Promyelocytic Leukemia HL-60 Cells Research Articles

CD34+ Derived Microparticles Regulate Apoptosis in Normal and Acute Myeloid Leukemia Cells

Introduction Microparticles (MPs) are small vesicles 100nm-1μm derived from the apoptotic or stimulated cells. The mechanism of their production is distinctive from exosomes or apoptotic bodies. MPs have been detected in the blood in many pathological conditions associated mainly with endothelial injury, thrombosis and inflammation. Our previous study showed that MPs originated also from CD34+ cells of umbilical cord blood, which is an alternative source for hemopoeitic stem cell transplantation. MPs considered as markers of cell activation, as well as apoptosis. Apoptosis is a complex interaction network regulated either through death receptor like FAS or through the internal pathway of Bcl2, Bax. The two pathways activate the executor of cell death program, caspases. The aim of this study is to elucidate the role of MPs in apoptosis of hemopoietic cells.Methods Umbilical cord blood units (UCB) were collected after informed consent. The units that were used in this study, were rejected as not appropriate for transplantation due to low volume. The HL60 promyelocytic leukemia cell line was cultured in RPMI (Life Technologies) supplemented with 10% fetal calf serum (FCS) and 1% penicillin-strepromycin. CD34+ MPs were isolated from the plasma of UCBs after centrifugation and magnetic bead MACS purification (Miltenyi Biotec). The number of CD34+ MPs was estimated by flow cytometry using CD34-PE and Annexin V-FITC Abs. Mononuclear cells (MNC) were collected after density gradient centrifugation on lymphoprep (Fresenius) and were cultured for 3 and 6 days in the presence of CD34+ MPs. Viability assays were performed using 7-AAD in flow cytometry. In another set of experiments different numbers of CD34+ MPs were used in MNC cultures. RNA was extracted from MNC using Qiagen RNA extraction kit and reverse transcribed into cDNA using Superscript II reverse transcriptase (Invitrogen) with random primers (Promega). RT-PCR was performed using Platinum Pfx polymerase (Invitrogen). The primers for FAS, BCL2, BAX, caspase 3, survivin and GAPDH genes were used. The PCR products were analysed in an agarose gel electrophoresis.Results Cell viability increased in UCB derived MNC (UCB-MNC) incubated with CD34+ MPs (800 /ml) after 3 day vs. 6 days of culture. The UCB-MNC viability was higher using 800/ml CD34+ MPs vs. 400/ml. In contrast, CD34+ MPs (800 /ml vs. 400/ml) did not affect the viability in one day MNC culture. Purified CD34+ MPs were applied to UCB-MNC cultures and by RT-PCR was shown increased expression of BCL2 gene as well as FAS and caspase-3 genes. The promyelocytc cell line HL60 has been used in order to analyze the effect of CD34+ MPs in leukemic cells. The expression of Bcl2 was decreased in HL60 cells co-incubated with CD34+ MPs. This result shows an opposite effect of CD34+ MPs in the apoptotic gene Bcl2 for the HL60 cells indicating that there are different mechanisms of MP function in various cell types.Conclusions In this study we have identified and monitored the time- and dose-dependent effect of CD34-derived microparticles in the viability of UCB mononuclear cells. Additionally, CD34+ MPs function is accosiated with the high expression of the pro- and anti-apoptotic Bcl2 and apoptotic FAS. In contrast CD34+ MPs decreases the expression of Bcl2 in the promyelocytic leukemia cell line HL60. Therefore the stem cell derived microparticles might serve as a potential regulator of apoptosis in normal and malignant hematopoietic cells. DisclosuresNo relevant conflicts of interest to declare.

