Acute Myeloid Leukemia HL-60 Research Articles

Novel indole retinoid derivative induces apoptosis and cell cycle arrest and modulates AKT and ERK signaling in HL-60 cells.

Chemotherapy with targeted drugs is the first line therapy option for acute and chronic myeloid leukemia. However, hematopoietic stem cell transplantation may be used in high-risk patients or patients with failed responses to chemo drugs. Discovery and development of more effective new agents with lower side effects is the main aim of leukemia treatment. In this study, a novel retinoid compound with tetrahydronaphthalene ring was synthesized and evaluated for anticancer activity in human chronic and acute myeloid leukemia cell lines K562 and HL-60. Novel N-(1H-indol-1-yl)-5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalene-2-carboxamide was synthesized based on molecular hybridization of the two different bioactive structures retinoid head and indole. The effects of the synthesized carboxamide compound, which was referred to as compound 5, were determined in K562 chronic myeloid leukemia and HL-60 acute myeloid leukemia cell lines and L929 fibroblast cell line, which served as a control. Colorimetric MTT and caspase3 activity tests, flow cytometry, western blot, and microscopic examinations were used to evaluate biological activity. Compound 5 more effectively induced cell death in HL60 cells in comparison to K562 cells and L929 fibroblast cells. Therefore, further mechanism of cell death was investigated in HL60 cell line. It was found that compound 5 induced remarkable cytotoxicity, caspase3 activation, and PARP fragmentation in HL60 cells. Flow cytometric staining showed that the percentage of cells arrested in G0/G1 was also increased with compound 5 treatment. Important modulator proteins of cell proliferation p-ERK, p-AKT, and p-m-TOR were also found to be inhibited with compound 5 treatment. Collectively, our results reveal compound 5, which is a novel indole retinoid compound as a potential active agent for the treatment of acute promyelocytic leukemia.

Green synthesis of copper oxide spindle like nanostructure using Hibiscus cannabinus flower extract for antibacterial and anticancer activity applications

In this study, CuO nanospindle synthesized using petal extract of Hibiscus cannabinus (H. cannabinus) was attempted to have better antibacterial activity against Gram-positive and Gram-negative bacteria. Cytotoxic activity was found to be 70 % against human acute myeloid leukemia HL60 cell line at 500 µg/ml. Morphological features of CuO was analyzed by scanning electron microscopy (SEM). Structural properties were analyzed by X-ray diffraction (XRD) pattern and the Fourier transform infrared (FTIR) spectrum of CuO provides additional evidence for the formation of monoclinic crystal structured CuO. Energy dispersive X-ray spectroscopy (EDAX) analysis exposed the pristine properties of CuO nanospindles.

Anti-leukemic activity of Cyperus rotundus L. on human acute myeloid leukemia HL-60 cells in vitro

Context: Acute myeloid leukemia (AML) is the most common form of acute leukemia. Currently, many people use medicinal herbs for the treatment of cancers. Nut grass (Cyperus rotundus L.) is a medicinal plant widely used in conventional medicine due to its role as an anti-cancer. Aims: To evaluate the effect of Cyperus rotundus tuber (CRT) ethanolic extract on cell proliferation, differentiation, cell cycle, and apoptotic of HL-60 cells. Methods: HL-60 cells line as a model for AML was cultured under the influence of CRT extract concentrations (35.4, 354, and 3540 µg/mL) for 48 h. Furthermore, the cell was subjected to carboxyfluorescein succinimidyl ester staining for proliferation, using a CD117 marker for differentiation. Annexin V-FITC and PI for cell cycle and apoptosis. The effect of this herb was studied by flow cytometry. The data were statistically analyzed with one-way ANOVA (p≤0.05) and the Tukey test using SPSS version 16 for Windows. Results: The results showed that the CRT inhibited proliferation activity, differentiation, cell cycle arrest, and apoptosis. Conclusions: The data clearly showed the potential anti-cancer activity of CRT on HL-60 cells and suggested that it could help develop promising therapeutic agents for AML treatments.

