scholarly journals Decitabine Downregulates TIGAR to Induce Apoptosis and Autophagy in Myeloid Leukemia Cells

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Lanzhu Li ◽  
Wenjie Liu ◽  
Qian Sun ◽  
Han Zhu ◽  
Ming Hong ◽  
...  
Keyword(s):  
Myeloid Leukemia ◽  
Dna Methyltransferase ◽  
Negative Impact ◽  
Cell Metabolism ◽  
Leukemia Cell ◽  
K562 Cells ◽  
Glycolytic Pathway ◽  
Dependent Manner ◽  
Ros Production ◽  
Concentration Dependent Manner

Decitabine (DAC) is a well-known DNA methyltransferase inhibitor, which has been widely used for the treatment of acute myeloid leukemia (AML). However, in addition to hypomethylation, DAC in AML is also involved in cell metabolism, apoptosis, and immunity. The TP53-induced glycolysis and apoptosis regulator (TIGAR) functions to inhabit glycolysis and protect cancer cells from reactive oxygen species- (ROS-) associated apoptosis. Our previous study revealed that TIGAR is highly expressed in myeloid leukemia cell lines and AML primary cells and associated with poor prognosis in adult patients with cytogenetically normal AML. In the present study, it was found that in a time- and concentration-dependent manner, DAC downregulates the TIGAR expression, induces ROS production, and promotes apoptosis in HL-60 and K562 cells. However, blocking the glycolytic pathway partially reversed the combined effects of DAC and TIGAR knockdown on apoptosis, ROS production, and cell cycle arrest, indicating that DAC induced apoptosis through the glycolytic pathway. Furthermore, TIGAR also has a negative impact on autophagy, while DAC treatment upregulates autophagy-related proteins LC3, Beclin-1, ATG3, and ATG-5, downregulates p62, and promotes the formation of autophagosomes, indicating that DAC may activate autophagy by downregulating TIGAR. Taken together, DAC plays an unmethylated role in inducing apoptosis and activating autophagy in myeloid leukemia by downregulating TIGAR.

LukS-PV Induced HOXA9 Degradation in Acute Myeloid Leukemia Cells via Autophagy

2021 ◽  
Author(s):  
Ping Qiang ◽  
Chao Fang ◽  
Kaidi Song ◽  
Lan Shi ◽  
Yuanyuan Dai ◽  
...  
Keyword(s):  
Myeloid Leukemia ◽  
Leukemia Cells ◽  
Autophagic Flux ◽  
Dependent Manner ◽  
Prominent Feature ◽  
Concentration Dependent Manner ◽  
Over Expression ◽  
Autophagy Induction ◽  
Acute Myeloid Leukemia Cells ◽  
Acute Myeloid

Abstract Aberrant over-expression of HOXA9 is a prominent feature of AML driven by multiple oncogenes, thus therapeutic degradation of HOXA9 by autophagy may be an effective treatment strategy for AML. PVL is a pore forming cytotoxin secreted by Staphylococcus aureus, and it is composed of two subunits - LukS-PV and LukF-PV. Here, we show that LukS-PV can stimulate the conversion of LC3-I to LC3-II in AML cells in a concentration-dependent manner, and autophagic vacuoles can be found in LukS-PV-treated THP-1 cells. Furthermore, we find that an accumulation of LC3-positive structures in AML cells exposed to LukS-PV, indicating that an increased autophagic flux were formed. Therefore, LukS-PV induced autophagy of AML cells. We also demonstrated that LukS-PV could regulate the expression of HOXA9 at the protein level. HOXA9 molecules were detected in autophagosomes after LukS-PV treatment, indicating that autophagy induction accounted for the degradation of HOXA9.

