Author(s):  
Duanfeng Jiang ◽  
Xin Wu ◽  
Xiaoying Sun ◽  
Wei Tan ◽  
Xin Dai ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Signaling Pathway ◽  
Myeloid Leukemia ◽  
Mtor Signaling ◽  
Luciferase Reporter ◽  
Mtor Signaling Pathway ◽  
Acute Myeloid

Abstract Background Acute myeloid leukemia (AML) is a malignant clonal disease of hematopoietic stem- and progenitor-cell origin. AML features massive proliferation of abnormal blasts and leukemia cells in the bone marrow and the inhibition of normal hematopoiesis at onset. Exosomes containing proteins or nucleic acids are secreted by cells; they participate in intercellular communication and serve as key modulators of hematopoiesis. The purpose of this study was to investigate the effects of exosomes derived from bone marrow mesenchymal stem cells (BMSCs) on the regulation of AML and the underlying mechanisms mediated by microRNA (miRNA). Methods Dysregulated miR-7-5p in AML patients was identified using qRT-PCR and its clinical significance was explored. Bioinformatic analysis revealed the target gene OSBPL11 that could be regulated by miR-7-5p. The findings were validated using a dual-luciferase reporter assay and western blotting. The functional genes of the PI3K/AKT/mTOR signaling pathway were identified, and the functional significance of miR-7-5p in AML cells was determined using a functional recovery assay. AML cells were co-cultured with exosomes originating from BMSCs overexpressing miR-7-5p to determine cell–cell regulation by Exo-miR-7-5p, as well as in vitro and in vivo functional validation via gain- and loss-of-function methods. Results Expression of miR-7-5p was decreased in AML patients and cells. Overexpression of miR-7-5p curbed cellular proliferation and promoted apoptosis. Overexpression of OSBPL11 reversed the tumorigenic properties of miR-7-5p in AML cells in vitro. Exo-miR-7-5p derived from BMSCs induced formation of AML cells prone to apoptosis and a low survival rate, with OSBPL11 expression inhibited through the PI3K/AKT/mTOR signaling pathway. Exo-miR-7-5p derived from BMSCs exhibited tumor homing effects in vitro and in vivo, and inhibited AML development. Conclusions Exo-miR-7-5p derived from BMSCs negatively regulates OSBPL11 by suppressing the phosphorylation of the PI3K/AKT/mTOR signaling pathway, thereby inhibiting AML proliferation and promoting apoptosis. The data will inform the development of AML therapies based on BMSC-derived exosomes. Graphical Abstract

scholarly journals Potentially Curative Therapeutic Activity of NEO212, a Perillyl Alcohol-Temozolomide Conjugate, in Preclinical Cytarabine-Resistant Models of Acute Myeloid Leukemia

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3385
Author(s):  
Axel H. Schönthal ◽  
Steve Swenson ◽  
Radu O. Minea ◽  
Hye Na Kim ◽  
Heeyeon Cho ◽  
...  
Keyword(s):  
Cell Death ◽  
Acute Myeloid Leukemia ◽  
Side Effects ◽  
Anticancer Activity ◽  
Myeloid Leukemia ◽  
Perillyl Alcohol ◽  
Therapeutic Activity ◽  
Acute Myeloid

Despite progress in the treatment of acute myeloid leukemia (AML), the clinical outcome remains suboptimal and many patients are still dying from this disease. First-line treatment consists of chemotherapy, which typically includes cytarabine (AraC), either alone or in combination with anthracyclines, but drug resistance can develop and significantly worsen prognosis. Better treatments are needed. We are developing a novel anticancer compound, NEO212, that was created by covalent conjugation of two different molecules with already established anticancer activity, the alkylating agent temozolomide (TMZ) and the natural monoterpene perillyl alcohol (POH). We investigated the anticancer activity of NEO212 in several in vitro and in vivo models of AML. Human HL60 and U937 AML cell lines, as well as different AraC-resistant AML cell lines, were treated with NEO212 and effects on cell proliferation, cell cycle, and cell death were investigated. Mice with implanted AraC-sensitive or AraC-resistant AML cells were dosed with oral NEO212, and animal survival was monitored. Our in vitro experiments show that treatment of cells with NEO212 results in growth inhibition via potent G2 arrest, which is followed by apoptotic cell death. Intriguingly, NEO212 was equally potent in highly AraC-resistant cells. In vivo, NEO212 treatment strikingly extended survival of AML mice and the majority of treated mice continued to thrive and survive without any signs of illness. At the same time, we were unable to detect toxic side effects of NEO212 treatment. All in all, the absence of side effects, combined with striking therapeutic activity even in an AraC-resistant context, suggests that NEO212 should be developed further toward clinical testing.