Tetrazole and acylsulfonamide bioisosteric replacements of the carboxylic acid in a dual MCL-1/BCL-xL inhibitor are tolerated.

Overexpression of the anti-apoptotic protein MCL-1 is associated with a plethora of human cancers, and it reduces the sensitivity of cancer cells to approved chemotherapies. Accordingly, the discovery of MCL-1 inhibitors is an active area of interest. Many inhibitors of the anti-apoptotic MCL-1 protein bear a crucial carboxylic acid that may engage Arg263 in the BH3-binding groove. We previously described the salicylic acid-based dual MCL-1/BCL-xL inhibitor 17cd, which is currently undergoing lead optimization. As part of that process, we wished to investigate bioisosteric replacement of 17cd's key carboxylic acid. Herein we describe the synthesis of a variety of analogues of a simpler analogue of 17cd presenting carboxylic acid surrogates. The acylsulfonamide and tetrazole motifs, which exhibit comparable pKas to the carboxylic acid function, displayed similar, or better, binding affinities to MCL-1 and BCL-xL as the corresponding carboxylic acid-containing lead. Our best compound was acylsulfonamide 7d with a Ki of 800 nM against MCL-1 and 1.82 mM against BCL-xL, and demonstrated an improved effect on the viability of the HL60 acute myeloid leukemia cell line relative to the parent carboxylic acid-containing dual inhibitor from which it was derived.

Novel benzo chromene derivatives: design, synthesis, molecular docking, cell cycle arrest, and apoptosis induction in human acute myeloid leukemia HL-60 cells

A series of benzo[h]chromenes, benzo[f]chromenes, and benzo[h]chromeno[2,3-d]pyrimidines were prepared. All the newly synthesised compounds were selected by National Cancer Institute for single-dose testing against 60 cell lines. Benzo[h]chromenes 5a and 6a showed promising anti-cancer activity and selected for the five-dose testing. Compounds 5a and 6a suppressed cell growth in HL-60 by the induction of cell cycle arrest, which was confirmed using flow cytometry and Annexin V-FITC/PI assays showed at the G1/S phase by regulating the expression of CDK-2/CyclinD1, triggering cell apoptosis by activating both the extrinsic (Fas/Caspase 8) and intrinsic (Bcl-2/Caspase 3) apoptosis pathways, which were determined by the western blot. Benzo[h]chromenes 5a and 6a decreased the protein expression levels of Bcl-2, CDK-2, and CyclinD1 and increased the expression of caspase 3, caspase 8, and Fas. In silico molecular analysis of compounds 5a and 6a in CDK-2 and Bcl-2 was performed.

Niclosamide Inhibits Proliferation of Leukemia Cells and Synergizes with Chemotherapy

