Human Promyelocytic Leukemia Cell Line Research Articles

융복합적인 웰리스를 위한 야채수프의 인간 암세포 증식 억제효과

Abstract The present sturdy was designed to determine the effect of the antiproliferation in human cancer cells using the ordinary vegetable soup (VS), the soup with broccoli (VSB) and the soup with tomatoes(VST). Human cancer cells identify the cancer cell growth with MTS, using stomach cancer cell line(AGS), human promyelocytic leukemia (HL-60) and lung cancer cell line (A549). VSB and VST are effective on the cancer cell growth inhibition activities of AGS and have a significance compared with VS. VST has a significance with HL-60 and VSB works well in A549 more than VS. Mixed vegetable soup is considered to applicate with functional materials and using for wellness life. Key Words : Vegetable soup, AGS, HL-60, A549, Cytotoxic effect, Wellness, Convergence Received 8 June 2015, Revised 22 July 2015Accepted 20 August 2015Corresponding Author: Jae-Hyeok Lee(Nambu University)Email: jhlee@nambu.ac.krⒸ The Society of Digital Policy & Management. All rights reserved. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is ISSN: 1738-1916 properly cited.

Four triarylantimony(V) carboxylates: syntheses, structural characterization and in vitro cytotoxicities

Four new organoantimony carboxylates, (R–COO)2SbR′3 [R–COOH = (±)-2-phenoxypropionic acid and R′ = phenyl (1), 4-fluorophenyl (2), 3-fluorophenyl (3), 3,4,5-trifluorophenyl (4)], were synthesized and structurally characterized by elemental analysis, 1H, 13C NMR, IR and X-ray single crystal diffraction. Structural analyses reveal that 1–3 show similar five-coordinate trigonal bipyramidal geometries, binding with three aryl groups and two deprotonated unidentate ligands. Unexpectedly, 4 exhibits pentagonal bipyramidal arrangement accompanied by two Sb–O (carbonyl) coordination bonds. In vitro cytotoxic activities of 1–4 have been determined by the MTT method against four cancer cell lines. Studies reveal that 1–4 have an activity similar to cisplatin on lung cancer cell line A549 and but also exhibit excellent cytotoxicity against cisplatin-insensitive colon cancer cell lines HCT-116, Caco-2 and human promyelocytic leukemia cell line HL-60. Additionally, the results showed that most of these triarylantimony(V) complexes exhibited enhanced cytotoxicity compared with the ligand and four triarylantimony dichloride precursors, which clearly implied a positive synergistic effect. Also interestingly, it was found that 3- or 4- mono-fluoro-substituted triphenylantimony, compounds 2 and 3, exhibit higher in vitro cytotoxicities toward the four cancer cell lines than the tri-3,4,5-trifluoro-substituted and without-fluoro-substituted triphenylantimony complexes. The structure-activity relationship of the cytotoxicity of 1–4 is discussed.

Changes of Apolipoprotein M Gene Expression During the Cell Differentiation and Apoptosis Induced by Simvastatin in Combination with All-Trans Retinoic Acid in Human Promyelocytic Leukemia Cell Line NB4.

We examined the effect of simvastatin (SV) alone and in combination with all-trans retinoic acid (ATRA) on proliferation, differentiation, apoptosis and apolipoprotein M (apoM) expression in the human promyelocytic leukemia cell line NB4. The NB4 cells were incubated with 10μM Simvastatin (10SV) and 0.5μM ATRA alone or in combination, taking NB4 cells without any treatment as normal controls. The cells of different groups were collected at 24, 48 and 72h post-incubation for further detection. Their morphological changes were observed after Wright stain. MTT method was used to assay the growth inhibition rate and flow cytometry to detect CD11b expression level and the early stage apoptosis ratio. Real-time quantitative reverse transcriptase-polymerase chain reaction was used to detect the apoM gene expression levels. As expected 0.5μM ATRA did not affect proliferation or apoptosis, strongly induced differentiation and decreased apoM expression.10SV inhibited proliferation, increased apoptosis, induced differentiation and increased apoM expression in a time-dependent manner. The addition of ATRA to SV did not increase the effect of SV on proliferation and apoptosis, but increased the effect of SV on differentiation. And completely abrogated the effect of SV on apoM expression. Together these results show that SV has anti-leukemic properties by itself and that combined therapy may have a place in the current anti-leukemic arsenal.