Synthesis and anticancer evaluation of sulfur containing 9-anilinoacridines

2021 ◽  
Vol 16 ◽  
Author(s):  
Pranav Gupta ◽  
Radhika V. Kumar ◽  
Chul-Hoon Kwon ◽  
Zhe-Sheng Chen
Keyword(s):  
Cell Cycle ◽  
Anticancer Activity ◽  
Topoisomerase Ii ◽  
Critical Role ◽  
K562 Cells ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
In Vivo Models ◽  
Topo Ii ◽  
Sulfur Containing

Background: DNA topoisomerases are a class of enzymes that play a critical role in fundamental biological processes of replication, transcription, recombination, repair and chromatin remodeling. Amsacrine (m-AMSA), the best-known compound of 9-anilinoacridines series was one of the first DNA-intercalating agents to be considered as a Topoisomerase II inhibitor. Objective: A series of sulfur containing 9-anilinoacridines related to amsacrine were synthesized and evaluated for their anticancer activity. Methods: Cell viability was assessed by the MTT assay. The topoisomerase II inhibitory assay was performed using the Human topoisomerase II Assay kit and flow cytometry was used to evaluate the effects on cell cycle of K562 cells. Molecular docking was performed using Schrödinger Maestro program. Results: Compound 36 was found to be the most cytotoxic of the sulfide series against SW620, K562, and MCF-7. The limited SAR suggested the importance of the methansulfonamidoacetamide side chain functionality, the lipophilicity and relative metabolic stability of 36 in contributing to the cytotoxicity. Topoisomerase II α inhibitory activity appeared to be involved in the cytotoxicity of 36 through inhibition of decatenation of kinetoplast DNA (kDNA) in a concentration dependent manner. Cell cycle analysis further showed the Topo II inhibition through accumulation of K562 cells in G2/M phase of cell cycle. Docking of 36 into the Topo II α-DNA complex suggested that it may be an allosteric inhibitor of Topo II α. Conclusion: Compound 36 exhibits anticancer activity by inhibiting topoisomerase II and it could further be evaluated in in vivo models.

scholarly journals Ca2+ signalling in K562 human erythroleukaemia cells: effect of dimethyl sulphoxide and role of G-proteins in thrombin- and thromboxane A2-activated pathways

1995 ◽  
Vol 312 (1) ◽  
pp. 151-158 ◽  
Author(s):  
C P Thomas ◽  
M J Dunn ◽  
R Mattera
Keyword(s):  
G Proteins ◽  
Pcr Amplification ◽  
Thromboxane A2 ◽  
K562 Cells ◽  
Protein S ◽  
Term Treatment ◽  
Dependent Manner ◽  
Short Term Treatment ◽  
Concentration Dependent Manner ◽  
Prostaglandin F2 Alpha

The human leukaemic cell line K562 is a pluripotent stem cell with the potential to mature along a megakaryocytic or erythroid line. In these cells, thrombin and U46619 (9,11-dideoxy-9 alpha, 11 alpha-methanoepoxy prostaglandin F2 alpha), a thromboxane A2 analogue, increased intracellular Ca2+ in a rapid and concentration-dependent manner. The peak transient observed with both thrombin and U46619 was preserved upon stimulation in the absence of extracellular calcium and blunted with phorbol myristate acetate, suggestive of activation of phospholipase C. Short-term treatment with leupeptin abolished the calcium response to thrombin, but did not alter that to U46619. Both pertussis toxin (PT) and DMSO pretreatment inhibited thrombin- but not U46619-stimulated intracellular calcium elevation, indicating that these agonists signal through different G-proteins. Western blot analysis of crude membranes from K562 cells revealed the presence of G12 alpha and G13 alpha; the other known PT-substrates, Gi1 alpha and G0 alpha, were not detected. Consistent with this observation, ADP-ribosylation experiments revealed the presence of two PT substrates which co-migrated with human erythrocyte G12 alpha and G13 alpha. An antibody raised against Gq/11 alpha, a subfamily of G-protein alpha subunits unmodified by PT, specifically recognized 42 kDa protein(s) in K562 cells. PCR amplification of reverse-transcribed K562 RNA followed by DNA sequencing showed that these cells express messages for both Gq alpha and G11 alpha. Treatment of K562 cells with DMSO reduced the levels of thrombin receptor mRNA, without simultaneous changes in the expression of G12 alpha and G13 alpha. We have thus identified Ca(2+)-mobilizing agonists and related G-proteins in K562 cells, together with changes induced by DMSO in this signalling pathway.