There have been significant advances in the treatment of acute childhood leukemia, which accounts for 25% of all childhood cancer cases. The 5-year survival rate for children with acute lymphoblastic leukemia (ALL) is 90%; however, there are few therapies available for relapsed disease. Pediatric acute myeloid leukemia (AML) has a 5-year survival rate of 65%, but current treatments are associated with significant morbidity and mortality. Less toxic and more effective therapies are needed to improve outcomes for patients with acute childhood leukemia. We previously showed that the cAMP-responsive element binding protein (CREB) plays an important role in leukemia cell proliferation and is overexpressed in blast cells from both ALL and AML patients. Niclosamide, an FDA-approved oral drug that has been used for decades to safely treat tapeworm infections, suppresses AML cell proliferation through inhibition of CREB activation and oxidative phosphorylation (Chae, et al. 2016). As a result of our preclinical studies, a Phase I clinical trial with niclosamide and cytarabine for relapsed/refractory pediatric AML is in progress. The effects of niclosamide in ALL cells or mechanisms of resistance to niclosamide have not been previously studied. The purpose of this study was to determine the antileukemic effects of niclosamide in ALL and to investigate additional synergistic effects of niclosamide in combination with drugs that are known to be effective against ALL or AML. To determine the effects of niclosamide on ALL proliferation, we treated two human B-ALL cell lines, Nalm6 and REH, and two human T-ALL cell lines, Jurkat and Loucy, with niclosamide alone or in combination with vincristine. Cells (2x104) were treated with 0.01-10µM niclosamide or 0.1% DMSO control. After 72 hours, CellTiter-Glo assays were performed to assess the concentration of drug that inhibited cell viability by 50% (IC50). The IC50 values for Nalm6 and REH were 0.45±0.13µM and 0.51±0.11µM, respectively (n=3). IC50 values for Jurkat and Loucy were 0.21±0.30µM and 0.58±0.11µM, respectively (n=3). Next, we investigated the potential synergistic effects between niclosamide and the chemotherapy drug, vincristine. The combination index (CI) values were calculated using the CompuSyn software (Chou-Talalay method). Simultaneous treatment of Nalm6 cells (ED75, 0.547; ED90, 0.316; ED95, 0.219; n=3) and Jurkat cells (ED75, 0.790; ED90, 0.686; ED95, 0.625; n=3) with niclosamide and vincristine had synergistic effects on cellular viability, indicating activity against both B-ALL and T-ALL. To study potential mechanisms of resistance to niclosamide, we performed a CRISPR/Cas9 library screen with HL60 human AML cells. Downregulation of BCL-2, an anti-apoptotic gene, sensitized cells to niclosamide treatment. Therefore, we investigated the effects of combining niclosamide with the BCL-2 inhibitor venetoclax in human AML cell lines, HL60 and U937, and in primary AML cells. CI values indicated synergy between niclosamide and venetoclax in HL60 cells (ED75, 0.251; ED90, 0.103; ED95, 0.063; n=5), U937 cells (ED75, 0.628; ED90, 0.614; ED95, 0.614; n=3), and patient sample 186 (ED75, 0.226; ED90, 0.301; ED95, 0.383; n=3). To investigate the effects of pretreatment with niclosamide, HL60 cells were cultured with niclosamide or vehicle for 3 days, followed by venetoclax for 3 days. Pretreatment with 300nM niclosamide significantly decreased the IC50 of venetoclax from 17.7±4.5nM to 1.87±0.46nM (n=3, p<0.05), indicating that niclosamide pretreatment sensitized HL60 cells to venetoclax. Our study established that both B-ALL and T-ALL cells are sensitive to niclosamide. Furthermore, niclosamide has synergistic effects when combined with standard chemotherapeutic agents such as vincristine and venetoclax. Our results demonstrate that niclosamide is a promising therapeutic agent for both AML and ALL and should be considered in future clinical trials.

Antiproliferative Activity and Apoptotic Potential of Curcumin on Human Acute Myeloid Leukemia Cell Line (HL-60)

Curcuma Longa or also known as turmeric is a prominent natural remedy in Asia that has been utilized to heal diseases for decades. It has been demonstrated to have substantial biological activities, including anticarcinogenic, antimutagenic, antioxidant, anti-inflammatory, anti-infectious, hypocholesterolemic, and chemopreventive properties. Curcumin is a therapeutic substance extracted from Curcuma Longa that is thought to have anti-cancer properties against a variety of cancer types. However, its anti-cancer potential on acute myeloid leukemia (AML) remains uncertain [1,2]. &#x0D; &#x0D; The objective of this intervention study was to examine the anti-proliferative and apoptotic effects of curcumin on the HL-60 cell line of acute myeloid leukemia. A stock solution of pure curcumin compound was obtained by dissolving it in dimethyl sulfide (DMSO). HL-60 cells were treated with six different concentrations which were 100, 50, 25, 12.5, 6.25, 3.125 µg/ml and incubated at three distinct incubation period (24, 48 and 72 hours). The in vitro cell viability was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and quantified using a microplate reader at 570 nm. Acridine orange (AO) and propidium iodide (PI) staining were employed to evaluate morphological changes. &#x0D; &#x0D; MTT assays results show that curcumin has a high cytotoxicity effect on HL-60 cells. The maximal half inhibitory concentration (IC50) value of curcumin was consistently decreased when the incubation time increased. The IC50 of curcumin on HL-60 cells were reported to be 13, 8, and 3.5 µg/ml at 24, 48 and 72 hours of incubation, respectively. There was a significantly different IC50 value (p&lt;0.05) of curcumin between the incubation periods (Figure 1). The morphological alteration was shown in AO/PI staining by the appearance of early apoptosis, late apoptosis, and necrotic cells.&#x0D; These findings illustrated that curcumin revealed an effective anti-cancer action on human acute myeloid leukemia HL-60 cell line. Further research is required to determine the mechanism of cell death in HL-60 cells treated with pure curcumin compound.&#x0D; &#x0D; In conclusion, the study revealed the role of putative targeted genes in the biological mechanism in gout pathogenesis has provides insight of the potential biomarkers in developing the personalized medicine better treatment for gout patient in ensuring better patient healthcare.