Epithelium-Specific Ets-Like Transcription Factor 1, ESE-1, Regulates ICAM-1 Expression in Cultured Lung Epithelial Cell Lines.

Cystic fibrosis (CF) patients suffer from chronic airway inflammation with excessive neutrophil infiltration. Migration of neutrophils to the lung requires chemokine and cytokine signaling as well as cell adhesion molecules, such as intercellular adhesion molecule-1 (ICAM-1), which plays an important role in mediating adhesive interactions between effector and target cells in the immune system. In this study, we investigated the relationship between ICAM-1 and epithelium-specific ETS-like transcription factor 1 (ESE-1) and found that ICAM-1 expression is upregulated in cell lines of CF (IB3-1) as well as non-CF (BEAS-2B and A549) epithelial origin in response to inflammatory cytokine stimulation. Since ESE-1 is highly expressed in A549 cells without stimulation, we examined the effect of ESE-1 knockdown on ICAM-1 expression in these cells. We found that ICAM-1 expression was downregulated when ESE-1 was knocked down in A549 cells. We also tested the effect of ESE-1 knockdown on cell-cell interactions and demonstrate that the knocking down ESE-1 in A549 cells reduce their interactions with HL-60 cells (human promyelocytic leukemia cell line). These results suggest that ESE-1 may play a role in regulating airway inflammation by regulating ICAM-1 expression.

Amurensiosides L-P, Five New Cardenolide Glycosides from the Roots of Adonis amurensis

Five new cardenolide glycosides, amurensiosides L-P (1-5), were isolated from the roots of Adonis amurensis. Their structures were determined based on extensive spectroscopic analysis, including two-dimensional (2D) NMR data, and on the results of hydrolytic cleavage. Compounds 1-5 were evaluated for their cytotoxic activities against HL-60 human promyelocytic leukemia and HSC-2 human oral squamous cell carcinoma cell lines.

Anti-proliferative and Apoptosis Inducing Activity of Lactobacillus brevis OPK-3 Isolated from Kimchi on Leukemia Cell Lines

In the present work we investigated the effects of lactic acid bacteria (LAB) isolated from kimchi on prolifera-tion and apoptosis of cancer cells. The cell-free supernatant concentrate of Lactobacillus brevis OPK-3 significantly retar-ded the proliferation of human acute promyelocytic (HL60), human histiocytic (U937), and mouse lymphocytic (L1210)leukemia cell lines in vitro at concentrations over 2.25-9.0 mg/mL. The treatments of the concentrate leaded to the increasedapoptosis and decreased mitochondrial transmembrane potential in cultured U937 leukemia cell lines. In addition, the treat-ments of the concentrate showed the increased expression of p53 gene in cultured U937 and HL60 leukemia cell lines. Onthe other hand, the cell-free supernatant concentrate of control L. brevis strain (KCCM 41028) showed a relatively littleeffect on the cancer cell proliferation, apoptosis, and mitochondrial transmembrane potential at the similar concentrationranges compared with the L. brevis OPK-3 samples. These results suggest that the consumption of L. brevis OPK-3 could bebeneficial for the inhibitory action on leukemia cell proliferation and for the stimulatory action on the cancer cell apoptosis.

