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Ultrasonics Sonochemistry Mar 2009Three novel lipid-shell-type microbubbles (MBs), AS-0100, BG6356A and BG6356B, have been evaluated for their impact on ultrasound (US)-induced cell death and free... (Comparative Study)
Comparative Study
Three novel lipid-shell-type microbubbles (MBs), AS-0100, BG6356A and BG6356B, have been evaluated for their impact on ultrasound (US)-induced cell death and free radicals production. Previously studied and well-characterized US exposure conditions were employed in which human myelomonocytic lymphoma U937 cells were exposed to 1MHz pulsed US beam (0.3W/cm(2), 10% duty factor) for 1min with or without MBs. Three different concentrations of each MB were used. Apoptosis and cell lysis were assessed by examining phosphatidylserine externalization and by counting viable cells, respectively, 6h post-exposure. Free radicals production and scavenging activities were evaluated using electron paramagnetic resonance (EPR)-spin trapping. The results showed that only AS-0100 and BG6356A were able to enhance the US-induced apoptosis, mainly by increasing the secondary necrosis. Apoptosis and cell lysis seemed to depend more on mechanical forces exerted by oscillating MBs while free radicals played a trivial role. BG series MBs exhibited pronounced scavenging activities. Generally, despite the need for further optimization, AS-0100 and BG6356A appear to be promising as adjuncts in cases where US-induced cell death is required.
Topics: Cell Death; Contrast Media; Free Radicals; Humans; Microbubbles; Sonication; U937 Cells
PubMed: 19014893
DOI: 10.1016/j.ultsonch.2008.10.003 -
Iranian Journal of Allergy, Asthma, and... Dec 2020The T-cell immunoglobulin and mucin-3 (TIM-3)/galectin-9 (Gal-9) autocrine loop is an indispensable signaling in acute myeloid leukemia (AML) cells, which induces their...
Oridonin Could Inhibit Inflammation and T-cell Immunoglobulin and Mucin-3/Galectin-9 (TIM-3/Gal-9) Autocrine Loop in the Acute Myeloid Leukemia Cell Line (U937) as Compared to Doxorubicin.
The T-cell immunoglobulin and mucin-3 (TIM-3)/galectin-9 (Gal-9) autocrine loop is an indispensable signaling in acute myeloid leukemia (AML) cells, which induces their self-renewal through activation of nuclear factor-kappa b (NF-kB) and β-catenin pathways. In this study, we evaluated the effects of oridonin and doxorubicin on the TIM-3/Gal-9 autocrine loop. We also evaluated oridonin anti-inflammatory and anti-cancer properties on U937 cells, as an AML cell line in comparison to doxorubicin as a common anthracycline drug for AML treatment. Cell counting kit-8 (CCK-8) was applied to evaluate the cytotoxicity of oridonin and doxorubicin on U937 cells and also to determine the impact of galectin-9 (Gal-9) on their proliferation. The effects of oridonin and doxorubicin on Gal-9, TIM-3, and interleukin-1β (IL-1β) gene expression were determined by real-time polymerase chain reaction (RT-PCR). The Gal-9 secretion level was measured by enzyme-linked immunosorbent assay (ELISA) and activation of NF-kB pathway was assessed by western blotting. In a dose-dependent manner, oridonin and doxorubicin were capable to eradicate U937 cells while Gal-9 expanded them. Following the treatment of U937 cells with oridonin, the expression of Gal-9, TIM-3, and IL-1β genes was down-regulated, and the Gal-9 secretion and NF-kB phosphorylation were diminished, whereas doxorubicin increased all of these factors. Doxorubicin is a common treatment agent in AML, but it may induce inflammation and up-regulate the TIM3/Gal-9 autocrine loop, consequently can enhance the possibility of disease relapse. Meanwhile, oridonin is capable to inhibit the essential signaling pathways in AML cells and reduce the inflammation and expansion of tumor cells and postpone AML recurrence.
Topics: Cell Line, Tumor; Diterpenes, Kaurane; Doxorubicin; Galectins; Hepatitis A Virus Cellular Receptor 2; Humans; Immunoglobulins; Inflammation; Leukemia, Myeloid, Acute; NF-kappa B; Signal Transduction; T-Lymphocytes; U937 Cells
PubMed: 33463129
DOI: 10.18502/ijaai.v19i6.4929 -
European Review For Medical and... Apr 2019The aim of this study was to elucidate the biological function of long non-coding RNA (lncRNA) HOTTIP (HOXA transcript at the distal tip) in the development of acute...