LncRNA-PAX8-AS1 Silencing Decreases Cell Viability, Enhances Apoptosis, and Suppresses Doxorubicin Resistance in Myeloid Leukemia via the miR-378g/ERBB2 Axis.

Objective Considering the role of lncRNAs reported as regulators in acute myeloid leukemia (AML) progression, the current research aims to investigate the role of PAX8-AS1 in chemo-resistant AML. Methods Human AML cells HL60 and human doxorubicin (ADM)-resistant AML cells (HL60/ADM cells) were used to establish in vitro models of chemo-sensitive AML and refractory/recurrent AML, respectively. CCK-8 assay and flow cytometry were used to determine cell resistance to ADM, viability, and apoptosis. PAX8-AS1, miR-378g, and ERBB2 expressions in the models and/or AML patients were quantified via qRT-PCR or Western blot. The miRNA/mRNA axis targeted by PAX8-AS1 was analyzed using Starbase, TargetScan, or GEO and validated through a dual-luciferase reporter assay. The expressions of Bcl-2, Bax, and C Caspase-3 in cells were quantitated by Western blot. Results The highly expressed PAX8-AS1 was observed in AML patients and HL60 cells, which was more evident in refractory/recurrent AML patients and HL60/ADM cells. Compared with that in ADM-treated parental HL60 cells, the viability of ADM-treated HL60/ADM cells remained strong. PAX8-AS1 overexpression increased viability and Bcl-2 expression, while diminishing apoptosis, Bax, and C Caspase-3 expressions in HL60 cells. However, the abovementioned aspects were oppositely impacted by PAX8-AS1 silencing in HL60/ADM cells. PAX8-AS1 directly targeted miR-378g, whose expression pattern is opposite to that of PAX8-AS1 in AML. MiR-378g upregulation abrogated the effects of PAX8-AS1 overexpression on HL60 cells. MiR-378g downregulation offset PAX8-AS1 silencing-induced effects on HL60/ADM cells. Moreover, ERBB2 was recognized as the target of miR-378g, with a higher expression in HL60/ADM cells than in HL60 cells. Conclusion PAX8-AS1 silencing decreases cell viability, enhances apoptosis, and suppresses ADM resistance in AML via regulating the miR-378g/ERBB2 axis.

Mining of transcriptome identifies CD109 and LRP12 as possible biomarkers and deregulation mechanism of T cell receptor pathway in Acute Myeloid Leukemia