scholarly journals Induction of apoptosis by Kola nut extract as a recent and promising treatment strategy for Leukemia

Bionatura ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 1725-1732
Author(s):  
Hamdah Alsaeedi ◽  
Rowaid Qahwaji ◽  
Talal Qadah
Keyword(s):  
Cell Cycle ◽  
Cell Line ◽  
Leukemia Cell ◽  
K562 Cells ◽  
Myelogenous Leukemia ◽  
Time Dependent ◽  
Leukemia Cell Line ◽  
Apoptotic Cells ◽  
Dependent Manner ◽  
Anti Cancer

Kola nut extracts have recently been reported to contain chemopreventive compounds providing several pharmacological benefits. This study investigated Kola nut extracts' anti-cancer activity on human immortalized myelogenous leukemia cell line K562 through apoptosis and cell cycle arrest. Fresh Kola nuts were prepared as powder and dissolved in DMSO. Different concentrations (50, 100, 150, 200, and 250 μg/ml) of working solutions were prepared. The K562 cells were treated with the different concentrations of Kola nut extract or vehicle control (10% DMSO) followed by incubation at 37°C for 24, 48, and 72 hours, respectively. Treatment activity was investigated in K562 cells; by Resazurin, and FITC/Propidium Iodide and 7-AAD stained cells to evaluate apoptotic cells and the cell cycle's progression. Inhibition of leukemia cell proliferation was observed. The extract effectively induced cell death, early and late apoptosis by approximately 30% after 24 and 48 hours incubation, and an increase in the rate of dead cells by 50% was observed after 72 hours of incubation. Also, cell growth reduction was seen at high dose concentrations (150 and 200 µg/ml), as evident by cell count once treated with Kola nut extract. The total number of apoptotic cells increased from 5.8% of the control group to 27.4% at 250 µg/ml concentration. Moreover, Kola nut extracts' effects on K562 cells increased gradually in a dose and time-dependent manner. It was observed that Kola nut extracts could arrest the cell cycle in the G2/M phase as an increase in the number of cells by 29.8% and 14.6 % were observed from 9.8% and 5.2% after 24 and 48 hours of incubation, respectively. This increase was detected in a dose and time-dependent manner. Kola nut extracts can be used as a novel anti-cancer agent in Leukemia treatment as it has shown significant therapeutic potential and therefore provides new insights in understanding the mechanisms of its action. Keywords: Kola nut extracts, Leukemia, K562 cell line, Apoptosis, Cancer.

Abstract 16939: Metabolic and Electrophysiological Alterations Underlie Proarrhythmic Properties of Highly Reactive Isolevuglandins in Atrial Cardiomyocytes

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Tuerdi Subati ◽  
Zhenjiang Yang ◽  
Isis L Christopher ◽  
Joseph C Van Amburg ◽  
Matthew B Murphy ◽  
...  
Keyword(s):  
Membrane Potential ◽  
High Throughput Screening ◽  
Cell Metabolism ◽  
Resting Membrane Potential ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Atp Production ◽  
Atrial Cardiomyocytes ◽  
Extracellular Flux ◽  
Mitochondrial Transition Pore

