Promyelocytic Leukemia Cell Line HL-60 Research Articles

Synthesis of New Chiral β-Carbonyl Selenides with Antioxidant and Anticancer Activity Evaluation-Part I.

A series of unsymmetrical phenyl β-carbonyl selenides with o-amido function substituted on the nitrogen atom with chiral alkyl groups was obtained. The compounds form a series of enantiomeric and diastereomeric pairs and present the first examples of this type of chiral Se derivatives. All obtained selenides were further evaluated as antioxidants and anticancer agents to define the influence of the particular stereochemistry of the attached functional groups on the bioactivity of the molecules. The highest H2O2 reduction potential was observed for N-(cis-2-hydroxy-1-indanyl)-2-((2-oxopropyl)selanyl)benzamide, and the best radical scavenging properties for N-(-1-hydroxy-2-butanyl)-2-((2-oxopropyl)selanyl)benzamide. Also, both enantiomers of the N-(1-hydroxy-2-butanyl) selenide expressed the highest cytotoxic potential towards human promyelocytic leukemia HL-60 cell line with similar IC50 values 14.4 ± 0.5 and 16.2 ± 1.1 µM, respectively. On the other hand, breast cancer cell line MCF-7 was most sensitive to N-((R)-(-)-1-hydroxy-2-butanyl)- 2-((2-oxopropyl)selanyl)benzamide (IC50 of 35.7 ± 0.6 µM). The structure-activity dependence of the obtained Se derivatives was discussed, and the most potent compounds were selected.

Cytotoxicity and Induction of G1 Phase Cell Cycle Arrest in human acute promyelocytic leukemia HL60 cells by indole alkaloids isolated from Dialium corbisieri seeds.

The phytochemical investigation of Dialium corbisieri seeds led to the isolation of five monoterpenoid indole alkaloids along with a phytoserotonin, 1-6 and among the known compounds, the spectroscopic data of (5S)-methoxy-akuammiline (1) was reported for the first time. The structures were elucidated based on NMR spectroscopic techniques such as UV, IR, HRESITOFMS, and ECD spectrum calculations. The isolated compounds were evaluated for their cytotoxicity and cell progression in the human acute promyelocytic leukemia HL60 cell line.

Effect and Mechanism of Atorvastatin on Reversing Drug Resistance in Leukemia by Regulating Glycolysis through PTEN/mTOR Pathway

To investigate the influence and mechanism of atorvastatin on glycolysis of adriamycin resistant acute promyelocytic leukemia (APL) cell line HL-60/ADM. HL-60/ADM cells in logarithmic growth phase were treated with different concentrations of atorvastatin, then the cell proliferation activity was measured by CCK-8 assay, the apoptosis was detected by flow cytometry, the glycolytic activity was checked by glucose consumption test, and the protein expressions of PTEN, p-mTOR, PKM2, HK2, P-gp and MRP1 were detected by Western blot. After transfection of PTEN-siRNA into HL-60/ADM cells, the effects of low expression of PTEN on atorvastatin regulating the behaviors of apoptosis and glycolytic metabolism in HL-60/ADM cells were further detected. CCK-8 results showed that atorvastatin could inhibit the proliferation of HL-60/ADM cells in a concentration-dependent and time-dependent manner (r=0.872, r=0.936), and the proliferation activity was inhibited most significantly when treated with 10 μmol/L atorvastatin for 24 h, which was decreased to (32.3±2.18)%. Flow cytometry results showed that atorvastatin induced the apoptosis of HL-60/ADM cells in a concentration-dependent manner (r=0.796), and the apoptosis was induced most notably when treated with 10 μmol/L atorvastatin for 24 h, which reached to (48.78±2.95)%. The results of glucose consumption test showed that atorvastatin significantly inhibited the glycolytic activity of HL-60/ADM cells in a concentration-dependent and time-dependent manner (r=0.915, r=0.748), and this inhibition was most strikingly when treated with 10 μmol/L atorvastatin for 24 h, reducing the relative glucose consumption to (46.53±1.71)%. Western blot indicated that the expressions of p-mTOR, PKM2, HK2, P-gp and MRP1 protein were decreased in a concentration-dependent manner (r=0.737, r=0.695, r=0.829, r=0.781, r=0.632), while the expression of PTEN protein was increased in a concentration-dependent manner (r=0.531), when treated with different concentrations of atorvastatin for 24 h. After PTEN-siRNA transfected into HL-60/ADM cells, it showed that low expression of PTEN had weakened the promoting effect of atorvastatin on apoptosis and inhibitory effect on glycolysis and multidrug resistance. Atorvastatin can inhibit the proliferation, glycolysis, and induce apoptosis of HL-60/ADM cells. It may be related to the mechanism of increasing the expression of PTEN, inhibiting mTOR activation, and decreasing the expressions of PKM2 and HK2, thus reverse drug resistance.

