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Purification of the crude ethanol extracts from leaves and stems of Psychotria cupularis (Mull.Arg.) Standl., Rubiaceae, resulted in the isolation of the known monoterpene indole alkaloids ophiorine B and lyalosidic and strictosidinic acids. The antileishmanial activity values found for the isolated compounds highlighted ophiorine B as the most active against Leishmania (Viannia) braziliensis (IC50 100.50 μg/ml or 196.1 μM) and Leishmania (Leishmania) amazonensis (IC50 3.69 μg/ml or 7.2 μM) with a selectivity index of 108.6 to the human acute monocytic leukemia THP-1 cells. To the best of our knowledge, this is the first time that antileishmanial β-carboline glucoalkaloids were isolated from the studied material plant, contributing to the pharmacological potential of the genus.

Kagocel® is used in Russia for the treatment of viral infections. In terms of its chemical structure, Kagocel® active ingredient is a copolymer of gossypol polyphenol and carboxymethylcellulose. The study investigated antiviral and cytokine-inducing activity of Kagocel®, as well as its toxic effects. The aim of the study was to investigate the effect of Kagoce ® active ingredient on the induction of expression of the innate immune system receptor genes (Toll-like receptors, TLR) in the THP-1 human acute monocytic leukemia cell line with different levels of differentiation. Materials and methods: the effect of Kagocel active ingredient was investigated at the concentrations of 0.2 and 2 mg/mL in the THP-1 human acute monocytic leukemia cell line with different levels of differentiation: non-differentiated monocytes, and monocytes differentiated into macrophage-like cells. Comparative analysis of the activity of TLR 2, 3, 4, 7, 8, 9 genes was carried out by quantitative RT-PCR. The study determined standard deviations of the levels of gene expression in the experimental cells (2deltaCq ± SD) relative to the expression in the control cells. Results: Kagocel active ingredient at the concentration of 0.2 mg/mL induced activation of TLR2 expression in THP-1 monocytes by 3.5 times, TLR3 by 2 times, TLR4 by 1.6 times, and at the concentration of 2 mg/mL also induced activation of TLR7 and TLR8 by 1.4 times, and TLR9 by 2 times. The levels of TLR2, TLR3, TLR9 induction were significantly higher in THP-1 monocytes partially differentiated into macrophage-like cells, and the highest stimulation level was observed for TLR2 (8 times). Conclusions: the results obtained characterise Kagocel® as a stimulator of TLR genes in the THP-1 cell line. The number of TLR genes induced in THP-1 monocytes was shown to increase with the increase in the product concentration. THP-1 monocyte differentiation into macrophage-like cells enhances susceptibility to Kagocel®. The positive regulation of TLR genes activity may account for antiviral and interferon-inducing properties of Kagocel®, and also suggests the possibility of expanding the use of the product for various immune-associated diseases.

A 7-year-old castrated male domestic shorthair cat was presented for evaluation of decreased appetite and respiratory signs. A CBC run on presentation revealed severe nonregenerative anemia, thrombocytopenia, and leukocytosis characterized by a prominent population of blasts, having morphologic features suggestive of a monocytic lineage. The cat tested positive for FIV, FeLV, Mycoplasma haemominutum, and only mild abnormalities were identified on the chemistry panel. Bone marrow biopsies were obtained to investigate the bicytopenia and the possibility of a hematopoietic neoplasm. Although the bone marrow aspirate was nondiagnostic, the core biopsy was markedly hypercellular with a population of blasts, largely replacing the normal hematopoietic tissue. Immunohistochemical staining revealed that the blasts were CD3-negative, Pax5-negative, dimly CD18-positive, and moderately positive for Iba1. These findings, in addition to the prominent monocytic differentiation seen in peripheral blood, supported a diagnosis of acute monocytic leukemia. Palliative antiviral and antibiotic treatment and blood transfusion were performed. The patient was discharged on his fourth day of hospitalization. However, 15 days following discharge, the cat was euthanized due to the worsening of his systemic signs. This report discusses the classifications of myeloid leukemias, implications of infectious diseases in the pathogenesis of neoplasia in cats, and the use of Iba1, a "pan-monocytic/histiocytic" marker, in the diagnosis of acute leukemia.

Our previous research has shown that monocytic leukemia-associated antigen-34 (MLAA-34) was a novel antiapoptotic molecule with unique expression in acute monocytic leukemia (M5), making it an ideal target for T-cell-based immunotherapy. Here, we sought to identify HLA-A*0201-restricted cytotoxic T-lymphocyte (CTL) epitope of MLAA-34 by reverse immunology. In all, 10 HLA-A*0201 restricted epitopes of MLAA-34 were predicted by bioinformatics. MLAA-34324-332, MLAA-34293-301, and MLAA-34236-244 showed the strongest HLA-A*0201-binding affinity. The percentages of HLA-A*0201-MLAA-34236-244 tetramer+ CD8+ T cells in MLAA-34236-244-induced CTLs were raised apparently. Enzyme-linked immunospot showed that MLAA-34236-244 and MLAA-34324-332-specific CTLs produced a higher amount of interferon-γ. MLAA-34236-244-induced CTLs presented a stronger cytotoxic effect on THP-1 cells (HLA-A*0201+MLAA-34+) at various effector to target ratios. MLAA-34236-244 peptide vaccine could inhibit the tumor growth and improve mean survival time of leukemia-bearing human peripheral blood lymphocyte reconstituting severe combined immunodeficient mice. Mice immunized with MLAA-34236-244 vaccine had increased percentages of MLAA-34236-244 tetramer+ CD8+ T cells in the spleen after each round of immunization. High-purity CD8+ and CD4+ T cells were sorted by Dynabeads as effector cells. The killing activity of CD8+ T cells was higher than that of CD4+ T cells. CTLs derived from the MLAA-34 peptide vaccine group were significantly higher than other therapeutic groups and showed specific cytotoxicity to THP-1 cells. Increased interferon-γ and interleukin (IL)-2 and decreased IL-10 and IL-4 were seen in the MLAA-34236-244 peptide vaccine group. MLAA-34236-244 peptide (ILDRHNFAI) is an effective HLA-A*0201-restricted CTL epitope and that it may serve as a promising strategy in designing antigen-specific immunotherapy against MLAA-34-positive acute monocytic leukemia.