Anti-Leukemic Activity of Daratumumab in Acute Myeloid Leukemia Cells and Patient-Derived Xenografts

Daratumumab is a human antibody that binds to CD38 on the cell surface and induces cell killing by multiple mechanisms including complement mediated cytotoxicity (CDC), antibody-dependent cellular cytotoxicity (ADCC), antibody-dependent cell phagocytosis (ADCP) and apoptosis. In pre-clinical and clinical studies, daratumumab has been shown to effectively kill multiple myeloma (MM) cells and to enhance the potency of other treatments against MM. The purpose of the study was to investigate in vitro and in vivo efficacy of daratumumab against 9 acute myeloid leukemia (AML) cell lines and patient-derived samples.First, we evaluated the expression of CD38, complement inhibitory proteins (CIP) CD46, CD55, CD59, and FcgR1 (CD64) on AML cell lines (n=9), AML patient cells (n=10) and healthy donor bone marrow using flow cytometry. CD38 enumeration showed a substantial variation between cell lines (12,827±19, 320 molecules/cell) and between AML patients (11,560±8, 175 molecules/cell), while CD38 expression was more consistent in bone marrow (BM) from healthy donors (1,176±355 molecules/cell). The daratumumab-induced apoptosis observed in cell lines (MOLM-13, MOLM-16, MV-4-11, NB4) in vitro was not correlated with CD38 expression levels. Daratumumab induced minimal ADCC (5-20%) and low levels of (2-5%) CDC mediated cell killing in 6 AML cell lines tested. We did not observe a direct correlation between CD38 expression and ADCC, CDC, nor between CDC and CIP expression. Interestingly, treatment of two human Acute Promyelocytic Leukemia (M3) cell lines HL-60 and NB-4 with all-trans retinoic acid (ATRA) induced a 10-30-fold increase in CD38 expression, suggesting that ATRA could be used in combination with daratumumab.While we, and others, have shown that pre-incubation of primary AML cells with anti-CD38 antibodies inhibits engraftment in NSG mice, we aimed at evaluating the anti-leukemic activity of daratumumab in a therapeutic xenograft model using 3 different AML patients. NSG mice (10/group/patient) were transplanted with T cell-depleted AML cells and BM aspirates were collected 4-6 weeks later to assess leukemia burden in each mouse prior to treatment. Animals were untreated (Ctrl) or received daratumumab (10 mg/kg), or IgG1 isotype once a week for five weeks. We assessed AML burden (% huCD45+ CD33+) in BM, spleen (SPL) and peripheral blood (PB) within 5 days after the last treatment. First, we evaluated an AML (#3406, FLT3-ITD, see figure) with high expression of CD38 (13,445 molecules/cell) and low CD64 (489/cell) was evaluated. Daratumumab significantly reduced leukemia burden in SPL and PB, but had no effect in BM. The same daratumumab-induced reduction in peripheral blasts and lack of effect in BM was observed in 2 other AML patient xenografts (#7577, M1 IDH mutant/FLT3-ITD with 6,529 CD38 molecules/cell; #8096, M2 with 335 CD38 molecules/cell). Interestingly, we observed that daratumumab treatment led to a drastic reduction in CD38 surface expression in AML blasts including in BM, indicating that daratumumab efficiently targeted CD38 in bone marrow blasts. Our results suggest that the bone marrow microenvironment can impair the anti-leukemic activity of daratumumab observed in other tissues. Ongoing xenograft studies are testing whether induction with chemotherapy (Ara-C+doxorubicin), or with other agents disrupting the bone marrow microenvironment, can enhance the anti-leukemic activity of daratumumab. [Display omitted] DisclosuresDos Santos:Janssen R&D: Research Funding. Xiaochuan:Janssen R&D: Research Funding. Doshi:Janssen R&D: Employment. Sasser:Janssen R&D: Employment. Danet-Desnoyers:Janssen R&D: Research Funding.

The Role of Peroxiredoxin III and Sulfiredoxin for Mitochondrial ROS Production to Arsenic Trioxide in Acute Promyelocytic Leukemia Cells