In vitro and in vivo anti-leukemia activity of the stem bark of Salacia impressifolia (Miers) A. C. Smith (Celastraceae)

Ethnopharmacological relevanceSalacia impressifolia (Miers) A. C. Smith (family Celastraceae) is a traditional medicinal plant found in the Amazon Rainforest known as “miraruíra”, "cipó-miraruíra" or “panu” and is traditionally used to treat dengue, flu, inflammation, pain, diabetes, male impotency, renal affections, rheumatism and cancer. Aim of the study: The aim of this study was to investigate in vitro and in vivo anti-leukemia activity of the stem bark of S. impressifolia in experimental models. Materials and methods: The in vitro cytotoxic activity of extracts, fractions and quinonemethide triterpenes (22-hydroxytingenone, tingenone and pristimerin) from the stem bark of S. impressifolia in cultured cancer cells was determined. The in vivo antitumor activity of the ethyl acetate extract (EAE) and of its fraction (FEAE.3) from the stem bark of S. impressifolia was assessed in C.B-17 severe combined immunodeficient (SCID) mice engrafted with human promyelocytic leukemia HL-60 cells. Results: The extract EAE, its fraction FEAE.3, and quinonemethide triterpenes exhibited potent cytotoxicity against cancer cell lines, including in vitro anti-leukemia activity against HL-60 and K-562 cells. Moreover, extract EAE and its fraction FEAE.3 inhibited the in vivo development of HL-60 cells engrafted in C.B-17 SCID mice. Tumor mass inhibition rates were measured as 40.4% and 81.5% for the extract EAE (20 mg/kg) and for its fraction FEAE.3 (20 mg/kg), respectively. Conclusions: Ethyl acetate extract and its fraction from the stem bark of S. impressifolia exhibit in vitro and in vivo anti-leukemia activity that can be attributed to their quinonemethide triterpenes. These data confirm the ethnopharmacological use of this species and may contribute to the development of a novel anticancer herbal medicine.

A novel platinum complex containing a piplartine derivative exhibits enhanced cytotoxicity, causes oxidative stress and triggers apoptotic cell death by ERK/p38 pathway in human acute promyelocytic leukemia HL-60 cells

Piplartine (piperlongumine) is a plant-derived compound found in some Piper species that became a novel potential antineoplastic agent. In the present study, we synthesized a novel platinum complex containing a piplartine derivative cis-[PtCl(PIP-OH)(PPh3)2]PF6 (where, PIP-OH = piplartine demethylated derivative; and PPh3 = triphenylphosphine) with enhanced cytotoxicity in different cancer cells, and investigated its apoptotic action in human promyelocytic leukemia HL-60 cells. The structure of PIP-OH ligand was characterized by X-ray crystallographic analysis and the resulting platinum complex was characterized by infrared, molar conductance measurements, elemental analysis and NMR experiments. We found that the complex is more potent than piplartine in a panel of cancer cell lines. Apoptotic cell morphology, increased internucleosomal DNA fragmentation, without cell membrane permeability, loss of the mitochondrial transmembrane potential, increased phosphatidylserine externalization and caspase-3 activation were observed in complex-treated HL-60 cells. Treatment with the complex also caused a marked increase in the production of reactive oxygen species (ROS), and the pretreatment with N-acetyl-L-cysteine, an antioxidant, reduced the complex-induced apoptosis, indicating activation of ROS-mediated apoptosis pathway. Important, pretreatment with a p38 MAPK inhibitor (PD 169316) and MEK inhibitor (U-0126), known to inhibit ERK1/2 activation, also prevented the complex-induced apoptosis. The complex did not induce DNA intercalation in cell-free DNA assays. In conclusion, the complex exhibits more potent cytotoxicity than piplartine in a panel of different cancer cells and triggers ROS/ERK/p38-mediated apoptosis in HL-60 cells.