A 70-year-old Japanese man undergoing remission induction therapy for acute monocytic leukemia (AML-M5b) developed fever and headache, and was started on antibiotics and liposomal amphotericin B (L-AMB). There was no improvement, and computed tomography and contrast-enhanced magnetic resonance imaging revealed acute rhinosinusitis and brain abscess. Successful endoscopic endonasal surgery was performed at this point, providing drainage for the rhinosinusitis and abscess. Histopathological findings showed the mucormycosis.

Objective The prevalence of childhood asthma has been increasing in recent years. This study aims to investigate the involvement of the key molecules of IL-1 (interleukin-1) signaling pathways in pediatric patients with asthma. Methods Differentially expressed genes (DEGs) associated with IL-1 signaling pathways were identified with RNA-seq from peripheral blood samples collected from asthmatic or healthy children and were further verified in clinical peripheral blood samples. Cellular models and asthmatic mice were subsequently developed to validate the identified asthmatic markers. Results Among the DEGs identified by RNA-seq, eight signal transducers associated with the IL-1 signaling network, namely IL-1RN, IL-1β, IL-1RAP, IRAK3, IL-1R1, MYD88, IRAK2 and PELI1, were found to be substantially upregulated in children with asthma. Interestingly, a significant serially increased expression of four genes (IL-1RN, IL-1RAP, IRAK3 and PELI1) were observed in healthy subjects, patients with chronic persistent asthma and patients with acute exacerbation asthma. In particular, these four genes were continuously overexpressed in recurrent patients. A significant induction of the above four genes was then observed in house dust mite (HDM)-stimulated peripheral blood mononuclear cells (PBMCs) and ovalbumin (OVA)-induced asthmatic mice. In addition, a time-dependent induction of IL-1RAP and PELI1 was also detected in HDM-treated THP-1 cells, an acute monocytic leukemia cell line. Conclusions These results demonstrate that IL-1RN, IL-1RAP, IRAK3 and PELI1, which are signal transducers of the IL-1 signaling pathway, could serve as biomarkers for the pathogenesis of childhood asthma and for potential therapeutic targets of asthma.

Introduction Increasing evidence has demonstrated that plasmacytoid dendritic cells (PDCs) in the tumor microenvironment (TME) play an important role in tumorigenesis and progression. PDC infiltration has been found in certain malignancies such as classic Hodgkin's lymphoma and chronic myelomonocytic leukemia. Our previous work reported that PDC infiltration could occur in acute myeloid leukemia (AML), but the clinical significance of PDC in AML has not been thoroughly investigated. Patients and methods Here, we evaluated the clinical significance of PDC to AML transition in a leukemia microenvironment. The frequency of PDCs in 80 acute myelomonocytic leukemia (AML-M4) and 83 acute monocytic leukemia (AML-M5) patients was determined by flow cytometry. Results We found 62 cases with PDC infiltration. These patients showed higher numbers of bone marrow blasts, higher mean Hb concentration, and required more cycles of chemotherapy before achieving complete remission (CR), but had lower white blood cell and platelet counts compared to patients without PDC infiltration. Drug sensitivity analysis showed that patients with PDC infiltration had lower sensitivity to standard chemotherapy regimens. Kaplan-Meier survival curves demonstrated that patients with PDC infiltration had a shorter overall survival (OS) time and progression-free survival time. Discussion These results suggested that PDC infiltration can be used for risk stratification of AML-M4/M5, and PDCs may transdifferentiate into leukemia in an AML microenvironment.

Background/aim Anticancer peptide PNC-27 binds to HDM-2 protein on cancer cell membranes inducing the formation of cytotoxic transmembrane pores. Herein, we investigated HDM-2 membrane expression and the effect of PNC-27 treatment on human non-stem cell acute myelogenous leukemia cell lines: U937, acute monocytic leukemia; OCI-AML3, acute myelomonocytic leukemia and HL60, acute promyelocytic leukemia. Materials and methods We measured cell surface membrane expression of HDM-2 using flow cytometry. Cell viability was assessed using MTT assay while direct cytotoxicity was measured by lactate dehydrogenase (LDH) release and induction of apoptotic markers annexin V and caspase-3. Results HDM-2 is expressed at high levels in membranes of U937, OCI-AML3 and HL-60 cells. PNC-27 can bind to membrane HDM-2 to induce cell necrosis and LDH release within 4 h. Conclusion Targeting membrane HDM-2 can be a potential strategy to treat leukemia. PNC-27 targeting membrane HDM-2 demonstrated significant anti-leukemia activity in a variety of leukemic cell lines.

Acute myeloid leukemia (AML), which is characterized by an overproliferation of blood cells, is divided into several subtypes in adults and children. Of those subtypes, acute monocytic leukemia (M4/M5, AMoL) is reported to be associated with abnormal gene fusions that result in monocytic cell differentiation being blocked. However, few studies have shown a relationship between cellular metabolism and the initiation of AMoL. Here, we use the open-access database TCGA to analyze the expression of enzymes in the metabolic cycle and find that PFKFB4 is highly expressed in AMoL. Subsequently, knocking down PFKFB4 in THP-1 and U937 cells significantly inhibits cell growth and increases the sensitivity of cells to chemical drug-induced apoptosis. In line with the gene-editing alterations, treatment with a PFKFB4 inhibitor exhibits similar effects on THP-1 and U937 proliferation and apoptosis. In addition, we find that PFKFB4 functions as a reliable target of the epigenetic regulator MLL, which is a well-known modulator in AMoL. Mechanistically, MLL promotes PFKFB4 expression at the transcriptional level through the putative E2F6 binding site in the promoter of the pfkfb4 gene. Taken together, our results suggest PFKFB4 serves as a downstream target of MLL and functions as a potent therapeutic target in AMoL.