OBJECTIVE
The aim of this study was to elucidate the biological function of long non-coding RNA (lncRNA) HOTTIP (HOXA transcript at the distal tip) in the development of acute myeloid leukemia (AML), and to investigate the potential mechanism.
PATIENTS AND METHODS
Relative expression levels of HOTTIP, microRNA-608 and DDA1 in AML patients were determined by quantitative Real-time polymerase chain reaction (qRT-PCR). Meanwhile, the expressions of these genes in AML cell lines were detected as well. The regulatory effects of HOTTIP, microRNA-608 and DDA1 on the proliferative ability and cell cycle progression of AML cells were examined by cell counting kit-8 (CCK-8) and flow cytometry, respectively. Dual-luciferase reporter gene assay was performed to confirm the binding condition of microRNA-608 to HOTTIP and DDA1. Finally, the specific role of HOTTIP/microRNA-608/DDA1 axis in the development of AML was verified through a series of rescue experiments.
RESULTS
HOTTIP was highly expressed in AML-M5 patients than normal controls. No significant difference in HOTTIP expression was found between patients with other subtypes of AML (M0, M1, M2, M3, M4 and M6) and normal controls. HOTTIP expression was significantly up-regulated in AML cell lines U-937 and THP-1. Up-regulation of HOTTIP remarkably promoted the proliferative potential and cell cycle progression of AML cells. Dual-luciferase reporter gene indicated that HOTTIP could bind to microRNA-608, which was lowly expressed in AML-M5 patients. Overexpression of microRNA-608 significantly inhibited the proliferative ability and cell cycle progression of U-937 and THP-1 cells. More importantly, microRNA-608 could partially reverse the regulatory effect of HOTTIP on AML cells. Meanwhile, DDA1 was verified as the target of microRNA-608. Subsequent experiments elucidated that DDA1 significantly accelerated the proliferation and cell cycle of AML cells. Furthermore, DDA1 could reverse the inhibitory effect of microRNA-608 on proliferative ability and cell cycle progression of AML cells.
CONCLUSIONS
HOTTIP accelerated the proliferative ability and cell cycle of AML cells via up-regulating DDA1 expression by sponging microRNA-608.
Topics: Cell Cycle; Cell Proliferation; DNA-Binding Proteins; Disease Progression; Gene Expression Regulation, Neoplastic; Humans; Leukemia, Myeloid, Acute; MicroRNAs; RNA, Long Noncoding; U937 Cells
PubMed: 31002141
DOI: 10.26355/eurrev_201904_17569 -
MBio Apr 2016As key components of innate immune defense, macrophages are essential in controlling bacterial pathogens, including group A Streptococcus(GAS). Despite this, only a...
UNLABELLED
As key components of innate immune defense, macrophages are essential in controlling bacterial pathogens, including group A Streptococcus(GAS). Despite this, only a limited number of studies have analyzed the recovery of GAS from within human neutrophils and macrophages. Here, we determined the intracellular fate of GAS in human macrophages by using several quantitative approaches. In both U937 and primary human macrophages, the appearance over time of long GAS chains revealed that despite GAS-mediated cytotoxicity, replication occurred in viable, propidium iodide-negative macrophages. Whereas the major virulence factor M1 did not contribute to bacterial growth, a GAS mutant strain deficient in streptolysin O (SLO) was impaired for intracellular replication. SLO promoted bacterial escape from the GAS-containing vacuole (GCV) into the macrophage cytosol. Up to half of the cytosolic GAS colocalized with ubiquitin and p62, suggesting that the bacteria were targeted by the autophagy machinery. Despite this, live imaging of U937 macrophages revealed proficient replication of GAS after GCV rupture, indicating that escape from the GCV is important for growth of GAS in macrophages. Our results reveal that GAS can replicate within viable human macrophages, with SLO promoting GCV escape and cytosolic growth, despite the recruitment of autophagy receptors to bacteria.
IMPORTANCE
Classically regarded as an extracellular pathogen, GAS can persist within human epithelial cells, as well as neutrophils and macrophages. Some studies suggest that GAS can modulate its intracellular vacuole to promote survival and perhaps replicate in macrophages. However, an in-depth single-cell analysis of the dynamics of survival and replication is lacking. We used macrophage-like cell lines and primary macrophages to measure the intracellular growth of GAS at both the population and single-cell levels. While CFU counts revealed no increase in overall bacterial growth, quantitative fluorescence microscopy, flow cytometry, and time-lapse imaging revealed bacterial replication in a proportion of infected macrophages. This study emphasizes the importance of single-cell analysis especially when studying the intracellular fate of a pathogen that is cytotoxic and displays heterogeneity in terms of intracellular killing and growth. To our knowledge, this study provides the first direct visualization of GAS replication inside human cells.