Backgrounds: The Arsenic trioxide (ATO) is an effective cancer therapeutic drug for acute promyelocytic leukemia (APL), but in some cases, APL cells are resistant to ATO treatment. ATO exerts its effect mainly raising oxidative stress. However, not only the mechanisms of reactive oxygen species (ROS) generation by ATO but involvement of redox enzymes including peroxiredoxin (PRX) during ATO-induced apoptosis and its resistance remain elusive. Recently, Rhee et al had reported that PRX III and sufiredoxin together protect mice from pyrazole-induced oxidative liver injury was found (Antioxid & Redox Signal, 2012:17:1351-1361). Aims of current study are to elucidate that the changes of redox enzyme could be a mechanism of anti-leukemia effect in APL-derived NB4 cells during ATO treatment and to find ways to potentiate the anti-leukemic effects of ATO on APL cells.Methods: NB4, one of the human acute promyelocytic leukemia cell lines, was treated with 0~10 μM arsenic trioxide to induce apoptosis for 16-48 hours in RPMI-1640 medium supplemented with 10% FBS in CO2humidified atmosphere at 37°C. Apoptosis was measured by staining with 7-amino-actinomycin D (7-AAD) with flow cytometry. 2, 7-dichlrodihydro-fluorescein-diacetate (H2DCF-DA) and MitoSOX Red was used to detect cellular and mitochondrial ROS. SO2 form for PRX I, PRX II, and PRX III was detected by western blot assay using PRX SO2 form-specific antibody. Sulfiredoxin (SRX) and caspase 3, 9 were also detected by western blot analysis. To evaluate the effect of SRX depletion, NB4 cells were transfected with small interfering RNA (siRNA).Results: Intracellular ROS of NB4 cells was increased significantly after 16 hour of ATO treatment but decreased after 24 hour of ATO treatment. Mitochondrial ROS of NB4 cells was increased significantly after 39 hour of ATO treatment. Apoptosis of NB4 cell after ATO treatment was increased as time elapsed (24% on 16hr, 26% on 24hr, 48% on 39hr, and 60% on 48hr). Increased cysteine sulfinic acid (Cys–SO2H) PRX III, inactive and oxidized form, was observed as a hyperoxidation reaction in NB4 cells after ATO treatment in concordance with mitochondrial ROS increment of NB4 cells. Increased expressions of cleaved caspase-9 and cleaved caspase-3 were also observed during NB4 cell apoptosis by ATO treatment. Meanwhile, SRX expression was increased in NB4 cells after ATO treatment. Down regulation of SRX by siRNA promoted ROS generation and apoptosis in ATO-treated NB4 cells.Conclusions: Our data showed inactivation of PRX III by Cys–SO2H formation as hyperoxidation is developed during ATO-induced mitochondrial ROS generation and apoptosis process in APL cells. In addition, ATO promotes expression of SRX, which is known as reducing enzyme of Cys–SO2H PRX and which leads to down regulation of ROS accumulation in APL cells. These findings might be due to protective effect of SRX from ATO on mitochondrial oxidative stress. These findings suggest ATO-induced anti-leukemic activity could be down regulated by an enhancing PRX III reduction after ATO-induced SRX activation. Currently, the effect of down regulation of SRX by siRNA are being investigated to amplify the apoptosis in ATO-treated NB4 cells. Our study may provide the insights for finding novel targets in the development of new therapies, which potentiate ATO-induced apoptosis in APL cells. DisclosuresNo relevant conflicts of interest to declare.

Lipid raft-associated β-adducin is required for PSGL-1-mediated neutrophil rolling on P-selectin.

Lipid rafts, a liquid-ordered plasma membrane microdomain, are related to cell-surface receptor function. PSGL-1, a major surface receptor protein for leukocyte, also acts as a signaling receptor in leukocyte rolling. To investigate the role of lipid raft in PSGL-1 signaling in human neutrophils, we quantitatively analyzed lipid raft proteome of human promyelocytic leukemia cell line HL-60 cells and identified a lipid raft-associated protein β-adducin. PSGL-1 ligation induced dissociation of the raft-associated protein β-adducin from lipid rafts and actin, as well as phosphorylation of β-adducin, indicating a transient uncoupling of lipid rafts from the actin cytoskeleton. Knockdown of β-adducin greatly attenuated HL-60 cells rolling on P-selectin. We also showed that Src kinase is crucial for PSGL-1 ligation-induced β-adducin phosphorylation and relocation. Taken together, these results show that β-adducin is a pivotal lipid raft-associated protein in PSGL-1-mediated neutrophil rolling on P-selectin.