Background: Hypertension is one of the most common risk factors for atrial fibrillation (AF), although the precise cellular and molecular mechanism(s) by which hypertension leads to AF are not well understood. Isolevuglandins (IsoLGs) are highly reactive dicarbonyl products of lipid peroxidation responsible for a major component of oxidative stress-related injury. In a mouse model of hypertension, we recently demonstrated that IsoLGs are elevated in hypertensive mouse atria and that an IsoLG scavenger reduced both IsoLG burden and AF susceptibility. Hypothesis: In this study, we hypothesized that IsoLGs can promote AF by inducing proarrhythmic metabolic and electrophysiologic (EP) changes in atrial cardiomyocytes. Methods and Results: Using standard patch clamp methods, we found significant changes in action potential properties of isolated mouse atrial cardiomyocytes exposed to IsoLGs (1μM, n=15 cells), including elevation of resting membrane potential, shortening of APD and reduction of V max . Acute IsoLG treatment led to a reduction of intracellular ATP production in atrial HL-1 cardiomyocytes, as measured by using a luminescence assay. Employing TMRM and Mitotracker Green staining for confocal and high-throughput screening (HTS) live-cell imaging assays, we also found that IsoLGs decreased mitochondrial membrane potential (compared to control, TMRM fluorescence decreased by 23%, 28%, 36% and 42%, respectively, when exposed to 0.01, 0.1, 0.5 and 1μM concentrations of IsoLG) accompanied by increased apoptosis (Cell Event Caspase-3/7 Green Detection Reagent) in a concentration-dependent manner, suggesting a prolonged mitochondrial transition pore opening. Moreover, cell metabolism assays performed using Agilent’s Seahorse XF96 extracellular flux analyzer revealed that IsoLGs exert a concentration dependent decrease in basal oxygen consumption rate and ATP production in HL-1 atrial cardiomyocytes. Conclusion: Together, these findings indicate that IsoLGs promote proarrhythmic EP and mitochondrial effects in atrial cells and thus may provide a novel therapeutic target for AF.

scholarly journals Inter-α inhibitor proteins maintain neutrophils in a resting state by regulating shape and reducing ROS production

2018 ◽  
Vol 2 (15) ◽  
pp. 1923-1934 ◽  
Author(s):  
Soe Soe Htwe ◽  
Hidenori Wake ◽  
Keyue Liu ◽  
Kiyoshi Teshigawara ◽  
Barbara S. Stonestreet ◽  
...  
Keyword(s):  
Resting State ◽  
Smooth Surface ◽  
Spherical Shape ◽  
Human Neutrophils ◽  
Dependent Manner ◽  
Ros Production ◽  
Concentration Dependent Manner ◽  
Key Points

Key Points IAIP, but not bikunin, maintains spherical shape, small size, and smooth surface of human neutrophils and supports capillary passage. IAIP reduced ROS production from neutrophils in a concentration-dependent manner probably through the p47phox phosphorylation on Ser328.

scholarly journals Minocycline reduces inflammatory response and cell death in a S100B retina degeneration model

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Pia Grotegut ◽  
Natarajan Perumal ◽  
Sandra Kuehn ◽  
Andreas Smit ◽  
H. Burkhard Dick ◽  
...  
Keyword(s):  
Cell Death ◽  
Body Weight ◽  
Optic Nerve ◽  
Inflammatory Response ◽  
Negative Impact ◽  
Dependent Manner ◽  
Label Free ◽  
Proteomics Analysis ◽  
Concentration Dependent Manner ◽  
Minocycline Treatment

Abstract Background Previous studies noted that intravitreal injection of S100B triggered a glaucoma-like degeneration of retina and optic nerve as well as microglia activation after 14 days. The precise role of microglia in our intravitreal S100B model is still unclear. Hence, microglia were inhibited through minocycline. The aim is to investigate whether microglia have a significant influence on the degeneration process or whether they are only a side effect in the model studied here. Methods Minocycline was applied daily in rats by intraperitoneal injection using two different concentrations (13.5 mg/kg body weight, 25 mg/kg body weight). One day after treatment start, S100B or PBS was intravitreally injected in one eye per rat. The naïve groups received no injections. This resulted in a total of five groups (naïve n = 14, PBS n = 14, S100B n = 13, 13.5 mg/kg mino n = 15, 25 mg/kg mino n = 15). At day 14, electroretinogram measurements were performed, followed by immunofluorescence and label-free quantitative proteomics analysis. The focus of these investigations was on the survival of RGCs as well as their axons, the response of the microglia, and the identification of further pathological modes of action of S100B. Results The best signal transmission was detected via ERG in the 13.5 mg/kg mino group. The inhibition of the microglia protected optic nerve neurofilaments and decreased the negative impact of S100B on RGCs. However, the minocycline treatment could not trigger complete protection of RGCs. Furthermore, in retina and optic nerve, the minocycline treatment reduced the number and activity of S100B-triggered microglia in a concentration-dependent manner. Proteomics analysis showed that S100B application led to numerous metabolic functions and cellular stress, mainly an increased inflammatory response, glycolysis, and mitochondrial dysfunction, which caused oxidative stress in the retina. Importantly, the protective capability of lower dose of minocycline was unraveled by suppressing the apoptotic, inflammatory, and the altered metabolic processes caused by S100B insult in the retina. Conclusion Intravitreally injected S100B not only led to a pro-inflammatory microglial reaction, but also a mitochondrial and metabolic dysfunction. Also, these results suggest that an excessive microglial response may be a significant degenerative factor, but not the only trigger for increased cell death.