Cytotoxic Mechanism of Momilactones A and B against Acute Promyelocytic Leukemia and Multiple Myeloma Cell Lines.

Simple SummaryThough the anticancer potentiality of momilactones has been reported in several studies, their cytotoxic mechanism has not been comprehensively scrutinized. In this study, we investigated the cytotoxicity of momilactones A (MA) and B (MB) against acute promyelocytic leukemia (APL) HL-60 and multiple myeloma (MM) U266 cell lines. According to MTT results, MB and the mixture MAB (1:1, w/w) show a substantial inhibition on the cell viability of HL-60 and U266, with IC50 ranging from 4.49 to 5.59 µM. Besides, MB and MAB at 5 µM inhibit HL-60 cells through the regulations of relevant proteins to apoptosis-inducing factors (p-38, BCL-2, and caspase-3) and cell cycle arrest at G2 phase (p-38, CDK1, and cyclin B1). Meanwhile, these compounds enhance U266 apoptosis by altering p-38, BCL-2, and caspase-3 signaling pathways. Significantly, momilactones exhibit a minor effect on a non-cancerous cell line (MeT-5A), implying that they are promising candidates for developing novel anti-APL and anti-MM medicines.This is the first study clarifying the cytotoxic mechanism of momilactones A (MA) and B (MB) on acute promyelocytic leukemia (APL) HL-60 and multiple myeloma (MM) U266 cell lines. Via the MTT test, MB and the mixture MAB (1:1, w/w) exhibit a potent cytotoxicity on HL-60 (IC50 = 4.49 and 4.61 µM, respectively), which are close to the well-known drugs doxorubicin, all-trans retinoic acid (ATRA), and the mixture of ATRA and arsenic trioxide (ATRA/ATO) (1:1, w/w) (IC50 = 5.22, 3.99, and 3.67 µM, respectively). Meanwhile MB, MAB, and the standard suppressor doxorubicin substantially inhibit U266 (IC50 = 5.09, 5.59, and 0.24 µM, respectively). Notably, MB and MAB at 5 µM may promote HL-60 and U266 cell apoptosis by activating the phosphorylation of p-38 in the mitogen-activated protein kinase (MAPK) pathway and regulating the relevant proteins (BCL-2 and caspase-3) in the mitochondrial pathway. Besides, these compounds may induce G2 phase arrest in the HL-60 cell cycle through the activation of p-38 and disruption of CDK1 and cyclin B1 complex. Exceptionally, momilactones negligibly affect the non-cancerous cell line MeT-5A. This finding provides novel insights into the anticancer property of momilactones, which can be a premise for future studies and developments of momilactone-based anticancer medicines.

Establishment and Biochemical Characterization of a Multidrug-resistant Promyelocytic Leukemia Cell Line HL-60/CDDP

The present study reports on the establishment, validation and biochemical characterization of a novel chemoresistant variant of the HL-60 acute myeloid leukemia (AML) cell line developed at the Laboratory of Experimental Chemotherapy at the Faculty of Pharmacy of MU-Sofia. Selection of the chemoresistant strain (HL-60/CDDP) has been carried out by prolonged serial exposures of the parent chemosensitive HL-60 cell line to gradually increasing concentrations of the metal complex. In its final variant, the resultant HL-60/CDDP test system showed significantly altered chemosensitivity profiles to the Pt(II)-based drugs cisplatin, carboplatin, oxaliplatin and was maintained in an RPMI-1640 medium containing 25 μM cisplatin. The promyelocytic cells also showed diminished susceptibility to differentiation therapy with arsenic trioxide As2O3. The emergence of the multiresistant phenotype is suggested to be most likely due to common biochemical properties of the screened compounds, including their strong affinity and high reactivity with sulfhydryl SH-groups. The presented study is focused on elucidating the multidrug resistance patterns in the newly established leukemic model that can be used as a potential test system for exploring the drug-resistance reversal capacity of various drugs and experimental compounds.