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 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.

scholarly journals Anti-leukemia properties of cadmium nanoparticles in the in vitro and in vivo condition: A chemobiological study

2021 ◽  
Author(s):  
Yudi Miao ◽  
Behnam Mahdavi ◽  
Mohammad Zangeneh
Keyword(s):  
Acute Myeloid Leukemia ◽  
Cell Lines ◽  
Aqueous Extract ◽  
Myeloid Leukemia ◽  
Antioxidant Properties ◽  
Leukemia Cell ◽  
Sem Images ◽  
Acute Myeloid

IntroductionThe present study investigated the anti-acute myeloid leukemia effects of Ziziphora clinopodides Lam leaf aqueous extract conjugated cadmium nanoparticles.Material and methodsTo synthesize CdNPs, Z. clinopodides aqueous extract was mixed with Cd(NO3)2 .4H2O. The characterization of the biosynthesized cadmium nanoparticles was carried out using many various techniques such as UV-Vis. and FT-IR spectroscopy, XRD, FE-SEM, and EDS.ResultsThe uniform spherical morphology of NPs was proved by FE-SEM images with NPs the average size of 26.78cnm. For investigating the antioxidant properties of Cd(NO3)2, Z. clinopodides, CdNPs, and Daunorubicin, the DPPH test was used. The cadmium nanoparticles inhibited half of the DPPH molecules in a concentration of 196 µg/mL. To survey the cytotoxicity and anti-acute myeloid leukemia effects of Cd(NO3)2, Z. clinopodides, CdNPs, and Daunorubicin, MTT assay was used on the human acute myeloid leukemia cell lines i.e., Murine C1498, 32D-FLT3-ITD, and Human HL-60/vcr. The IC50 of the cadmium nanoparticles was 168, 205, and 210 µg/mL against Murine C1498, 32D-FLT3-ITD, and Human HL-60/vcr cell lines, respectively. In the part of in vivo study, DMBA was used for inducing acute myeloid leukemia in mice. CdNPs similar to daunorubicin ameliorated significantly (p≤0.01) the biochemical, inflammatory, RBC, WBC, platelet, stereological, histopathological, and cellular-molecular parameters compared to the other groups.ConclusionsAs mentioned, the cadmium nanoparticles had significant anti-acute myeloid leukemia effects. After approving the above results in the clinical trial studies, these cadmium nanoparticles can be used as a chemotherapeutic drug to treat acute myeloid leukemia in humans.

scholarly journals The Salt-Inducible Kinase inhibitor YKL-05-099 suppresses MEF2C function and acute myeloid leukemia progressionin vivo

2019 ◽  
Author(s):  
Yusuke Tarumoto ◽  
Shan Lin ◽  
Jinhua Wang ◽  
Joseph P. Milazzo ◽  
Yali Xu ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Disease Progression ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Kinase Inhibitor ◽  
Clinical Investigation ◽  
Genetic Targeting ◽  
Acute Myeloid

AbstractLineage-defining transcription factors (TFs) are compelling targets for leukemia therapy, yet they are among the most challenging proteins to modulate directly with small molecules. We previously used CRISPR screening to identify a Salt-Inducible Kinase 3 (SIK3) requirement for the growth of acute myeloid leukemia (AML) cell lines that overexpress the lineage TF MEF2C. In this context, SIK3 maintains MEF2C function by directly phosphorylating histone deacetylase 4 (HDAC4), a repressive cofactor of MEF2C. Here, we evaluated whether inhibition of SIK3 with the tool compound YKL-05-099 can suppress MEF2C function and attenuate disease progression in animal models of AML. Genetic targeting of SIK3 or MEF2C selectively suppressed the growth of transformed hematopoietic cells underin vitroandin vivoconditions. Similar phenotypes were obtained when exposing cells to YKL-05-099, which caused cell cycle arrest and apoptosis in MEF2C-expressing AML cell lines. An epigenomic analysis revealed that YKL-05-099 rapidly suppressed MEF2C function by altering the phosphorylation state and nuclear localization of HDAC4. Using a gatekeeper allele ofSIK3, we found that the anti-proliferative effects of YKL-05-099 occurred through on-target inhibition of SIK3 kinase activity. Based on these findings, we treated two different mouse models of MLL-AF9 AML with YKL-05-099, which attenuated disease progressionin vivoand extended animal survival at well-tolerated doses. These findings validate SIK3 as a therapeutic target in MEF2C-positive AML and provide a rationale for developing drug-like inhibitors of SIK3 for definitive pre-clinical investigation and for studies in human patients with leukemia.Key PointsAML cells are uniquely sensitive to genetic or chemical inhibition of Salt-Inducible Kinase 3in vitroandin vivo.A SIK inhibitor YKL-05-099 suppresses MEF2C function and AMLin vivo.