Topics: Bacterial Proteins; Cytosol; Humans; Macrophages; Microbial Viability; Streptococcal Infections; Streptococcus pyogenes; Streptolysins; U937 Cells; Virulence Factors
PubMed: 27073088
DOI: 10.1128/mBio.00020-16 -
Blood May 2011CCAAT/enhancer binding protein-α (CEBPA) mutations in acute myeloid leukemia (AML) patients with a normal karyotype (NK) confer favorable prognosis, whereas NK-AML...
CCAAT/enhancer binding protein-α (CEBPA) mutations in acute myeloid leukemia (AML) patients with a normal karyotype (NK) confer favorable prognosis, whereas NK-AML patients per se are of intermediate risk. This suggests that blocked CEBPA function characterizes NK-AML with favorable outcome. We determined the prognostic significance of CEBPA DNA binding function by enzyme-linked immunosorbent assay in 105 NK-AML patients. Suppressed CEBPA DNA binding was defined by 21 good-risk AML patients with inv(16) or t(8;21) (both abnormalities targeting CEBPA) and 8 NK-AML patients with dominant-negative CEBPA mutations. NK-AML patients with suppressed CEBPA function showed a better overall survival (P = .0231) and disease-free survival (P = .0069) than patients with conserved CEBPA function. Suppressed CEBPA DNA binding was an independent marker for better overall survival and disease-free survival in a multivariable analysis that included FLT3-ITD, NPM1 and CEBPA mutation status, white blood cell count, age and lactate dehydrogenase. These data indicate that suppressed CEBPA function is associated with favorable prognosis in NK-AML patients.
Topics: Adolescent; Adult; Aged; Base Sequence; CCAAT-Enhancer-Binding Proteins; Core Binding Factor Alpha 2 Subunit; DNA, Neoplasm; Female; Humans; Kaplan-Meier Estimate; Karyotyping; Leukemia, Myeloid, Acute; Male; Middle Aged; Mutation; Nucleophosmin; Oncogene Proteins, Fusion; Prognosis; RNA, Messenger; RNA, Neoplasm; RUNX1 Translocation Partner 1 Protein; U937 Cells; Young Adult
PubMed: 21389317
DOI: 10.1182/blood-2010-11-320747 -
BMC Cancer Nov 2021Despite of the frequently reported Dnmt3a abormality in classical myeloproliferative neoplasms (cMPNs) patients, few research explores how the Dnmt3a is regulated by...
BACKGROUND
Despite of the frequently reported Dnmt3a abormality in classical myeloproliferative neoplasms (cMPNs) patients, few research explores how the Dnmt3a is regulated by Jak2 mutation. In this study, we have investigated how the Dnmt3a is regulated by Jak2 mutation and its effects on downstream signaling pathways in cMPNs.
METHODS
Specimens of Jak2 positive cMPN patients and normal controls were collected. Murine BaF3 cell line was used to construct cell models. Dual-Glo luciferase assays and chromatin immunoprecipitation (ChIP)-qPCR were performed to detect the impact of Stat5a on transcription activity of Dnmt3a. Soft agar colony formation assay and cell counting assay were performed to detect cell proliferation. BrdU staining and flow cytometry were used to investigate cell cycle distribution. Western blotting and quantitative reverse-transcription PCR (qPCR) were performed to detect the expression levels of genes.
RESULTS
Firstly, the results of western blotting and qPCR revealed that compared with the control samples, Dnmt3a is downregulated in Jak2 positive samples. Then we explored the mechanism behind it and found that Dnmt3a is a downstream target of Stat5a, the transcription and translation of Dnmt3a is suppressed by the binding of aberrantly activated Stat5a with Dnmt3a promoter in Jak2 positive samples. We further revealed the region approximately 800 bp upstream of the first exon of the Dnmt3a promoter, which includes a gamma-activated sequence (GAS) motif of Stat5a, is the specific site that Stat5a binds to. Soft agar colony formation assay, cell counting assay, and BrdU staining and flow cytometry assay found that Dnmt3a in Jak2-BaF3 cells significantly affected the cell proliferation capacity and cell cycle distribution by suppressing Cdkn1a via miR-17-5p/Cdkn1a axis and mediated G0/G1 arrest.
CONCLUSIONS
Transcription and translation of Dnmt3a is downregulated by the binding of Stat5a with Dnmt3a promoter in Jak2 cells. The GAS motif at promoter of Dnmt3a is the exact site where the Stat5a binds to. Dnmt3a conducted G0/G1 arrest through regulating miR-17-5p/Cdkn1a axis. The axis of Stat5a/Dnmt3a/miR-17-5p/Cdkn1a potentially provides a treatment target for cMPNs.