Tunicamycin-induced neutrophil extracellular trap (NET)-like structures in cultured human myeloid cell lines.

The mechanism of neutrophil extracellular trap cell death (NETosis), a regulated cell death pathway relevant to infection, autoimmunity and sepsis, is not completely known. The reason for this, at least in part, is the lack of an in vitro system that recapitulates the NETosis pathway using established human cell lines. We show that exposure of a human promyelocytic leukemia cell line HL-60 to the glycosyltransferase inhibitor tunicamycin (TM) resulted in extrusion of decompacted genomic DNAs to extracellular space, morphologically similar to NETs. Immunostaining using antibodies against NET marker proteins and bacterial trapping assay showed biochemical similarities between the TM-induced extracellular DNA structures and NETs. The NET-like structures were also generated on exposure of TM to other myeloid cell lines, such as U937 and THP-1. Thus, our findings provide an experimental setting to induce NET-like structures using cultured human myeloid cell lines, which may help our understanding of the regulation and function of NETosis.

Cytotoxic and pro-apoptotic effects of Hypericum species. Metabolites profiling and dereplication procedures for the identification of bioactive ingredients

Hypericum perforatum or St John's wort of Hypericaceae family is one of the oldest used and most comprehensively investigated medicinal herbs, while preparations thereof are widely commercialized in EU and USA for the treatment of depression [1]. The genus Hypericum is considerably large including 490 species which are characterised by interesting phytochemical and biological profiles as well. Although most of the constituents of H. perforatum have been identified, the phytochemical studies as well as the biological properties of other related species are limited so far. In continuation of our studies for the discovery of new anti-neoplastic agents, 50 extracts of medicinal plants from Mediterranean biodiversity were investigated. The HL-60 human promyelocytic leukemia cell line was used to study the pro-apoptotic activity of the plant derived extracts. The cytotoxic and/or the pro-apoptotic capacity of each extract was estimated by trypan-blue exclusion method, the MTT assay and flow-cytometric analysis. Interestingly, from all extracts screened three methanol extracts exhibited the most significant cytotoxic activity and specifically those of H. triquetrifolium, H. perforatum, and H. rumeliacum. Based on these results, additional Hypericum species were collected and different extracts were produced (n = 22). All the derived extracts were subjected to profiling and dereplication procedures using HPLC-DAD and LC-(ESI)-HRMS/MS platforms. Interesting comparative results related to both known constituents such as naphodianthrones, phloroglucinol derivatives and flavonoids [2] as well as new metabolites were derived. Furthermore new findings concerning species and extract-specific negative and positive correlations were revealed.

Mechanisms of resistance to apoptosis in the human acute promyelocytic leukemia cell line NB4.

Current frontline therapies have improved overall survival in acute promyelocytic leukemia (APL) patients to exceptional rates; however, relapse is still a problem among high-risk and old patients. Therefore, the development of better and safer therapies continues to be a goal in the treatment of this disease. In the present work, we examined three different pathways that hinder cell death in the APL cell line NB4, shedding light on the mechanisms that underlie resistance to apoptosis in these cells and that might help provide them with a proliferative advantage. We found that the proteasome inhibitor MG-132 specifically induces in NB4 cells an Nrf2-mediated antioxidant response which counteracts mitochondria-dependent apoptosis induced by the lipophilic cation dequalinium. More importantly, we also demonstrated that high basal autophagy levels and the gain-of-function of mutant p53 are intrinsic mechanisms of resistance to apoptosis in this cell line. According to our results, the pharmacological inhibition of autophagy and p53 mutants are useful tools to explore resistance to apoptosis in APL and other types of cancer and could be the bases of new therapeutic approaches that improve the efficiency and allow dose reduction of the current treatments.