Acute Myeloid Leukemia (AML) is a heterogeneous disease with highest mortality compared to other types of leukemia. There is a need to find the gene abnormalities and mechanisms behind them due to their heterogenic nature. The present study is aimed to understand genes, pathways and biomarker proteins influenced by transcriptomic deregulation due to AML. Differentially expressed gene (DEG), protein-protein interaction network, gene ontology, KEGG pathway, variant analysis and secretome analyses were performed using different AML RNAseq datasets. A total of 655 DEGs including 291 up-regulated and 364 down-regulated genes, which were satisfied with a fold change of 1.5 were identified. Top hub genes for AML were identified as TP53, PTPRC and AKT1. This integrative bioinformatics approach revealed the deregulation of T Cell Receptor (TCR) pathway and altered immune response related genes. The survival analysis revealed the associated deregulation of multiple TCR pathway related genes. Variant analysis identified the benign and likely benign nature of many important target genes and markers screened, which were found to have an important role in the progression of AML. DEGs and secretome analysis found out a set of seven molecules represents potential biomarkers for AML. In vitro analytical validation showed overexpression pattern of CD109 and LRP12 in AML cell line and HL-60 cells than the normal human bone marrow-derived stromal cell line HS-5. Here we report first time for CD109 and LRP12 as a possible biomarkers for the diagnostic significance. Amino acid substitutions detected by variant analysis and deregulation of immune checkpoint molecules revealed their role in reducing immune response and inability to fight cancer cells. In conclusion, this study highlights the possibility of new biomarkers for AML and the mechanism of decrease in immune response due to the downregulation of co-stimulatory immune molecules, which needs further clinical validation investigations.

Targeting acute myeloid cell surface using a recombinant antibody isolated from whole-cell biopanning of a phage display human scFv antibody library.

To discover new therapeutic antibodies for treatment of acute myeloid leukemia (AML) without the requirement of a known antigen, a human single-chain variable fragment (scFv) library was used to isolate novel antibody fragments recognizing HL-60 AML cells. After three rounds of biopanning, scFv-expressing phages were selected to test for binding to the target cell by flow cytometry. The clone with highest binding specificity to HL-60 cells (designated y1HL63D6) was further investigated. Fluorescent staining indicated that y1HL63D6 scFv bound to a target located on the cell surface. Whole immunoglobulin, IgG-y1HL63D6 was then generated and tested for the binding against bone marrow mononuclear cells (BMMCs) from AML patients. Significantly higher fluorescent signals were observed for some patient samples when compared to normal BMMCs or non-AML patients' BMMCs. Next, the IgG-y1HL63D6 format was tested for antibody-dependent cell cytotoxicity (ADCC). The results demonstrated that IgG-y1HL63D6 but not the control antibody, trastuzumab, could mediate specific killing of HL-60 target cells. In conclusion, our results indicate that specific antibodies can be isolated by biopanning whole cells with a non-immunized human scFv antibody phage display library and that the isolated antibody against HL-60 cells showed therapeutic potential.

Quercetin induces autophagy-associated death in HL-60 cells through CaMKKβ/AMPK/mTOR signal pathway.

Acute myeloid leukemia (AML) is one of the most common malignancies of the hematopoietic progenitor cell in adults. Quercetin has gained recognition over the years because of its anti-cancer effect with minimal toxicity. Herein, we aim to investigate the anti-leukemia mechanism of quercetin and to decipher the signaling pathway of quercetin in HL-60 leukemic cells. We observed that quercetin induces apoptosis and autophagic cell death, in which both pathways play an important role in suppressing the viability of leukemia cells. Phosphorylated AMPK (p-AMPK) protein expressions are lower in primary AML cells, HL-60 cells, KG-1 and THP-1 cells than in peripheral blood monocular cells. After quercetin treatment, the expression of p-AMPK is increased while the expression of p-mTOR is decreased in a dose-dependent manner. Mechanistically, compound C, an AMPK phosphorylation inhibitor, upregulates the phosphorylation of mTOR and inhibits autophagy and apoptosis in quercetin-induced HL-60 cells, while silencing of CaMKKβ inhibits the quercetin-induced phosphorylation of AMPK, resulting in increased mTOR phosphorylation. Furthermore, silencing of CaMKKβ inhibits the autophagy in HL-60 cells. Taken together, our data delineate that quercetin plays its anti-leukemia role by inhibiting cell viability and inducing apoptosis and autophagy in leukemia cells. Quercetin inhibits the phosphorylation of mTOR by regulating the activity of AMPK, thus playing a role in the regulation of autophagy and apoptosis. CaMKKβ is a potential upstream molecule for AMPK/mTOR signaling pathway, through which quercetin induces autophagy in HL-60 cells.