Enhanced neutrophil autophagy and increased concentrations of IL-6, IL-8, IL-10 and MCP-1 in rheumatoid arthritis

Rheumatoid arthritis (RA) is a high morbidity and disability disease with numerous inflammatory cells infiltrating in interstitial of articular cartilages and bones. As the most abundant inflammatory cells, neutrophil has been reported that their apoptosis changed gradually in the circumstance of RA. Apoptosis, one modality of programmed cell death (PCD), is closely associated with autophagy, which indicates neutrophil autophagy may also alter in RA. Flow cytometry, western blotting, immunohistochemistry, immunofluorescence, transmission electron microscope and multiplex antibody microarray were used to comparative investigate the status of neutrophil autophagy in patients with RA and in vitro. The results showed that the expression of autophagy related LC3 protein was up-regulated with lower lysosomal pH in neutrophils from synovial fluid of RA and changed under stimulation of CQ and small RNA interferences (siRNAs) Atg5 transfection, which proved in acute promyelocytic leukemia HL-60 cell lines, predominantly a neutrophilic promyelocyte, treated by plasma and synovial fluid from RA. We further found out the concentration of IL-6, IL-8, IL-10 and MCP-1 was higher in their synovial fluid which may mediate neutrophil autophagy in RA via cytokine-cytokine receptor interaction and IL-17 signaling pathway. Our results indicate that neutrophil autophagy may be a novel perspective to understand the pathology which may provide a new maker to diagnose RA and IL-8, IL-10, MCP-1 specific antagonists and neutrophil autophagy target inhibitors may improve the therapeutic effect of RA someday.

VERNONIA AMYGDALINA DELILE EXHIBITS A POTENTIAL FOR THE TREATMENT OF ACUTE PROMYELOCYTIC LEUKEMIA.

The World Health Organization (WHO) has been on front line to encourage developing countries to identify medicinal plants that are safe and easily available to patients. Traditional medicine represents the first-treatment choice for the healthcare of approximately 80% of people living in developing countries. Also, its use in the United States has increased by 38% during within the last decade of the 20th century alone. Therefore, the aim of the present study was to explore the efficacy of a medicinal plant, Vernonia amygdalina Delile (VAD), as a new targeted therapy for the management of acute promyelocytic leukemia (APL), using HL-60 cells as a test model. To address our specific aim, HL-60 promyelocytic leukemia cells were treated with VAD. Live and dead cells were determined by acridine orange and propidium iodide (AO/PI) dye using the Cellometer Vision. The extent of DNA damage was evaluated by the comet assay. Cell apoptosis was evaluated by flow cytometry assessment. Data obtained from the AO/PI assay indicated that VAD significantly reduced the number of live cells in a dose-dependent manner, showing a gradual increase in the loss of viability in VAD-treated cells. We observed a significant increase in DNA damage in VAD-treated cells compared to the control group. Flow cytometry data demonstrated that VAD induced apoptosis in treated cells compared to the control cells. These results suggest that induction of cell death, DNA damage, and cell apoptosis are involved in the therapeutic efficacy of VAD. Because VAD exerts anticancer activity in vitro, it would be interesting to perform clinical trials to confirm its effectiveness as an anticancer agent towards the treatment of APL patients.

Ru(II)-Thymine Complex Causes Cell Growth Inhibition and Induction of Caspase-Mediated Apoptosis in Human Promyelocytic Leukemia HL-60 Cells.

Ruthenium-based compounds represent a class of potential antineoplastic drugs. Recently, we designed, synthesized, and identified the Ru(II)-thymine complex [Ru(PPh3)2(Thy)(bipy)]PF6 (where PPh = triphenylphosphine, Thy = thymine and bipy = 2,2′-bipyridine) as a potent cytotoxic agent with the ability to bind to DNA and human and bovine serum albumins. In this study, the underlying cytotoxic mechanism of the [Ru(PPh3)2(Thy)(bipy)]PF6 complex was assessed. This complex displayed potent cytotoxicity in different cancer cell lines; the morphology that is associated with apoptotic cell death, increased internucleosomal DNA fragmentation without cell membrane permeability, loss of the mitochondrial transmembrane potential, increased phosphatidylserine externalization, and caspase-3 activation were observed in human promyelocytic leukemia HL-60 cells that were treated with the complex. Moreover, pretreatment of HL-60 cells with Z-VAD(OMe)-FMK, a pan-caspase inhibitor, partially reduced the apoptosis that was induced by the complex, indicating that the apoptotic cell death occurred through a caspase-mediated pathway. In conclusion, the [Ru(PPh3)2(Thy)(bipy)]PF6 complex displays potent cytotoxicity to different cancer cells and induces caspase-mediated apoptosis in HL-60 cells.