Chromosomal translocations and generating fusion genes are closely associated with disease initiation and progression in acute myeloid leukemia (AML). In this study, we identified a novel t(X;17)(q28;q21) chromosomal rearrangement in a patient with acute monocytic leukemia. Using RNA-sequencing, we identified a KANSL1-MTCP1 and a KANSL1-CMC4 fusion gene. 5'-UTR sequences of the KANSL1 gene were found to become fused upstream of the coding sequence region of the MTCP1 and CMC4 genes, respectively, resulting in an aberrantly high expression of these genes. Functional studies revealed that overexpression of the MTCP1 gene induced an increased cell proliferation and partial blockage of cell differentiation, suggesting that the aberrant expression of MTCP1 is of critical importance in leukemogenesis.

IntroductionSystemic mastocytosis (SM) with an associated hematological neoplasm (SM-AHN) constitutes about 40% of all patients with SM. AHN commonly includes myeloid neoplasms and chronic myelomonocytic leukemia (CMML) is seen in about 30% of these patients.Case reportA 67-year-old male presented to hematologist with fatigue and significant weight loss. Abdominal ultrasound and computed tomography (CT) detected hepatosplenomegaly, abdominal lymphadenopathy, and ascites. He was anemic with leukocytosis and eosinophilia. Trephine biopsy showed > 30% of spindle-shaped mast cells. The KITD816V mutation was present. Serum tryptase level was elevated to 62 ng/mL. The patient was diagnosed with aggressive SM and received six cycles of cladribine with partial response. Three years later, he developed severe anemia. Eosinophilia and monocytosis (5.6 × 109/L) were demonstrated in blood film. Hepatosplenomegaly and abdominal lymphadenopathy were also present. Trephine biopsy did not demonstrate the presence of spindle-shaped mast cells, but dysplasia in erythroid and myeloid lineages was evident. The histological result of lymph node biopsy as well as blood and bone marrow findings were in line with CMML. He received hydroxyurea, but he transformed soon into fatal acute monocytic leukemia.ConclusionsThe prognosis of SM-AHN depends on AHN component. Leukemic transformation of AHN component may occur in a proportion of patients.

The aim of this work was to assess the significance of investigating clinical and laboratory parameters for diagnosing acute monocytic leukemia in children on the basis of a clinical case. The article demonstrates specific features of differentiating AML M5a from other forms of acute myeloid leukemia. According to the results of hematological, morphological and cytofluorimetric studies of blood and bone marrow samples, the diagnosis of acute myeloid leukemia was established. The morphological and phenotypic characteristics of blast cells hampered the diagnosis of an AML form. However, a comprehensive analysis of the expressed CD antigens allowed acute monocytic leukemia to be identified, which diagnosis was subsequently confirmed by a cytochemical study. Thus, the clinical diagnosis was established over a short period of time. This was of importance given the rising severity of the patient’s condition requiring immediate treatment, the initial hyperleukocytosis and the development of life-threatening complications associated with leukostasis in the lungs and the central nervous system. In the presented case, the clinical manifestations of the underlying disease and the results of flow cytofluorimetry were determining factors in initiating timely specific therapy.

Hepatitis B virus (HBV) chronically infects approximately 350 million people worldwide, and 600 000 deaths are caused by HBV-related hepatic failure. Golgi protein 73 (GP73) is a serum biomarker for liver diseases, including chronic hepatitis B. Here, we determine the effect of HBV infection on GP73 production and characterized the role of GP73 in HBV replication. Initially, we show that GP73 is highly produced in the sera of HBV-positive patients with chronic liver diseases and in HBV-stimulated leukocytes. In addition, HBV stimulation promotes GP73 production in peripheral blood mononuclear cells isolated from healthy donors and in macrophages derived from human acute monocytic leukemia cells (THP-1). Notably, the hepatitis B surface antigen (HBsAg), but not HBV replication, is required for the activation of GP73 expression. Moreover, in HepG2 cells and Huh7 cells, GP73 facilitates HBV replication and represses nuclear factor kappa B p50 expression, which in turn represses HBV replication and GP73 expression. Finally, we demonstrate that GP73 facilitates HBV replication by repressing the innate immune response and the nuclear factor kappa B signaling pathway. Taken together, we revealed a distinct positive feedback mechanism between HBV replication and GP73 production and suggest that GP73 acts as a potential antiviral target for HBV infection.

Acute myeloid leukemia (AML) is a highly aggressive disease that causes high mortality. Long noncoding RNA (lncRNA) have studied in recent years that could be a potential biomarker and therapeutic target. Therefore, it is urgently necessary to explore the novel lncRNAs in AML. Microarray analysis was performed to determine the differentially expressed lncRNAs between mononuclear cells of AML and normal samples. The biological function of lncRNA on cell proliferation and migration was measured in vitro. The predicted downstream target of lncRNA was validated by dual-luciferase reporter assay, RNA immunoprecipitation, RNA pull-down, and rescue experiments. The tumor formation and metastasis study were conducted in vivo. The expression of lncRNA in clinical samples was determined by a quantitative reverse transcription-polymerase chain reaction. LINC00449 was one of the most differentially expressed lncRNA which is mainly located in the cytoplasm. We found that overexpression of LINC00449 could inhibit the cell proliferation and invasion of AML cells in vitro and in vivo. Besides, miR-150 was identified as the downstream target gene that was negatively regulated by LINC00449 and FOXD3 was targeted by miR-150. The results were confirmed by dual-luciferase reporter assay, RNA immunoprecipitation, RNA pull-down, rescue experiments, and in vivo assays. Patients with AML with high expression of LINC0049 may characterize a favorable survival. All the above-mentioned findings indicated that the LINC00449/miR-150/FOXD3 signaling pathway might represent a novel prognostic biomarker or therapeutic target for the treatment of AML.