Design, synthesis, and biological evaluation of novel pyrido-dipyrimidines as dual topoisomerase II/FLT3 inhibitors in leukemia cells

Dual inhibition of topoisomerase (topo) II and FLT3 kinase, as in the case of C-1311, was shown to overcome the shortcomings of using topo II inhibitors solely. In the present study, we designed and synthesized two series of pyrido-dipyrimidine- and pseudo-pyrido-acridone-containing compounds. The two series were evaluated against topo II and FLT3 as well as the HL-60 promyelocytic leukemia cell line in vitro. Compounds 6, 7, and 20 showed higher potency against topo II than the standard amsacrine (AMSA), whereas compounds 19 and 20 were stronger FLT3 inhibitors than the standard DACA. Compounds 19 and 20 showed to be dual inhibitors of both enzymes. Compounds 6, 7, 19, and 20 were more potent inhibitors of the HL-60 cell line than the standard AMSA. The results of the in vitro DNA flow cytometry analysis assay and Annexin V-FITC apoptosis analysis showed that 19 and 20 induced cell cycle arrest at the G2/M phase, significantly higher total percentage of apoptosis, and late-stage apoptosis in HL-60 cell lines than AMSA. Furthermore, 19 and 20 upregulated several apoptosis biomarkers such as p53, TNFα, caspase 3/7 and increased the Bax/Bcl-2 ratio. These results showed that 19 and 20 deserve further evaluation of their antiproliferative activities, particularly in leukemia. Molecular docking studies were performed for selected compounds against topo II and FLT3 enzymes to investigate their binding patterns. Compound 19 exerted dual fitting inside the active site of both enzymes.

Attachment of Chiral Functional Groups to Modify the Activity of New GPx Mimetics.

A series of new chiral benzisoselenazol-3(2H)-ones and their corresponding diselenides bearing an o-amido function substituted on the nitrogen atom with various aliphatic and aromatic moieties were synthesized. All derivatives representing pairs of enantiomers or diastereoisomers were obtained to thoroughly evaluate the three-dimensional structure–activity correlation. First, bensisoselenazol-3(2H)-ones were synthesized by reacting 2-(chloroseleno)benzoyl chloride with an appropriate enantiomerically pure amine. Then, the Se–N bond was cleaved by a reduction–oxidation procedure using sodium borohydride and then air oxidation to obtain the corresponding diselenides. All derivatives were tested as antioxidants and anticancer agents. In general, the diselenides were more reactive peroxide scavengers, with the highest activity observed for 2,2′-diselenobis[N-(1S,2S)-(-)-trans-2-hydroksy-1-indanylbezamide]. The most cytotoxic derivative towards human promyelocytic leukemia HL-60 and breast cancer MCF-7 cell lines was N-[(1S,2R)-(-)-cis-2-hydroksy-1-indanyl]-1,2-benzizoselenazol-3(2H)-one. The structure–activity relationship of the obtained organoselenium derivatives was discussed.

Influence of ligand lipophilicity in Pt(II) complexes on their antiproliferative and apoptotic activities in tumour cell lines

One of the most widely used strategies for drug development is the coordination of bioactive ligands to transition metals, which could improve biological activity. Moreover, the incorporation of aromatic groups to ligands may allow an enhanced lipophilicity that can influence the cellular uptake and accumulation of the metallodrugs, thus increasing their activity. Herein, we have reported the synthesis and characterization of four Pt(II) complexes [PtCl2(L)], where L = 2-(1-pyrazolyl)-2-thiazoline (PzTn), 2-(1-pyrazolyl)-1,3-thiazine (PzTz), 2-(3,5-diphenyl-1-pyrazolyl)-2-thiazoline (DPhPzTn) or 2-(3,5-diphenyl-1-pyrazolyl)-1,3-thiazine (DPhPzTz). The study was aimed at analysing their potential anticarcinogenic ability in epithelial cervix carcinoma HeLa, human promyelocytic leukemia HL-60 and human histiocytic lymphoma U-937 tumour cell lines as well as checking whether the structural factors of the organic ligand may influence their biological activity. Our findings showed that PtDPhPzTn and PtDPhPzTz were far more effective in terms of cytotoxicity than their less lipophilic counterparts (PtPzTn and PtPzTz), especially in cells derived from solid cervical tumours, thereby suggesting that modulating the lipophilicity of the ligands can help improve the cytotoxic effect of the metal complexes.