A pyrrocidine derivative produced by fungus Neonectria ramulariae In-2 isolated from a Beetle Holotrichia picea

A new pyrrocidine A derivative, 19-epi-pyrrocidine A (1) was isolated from the insect–derived fungus Neonectria ramulariae In-2, together with known pyrrocidine A (2). The structure of 1 was determined by extensive 1D- and 2D-NMR, and MS spectral analyses. The absolute configuration of 2 was confirmed for the first time by X-ray crystallography. Compound 1 exhibited cytotoxicity against human acute promyelocytic leukemia HL60 cells (IC50 2.05 μM). In addition, semi-synthetic compounds 19-O-methyl-pyrrocidine A (3), 19-O-acetyl-pyrrocidine A (4), and 1,2-4,5-17,18-triepoxy-pyrrocidine A (5) were found to possess significant cytotoxicity, with IC50 values of 0.66 μM, 0.19 μM, and 2.00 μM, respectively.

梅毒螺旋体对人脑微血管内皮细胞趋化因子配体6、8、10表达的影响

Objective To evaluate the effects of Treponema pallidum (T. pallidum) on the expression of chemokine ligands (CXCL) in human brain microvascular endothelial cells (HBMECs) . Methods HBMECs were randomly divided into 4 groups, which were treated with viable T. pallidum suspension (T. pallidum group) , heat-inactivated T. pallidum suspension (inactivated T. pallidum group) , 200 μg/L lipopolysaccharide (LPS group) and cell culture medium (blank control group) , respectively, for 6, 12 and 24 hours. Fluorescence-based quantitative PCR and enzyme-linked immunosorbent assay (ELISA) were performed to determine the mRNA and protein expression of CXCL6, CXCL8 and CXCL10 in HBMECs in the above groups respectively. Transwell migration assay was conducted to evaluate the effects of T. pallidum-stimulated HBMECs on the chemotaxis of human promyelocytic HL-60 leukemia cells (HL-60 cells) . Results At 6, 12 and 24 hours, the T. pallidum group showed significantly higher mRNA expression of CXCL6, CXCL8 and CXCL10 in HBMECs compared with the blank control group and inactivated T. pallidum group (all P 0.05) . Compared with the LPS group, theT. pallidum group showed significantly decreased mRNA expression of CXCL6 and CXCL8 (P 0.05) at 6, 12 and 24 hours. At these time points, the levels of CXCL6 and CXCL8 in the culture supernatant of HBMECs were significantly higher in the T. pallidum group than in the blank control group and the inactivated T. pallidum group (all P 0.05) . Moreover, there were no significant differences in the level of CXCL10 in the culture supernatant of HBMECs among the T. pallidum group, the inactivated T. pallidum group and the blank control group (all P > 0.05) . The number of migratory HL-60 cells in the lower Transwell chambers was significantly higher in the T. pallidum group than in the inactivated T. pallidum group and the blank control group (both P < 0.05) . Conclusion Viable T. pallidum can up-regulate the gene expression of CXCL6, CXCL8 and CXCL10 in HBMECs, promote the secretion of CXCL6 and CXCL8, and enhance the chemotactic effect of HBMECs on HL-60 cells, which may play a certain role in the occurrence of neurosyphilis. Key words: Neurosyphilis; Treponema pallidum; Chemotactic factors; Cell migration assays, leukocyte; Human brain microvascular endothelial cells; HL-60 cells

Limonoids from seeds of Azadirachta indica A. Juss. and their cytotoxic activity

Four new limonoid-type nortriterpenoids, 1-detigloyl-1-O-methacryloylsalannin (1), 28-deoxo-2,3-dihydronimbolide (2), 12-acetoxy-3-O-acetyl-7-O-tigloylvilasinin (3) and 12-acetoxy-3-O-acetyl-7-O-methacryloylvilasinin (4), along with five known ones, were isolated from seeds of Azadirachta indica A. Juss. Their structures were elucidated by various spectroscopic methods, including UV, IR, MS, NMR, X-ray crystallography, quantum chemical calculation, as well as by comparison of their spectroscopic data with those reported. In the in vitro cytotoxic assay, 2 showed inhibitory activity against human breast cancer MDA-MB-231 cell line with IC50 value of 7.68±1.74μmol/L, and 5 inhibited growth of human cervical cancer Hela cell line, melanoma A375 cell line and promyelocytic leukemia HL-60 cell line, with IC50 12.00±2.08,17.44±2.11, and13.95±5.74μmol/L, respectively.