Eglerisine, a Novel Sesquiterpenoid Tropolone from Dulacia egleri with Antiproliferative Effect against an Acute Myeloid Leukemia Lineage

Planta Medica ◽  
2019 ◽  
Vol 86 (01) ◽  
pp. 55-60 ◽  
Author(s):  
Leice M. R. de Novais ◽  
Luiz F. Ferreira ◽  
Paulo T. de Sousa ◽  
Tereza A. N. Ribeiro ◽  
Marcos J. Jacinto ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Cell Metabolism ◽  
Leukemia Cell ◽  
2D Nmr ◽  
Absolute Number ◽  
Leukemia Cell Line ◽  
Human Leukemia ◽  
Acute Myeloid

AbstractChemical investigation of the stems of Dulacia egleri resulted in the isolation of eglerisine (1), a compound with a rare sesquiterpenoid tropolone skeleton. Its structure was determined by analysis of spectrometric and spectroscopic data, including HRESIMS, 1D, and 2D NMR. The antiproliferative effects of eglerisine were tested in human leukemia lineages. In the Kasumi-1 lineage, an acute myeloid leukemia cell line, eglerisine reduced cell metabolism, as determined by the resazurin assay. Eglerisine did not induce cell death by either apoptotic or necrotic mechanisms. However, a reduction of the absolute number of cells was observed. Eglerisine induced cell cycle arrest after 72 h of treatment by phosphorylation of H2AX histone, reducing the S phase and increasing the G2 phase of the cell cycle.

Specific MiRNA Silencing by Lentivirus Mediated Antagomir Expression in Chronic Myeloid Leukemia (CML) Cells.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1017-1017
Author(s):  
Michaela Scherr ◽  
Letizia Venturini ◽  
Karin Battmer ◽  
Michael Schaller-Schoenitz ◽  
Daniel Schaefer ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Mrna Translation ◽  
K562 Cells ◽  
Mature Mirnas ◽  
Dependent Manner ◽  
Aberrant Expression ◽  
Over Expression ◽  
Micro Rnas