G2/M cell cycle arrest and apoptosis induced by COH-203 in human promyelocytic leukemia HL-60 cells.

The combretastatin A-4/oltipraz hybrid (COH), 5-(3-amino-4-methoxyphenyl)-4-(3,4,5-trimethoxyphenyl)-3H−1,2-dithiole-3-one (COH-203) is one of the COH compounds synthesized by our previous study, which has been reported to affect a number of cancer cell lines, such as SGC-7901, KB, HT-1080, HepG2, SMMC-7721 and BEL-7402. The sensitivity of human acute leukemia cell lines to COH-203, and the mechanism underlying its anti-proliferative effects remain unknown, which was investigated in the present study. In the present study, it was demonstrated that COH-203 had notable time- and dose-dependent antiproliferative effects on the human acute promyelocytic leukemia HL-60 cell line. Furthermore, COH-203 treatment resulted in cell cycle arrest at G2/M phase in a dose-dependent manner, and subsequently induced apoptosis. Western blot analysis revealed that upregulation of cyclin B was associated with G2/M arrest. In addition, treatment with COH-203 resulted in downregulated expression of Bcl-2. This result revealed that COH-203-induced apoptosis in HL-60 cells may occur via the mitochondrial pathway in a caspase-dependent manner.

Synthesis, Characterization and Antiproliferative Evaluation of Pt(II) and Pd(II) Complexes with a Thiazine-Pyridine Derivative Ligand.

Chemical, pharmacological, and clinical research on anticancer coordination complexes has led to noteworthy anticancer drugs such as cisplatin, carboplatin and oxaliplatin. Although these compounds are effective chemotherapeutic agents in the treatment of different tumors, they are associated with high toxicity and numerous side effects. Several studies have shown that the range of platinum complexes with antitumor activity is not limited to structural analogs of cisplatin. Therefore, the development of convenient anticancer drugs that can be effectively used for the treatment of human tumors has become the main goal of most research groups in this field. In this sense, active platinum complexes without NH groups, transplatinum complexes, multinuclear complexes, cationic complexes, and several classes of palladium(II) complexes have emerged. Herein, the synthesis and characterization of two Pt(II) or Pd(II) complexes with PyTz (2-(2-pyridyl)iminotetrahydro-1,3-thiazine), a thiazine derivative ligand, with the formula [MCl2(PyTz)]·C2H6O (M = Pt(II) or Pd(II)) were reported. The potential anticancer ability of both complexes was evaluated in epithelial cervix carcinoma HeLa, human ovary adenocarcinoma SK-OV-3, human histiocytic lymphoma U-937, and human promyelocytic leukemia HL-60 cell lines. Interestingly, the Pt(II) complex showed great cytotoxic potential against all tumor cell lines tested, whereas the Pd(II) complex displayed slight antitumor actions.

Amplification of Cord Blood-Derived Cytotoxic T Lymphocytes using HL-60 cell Derived Exosomes

IntroductionDendritic cell (DCs) based cytotoxic T lymphocytes (CTLs) are commonly used in immunotherapy due to their specificity. The selection of appropriate cell origin and tumor antigen is the key point. The objective was to culture DCs and CTLs simultaneously from cord blood, and deliver antigen information using tumor derived exosomes.Material and methodsExosomes were collected from the human promyelocytic leukemia cell line HL-60 using ultracentrifugation. Prepared DCs from adherent cord blood mononuclear cells (MNCs) using SCF, GM-CSF, and IN-4. TNF-α and microRNA removed tumor-exosome were used to induce DCs maturation. DCs matured in the presence of HL-60 cell membrane protein extract or no antigen were set as control. CTLs was cultured from non-adherent MNCs by adding IFN-γ, IL-15, SCF, FLT-3L, anti-CD3, anti-CD28 and IL-2. The CTLs were analyzed by flow cytometry, cytotoxicity experiments and ELISA.ResultsDCs can be obtained from cord blood and express costimulatory molecules. After 15 days, the total number of the cells expanded 26.3 times, and more than 82% of the cells expressed CD3+CD8+ in the most amplified HL-60-Ex-DCs-CTL group. These CD3+CD8+ T cells generated by HL-60-Ex-DCs displayed specific cytotoxicity towards HL-60 and low lethality towards unrelated BALL-1 cells. ELISA results showed that the expressions of TNF-α and IFN-γ in HL-60-Ex-DCs or HL-60mPr-DCs activated CTLs were upregulated compared with the control group.ConclusionsCord blood CTLs generated by HL-60 derived exosome activated DCs displayed specific cytotoxicity towards HL-60 promyelocytic leukemia cells. Therefore cord blood and tumor derived exosomes provided a good source for adoptive immunotherapy.