Modulation of microglial functions by methyl jasmonate.

Neuroinflammation contributes to the neurodegenerative processes in Alzheimer’s disease (AD); therefore, characterization of novel drug candidates aimed at combatting inflammation in the central nervous system is one of the potential avenues for the development of effective AD treatment and prevention strategies. Non-neuronal microglial cells orchestrate neuroinflammatory reactions, and their adverse activation has been linked to AD pathogenesis. Methyl jasmonate (MJ) has anti-cancer properties and has also been shown to reduce peripheral inflammation in pre-clinical models. Recently, anti-neuroinflammatory activity of MJ was demonstrated in mice, but the exact cellular and molecular mechanisms responsible for this beneficial effect are unknown. We hypothesized that MJ can regulate select microglial functions, and used two different in vitro models of microglia to test this hypothesis. MJ inhibited the production of damaging reactive oxygen species by differentiated human HL-60 promyelocytic leukemia cells without reducing their viability. MJ also selectively upregulated phagocytic activity of murine BV-2 microglia, but had no effect on nitric oxide secretion by these cells. Since microglial phagocytosis can be beneficial for clearance of amyloid β aggregates in AD, the observed upregulation of phagocytic activity by MJ, combined with its inhibitory effect on reactive oxygen species production, supports continued studies of MJ as a candidate drug for managing adverse neuroinflammation in AD.

Design, synthesis, in vitro antiproliferative activity and apoptosis-inducing studies of 1-(3′,4′,5′-trimethoxyphenyl)-3-(2′-alkoxycarbonylindolyl)-2-propen-1-one derivatives obtained by a molecular hybridisation approach

Inhibition of microtubule function using tubulin targeting agents has received growing attention in the last several decades. The indole scaffold has been recognized as an important scaffold in the design of novel compounds acting as antimitotic agents. Indole-based chalcones, in which one of the aryl rings was replaced by an indole, have been explored in the last few years for their anticancer potential in different cancer cell lines. Eighteen novel (3′,4′,5′-trimethoxyphenyl)-indolyl-propenone derivatives with general structure 9 were synthesized and evaluated for their antiproliferative activity against a panel of four different human cancer cell lines. The highest IC50 values were obtained against the human promyelocytic leukemia HL-60 cell line. This series of chalcone derivatives was characterized by the presence of a 2-alkoxycarbonyl indole ring as the second aryl system attached at the carbonyl of the 3-position of the 1-(3′,4′,5′-trimethoxyphenyl)-2-propen-1-one framework. The structure–activity relationship (SAR) of the indole-based chalcone derivatives was investigated by varying the position of the methoxy group, by the introduction of different substituents (hydrogen, methyl, ethyl or benzyl) at the N-1 position and by the activity differences between methoxycarbonyl and ethoxycarbonyl moieties at the 2-position of the indole nucleus. The antiproliferative activity data of the novel synthesized compounds revealed that generally N-substituted indole analogues exhibited considerably reduced potency as compared with their parent N-unsubstituted counterparts, demonstrating that the presence of a hydrogen on the indole nitrogen plays a decisive role in increasing antiproliferative activity. The results also revealed that the position of the methoxy group on the indole ring is a critical determinant of biological activity. Among the synthesized derivatives, compound 9e, containing the 2-methoxycarbonyl-6-methoxy-N-1H-indole moiety exhibited the highest antiproliferative activity, with IC50 values of 0.37, 0.16 and 0.17 μM against HeLa, HT29 and MCF-7 cancer cell lines, respectively, and with considerably lower activity against HL-60 cells (IC50: 18 μM). This derivative also displayed cytotoxic properties (IC50 values ∼1 μM) in the human myeloid leukemia U-937 cell line overexpressing human Bcl-2 (U-937/Bcl-2) via cell cycle progression arrest at the G2-M phase and induction of apoptosis. The results obtained also demonstrated that the antiproliferative activity of this molecule is related to inhibition of tubulin polymerisation. The presence of a methoxy group at the C5- or C6-position of the indole nucleus, as well as the absence of substituents at the N-1-indole position, contributed to the optimal activity of the indole-propenone-3′,4′,5′-trimethoxyphenyl scaffold.