Abstract Micro RNAs (miRNA) are small non-coding RNAs that regulate gene expression by specific hybridization to complementary sequences in the 3′ untranslated region of corresponding mRNAs. Concomitant recruitment of specific multi-protein complexes results either in inhibition of mRNA translation or mRNA degradation. miRNAs are processed in a regulated multi-step process from primary transcripts into mature miRNAs by cellular components which are also at least partially involved in the process of RNA interference (RNAi). Aberrant expression of specific miRNAs has recently been described in human lymphoma and leukemia. In particular, BCR-ABL and c-MYC dependent over-expression of the polycistronic and oncogenic miR-17-92 cluster (encoding miR-17, miR-18a, miR-19a, miR-20a, miR-19b, and miR-92) has been described in chronic myeloid leukemia (CML) cell lines, primary CD34+ cells from CML patients (Venturini et al. 2007), and in lung cancer. In BCR-ABL positive K562 cells, miR-17-92 encoded miRNAs repress luciferase activity in miRNA-specific reporter assays. In addition, lentivirus-mediated over-expression of miR-17-92 increases both cell proliferation and sensitivity to imatinib induced cell death. To analyse the function of individual miRNAs of the miR-17-92 polycistron, we generated lentivirus-based strategies to induce stable miRNA-specific loss- and gain-of function phenotypes for miR-18a, miR-19b, and miR-20a, respectively. Over-expression of miRNAs embedded within miR-30-derived sequences from an internal SFFV-LTR promoter allows isolation of K562 cells with increased miRNA expression. In contrast, expression of complementary oligonucleotides (antagomirs) from a H1 promoter located in the lentiviral 3′LTR can induce stable hypomorphic miRNA-phenotypes. In lentivirally transduced K562 cells, individual silencing of miR-18a, miR-19b, and miR-20a by the corresponding antagomirs (ant-miR-18a, ant-miR-19b, ant-miR-20a) specifically relieves miRNA-mediated reporter gene repression. Correspondingly, inhibition of miRNA-function correlates to reduced ‘miRNA’-amplification by miRNA-specific quantitative RT-PCR. Furthermore, protein expression of E2F-1, a known miR-20 target, is enhanced by lentivirally expressed anti-miR-20 in a dose-dependent manner, whereas over-expression of miR-20a reduces E2F-1 levels. Finally, combined over-expression of specific miRNAs and antagomirs reveals specific induction of cell proliferation by miR-18a but strong inhibition by miR-20a in K562 cells, respectively. In contrast, anti-miR-18a, but not anti-miR-19b, anti-miR-20a, or control antagomirs inhibits proliferation of K562 cells. These data demonstrate individual and complementary functions of miR-17-92 encoded miRNAs in CML and identify potential targets for specific therapeutic intervention on the miRNA level.

A Novel Non-Genetic Photostable Approach to Labelling Acute Myeloid Leukemia and Bone Marrow Cells with Quantum Dots

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4818-4818
Author(s):  
Yanwen Zheng ◽  
Zhengwei Mao ◽  
Bin Yin
Keyword(s):  
Bone Marrow ◽  
Quantum Dots ◽  
Acute Myeloid Leukemia ◽  
Blood Cells ◽  
Myeloid Leukemia ◽  
Hematopoietic Cells ◽  
Leukemia Cell ◽  
Leukemia Cells ◽  
Dependent Manner ◽  
Acute Myeloid

Abstract Abstract 4818 Acute myeloid leukemia (AML) is a detrimental disease with difficult diagnosis and treatment. Understanding the biology of AML at the molecular and cellular levels would be essential to successful management of the disease. However, the notoriously known difficulty in manipulation of leukemia cells has long hindered the dissection of AML pathogenesis. The advent of CdSe/ZnS quantum dots (QDs) represents an important advancement in the research field of nanotechnology, which have recently also been applied for imaging of live cells. Here, we have introduced a non-genetic approach of marking blood cells, by taking advantage of QD technology. We compared QDs complexed with different vehicles, including a peptide Tat (QDs-Tat), cationic polymer Turbofect (QDs-Tf) and liposome Lipofectamine 2000 (QDs-Lip), in their abilities to mark cells. QDs-Tat showed the highest efficiency in delivery into hematopoietic cells, among the three vehicles. We then examined QDs-Tat labelling of leukemia cell lines, and found that QDs-Tat could label 293T, bone marrow (BM) cells, THP-1, MEG-01 and HL-60 with a decreasing efficiency. The efficiency of QDs-Tat delivery was dependent on the concentration of QDs-Tat applied, but not the length of incubation time. In addition, more uniform intracellular distributions of QDs in 293T and leukemia cells were obtained with QDs-Tat, compared with the granule-like formation obtained with QDs-Lip. Clearly, QD fluorescence was sharp and tolerant to repetitive photo excitations, and could be detected in 293T for up to one week following labelling. In summary, our results suggest that QDs have provided a photostable, non-genetic and transient approach that labels normal and malignant hematopoietic cells in a cell type-, vehicle-, and QD concentration-dependent manner. We expect for potentially wide applications of QDs as an easy and fast tool assisting investigations of various types of blood cells in the near future. Disclosures: No relevant conflicts of interest to declare.

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