Development of Efficient Synthetic Method for Tautomeric Dihydropyrimidines and Analysis of Their Functionality

I here present the results of our studies on the synthesis and functional analysis of tautomeric dihydropyrimidines (DPs) and related compounds in two sections. In the first section, we describe our experimental and theoretical studies on the thermodynamics and properties of 2-substituted 1,4- and 1,6-dihydropyrimidine-5-carboxylates by 1H NMR measurements and density functional theory (DFT) calculations, respectively. The concentration ratios of tautomers a/b of DPs 1, 2, and 3 were determined under various conditions to determine the effects of temperature, solvent, and concentration on thermodynamics data. The obtained free energy differences (ΔG), enthalpy differences (ΔH), and entropy differences (ΔS) are discussed in terms of the molecular structures, dipole moments (DM), and electrostatic potential maps obtained by DFT calculations to clarify the nature of DPs 4-8. In the second section, an efficient synthetic method developed for 6-unsubstituted 3,4-dihydropyrimidin-2(1H)-thiones 9 and 2-ones 10 is described. The novelties of the synthesis protocol are as follows: 1) the use of Lewis acid-mediated reaction, 2) good to high yields, and 3) its broad scope of applicability to aldehydes and ureas. Hitherto unavailable 6-unsubstituted 2-amino DP 11 and 2-aryl DP 12 were obtained from 9 by a substitution reaction with the amine and the Liebeskind-Srogl reaction, respectively. The compounds 9, 10, and related 6-methyl derivatives 19-21 were assessed for their antiproliferative effect on the human promyelocytic leukemia cell line HL-60. 4,4-Dipropyl derivative 20 showed relatively strong activity with an IC50 value of 341 nM.

Synthesis of novel 6-unsubstituted 2-aminodihydropyrimidines by Sc(OTf)3-mediated amination and their antiproliferative effect on HL-60 cells

An efficient method of synthesis of novel 6-unsubstituted 2-aminodihydropyrimidines 9 has been developed. The substitution reaction of 2-methylthiodihydropyrimidines 7 and primary amines in the presence of a catalytic amount of Sc(OTf)3 with heating proceeds smoothly to give 9 in good to high yields. This amination protocol can be applied to various aryl- and alkylamines. Other 2-methylthiodihydropyrimidines 10 having different substituent patterns at 4- and 6-positions also reacted with aniline under the same conditions to give corresponding 2-anilinodihydropyrimidines 11 in high yields. These compounds 9 were assessed for their antiproliferative effect on the human promyelocytic leukemia cell line HL-60. The 2-benzyl derivative 9i showed a relatively high activity with an IC50 of <100 nM. The high activity of 9i was comparable to that of all-trans retinoic acid (223.1 nM). The results of the trypan blue exclusion test of 9i indicated that necrosis-like cell death occurred.