Gallium (III) Complexes with 5-Bromosalicylaldehyde Benzoylhydrazones: In Silico Studies and In Vitro Cytotoxic Activity.

Gallium (III) complexes with the ligands 5-bromosalicylaldehyde-4-hydroxybenzoylhydrazone and 5-bromosalicylaldehyde isonicotinoylhydrazone were synthesized to receive compounds with improved antiproliferative action. Compounds were characterized by elemental analysis, IR, and NMR spectroscopy. Density functional theory calculations with Becke’s 3-parameter hybrid functional and 6-31+G(d,p) basis set were carried out to investigate the structural features of the ligands and Ga(III) complexes. Cytotoxic screening by MTT-dye reduction assay was carried out using cisplatin and melphalan as reference cytotoxic agents. A general formula [Ga(HL)2]NO3 for the complexes obtained was suggested. The complexes are mononuclear with the Ga(III) ions being surrounded by two ligands. The ligands acted as monoanionic tridentate (ONO) donor molecules. The analysis revealed coordination binding through deprotonated phenolic-oxygen, azomethine-nitrogen, and amide-oxygen atoms. The bioassay demonstrated that all compounds exhibited concentration-dependent antiproliferative activity at low micromolar concentrations against the acute myeloid leukemia HL-60 and T-cell leukemia SKW-3 cell lines. IC50 values of 5-bromo-derivative ligands and gallium (III) complexes are lower than those of cisplatin and much lower than these of melphalan. The coordination to gallium (III) additionally increased the cytotoxicity compared to the metal-free hydrazones.

Effect of Hypoxia on CD47 Expression in Human Acute Myeloid Leukemia Cell Lines

To investigate the effect of hypoxia on hypoxia-inducible factor 1α (HIF-1α) and CD47 expression in human acute myeloid leukemia (AML) cell lines. The CD47 expression in AML U937, HL-60, and K562 cells lines were detected by flow cytometry. U937, HL-60, and K562 cells were all divided into hypoxia-treated group and conventional oxygen group. The hypoxia-treated group was cultured with 1% O2, while the conventional oxygen group was cultured with 20% O2, then the cells were collected after 24 hours. Real time PCR was used to examine the mRNA changes of CD47 gene. Western blot assay was applied to detect the protein expression of HIF-1α and CD47. The expression of CD47 in U937, HL-60, and K562 cells was 98% (98%±0.03%), 99% (99%±0.05%), and 75% (75%±0.11%), respectively. The real time PCR showed that the mRNA expression of CD47 in U937 and HL-60 cells were up-regulated in the hypoxia-treated group (P<0.05), while in K562 cells was not (P>0.05). Western blot result showed that the protein levels of HIF-1α and CD47 of U937, HL-60, and K562 cells in the hypoxia-treated group were increased compared with the conventional oxygen group (P<0.05). The hypoxia can up-regulate the expression of CD47 in acute myeloid leukemia cells, which may be related to HIF-1α.

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.

Dual Targeting of Anti-Apoptotic Proteins Enhances Chemosensitivity of the Acute Myeloid Leukemia Cells.

Acute myeloid leukemia (AML) is a type of blood cancer characterized by fast cellular proliferation. Myeloid cell leukemia-1 (Mcl-1) and survivin, as anti-apoptotic proteins, are involved in cancer growth and resistance to chemotherapy. The aim of this study was to examine the combination effect of Mcl-1 and survivin specific siRNAs on chemosensitivity of the human HL-60 AML cells. SiRNAs transfection was performed by using Lipofectamine™2000 reagent. The mRNA expression was analyzed by real-time quantitative PCR. The apoptosis analysis was measured by ELISA cell death assay. siRNAs markedly suppressed mRNA expression levels of Mcl-1 and survivin in a time-dependent manner, resulting in reduction of leukemic cell proliferation and enhanced spontaneous cell death. Surprisingly, Mcl-1 siRNA and survivin siRNA synergistically enhanced the cell toxic effects of etoposide. Furthermore, down-regulation of Mcl-1 and survivin significantly enhanced the apoptotic effect of etoposide. Our investigation suggests that suppression of Mcl-1 and survivin by siRNA can effectually inhibit cell growth and overcome chemoresistance of AML cells. Therefore siRNAs may be an important adjuvant in chemotherapy for AML patients.