Zoledronic acid exerts antitumor effects in NB4 acute promyelocytic leukemia cells by inducing apoptosis and S phase arrest

The aim of this study was to investigate the antitumor effect of zoledronic acid (ZOL) in the NB4 human acute promyelocytic leukemia (APL) cell line and explore the potential mechanism of action of this compound. NB4 cells were exposed to various concentrations (0–200μM) of ZOL. Cell viability was measured by MTS assay. The extent of cell apoptosis and distribution of cells in the different phases of the cell cycle were analyzed with flow cytometry. The expression of apoptosis- and cell cycle-related proteins was assayed by Western blot. The combined effect of ZOL and arsenic trioxide (ATO) on the proliferation of NB4 cells was also determined. The results of this study indicate that ZOL inhibits cell proliferation in a time- and dose-dependent fashion and also induces apoptosis and S phase arrest in a dose-dependent manner. The Western blot analysis confirmed the induction of apoptosis and S phase arrest, revealing that the pro-apoptosis proteins Bax, Puma and activated caspase-9 were upregulated and the anti-apoptosis proteins Bcl-2 and Bcl-xL were downregulated. ZOL at a concentration of 50μM synergized with 0.5μM ATO on the growth inhibition of NB4 cells. Taken together, our data indicate that ZOL exerts a potent antitumor effect on NB4 cells by inducing apoptosis and cell cycle arrest, and that ZOL can synergize with the traditional chemotherapy drug ATO.

A systematic assessment of mitochondrial function identified novel signatures for drug-induced mitochondrial disruption in cells.

Mitochondrial perturbation has been recognized as a contributing factor to various drug-induced organ toxicities. To address this issue, we developed a high-throughput flow cytometry-based mitochondrial signaling assay to systematically investigate mitochondrial/cellular parameters known to be directly impacted by mitochondrial dysfunction: mitochondrial membrane potential (MMP), mitochondrial reactive oxygen species (ROS), intracellular reduced glutathione (GSH) level, and cell viability. Modulation of these parameters by a training set of compounds, comprised of established mitochondrial poisons and 60 marketed drugs (30 nM to 1mM), was tested in HL-60 cells (a human pro-myelocytic leukemia cell line) cultured in either glucose-supplemented (GSM) or glucose-free (containing galactose/glutamine; GFM) RPMI-1640 media. Post-hoc bio-informatic analyses of IC50 or EC50 values for all parameters tested revealed that MMP depolarization in HL-60 cells cultured in GSM was the most reliable parameter for determining mitochondrial dysfunction in these cells. Disruptors of mitochondrial function depolarized MMP at concentrations lower than those that caused loss of cell viability, especially in cells cultured in GSM; cellular GSH levels correlated more closely to loss of viability in vitro. Some mitochondrial respiratory chain inhibitors increased mitochondrial ROS generation; however, measuring an increase in ROS alone was not sufficient to identify mitochondrial disruptors. Furthermore, hierarchical cluster analysis of all measured parameters provided confirmation that MMP depletion, without loss of cell viability, was the key signature for identifying mitochondrial disruptors. Subsequent classification of compounds based on ratios of IC50s of cell viability:MMP determined that this parameter is the most critical indicator of mitochondrial health in cells and provides a powerful tool to predict whether novel small molecule entities possess this liability.

Influence of I2PP2A gene silencing by RNA interference on proliferation and apoptosis of human acute promyelocytic leukemia cell line NB4-R1