The essential oil obtained from Melaleuca alternifolia (TTO) is recognized due to its antimicrobial properties. The TTO was purchased from the Romanian market, to be used in experiments regarding t...

Fat mass obesity-associated protein (FTO) is a DNA/RNA demethylase involved in the epigenetic regulation of various genes and is considered a therapeutic target for obesity, cancer, and neurological disorders. Here, we aimed to design novel FTO-selective inhibitors by merging fragments of previously reported FTO inhibitors. Among the synthesized analogues, compound 11b, which merges key fragments of Hz (3) and MA (4), inhibited FTO selectively over alkylation repair homologue 5 (ALKBH5), another DNA/RNA demethylase. Treatment of acute monocytic leukemia NOMO-1 cells with a prodrug of 11b decreased the viability of acute monocytic leukemia cells, increased the level of the FTO substrate N6-methyladenosine in mRNA, and induced upregulation of MYC and downregulation of RARA, which are FTO target genes. Thus, Hz (3)/MA (4) hybrid analogues represent an entry into a new class of FTO-selective inhibitors.

Chronic myelomonocytic leukosis (CMML) is rarely diagnosed and amounts to 1 per 100 thousand of adults per year, more often in men over 60 years. The clinical case of the rare, prolonged course of myelodysplastic chronic myelomonocytic leukosis (MD-CMML) in a middle-aged woman with rapid transformation into acute monocytic leukemia (AMoL-M5в) with the atypical fulminant course is presented. A retrospective analysis of the course of the disease drew attention to the severe vasculitis suffered by the patient 19 years ago, which could be regarded as the debut of CML in the presence of characteristic pathological changes in the hemogram. Non-pronounced clinical manifestations in the form of moderate cervical lymphadenopathy, skin lesions in the form of transient erythema, spotty eruptions over the next 10 years, fit into the clinical picture of MD-CMML. A detailed picture of the disease was observed after viral infection, bronchitis, antibiotic therapy. Absence of significant blastemia and severe inhibition of normal hematopoiesis with expressed extramedular manifestations of the disease in the patient were not typical for the course of AMoL-M5b in this case. The progression of skin lesions was noteworthy, which gave reason for unfavorable prognosis. For several weeks, the spread of erythematous elements was observed throughout the body with itching, not controlled by antihistamines and corticosteroid drugs; the appearance of maculopapular rashes, merging in places; small-point hemorrhages like vasculitis over the entire surface of the skin. Notable was the development of severe hemorrhagic syndrome without severe thrombocytopenia, significant changes in the coagulogram, as a manifestation of early severe coagulopathy.

Investigating the factors that influence the inflammatory response of microglial cells is crucial for understanding the pathogenesis of cryptococcal meningitis (CM). MicroRNAs (miRNAs/miRs) play an important role in inducing host defenses and activating the immune response during microbial infection; however, the regulatory mechanisms of miRNAs in cryptococcal meningitis remain poorly defined. In a previous study, the authors assessed the miRNA profiles of THP‑1 (human acute monocytic leukemia cells) cells following Cryptococcus neoformans (C. neoformans) infection. In the present study, it was found that miR‑4792 expression was downregulated in BV2 cells infected with C. neoformans, whilst that of its target gene, epidermal growth factor receptor (EGFR), was upregulated. Infected cells in which miR‑4792 was overexpressed exhibited a decreased EGFR transcript expression, reduced mitogen‑activated protein kinase (MAPK) signaling and a decreased secretion of inflammatory cytokines. In addition, following antifungal treatment in patients with cryptococcal meningitis, the levels of miR‑4792 in the cerebrospinal fluid significantly increased, whilst the expression of EGFR significantly decreased. In addition, receiver operator characteristic analysis revealed miR‑4792 (AUCROC=0.75) and EGFR (AUCROC=0.79) as potential diagnostic markers in patients with cryptococcal meningitis.

A previously healthy 8-month-old female infant presenting with lethargy and bilateral eye redness and cloudiness had bilateral hypopyon uveitis, which persisted despite topical steroids. Cytology of the anterior chamber and cerebrospinal fluid and flow cytometry of cerebrospinal fluid revealed malignant cells consistent with acute monocytic leukemia. Bone marrow aspirates and biopsies showed no evidence of disease. She was treated with systemic and intrathecal chemotherapy, with subsequent remission and resolution of pseudo-hypopyon. Anterior chamber involvement is a rare presentation of acute myeloid leukemia and may indicate concurrent central nervous system involvement. This has important therapeutic implications, because additional treatment modalities such as intrathecal chemotherapy, local chemotherapy, and ocular radiation may be required to overcome the “pharmacologic sanctuary” created by the blood–ocular barrier. [ J Pediatr Ophthalmol Strabismus . 2021;58(5):e30–e33.]