Effects of SIDT2 on the miR-25/NOX4/HuR axis and SIRT3 mRNA stability lead to ROS-mediated TNF-α expression in hydroquinone-treated leukemia cells.

Our previous studies indicated that the benzene metabolite hydroquinone (HQ) evokes the ROS/p38 MAPK/protein phosphatase 2A/tristetraprolin axis, leading to increased TNF-α expression in human acute myeloid leukemia cell lines U937 and HL-60. In this study, we aimed to identify the upstream pathway involved in ROS-mediated TNF-α expression. HQ treatment increased SIDT2 expression, which subsequently decreased miR-25 and SIRT3 expression in U937 cells. Notably, miR-25 downregulation promoted SIDT2 expression in HQ-treated U937 cells. SIDT2 induced lysosomal degradation of SIRT3 mRNA, but inhibited miR-25 expression through a lysosome-independent pathway. MiR-25 inhibition reduced NOX4 mRNA turnover, resulting in increased NOX4 protein levels. NOX4 induces mitochondrial ROS production and HuR downregulation. Restoration of HuR expression increased SIRT3 expression, suggesting that NOX4-mediated HuR downregulation promotes SIDT2-mediated degradation of SIRT3 mRNA. Inhibition of NOX4 or SIRT3 overexpression abolished HQ-induced ROS production, thereby abolishing TNF-α upregulation. Overall, these results indicate that SIDT2 regulates the miR-25/NOX4/HuR axis and SIRT3 mRNA destabilization, leading to ROS-mediated TNF-α upregulation in HQ-treated U937 cells. HQ-induced increase in TNF-α expression in HL-60 cells was also mediated through a similar pathway.

Molecular Mechanism Investigation on Monomer Kaempferol of the Traditional Medicine Dingqing Tablet in Promoting Apoptosis of Acute Myeloid Leukemia HL-60 Cells.

The traditional medicine Dingqing Tablet produces effective efficacy in treating acute myeloid leukemia, but its specific mechanism remains to be investigated. Dingqing Tablet consists of Codonopsis, Indigo Naturalis, Cortex Moutan, Radix Notoginseng, Citrus Reticulata, and Eolite. The active components of Dingqing Tablets were screened by the TCMSP database. Meanwhile, the SwissTargetPrediction database was utilized to predict the corresponding targets. Relevant disease targets of acute myeloid leukemia were obtained from GeneCards. The obtained targets of Dingqing Tablets and genes of acute myeloid leukemia were used, and the overlapped genes were presented in the Venn diagram. A drug-component-target network was constructed via Cytoscape 3.6.0 software. Molecular docking methodology was also used with AutoDock Vina 1.1.2. Furthermore, the effects of kaempferol on the proliferation and apoptosis of HL-60 cells were identified using 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide (MTT), 5-Ethynyl-2′-deoxyuridine (EDU), flow cytometry, and TdT-mediated dUTP nick-end labeling (TUNEL) assays. The combination of kaempferol and AKT1 was verified using an immunoprecipitation (IP) experiment and the effects of Kaempferol on HL-60 cell apoptosis by western blot (WB) and qPCR. The key component kaempferol and the core target gene AKT1 were sorted out using a drug-component target network diagram. Molecular docking results revealed that the binding energy between kaempferol and AKT1 was lower than -5 kcal/mol. MTT and EDU assays indicated that kaempferol markedly inhibited the proliferation of HL-60 cells. Flow cytometry and TUNEL assays suggested that kaempferol substantially promoted HL-60 cell apoptosis. IP assay results testified that kaempferol could bind to AKT1, thereby reducing the level of P-AKT and promoting HL-60 cell apoptosis. The monomer kaempferol of Dingqing Tablet could promote apoptosis of HL-60 cells, and the mechanism might correlate with the combination of kaempferol and AKT1, reducing the level of P-AKT and promoting the expression of the apoptotic signaling pathway.