Topics: Aminopyridines; Animals; Binding Sites; Blotting, Western; Case-Control Studies; Cell Count; Cell Line; Cell Line, Tumor; Cell Proliferation; Cyclin-Dependent Kinase Inhibitor p21; DNA Methyltransferase 3A; Down-Regulation; Exons; G1 Phase Cell Cycle Checkpoints; Humans; Imidazoles; Janus Kinase 2; K562 Cells; Mice; MicroRNAs; Monocytes; Mutation; Myeloproliferative Disorders; Promoter Regions, Genetic; Pyrazoles; Pyridazines; STAT5 Transcription Factor; Signal Transduction; Transcription, Genetic; Tumor Stem Cell Assay; Tumor Suppressor Proteins; U937 Cells
PubMed: 34773997
DOI: 10.1186/s12885-021-08915-0 -
British Journal of Cancer Aug 2017Lurbinectedin is a novel anticancer agent currently undergoing late-stage (Phase II /III) clinical evaluation in platinum-resistant ovarian, BRCA1/2-mutated breast and...
BACKGROUND
Lurbinectedin is a novel anticancer agent currently undergoing late-stage (Phase II /III) clinical evaluation in platinum-resistant ovarian, BRCA1/2-mutated breast and small-cell lung cancer. Lurbinectedin is structurally related to trabectedin and it inhibits active transcription and the DNA repair machinery in tumour cells.
METHODS
In this study we investigated whether lurbinectedin has the ability to modulate the inflammatory microenvironment and the viability of myeloid cells in tumour-bearing mice.
RESULTS
Administration of lurbinectedin significantly and selectively decreased the number of circulating monocytes and, in tumour tissues, that of macrophages and vessels. Similar findings were observed when a lurbinectedin-resistant tumour variant was used, indicating a direct effect of lurbinectedin on the tumour microenviroment. In vitro, lurbinectedin induced caspase-8-dependent apoptosis of human purified monocytes, whereas at low doses it significantly inhibited the production of inflammatory/growth factors (CCL2, CXCL8 and VEGF) and dramatically impaired monocyte adhesion and migration ability. These findings were supported by the strong inhibition of genes of the Rho-GTPase family in lurbinectedin-treated monocytes.
CONCLUSIONS
The results illustrate that lurbinectedin affects at multiple levels the inflammatory microenvironment by acting on the viability and functional activity of mononuclear phagocytes. These peculiar effects, combined with its intrinsic activity against cancer cells, make lurbinectedin a compound of particular interest in oncology.
Topics: Animals; Antineoplastic Agents, Alkylating; Apoptosis; Carbolines; Caspase 8; Cell Adhesion; Cell Movement; Chemokine CCL2; Dioxoles; Down-Regulation; Female; Fibrosarcoma; Gene Expression; Gene Expression Profiling; HL-60 Cells; Heterocyclic Compounds, 4 or More Rings; Humans; Interleukin-8; Leukocyte Count; Macrophages; Mice; Mice, Inbred C57BL; Monocytes; Neovascularization, Pathologic; Ovarian Neoplasms; Tetrahydroisoquinolines; Trabectedin; Tumor Microenvironment; U937 Cells; Vascular Endothelial Growth Factor A; Xenograft Model Antitumor Assays; rho GTP-Binding Proteins
PubMed: 28683469
DOI: 10.1038/bjc.2017.205 -
Molecular Medicine Reports Sep 2015Neutrophil elastase (NE) is an early myeloid-specific serine protease, which is predominantly produced by promyelocytes. A previous study demonstrated that NE has an...
Neutrophil elastase (NE) is an early myeloid-specific serine protease, which is predominantly produced by promyelocytes. A previous study demonstrated that NE has an important role in the development of acute promyelocytic leukemia (APL). The process of APL was shown to be accelerated in animals that expressed abundant NE, whereas NE‑deficient mice were protected from APL development; thus suggesting an important role for NE in the development of APL. The present study aimed to investigate the effects and possible mechanisms of NE. Up- and downregulation of NE in various leukemia cell lines was conducted in order to explore its significance in the occurrence and procession of leukemia, with the aim of identifying novel targeted therapeutic drugs for the treatment of leukemia. NE was overexpressed in cells following infection with an adenovirus, and Cell Counting kit‑8 and flow cytometry results demonstrated that cell proliferation was promoted, and cell apoptosis was inhibited, as compared with the untreated cells. NE was downregulated in the cells by both RNA interference and treatment with GW311616A, a specific inhibitor of NE, following which cell growth was shown to be inhibited and apoptosis was induced. These results suggested that NE may promote the development of APL, therefore, NE may be a therapeutic target and its inhibitor GW311616A may be a potential therapeutic drug for leukemia. Furthermore, the apoptosis‑associated protein B‑cell lymphoma 2 (Bcl‑2)‑associated X protein was significantly increased, whereas Bcl‑2 was markedly decreased in the cells with downregulated NE. Further experiments revealed that the probable apoptosis‑associated signaling pathway was the phosphoinositide 3‑kinase/AKT pathway. The present study is the first, to the best of our knowledge, to demonstrate that GW311616A, a specific NE inhibitor, may act as a potential targeted drug for leukemia, which may have a profound impact on the future of leukemia-targeted therapy.