The ectopic overexpression of transient receptor potential vanilloid-1 (TRPV1) has been detected in numerous solid cancers including breast, prostate, pancreatic, and tongue epithelium cancer. However, the expression of TRPV1 in hematological malignancies remains unknown. Here we show through in silico analysis that elevated TRPV1 mRNA expression occurs in a range of hematological malignancies and present an optimized flow cytometry method to rapidly assess TRPV1 protein expression for both cell lines and primary patient samples. Three anti-TRPV1 antibodies were evaluated for intracellular TRPV1 detection using flow cytometry resulting in an optimized protocol for the evaluation of TRPV1 in hematological malignant cell lines and patients’ peripheral blood mononuclear cells (PBMC). Overexpression of TRPV1 was observed in THP-1 (acute monocytic leukemia) and U266B1 (multiple myeloma, MM), but not U937 (histiocytic lymphoma) compared to healthy PBMC. TRPV1 was also detected in all 49 patients (including B-cell non-Hodgkin’s lymphoma (B-NHL), MM and others, and 20 healthy controls. TRPV1 expression was increased in 8% of patients (MM=2, B-NHL=2). In conclusion, we provide an optimized flow cytometry method for routine expression analysis of clinical samples and show that TRPV1 is increased in 8% of patients with hematological malignancies.

Background Leukemia is a cancer of blood and bone marrow cells, causing about 300,000 deaths worldwide. Photodynamic therapy (PDT) is a promising alternative for the treatment of malignant tumors. KillerRed is a genetically encoded red fluorescent protein photosensitizer (PS). In this study, we aimed to investigate the effects of KillerRed-mediated PDT on chronic myelogenous leukemia K562 cells, acute monocytic leukemia NB4 cells, and acute monocytic leukemia THP1 cells. Methods KillerRed was expressed in Escherichia coli cells, purified by Q-Sepharose column, and confirmed by western-blotting. The PDT effect on cell proliferation was evaluated by Cell Counting Kit-8 (CCK-8). Cell apoptosis was determined by PE Annexin V/7-AAD staining and flow cytometry. The distribution of KillerRed in leukemia cells was detected by confocal laser scanning microscopy (CLSM) and western-blotting. The ROS generation was measured by flow cytometry. Results Pure KillerRed was obtained with a yield of about 37 mg per liter of bacterial cells. KillerRed photodynamic inactivated the leukemia cells in a concentration-dependent manner, but exhibited no obvious dark toxicity. PDT mediated by KillerRed could also induce apoptotic response (mainly early apoptosis) in the three cell lines. The CLSM imaging indicated that KillerRed was distributed within the cytoplasm and nuclei of leukemia cells, causing damages to the cytoplasm and leaving the nuclear envelope intact during light irradiation. KillerRed distributed both in the cytosol and nuclei was confirmed by western blotting, and ROS significantly increased in PDT treated cells compared to the cells treated with KillerRed alone. Conclusions Our studies demonstrated that KillerRed-mediated PDT could effectively inactivate K562, NB4, and THP1 leukemia cells and trigger cell apoptosis, and it has potential to be used individually or complementally, in the treatment of leukemia.

Leukemia is a malignant disease that originates in the bone marrow, local of blood cells production. Chemotherapy treatment is one of the alternatives to improve the survival of patients. In this context, the search for new compounds with potential cytotoxic action is justified. The present work evaluated the cytotoxic activity of 16 new synthetic analogs of 3-alkylpyridine alkaloids. The cytotoxic profiles were determined by MTT in vitro assay against THP-1 (acute monocytic leukemia), K562 (chronic myeloid leukemia) and PBMC (peripheral blood mononuclear) human cells. To investigate the mechanism of action, cell cycle analysis and alterations of TP53, p21, Bax, Bcl2, NOX-1, NOX-2, NOX-4 and p47-phox gene expressions were performed by qPCR, along with the measurement of reactive oxygen species (2’,7’-dichlorodihydrofluorescein diacetate and dihydroethidium). Compounds 4c, 5b, 5c and 6d were the most active and selective for THP-1 and compounds 7c and 11 were found to be more active for K562. All of this induced apoptosis in the tested strains. Concerning the investigation of the mechanism of action, it was observed that the pathway being activated is a p53-independent pathway. The data presented in this work indicate that 3-alkylpyridine alkaloid analogues are a potential class of compounds with cytotoxic action.

Background: We investigated the activation of N-acetylgalactosamine-transferase11 (GALNT11) and the role of cyclophosphamide and cytarabine in expression of this enzyme in AML and CML patients. Methods: GALNT11 activity and expression levels were evaluated in human chronic myelogenous leukemia cells (K562) and human acute monocytic leukemia cells (THP1) after incubation with different concentrations of cyclophosphamide (Cyclo) and cytarabine (Cyta). Anti-proliferative effects of Cyclo and Cyta were examined by MTT assay. Real time-PCR and ELISA assays were applied to investigate the expression and activity of GALNT11, respectively. Results: The IC50 values for Cyclo were 34.73±0.12 μM for K562 and 36.16±0.23 µM for THP1 cells. These valuses for Cyta were also 0.38±0.15 μM for K562 and 0.52±0.18 µM for THP1 cells . Conclusion: The activation and expression of GALNT11 increased in acute and chronic leukemia as glycosylation disorders. Also cyclophosphamide and specially cytarabine cause significant increase in activation and expression of GALNT11 which inhibits glycosylation and tumorogenesis dependent signaling pathway.

Background: Peniciketal A (Pe-A), a spiroketal compound, shows potent anticancer activities in human acute monocytic leukemia. However, the detailed mechanisms and potent targets of Pe-A remain largely unexplored. Here, we investigated the differentially expressed proteins between the Pe-A-treated group and the control group on human acute monocytic leukemia cell line THP-1. Methods: The DEPs were analyzed by the liquid chromatography-tandem mass spectrometry (LC-MS/MS) with TMT label. The function and feature of the identified proteins were analyzed by the bioinformatic analysis. Western blotting was used to evaluate protein expression. Results: The DEPs were primarily sub located in the cytoplasm and the nucleus by regulating 21 pathways enriched through the Kyoto Encyclopedia of Genes and Genomes (KEGG). Moreover, we preliminarily demonstrated that glucose-6-phosphate 1-dehydrogenase (G6PD), prolow-density lipoprotein receptor-related protein 1 (LRP1) and Calreticulin (CALR) might be the potent targets of Pe-A on death induction of THP-1 cells. Conclusion: Collectively, this study not only provides a global proteomic profile as the supplementary data of our previous studies but also provides interesting information that Pe-A may exert more bio-activities.