Antineoplastic Activity In Vitro of 2-amino-5-benzylthiasol Derivative in the Complex with Nanoscale Polymeric Carriers

The main problems of contemporary chemotherapy are the insufficient efficacy of antitumor drugs and low selectivity of their action, development of multidrug resistance, and poor water solubility of antitumor drugs. One of the ways to improve the targeted delivery of drugs and increase their solubility is the use of polymeric nanoscale carriers. The newly synthesized thiazole derivative (N-(5-benzyl-1,3-thiazol-2-yl)-3,5-dimethyl-1-benzofuran-2-carboxamide, BF1) is cytotoxic in its activity towards some tumor cell lines. The aim of this study was to investigate the action of BF1 conjugated with novel polymeric carriers based on polyethylene glycol (PEG). The synthesized complexes exhibited a higher level of cytotoxicity towards specific tumor cell lines than the pure (unconjugated) thiazole derivative or/and doxorubicin (positive control). Complexes 4, 14 and 8, 18 were the most toxic to the human hepatocarcinoma HepG2 and the rat glioma C6 cell lines. Complex 6 exhibited a high level of toxicity towards human glioblastoma T98G and human promyelocytic leukemia HL-60 cell lines. Thus, complexes 4 and 14 based on poly(VEP-co-GMA)-graft-mPEG, complex 6 based on poly(PEGMA), and complexes 8 and 18 based on poly(PEGMA-co-DMM) selectively increase the toxic action of thiazole derivative BF1 towards tumor cells.

Exploring the Anti-Cancer Mechanism of Novel 3,4'-Substituted Diaryl Guanidinium Derivatives.

We previously identified a guanidinium-based lead compound that inhibited BRAF through a hypothetic type-III allosteric mechanism. Considering the pharmacophore identified in this lead compound (i.e., “lipophilic group”, “di-substituted guanidine”, “phenylguanidine polar end”), several modifications were investigated to improve its cytotoxicity in different cancer cell lines. Thus, several lipophilic groups were explored, the di-substituted guanidine was replaced by a secondary amine and the phenyl ring in the polar end was substituted by a pyridine. In a structure-based design approach, four representative derivatives were docked into an in-house model of an active triphosphate-containing BRAF protein, and the interactions established were analysed. Based on these computational studies, a variety of derivatives was synthesized, and their predicted drug-like properties calculated. Next, the effect on cell viability of these compounds was assessed in cell line models of promyelocytic leukaemia and breast, cervical and colorectal carcinomas. The potential of a selection of these compounds as apoptotic agents was assessed by screening in the promyelocytic leukaemia cell line HL-60. The toxicity against non-tumorigenic epithelial MCF10A cells was also investigated. These studies allowed for several structure-activity relationships to be derived. Investigations on the mechanism of action of representative compounds suggest a divergent effect on inhibition of the MAPK/ERK signalling pathway.

Evaluation of NAMI-A Cytotoxic Effects toward Leukemia Cell Lines: A Slippery Ground Giving Misleading Messages.

The expansion of metal-based complexes in the last 20 years has been very intense and many metals have been involved. Among the many compounds studied, the ruthenium-based complex NAMI-A embodies the unique paradigm of the ability to selectively inhibiting and preventing the development and the growth of distant metastases originating from solid tumors in all the tumor models on which it has been tested. An activity that can be detected only in vivo since the compound is virtually free of measurable direct cell cytotoxicity in vitro. Recently, a published paper reported on a significant in vitro cytotoxicity against some leukemic cells. The present study was undertaken to reproduce those experiments to further support this novel antileukemic activity that would have put NAMI-A on a new trajectory for development. Our results do not confirm the efficacy of NAMI-A in vitro against the human HL-60 promyelocytic leukemia cell line either using test cultures identical to those reported in the study of reference or in even more stressed conditions, supporting the lack of in vitro direct cell cytotoxicity of NAMI-A. The present study also helps to elucidate that many factors can influence the outcome of in vitro tests of cytotoxicity and suggests caution to speculate on possible therapeutic properties based on the results of simple and reductive in vitro tests of cytotoxicity.

First identification of Anaplasma phagocytophilum in both a biting tick Ixodes nipponensis and a patient in Korea: a case report

BackgroundHuman granulocytic anaplasmosis (HGA) is a tick-borne infectious disease caused by Anaplasma phagocytophilum. To date, there have been no reported cases of A. phagocytophilum infection found in both the biting tick and the patient following a tick bite.Case presentationAn 81-year-old woman presented with fever following a tick bite, with the tick still intact on her body. The patient was diagnosed with HGA. The tick was identified as Ixodes nipponensis by morphological and molecular biological detection methods targeting the 16S rRNA gene. The patient’s blood was cultured after inoculation into the human promyelocytic leukemia cell line HL-60. A. phagocytophilum growth was confirmed via culture and isolation. A. phagocytophilum was identified in both the tick and the patient’s blood by Anaplasma-specific groEL- and ankA-based nested polymerase chain reaction followed by sequencing. Moreover, a four-fold elevation in antibodies was observed in the patient’s blood.ConclusionWe report a case of a patient diagnosed with HGA following admission for fever due to a tick bite. A. phagocytophilum was identified in both the tick and the patient, and A. phagocytophilum was successfully cultured. The present study suggests the need to investigate the possible incrimination of I. nipponensis as a vector for HGA in Korea.