Decoding the Mechanism of Shen Qi Sha Bai Decoction in Treating Acute Myeloid Leukemia Based on Network Pharmacology and Molecular Docking

Traditional Chinese Medicine (TCM) has been shown to be efficacious in treating leukemia for thousands of years. It has been shown that Shen Qi Sha Bai Decoction (SQSBD) has been extensively used in the treatment of acute myeloid leukemia (AML). However, the mechanism of SQSBD in treating AML remains unclear. In this study, we employed network pharmacology to analyze the potential active components and elucidate molecular mechanism of SQSBD in treating AML. A total of 268 active components were identified from SQSBD, among which 9 key components (Quercetin, luteolin, kaempferol, licochalcone A, formononetin, wogonin, β-sitosterol, oroxylin A, naringenin, and baicalein) were hit by the 6 hub targets (CDK1, MAPK1, JUN, PCNA, HSB1, STAT3) associated with leukemia. Molecular docking showed that two core active components, quercetin and licochalcone A, exhibited the highest component-like properties (DL), and could bind well to CDK1 and MAPK1 protein. The experimental validation of these two components showed that quercetin inhibited cell growth through CDK1 dephosphorylation-mediated cell cycle arrest at G2/M phase in human AML U937 and HL60 cells, and licochalcone A induced cell differentiation in these leukemia cells via activation of MAPK1 and upregulation of CD11b. All these results indicate that SQSBD is effective in the treatment of AML, and quercetin and licochalcone A are the major candidate compounds for AML treatment.

Tyrosol, at the Concentration Found in Maltese Extra Virgin Olive Oil, Induces HL-60 Differentiation towards the Monocyte lineage

Tyrosol is a phenolic found in extra virgin olive oil (EVOO). In a Maltese monocultivar EVOO, it was present at a concentration of 9.23 ppm. The HL-60 acute myeloid leukaemia cell line, which can be differentiated to both monocytes and neutrophils, was exposed to tyrosol at this concentration and analysed for evidence of differentiation and effects of cytotoxicity. The polyphenol induced a 1.93-fold increase in cellular oxidative activity (p-value 0.044) and enhanced surface expression of CD11b and CD14. This indicates that tyrosol induces monocytic-like differentiation. An RNA-seq analysis confirmed the upregulation of monocyte genes and the loss of neutrophil genes concomitant with the bi-potential promyelocyte precursor moving down the monocytic pathway. A cell cycle analysis showed an accumulation of cells in the Sub G0/G1 phase following tyrosol exposure for 5 days, which coincided with an increase in apoptotic and necrotic markers. This indicates differentiation followed by cell death, unlike the positive monocyte differentiation control PMA. This selective cytotoxic effect following differentiation indicates therapeutic potential against leukaemia.

Modular Synthesis and Antiproliferative Activity of New Dihydro-1H-pyrazolo[1,3-b]pyridine Embelin Derivatives.

A set of new dihydro-1H-pyrazolo[1,3-b]pyridine and pyrazolo[1,3-b]pyridine embelin derivatives was synthesized through a multicomponent reaction from natural embelin, 3-substituted-5-aminopyrazoles and aldehydes. The synthesized compounds were evaluated against three hematologic tumor cell lines, HEL (acute erythroid leukemia), K-562 (chronic myeloid leukemia) and HL-60 (acute myeloid leukemia), and five breast cancer cell lines (SKBR3, MCF-7, MDA-MB-231, BT-549, HS-578T). The primate non-malignant kidney Vero cell line was used as the control of cytotoxicity. From the obtained results, some structure–activity relationships were outlined. Furthermore, in silico prediction of physicochemical properties and ADME parameters were determined for the derivatives with the best antiproliferative values.