Behçet’s disease is a multi-systemic vasculitis which is characterized by recurrent oral and genital ulceration with positive pathergy test. These features may also be seen in various hematological malignancies. In patients with leukemia who present with Behçet’s disease-like features, it is often difficult to ascertain whether the clinical manifestations are due to leukemia, or there is co-existing Behçet’s disease too. The authors report an Indian farmer who presented with clinical features suggestive of Behçet’s disease with profound neutropenia. On bone marrow examination he was found to have acute monocytic leukemia (AML-M5). Chemotherapy for leukemia did not relieve his oral and genital ulcers, for which glucocorticoids and colchicine had to be given. So the patient had co-existence of Behçet’s disease along with AML-M5, which has never been reported in the literature before.

Aim This study aimed to investigate the in vitro alterations of the expression of signal regulatory protein‐α (SIRP‐α) and CD36 in macrophages in the endometriosis condition. Methods The expression of SIRP‐α and CD36 was measured in peritoneal macrophages and peripheral blood mononuclear cells of endometriosis patients and control participants. The expressions of SIRP‐α and CD36 were measured in human acute monocytic leukemia (THP‐1) cell‐derived macrophages that were treated with interleukin‐6 (IL‐6)‐induced conditioned medium, eutopic versus normal endometrial homogenate, or lipopolysaccharide in the presence or absence of nuclear factor kappa‐B (NF‐κB) or transforming growth factor (TGF‐β) inhibitors, respectively. Results Peritoneal macrophages that were isolated from women with endometriosis exhibited an enhanced expression of SIRP‐α and a decreased expression of CD36 compared to control participants. Women with endometriosis had significantly higher levels of SIRP‐α and CD36 in peripheral circulating mononuclear cells than in control participants. SIRP‐α expression was significantly increased, whereas the CD36 expression was decreased in THP‐1 cell‐derived macrophages after treatment with eutopic endometrial homogenate. Intervention with IL‐6‐induced conditioned medium resulted in the downregulation of SIRP‐α but the upregulation of CD36 in THP‐1 cells. Incubation with the NF‐κBp50 inhibitor decreased the expression of CD36 and SIRP‐α in macrophages that were treated with normal endometrial homogenate, whereas the TGF‐β inhibitor enhanced the CD36 expression of THP‐1 cell‐derived macrophages treated with eutopic endometrial homogenate. Conclusion The eutopic endometrium could reduce the phagocytic ability of peritoneal macrophages in women with endometriosis through the modulation of SIRP‐α and CD36 expression. Inhibition of the TGF‐β signal pathway may be a potential therapeutic target for the treatment of endometriosis.

Leukemia cutis (LC) is a rare disorder that is distinguished by the infiltration of leukemic cells into the skin. This can be a manifestation of relapse of the previously treated leukemia. We report a case of a 70-year-old woman with acute monocytic leukemia (AMOL), whose disease relapsed and developed into LC after a successful induction therapy. Salvage chemotherapy has been applied successfully to prevent the development of LC in the patient's skin.

As the typical tyrosine kinase inhibitor, imatinib has been the first-line antineoplastic agent for both chronic myeloid leukemia and acute lymphoblastic leukemia. However, a large number of patients are still resistant to the benefits of imatinib, and they have a dissatisfactory prognosis. Salidroside, a compound that is extracted from natural plants, has been reported to have an excellent anticancer effect and few side effects. In the present study, we have developed a new combination therapy strategy of salidroside and imatinib for combating the growth of acute lymphoblastic leukemia. As demonstrated by the anti-proliferation assay, salidroside exhibited excellent cytotoxicity against myeloid leukemia cells. Moreover, cells treated by the combination therapy of salidroside and imatinib displayed a clear lower growth rate than cells only treated by imatinib, indicating that salidroside has a positive effect on enhancing the cytotoxicity of imatinib against leukemia cells. Subsequently, the underlying mechanisms were investigated. The results revealed that autophagy marker proteins in leukemia cells, including LC3, p62, and Beclin1, displayed a significant expression change after treating them with salidroside plus imatinib, with the levels of LC3 and Beclin1 dramatically increasing while the expression of p62 was significantly decreased. Moreover, an obvious down-regulation of p-PI3K, p-AKT and p-mTOR expression levels in leukemia cells after treatment with salidroside plus imatinib suggested that the PI3K/mTOR pathway plays an important role in the process of cell apoptosis induced by salidroside or imatinib. Further studies showed that pre-incubating the cells with an autophagy inhibitor dramatically inhibited the ability of imatinib to induce autophagy, but did not inhibit the ability of salidroside. The underlying causes were subsequently explored and the results showed that silencing AMPKα1, the most important regulator of autophagy, dramatically attenuates the ability of salidroside to induce cell apoptosis. These results together indicated that salidroside enhances the cytotoxicity of imatinib on acute monocytic leukemia via the induction of autophagy-related apoptosis through AMPK activation. The unique advantages of combination therapy were further confirmed by in vivo experiments, with the tumor-bearing cells treated with salidroside plus imatinib achieving the best anti-tumor effect.