scholarly journals Inhibition of EZH2 by chidamide exerts antileukemia activity and increases chemosensitivity through Smo/Gli-1 pathway in acute myeloid leukemia

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Xuejie Jiang ◽  
Ling Jiang ◽  
Jiaying Cheng ◽  
Fang Chen ◽  
Jinle Ni ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Histone Deacetylases ◽  
Myeloid Leukemia ◽  
Hdac Inhibitors ◽  
Annexin V ◽  
Fluorescein Isothiocyanate ◽  
Gli 1 ◽  
Acute Myeloid

Abstract Background Epigenetic dysregulation plays important roles in leukemogenesis and the progression of acute myeloid leukemia (AML). Histone acetyltransferases (HATs) and histone deacetylases (HDACs) reciprocally regulate the acetylation and deacetylation of nuclear histones. Aberrant activation of HDACs results in uncontrolled proliferation and blockade of differentiation, and HDAC inhibition has been investigated as epigenetic therapeutic strategy against AML. Methods Cell growth was assessed with CCK-8 assay, and apoptosis was evaluated by flow cytometry in AML cell lines and CD45 + and CD34 + CD38- cells from patient samples after staining with Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI). EZH2 was silenced with short hairpin RNA (shRNA) or overexpressed by lentiviral transfection. Changes in signaling pathways were detected by western blotting. The effect of chidamide or EZH2-specific shRNA (shEZH2) in combination with adriamycin was studied in vivo in leukemia-bearing nude mouse models. Results In this study, we investigated the antileukemia effects of HDAC inhibitor chidamide and its combinatorial activity with cytotoxic agent adriamycin in AML cells. We demonstrated that chidamide suppressed the levels of EZH2, H3K27me3 and DNMT3A, exerted potential antileukemia activity and increased the sensitivity to adriamycin through disruption of Smo/Gli-1 pathway and downstream signaling target p-AKT in AML cells and stem/progenitor cells. In addition to decreasing the levels of H3K27me3 and DNMT3A, inhibition of EZH2 either pharmacologically by chidamide or genetically by shEZH2 suppressed the activity of Smo/Gli-1 pathway and increased the antileukemia activity of adriamycin against AML in vitro and in vivo. Conclusions Inhibition of EZH2 by chidamide has antileukemia activity and increases the chemosensitivity to adriamycin through Smo/Gli-1 pathway in AML cells (Fig. 5). These findings support the rational combination of HDAC inhibitors and chemotherapy for the treatment of AML.

scholarly journals High incidence of alternatively spliced forms of deoxycytidine kinase in patients with resistant acute myeloid leukemia

Blood ◽  
2000 ◽  
Vol 96 (4) ◽  
pp. 1517-1524 ◽  
Author(s):  
Marjan J. T. Veuger ◽  
M. Willy Honders ◽  
Jim E. Landegent ◽  
Roel Willemze ◽  
Renée M. Y. Barge
Keyword(s):  
T Cells ◽  
Acute Myeloid Leukemia ◽  
Messenger Rna ◽  
Myeloid Leukemia ◽  
Deoxycytidine Kinase ◽  
Wild Type ◽  
Healthy Donors ◽  
Alternatively Spliced ◽  
Acute Myeloid

Deficiency of functional deoxycytidine kinase (dCK) is a common characteristic for in vitro resistance to cytarabine (AraC). To investigate whether dCK is also a target for induction of AraC resistance in patients with acute myeloid leukemia (AML), we determined dCK messenger RNA (mRNA) expression in (purified) leukemic blasts and phytohemagglutinin-stimulated T cells (PHA T cells) from patients with chemotherapy-sensitive and chemotherapy-resistant AML. In control samples from healthy donors (PHA T cells and bone marrow), only wild-type dCK complementary DNA (cDNA) was amplified. Also, in (purified) leukemic blasts from patients with sensitive AML, only wild-type dCK cDNAs were observed. These cDNAs coded for active dCK proteins in vitro. However, in 7 of 12 (purified) leukemic blast samples from patients with resistant AML, additional polymerase chain reaction fragments with a deletion of exon 5, exons 3 to 4, exons 3 to 6, or exons 2 to 6 were detected in coexpression with wild-type dCK. Deletion of exons 3 to 6 was also identified in 6 of 12 PHA T cells generated from the patients with resistant AML. The deleted dCK mRNAs were formed by alternative splicing and did code for inactive dCK proteins in vitro. These findings suggest that the presence of inactive, alternatively spliced dCK mRNA transcripts in resistant AML blasts may contribute to the process of AraC resistance in patients with AML.

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