Ortho-topolin riboside induced cell apoptosis through ERS pathway and inhibited DNMT1 activity in acute myeloid leukemia cells

We previously demonstrated that ortho-topolin riboside (oTR), a naturally occurring phytohormone, has potential anticancer effects via the mitochondrial apoptotic pathway in acute promyelocytic leukemia HL-60 cells and hepatocellular carcinoma SMMC-7721 cells. In the present study, we showed that oTR inhibited the of acute myeloid leukemia (AML) U937 cells. Cellular adenosine transporte uptake of oTR but not adenosine receptors was involved in the growth inhibition. We also found oTR induced cell apoptosis through the Endoplasmic Reticulum Stress (ERS) pathway, as evidenced by the upregulation of the ERS regulator glucose regulated protein 78. Exposure of U937 cells to oTR upregulated the surface marker CD11b, reduced the nuclear cytoplasmic ratio, and altered the horseshoe shape of nuclei, as determined by Wright-Giemsa staining. Further we found that oTR as an effective inhibitor decrease the DNA methyltransferase 1 (DNMT1) activity in a dose-dependent manner. Dock study showed that oTR can dock to the putative pocket of the DNMT1. We concluded that oTR induced apoptosis, promoted the cell differentiation and inhibited DNMT1 activity of U937 cells, suggesting its potential as a therapeutic agent for the treatment of AML.

Participation of delta annexin A3 in the ribosomal protein S19 C-terminus-dependent inhibitory mechanism of the neutrophil C5a receptor through delta lactoferrin.

Although C5a receptor (C5aR) interacting with its agonist C5a promotes acute inflammation during the initiation phase, the roles of the recycling C5aR during the resolution phase are still unclear. We found that C5aR interacted with its antagonist/agonist ribosomal protein S19 (RP S19) polymer or a RP S19 polymer functional analogue S-tagged C5a/RP S19, which connects an RP S19 C-terminus (IAGQVAAANKKH) to the S-tagged C5a C-terminus, promoted acute inflammation at the resolution phase via an activation of the apoptosis-inducing transcription factor delta lactoferrin (δLf) in neutrophils and the membrane mobilizing factor full-length annexin A3 (ANXA3) in macrophages. To confirm the antagonistic system of the recycling C5aR, S-tagged δLf-coupled BrCN-activated Sepharose 4B beads were incubated with cytoplasmic proteins and identified a neutrophil-specific δANXA3 via pull-down experiments. The S-tagged C5a/RP S19-induced agonistic functions in macrophage-like cells that were differentiated from human promyelocytic leukemia HL-60 cells by phorbol-12-myristate-13-acetate were suppressed by δLf and δANXA3 co-overexpression. δANXA3 seems to participate in the antagonistic system of the neutrophil C5aR involving IAGQVAAANKKH and δLf. Most likely, δANXA3 works as antagonist for the recycling C5aR on neutrophils during the resolution phase of acute inflammation.