Based on previous investigations where bis-bibenzyls isolated from liverworts showed various biological activities (cytotoxic, antimicrobial, and antiviral), we investigated their cytotoxic activity in several human cancer cell lines. From the methylene-chloride/methanol extract of the liverwort Pellia endiviifolia, three bis-bibenzyls of the perrottetin type were isolated, namely perrottetin E, 10′-hydroxyperrottetin E, and 10,10′-dihydroxyperrottetin E. The last two were found for the first time in this species. Their structures were resolved using 1D and 2D NMR, as well as by comparison with data in the literature. Cytotoxic activity of the isolated compounds was tested on three human leukemia cell lines, HL-60 (acute promyelocytic leukemia cells), U-937 (acute monocytic leukemia cells), and K-562 (human chronic myelogenous leukemia cells), as well as on human embryonal teratocarcinoma cell line (NT2/D1) and human glioblastoma cell lines A-172 and U-251, and compared to the previously isolated bis-bibenzyls (perrottetins) of similar structure. The isolated compounds exhibited modest activity against leukemia cells and significant activity against NT2/D1 and A-172. Overall, the most active cytotoxic compounds in this investigation were perrottetin E (1), isolated in this work from Pellia endiviifolia, and perrottetin F phenanthrene derivative (7), previously isolated from Lunularia cruciata and added for a comparison of their cytotoxic activity.

Cytotoxicity and apoptosis-inducing properties of compounds isolated from Garcinia subelliptica leaves were investigated. The hexane-soluble portion of MeOH extracts of G. subelliptica leaves that showed cytotoxic activity was separated to yield seven compounds 1−7. Chemical structure analysis using NMR spectroscopy and mass spectrometry confirmed that compound 1 was canophyllol, and compounds 2–7 were garcinielliptones N, O, J, G, F, and garcinielliptin oxide, respectively. Among them, garcinielliptone G (5) showed growth inhibition by causing apoptosis in THP-1 and Jurkat cells derived from human acute monocytic leukemia and T lymphocyte cells, respectively. Apoptosis induced by garcinielliptone G (5) was demonstrated by the detection of early apoptotic cells with fluorescein-labeled Annexin V and increases in cleaved caspase-3 and cleaved PARP protein levels. However, the addition of caspase inhibitor Z-VAD-FMK did not affect growth arrest or apoptosis induction. These results suggest that garcinielliptone G (5) can induce both caspase-3 activation and caspase-independent apoptosis. Therefore, garcinielliptone G (5) may be a potential candidate for acute leukemia treatment.

Solasonine, the main active ingredient of Solanum nigrum L., has been reported to exert extensive antitumor activity. However, the antitumor effects in acute monocytic leukemia and the exact mechanisms involved are unknown. In this study, we investigated the role of solasonine on inhibiting the progression of acute monocytic leukemia. Our findings showed that solasonine inhibited the proliferation of acute monocytic leukemic cell lines (THP-1 and MV4-11) in vitro. Solasonine promoted apoptosis and induced cell cycle arrest in the G2/M phase. Analysis of RNA-seq data suggested that solasonine correlated with increased expression of genes in the AMPK/FOXO3A pathway. Inhibition of AMPK with compound C followed by treatment with solasonine showed that solasonine reduced apoptosis, caused less cell cycle arrest, and inactivated the AMPK/FOXO3A axis in THP-1 and MV4-11 cells. Solasonine also inhibited tumor growth by the activation of the AMPK/FOXO3A axis. In conclusion, solasonine inhibited the progress of acute monocytic leukemia in vitro and in vivo and triggered the apoptosis and cell cycle arrest in the G2/M phase by upregulating the AMPK/FOXO3A pathway.

The activation of chimeric antigen receptor (CAR)-T cells can lead to persistently high levels of programmed cell death 1 (PD-1) antigen and eventually causes the exhaustion of T cells. The effectiveness of CAR-T cells targeting C-type lectin-like molecule-1 (CLL-1) combined with PD-1 silencing therapy for acute myeloid leukemia (AML) was evaluated in the present study. CLL-1 levels in primary AML bone marrow samples was examined using flow cytometric analysis. We designed a CLL-1 CAR-T, containing CLL-1-specific single-chain variable fragment, CD28, OX40, CD8 hinge and TM and CD3-ζ signaling domains. CLL-1 CAR-T with PD-1 silencing was constructed. It was confirmed that CLL-1 is expressed on the surface of AML cells. CLL-1 CAR-T showed specific lysing activity against CLL-1+ AML cells. PD-1 silencing enhanced the killing ability of CLL-1 CAR-T. Furthermore, it was found that CAR-T derived from healthy donor T cells was more effective in killing THP-1 cells (a human acute monocytic leukemia cell line) than those from patient-derived T cells. These results indicated that CLL-1 CAR-T and PD-1 knockdown CLL-1 CAR-T could be used as a potential immunotherapy to treat relapsed or refractory AML.

Background: Enhancer of zeste homolog 2 (EZH2) is a histone methyltransferase and a catalytic subunit of the polycomb repressive complex 2 (PRC2) that catalyzes the mono-, di-, and tri-methylation of histone H3 at Lys 27 (H3K27me3) to facilitate chromatin remodeling and gene silencing functions. The overexpression of EZH2 is associated with high levels of H3K27me3 in various types of cancers. Previous reports showed a significant association of EZH2 aberrations in pediatric cancers such as soft tissue sarcomas and glioblastoma. Recent reports in human subjects and animal models have also suggested a central role of EZH2 in the induction and progression of acute myeloid leukemia. Methods: In this study, we aimed to investigate the molecular status of EZH in cell lines derived from distinct pediatric leukemia to assess the efficacy of targeting EZH2 to suppress cancer cell survival and proliferation. Cell cytotoxicity and the half maximal inhibitory concentration (IC50) were measured by Alamar blue cytotoxicity assay. The molecular status of EZH2 was profiled by DNA sequencing and western blot analysis of EZH2 protein levels in THP-1, SEM, and MV4:11. In addition, Methylation of histone H3 was evaluated by immunoblotting and immunostaining analyses. Results: Our results showed that EZH2 protein is overexpressed in the pediatric monocytic cell line THP-1 , but not in other leukemia derived cell lines MV4;11 and SEM. Screening a panel of methyltransferase inhibitors revealed that three inhibitors; GSK126, UNC1999 and EPZ-5687 are the most potent inhibitors that suppressed EZH2 activity selectively on lysine 27 which resulted in increased apoptosis and inhibition of AKT and ERK protein phosphorylation in THP-1 cells. Our data demonstrated a significant increase in apoptosis in cells treated with drug combination (EZH2i and selinexor) compared to EZH2i inhibitors alone. Conclusions: Taken together, our data provide initial evidence that targeting EZH2 is a promising therapeutic strategy for the treatment of subtypes of pediatric AML. Also, combining EZH2 inhibitors with selinexor may increase the treatment efficacy in these patients. Findings from this study indicate further evaluation and consideration of these compounds for early phase clinical studies in selected pediatric malignancies in the future.