Potentiation of Differentiation and Apoptosis in a Human Promyelocytic Leukemia Cell Line by Garlic Essential Oil and Its Organosulfur Compounds.

The clinical course of acute leukemia is complicated, and it is often necessary to combine or change treatment methods due to the rapid increase and spread of malignant cells. In this study, the potential anti-leukemia activities of prepared garlic essential oil (GEO) and some organosulfur compounds contained therein were examined. Garlic essential oil component identification by gas chromatography-mass spectrometry (GC-MS). MTT assay evaluated cytotoxicity of tested samples. Leukemia cell differentiation was determined by NBT assay. Apoptosis and related mechanisms were investigated by western blotting. GC-MS analysis confirmed that the two most abundant constituents, diallyl disulfide (DADS) and diallyl trisulfide (DATriS), constituted 80% of the composition. GEO and DADS exhibited the best effects in terms of significant production of intracellular reactive oxygen species (ROS), induction apoptosis and potentiation differentiation of human promyelocytic leukemia cell line HL-60 cells. The GEO-mediated apoptosis was alleviated by the free radical scavenger N-acetyl-L-cysteine (NAC). The anti-leukemia activity of GEO and organosulfur compound DADS through the action of ROS elevation was herein confirmed.

Synthesis and structure of a new thiazoline-based palladium(II) complex that promotes cytotoxicity and apoptosis of human promyelocytic leukemia HL-60 cells

Cisplatin is one of the most widely used chemotherapeutic agents in the treatment of different tumors but has high toxicity and side effects. Therefore, the synthesis of new chemotherapeutic agents is necessary, so that they are effective in the treatment of cancer while avoiding such toxicity. In this study, we have synthesized and characterized a palladium(II) complex, [PdCl2(µ-PyTT)2]Cl2·4H2O (PdPyTT), with 2-(2-pyridyl)imine-N-(2-thiazolin-2-yl)thiazolidine (PyTT) as a ligand; besides, its cytotoxicity and pro-apoptotic capacity was tested in human promyelocytic leukemia HL-60 cell line. Similar to cisplatin, PdPyTT produced a time- and dose-dependent decrease in cell viability. Additionally, the palladium complex increased both the proportion of cells with apoptotic morphology and the activation of caspase-3 and -9. PdPyTT, like cisplatin, also increased intracellular ROS production and DNA oxidative damage. Therefore, our findings demonstrated the promising application of palladium(II) complexes as novel anti-leukemic agents.

Triterpenes from Poria cocos are revealed as potential retinoid X receptor selective agonists based on cell and in silico evidence.

Poria cocos is an edible and medicinal fungus that is widely used in Traditional Chinese Medicines as well as in modern applications. Retinoid X receptor (RXR) occupies a central place in nuclear receptor signaling, and a pharmacological RXR-dependent pathway is involved in myeloid cell function. Here, structural information for 82 triterpenes from P.cocos and 17 known RXR agonists was collected in a compound library and retrieved for a molecular docking study. Three triterpenes, 16α-hydroxytrametenolic acid (HTA), pachymic acid (PA), and polyporenic acid C (PPAC), were identified as novel RXR-specific agonists based on luciferase reporter assays and in silico evidence. Treatment with HTA, PA, and PPAC significantly induced differentiation of the human promyelocytic leukemia cell line HL-60 with EC50 values of 21.0±0.52, 6.7±0.37, and 9.4±0.65μM, respectively. These effects were partly blocked by the RXR antagonist UVI3003, suggesting that an RXR-dependent pathway may play an important role in their anti-acute promyelocytic leukemia (APL) effects. Taken together, triterpenes from P.cocos are revealed as naturally occurring RXR selective agonists with the potential for anti-cancer activity. These results suggest a novel approach to the treatment or prevention of APL.