Lp16-PSP, a Member of YjgF/YER057c/UK114 Protein Family Induces Apoptosis and p21WAF1/CIP1 Mediated G1 Cell Cycle Arrest in Human Acute Promyelocytic Leukemia (APL) HL-60 Cells

Lp16-PSP (Latcripin 16-Perchloric acid Soluble Protein) from Lentinula edodes strain C91-3 has been reported previously in our laboratory to have selective cytotoxic activity against a panel of human cell lines. Herein, we have used several parameters in order to characterize the Lp16-PSP-induced cell death using human acute promyeloid leukemia (HL-60) as a model cancer. The results of phase contrast microscopy, nuclear examination, DNA fragmentation detection and flow cytometry revealed that high doses of Lp16-PSP resulted in the induction of apoptosis in HL-60 cells. The colorimetric assay showed the activation of caspase-8, -9, and -3 cascade highlighting the involvement of Fas/FasL-related pathway. Whereas, Western blot revealed the cleavage of caspase-3, increased expression of Bax, the release of cytochrome c and decreased expression of Bcl-2 in a dose-dependent manner, suggesting the intrinsic pathway might be involved in Lp16-PSP-induced apoptosis as well. Low doses of Lp16-PSP resulted in the anchorage-independent growth inhibition, induction of G1 phase arrest, accompanied by the increased expression of p21WAF1/CIP1, along with the decreased expression of cyclin D, E, and cdk6. In addition, Lp16-PSP resulted in constitutive translocation inhibition of transcription factor nuclear factor kappa B (NF-κB) into the nucleus by decreasing the phosphorylation of IκBα. All these findings suggested Lp16-PSP as a potential agent against acute promyeloid leukemia; however, further investigations are ultimately needed.

ITR‑284 modulates cell differentiation in human chronic myelogenous leukemia K562 cells.

ITR‑284 is a carboxamide analog that can inhibit proliferation in human promyelocytic leukemia HL-60 cells. To understand the effects and molecular mechanisms of ITR‑284 in human erythromyeloblastoid leukemia, we treated K562 cells with different concentrations of ITR‑284 (0, 2, 4, 6, 8 and 10nM) and all-trans retinoic acid (ATRA) (0, 0.1, 0.5, 1, 5 and 10µM) for 24h. The IC50 of ITR‑284 was ~10nM in K562 cells treated for 24h as determined by MTT assay. May-Grünwald-Giemsa staining and nitro blue tetrazolium (NBT) assays were used to determine cell morphology changes and differentiation after ITR‑284 and ATRA treatment. In addition, mRNA expression levels of hematopoietic factors, including GATA‑1, NF-E2 and GATA‑2, were elevated, while expression levels of BCR‑ABL were downregulated in K562 cells after 24h of treatment with ITR‑284 as determined by quantitative reverse transcription polymerase chain reaction. In addition, western blot analyses showed that FOXM1, GLI1 and c-MYC protein levels were decreased by ITR‑284. Taken together, our data show that ITR‑284 induced K562 cell differentiation, which led to decreased tumorigenesis. Our findings suggest that ITR‑284 could be a potential candidate for treating chronic myelogenous leukemia.

Epicatechin acts synergistically with curcumin-induced cytogenotoxic effect in acute promyelocytic leukemia HL-60 cell line

Journal of Unexplored Medical Data is an open access journal, which considers well-conducted medical science studies, including clinical trials, pilot studies, research reports, original articles, reviews and short communications in the field of medical science.

Anti-allergic and Cytotoxic Effects of Sesquiterpenoids and Phenylpropanoids Isolated from Magnolia biondii

Ten sesquiterpenoids (1-10) and six phenylpropanoid derivatives (11-16) were isolated from the flower buds of Magnolia biondii Pamp. Their structures were determined by 1D- and 2D-NMR spectroscopy, mass spectrometry, and optical rotation. To evaluate their anti-allergic properties, the inhibitory effect of each isolate (1-16) on interleukin-2 (IL-2) gene expression was examined in Jurkat T cells. Among the isolated compounds, three sesquiterpenoids (2, 5, and 7) and two monoterpenoids (12 and 13) strongly inhibited IL-2 production in Jurkat T cells. Four compounds, (-)-parthenolide (2), eudesm-4(15)-eno-1β,6α-diol (5), biondinin D (12), and tiliroside (16), showed cytotoxicity against Jurkat T cells. In addition, (-)-parthenolide (2) exhibited cytotoxicity against the human cervical cancer HeLa cell line, the human breast cancer MCF-7, and human promyelocytic leukemia HL-60 cell lines.