To explore the effect of RNA interference of human I2PP2A gene on the proliferation and apoptosis of retinoic acid-resistant human acute promyelocytic leukemia (APL) cell line NB4-R1. Designed and constructed a RNA interference lentiviral vector I2PP2A-shRNA which targeted against I2PP2A gene, then transfected it into NB4-R1 via polybrene mediation. The I2PP2A expression levels before and after transfection were detected by qRT-PCR and Western blot, respectively. Meanwhile, the proliferation and apoptosis rates of each group were determined by CCK-8 and flow cytometry assay. The protein expressions of caspase-8 and PARP were detected by Western blot. Both qRT-PCR and Western blot data showed the I2PP2A expression level was significantly downregulated in the transfection group. The I2PP2A mRNA expression level decreased by (70.0 ± 9.6)% and (64.0 ± 6.2)% respectively, compared with blank control and negative control group, and the I2PP2A protein expression level showed a consistent trend. CCK-8 proliferation assay indicated the NB4-R1 cell proliferation rate in I2PP2A-shRNA transfection group significantly reduced compared to blank control group (P<0.05). Flow cytometry results showed that NB4-R1 apoptosis rate in I2PP2A-shRNA transfection group increased by (6.30 ± 0.67) times and (6.04 ± 0.56) times, respectively (P<0.01). After inhibition of I2PP2A, the total caspase-8 and total PARP expressions decreased by (44.0 ± 3.1)% and (57.0 ± 4.0)%, respectively; Meanwhile, the cleaved caspase-8 (p43) and cleaved PARP (p89) increased by (36.0 ± 2.5)% and (45.0 ± 4.8)%, respectively compared with blank control group (P<0.05). I2PP2A gene silenced by RNA interference could inhibit the proliferation and promote the apoptosis of NB4-R1, which may be regulated through caspase-8-induced exogenous apoptosis pathway.

6-(Hetero)Arylpurine nucleotides as inhibitors of the oncogenic target DNPH1: Synthesis, structural studies and cytotoxic activities

The 2′-deoxynucleoside 5′-phosphate N-hydrolase 1 (DNPH1) has been proposed as a new molecular target for cancer treatment. Here, we describe the synthesis of a series of novel 6-aryl- and 6-heteroarylpurine riboside 5′-monophosphates via Suzuki–Miyaura cross-coupling reactions, and their ability to inhibit recombinant rat and human DNPH1. Enzymatic inhibition studies revealed competitive inhibitors in the low micromolar range. Crystal structures of human and rat DNPH1 in complex with one nucleotide from this series, the 6-naphthylpurine derivative, provided detailed structural information, in particular regarding the possible conformations of a long and flexible loop wrapping around the large hydrophobic substituent. Taking advantage of these high-resolution structures, we performed virtual docking studies in order to evaluate enzyme–inhibitor interactions for the whole compound series. Among the synthesized compounds, several molecules exhibited significant in vitro cytotoxicity against human colon cancer (HCT15, HCT116) and human promyelocytic leukemia (HL60) cell lines with IC50 values in the low micromolar range, which correlated with in vitro DNPH1 inhibitory potency.

In vitro cytotoxicity of Artemisia vulgaris L. essential oil is mediated by a mitochondria-dependent apoptosis in HL-60 leukemic cell line.

BackgroundThe essential oil (EO) of Artemisia vulgaris L. has been traditionally used worldwide for treating a large number of diseases. Although major components in A. vulgaris EO have been shown to inhibit growth of different cancer cells, as pure compounds or part of other plants extracted oil, no information is known about its anti-proliferative activities. Therefore, the current investigation has evaluated the toxicity of the plant extracted oil from buds (AVO-b) and leaves (AVO-l) and characterized their growth inhibitory effects on cancer cells.MethodsAVO-b and AVO-l from A. vulgaris L. were extracted by hydrodistillation, and their effect on the viability of human HL-60 promyelocytic leukemia and various other cancer cell lines was tested using MTT assay. Flow cytometric analysis of apoptosis, DNA fragmentation assay, caspases enzymatic activities and Western blotting were used to determine the apoptotic pathway triggered by their action on HL-60 cells.ResultsLow concentrations of AVO-b and AVO-l inhibited the growth of HL-60 cells in a dose- and time-dependent manner. Employing flow cytometric, DNA fragmentation and caspase activation analyses, demonstrated that the cytotoxic effect of the oils is mediated by a caspase-dependent apoptosis. Kinetic studies in the presence and absence specific caspase inhibitors showed that activation of caspase-8 was dependent and subsequent to the activation of caspases-9 and -3. In addition, the essential oil caused a disruption of the mitochondrial transmembrane potential (ΔΨm), increased the release of cytochrome c to the cytosol, and altered the expression of certain members of Bcl-2 family (Bcl-2, Bax and Bid), Apaf-1 and XIAP. Interestingly, low doses of AVO-b and AVO-1 also induced apoptosis in various cancer cell lines, but not in noncancerous cells.ConclusionsThe results demonstrate that the EO-induced apoptosis in HL-60 cells is mediated by caspase-dependent pathways, involving caspases-3, -9, and -8, which are initiated by Bcl-2/Bax/Bid-dependent loss of ΔΨm leading to release of cytochrome c to the cytoplasm to activate the caspase cascade. The finding that AVO-b and AVO-l are more efficient to induce apoptosis in different cancer cell lines than noncancerous cells, suggests that A. vulgaris might be a promising source for new anticancer agents.