Topics: Apoptosis; Cell Line, Tumor; Cell Proliferation; Down-Regulation; Humans; K562 Cells; Leukemia, Promyelocytic, Acute; Leukocyte Elastase; Phosphatidylinositol 3-Kinases; Piperidines; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-bcl-2; RNA Interference; RNA, Small Interfering; Signal Transduction; U937 Cells; Up-Regulation; bcl-2-Associated X Protein
PubMed: 26081156
DOI: 10.3892/mmr.2015.3946 -
Journal of Dairy Science May 2011α-Lactalbumin is a ubiquitous calcium-binding milk protein with a well-characterized function in regulating the synthesis of lactose. An entirely different activity has... (Comparative Study)
Comparative Study
α-Lactalbumin is a ubiquitous calcium-binding milk protein with a well-characterized function in regulating the synthesis of lactose. An entirely different activity has been shown to occur when a complex is formed between calcium-free α-lactalbumin and oleic acid. This complex shows strong cytotoxic action against several cancer cells, and several mechanisms have been suggested to account for this cell-killing activity. Most studies have been performed using the human protein, but bovine α-lactalbumin shows similar activity. A new and simple 2-step method for purification of calcium-free α-lactalbumin has been developed, and the resulting highly purified preparation was used to generate a complex with oleic acid. Using 3 different cell lines and 2 types of cell viability assays, the bovine and human α-lactalbumin showed comparable cytotoxic activity. The effect was apparent after 15 min of incubation and was inhibited by the presence of fetal bovine serum or bovine serum albumin. The bovine protein might be a useful alternative to the human protein, but also raises the question whether cytotoxic activity could be generated in different kinds of food containing α-lactalbumin.
Topics: Animals; Cattle; Cell Count; Cell Line, Tumor; Culture Media, Serum-Free; Cytotoxins; HL-60 Cells; Humans; Lactalbumin; Milk; Milk, Human; Oleic Acid; Oleic Acids; Serum; U937 Cells
PubMed: 21524506
DOI: 10.3168/jds.2010-3622 -
Journal of Immunology Research 2021We recently showed that both nontypeable (NTHi) and its surface plasminogen- (Plg-) binding proteins interact with lipoprotein(a) (Lp(a)) in a lysine-dependent manner....
We recently showed that both nontypeable (NTHi) and its surface plasminogen- (Plg-) binding proteins interact with lipoprotein(a) (Lp(a)) in a lysine-dependent manner. Because Lp(a) can be taken up by macrophages, we postulated that it serves as an opsonin to enhance phagocytosis of NTHi by macrophages. Based on colony-forming unit (CFU) counts, Lp(a) was found to increase U937 macrophage-mediated phagocytosis of NTHi49247 and NTHi49766 by 34% and 43%, respectively, after 120 min. In contrast, Lp(a) did not enhance phagocytosis of BL21 or JM109, which were unable to bind to Lp(a). As with U937 macrophages, Lp(a) was capable of increasing phagocytosis of NTHi49247 by peripheral blood mononuclear cell-derived macrophages. Opsonic phagocytosis by Lp(a) was inhibited by the addition of recombinant kringle IV type 10 (rKIV), a lysine-binding competitor; moreover, Lp(a) did not increase phagocytosis of NTHi by U937 macrophages that were pretreated with a monoclonal antibody against the scavenger receptor CD36. Taken together, our observation suggests that Lp(a) might serve as a lysine-binding opsonin to assist macrophages in rapid recognition and phagocytosis of NTHi.
Topics: CD36 Antigens; Cell Line; Cell Line, Tumor; Escherichia coli; Haemophilus Infections; Haemophilus influenzae; Humans; Leukocytes, Mononuclear; Lipoprotein(a); Macrophages; Opsonin Proteins; Phagocytosis; U937 Cells
PubMed: 34765679
DOI: 10.1155/2021/2185568