Transfer of multidrug resistance among acute myeloid leukemia cells via extracellular vesicles and their microRNA cargo

The treatment of acute leukemia is still challenging due in part to the development of resistance and relapse. This chemotherapeutics resistance is established by clonal selection of resistant variants of the cancer cells. Recently, a horizontal transfer of chemo-resistance among cancer cells via extracellular vesicles (EVs) has been suggested.The aim of this research was to investigate the role of EVs in chemo-resistance in acute myeloid leukemia. For this purpose, the sensitive strain of the promyelocytic leukemia HL60 cell line was studied along with its multi-resistant strain, HL60/AR that overexpresses the multidrug resistance protein 1 (MRP-1). A chemo-resistance transfer between the two strains was established by treating HL60 cells with EVs generated by HL60/AR. This study reveals that EVs from HL60/AR can interact with HL60 cells and transfer at least partially, their chemo-resistance. EVs-treated cells begin to express MRP-1 probably due to a direct transfer of MRP-1 and nucleic acids transported by EVs. In this context, two microRNAs were highlighted for their high differential expression in EVs related to sensitive or chemo-resistant cells: miR-19b and miR-20a. Because circulating microRNAs are found in all biological fluids, these results bring out their potential clinical use as chemo-resistance biomarkers in acute myeloid leukemia.

Synthesis of naphthazarin derivatives and identification of novel thioredoxin reductase inhibitor as potential anticancer agent

Mammalian thioredoxin reductase (TrxR) enzymes play a crucial role in regulating multiple redox-based signaling pathways and have attracted increasing attention as promising anticancer drug targets. We report here the synthesis of a panel of naphthazarin derivatives and discovery of 2-methyl-5,8-dihydroxy-1,4-naphthoquinone (3, 2-methylnaphthazarin) as a potent cytotoxic agent with a submicromolar half maximal inhibitory concentration to the human promyelocytic leukemia HL-60 cells. Mechanism studies reveal that the compound selectively inhibits TrxR to induce oxidative stress-mediated apoptosis of HL-60 cells. Knockdown of TrxR sensitizes the cells to 3 insults, while overexpression of the functional enzyme confers resistance to the compound treatment, underpinning the physiological significance of targeting TrxR by 3. Clarification of the interaction of compound 3 with TrxR unveils a mechanism underlying the cellular action of the compound, and sheds light in considering development of the compound as a potential cancer chemotherapeutic agent.

Chebulinic Acid Isolated From the Fruits of Terminalia chebula Specifically Induces Apoptosis in Acute Myeloid Leukemia Cells.

Chebulinic acid, an ellagitannin found in the fruits of Terminalia chebula, has been extensively used in traditional Indian system of medicine. It has shown to have various biological activities including antitumor activity. The present study aims to investigate the cytotoxic potential of chebulinic acid in human myeloid leukemia cells. Interestingly, chebulinic acid caused apoptosis of acute promyelocytic leukemia HL-60 and NB4 cells but not K562 cells. In vitro antitumor effects of chebulinic acid were investigated by using various acute myeloid leukemia cell lines. Chebulinic acid treatment to HL-60 and NB4 cells induced caspase activation, cleavage of poly(ADP-ribose) polymerase, DNA fragmentation, chromatin condensation, and changes in the mitochondrial membrane permeability. Additionally, inhibition of caspase activation drastically reduced the chebulinic acid-induced apoptosis of acute promyelocytic leukemia cells. Our data also demonstrate that chebulinic acid-induced apoptosis in HL-60 and NB4 cells involves activation of extracellular signal-regulated kinases, which, when inhibited with ERK inhibitor PD98059, mitigates the chebulinic acid-induced apoptosis. Taken together, our findings exhibit the selective potentiation of chebulinic acid-induced apoptosis in acute promyelocytic leukemia cells. Copyright © 2017 John Wiley & Sons, Ltd.