Cytotoxicity, antioxidant and glutathione S-transferase inhibitory activity of palladium(II) chloride complexes bearing nucleobase ligands

Palladium(II) chloride complexes bearing the nucleobases, adenine, cytosine and guanine, have been synthesized and characterized by UV–vis spectrophotometric methods, magnetic susceptibility, molar conductivity, elemental analysis, FTIR and 1H-NMR. The complexes were found to have the general composition PdCl2(NH3L) (where L = adenine, cytosine or guanine). Square-planar geometry is proposed for these Pd(II) complexes based on magnetic evidence and electronic spectra. The complexes as well as the free nucleobase ligands show varying degrees of cytotoxicity on human promyelocytic leukemia (HL60) and human histiocytic leukemia (U937) cell lines, with cis-[PdCl2(NH3)(Gua)] showing IC50 values of 48.03 ± 9.67 and 11.12 ± 3.42 µM against HL60 and U937, respectively. The complexes as well as the ligands did not show anti-proliferative activity against a normal human cell line (NB1RGB). The complexes also show significant antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl radical as well as glutathione S-transferase inhibitory activity.

Endocan, a potential prognostic and diagnostic biomarker of acute leukemia.

Recent evidence indicated that endocan may be a potential cell marker and a new target for cancers including acute leukemia since the serum endocan level in patients with acute leukemia was associated with the status of the disease, i.e., endocan was higly expressed in untreated acute leukemia, but decreased after chemotherapy and increased again during bone marrow regeneration. The present study showed that there was high level expression of endocan in cytoplasm of bone marrow blasts of patients with acute myeloid leukemia or acute lymphoblastic leukemia. The expression level of endocan was significantly decreased when the patients underwent remission after chemotherapy and re-bounces back when the acute leukemia relapsed. No obvious change in expression of endocan was observed before and after chemotherapy if the patients showed no remission after chemotherapy. (N-(4-Hydroxyphenyl) retinamide), a potent anti-angiogenic agent, could not only down-regulate the expression of vascular epithelial growth factor, but also decrease endocan transcription and expression in NB4 cells, a human acute promyelocytic leukemia cell line. These observations suggest that endocan could act as a predictor for the severity and the prognosis of acute leukemia. The findings could be used as the basis for future targeted therapy directed against bone marrow angiogenesis in acute leukemia treatment.

Palladium(II) Complexes with N‐Heteroaromatic Bidentate Hydrazone Ligands: The Effect of the Chelate Ring Size and Lipophilicity on in vitro Cytotoxic Activity

Novel Pd(II) complex with N-heteroaromatic Schiff base ligand, derived from 8-quinolinecarboxaldehyde (q8a) and ethyl hydrazinoacetate (haOEt), was synthesized and characterized by analytical and spectroscopy methods. The structure of novel complex, as well as structures of its quinoline and pyridine analogues, was optimized by density functional theory calculations, and theoretical data show good agreement with experimental results. A cytotoxic action of the complexes was evaluated on cultures of human promyelocytic leukemia (HL-60), human glioma (U251), rat glioma (C6), and mouse fibrosarcoma (L929) cell lines. Among investigated compounds, only complexes with quinoline-based ligands reduce the cell numbers in a dose-dependent manner in investigated cell lines. The observed cytotoxic effect of two isomeric quinoline-based complexes is predominantly mediated through the induction of apoptotic cell death in HL-60 cell line. The cytotoxicity of most efficient novel Pd(II) complex is comparable to the activity of cisplatin, in all cell lines investigated.