Acutemonocytic leukemia (AMoL) is a distinct subtype of acute myeloid leukemia (AML) with poor prognosis. However, the molecular mechanisms and key regulators involved in the global regulation of gene expression levels in AMoL are poorly understood. In order to elucidate the role of microRNAs (miRNAs/miRs) and transcription factors (TFs) in AMoL pathogenesis at the network level, miRNA and TF expression level profiles were systematically analyzed by miRNA sequencing and TF array, respectively; this identified 285 differentially expressed miRNAs and 139 differentially expressed TFs in AMoL samples compared with controls. By combining expression level profile data and bioinformatics tools available for predicting TF and miRNA targets, a comprehensive AMoL-specific miRNA-TF-mediated regulatory network was constructed. A total of 26 miRNAs and 23 TFs were identified as hub nodes in the network. Among these hubs, miR-29b-3p, MYC, TP53 and NFKB1 were determined to be potential AMoL regulators, and were subsequently extracted to construct sub-networks. A hypothetical pathway model was also proposed for miR-29b-3p to reveal the potential co-regulatory mechanisms of miR-29b-3p, MYC, TP53 and NFKB1 in AMoL. The present study provided an effective approach to discover critical regulators via a comprehensive regulatory network in AMoL, in addition to enhancing understanding of the pathogenesis of this disease at the molecular level.

Acute myeloid leukemia (AML) is the fifth most common malignancy in children. Extramedullary involvement in acute myeloid leukemia is rare and can be seen in soft tissues, central nervous system, skin and lymphoreticular organs. The clinical presentations can often be non-specific and hence, the diagnosis can be very challenging, especially in cases without a prior hematologic diagnosis. We report a case of pediatric acute monocytic leukemia presenting with generalized lymphadenopathy and cutaneous rash. Fine-needle aspiration was performed from the lymph nodes and a cytologic diagnosis of infiltration by a lymphoreticular malignancy was suggested. Peripheral blood, bone marrow and cerebrospinal fluid involvement were noted subsequently. Flow cytometry on the bone marrow aspirate confirmed a diagnosis of acute monocytic leukemia. The index case besides highlighting an uncommon presentation of acute monocytic leukemia in a toddler, also emphasizes the need to consider acute monocytic leukemia as a cytomorphologic differential in such presentations.

Chinese tonic herbs are often used as remedies for the treatment of cancer or immunity related diseases. Cytokine regulation is one of the pathways that modulates the immune system. In the present study, we investigated the effects of commonly used Chinese herbs on cytokine regulation in human peripheral blood mononuclear cells (PBMC) and human acute monocytic leukemia cell line, THP-1. Among the 15 selected Chinese herbs, Paeonia lactiflora exhibited inhibitory effect on phytohemagglutinin (PHA)-activated PBMC proliferation and induced IFN-γ production. We also used a multiplexed flow cytometric bead-based assay to analyze the release of 17 cytokines and reverse transcription polymerase chain reaction (RT-PCR)/quantitative real-time PCR (qRT-PCR) to evaluate gene expression. Cuscuta chinensis induced both interleukin-8 and MIP-1β release in THP-1 cells and influenced mRNA transcription. Dioscorea opposita, Cinnamomum osmophloeum, and Glycyrrhiza uralensis enhanced secretion of granulocytemacrophage colony-stimulating factor (GM-CSF) and influenced GM-CSF gene expression. As such, different Chinese tonic herbs may regulate immunomodulatory functions in human cells via diverse processes such as the modulation of different cytokines and may be used as adjuvant immunity-boosting drugs. The present study is the first to use high-throughput multiplexed flow cytometric method to analyze cytokine regulatory effects of herbal extracts.

Background Acute myeloid leukemia (AML) with monocytic differentiation (M-AML) remains a diagnostic challenge largely due to lack of sensitive and specific markers for immature monocytes. The immunoglobulin-like inhibitory receptors, LILRB1 and LILRB4, are expressed on monocytes but have not yet been systematically evaluated in the clinical setting. Methods We evaluated the diagnostic performance of LILRB1 and LILRB4 as monocytic markers for both immature and mature monocytes in comparison to other myelomonocytic markers including CD14, CD15, CD33, CD36, and CD64 in eight cases of control bone marrow (BM, 5) and peripheral blood (PB, 3), 64 cases of (M-AML), and 57 cases of AML without monocytic differentiation (NM-AML) by flow cytometric immunophenotyping. Results In control BM, LILRB1 and LILRB4 were consistently expressed on monocytes at all stages of maturation, from CD34+ /CD14- monocytic precursors to CD14-/dim+ maturing and CD14+ mature monocytes. In M-AML, LILRB1 and LILRB4 were consistently expressed on monocytes, regardless of the degree of maturity, from CD14-/dim+ monoblasts/promonocytes to CD14+ mature monocytes but were not expressed on myeloblasts. The diagnostic performances as a monocytic marker assessed by sensitivity/specificity were 100%/100% for LILRB1/LILRB4, 100%/82% for CD11b, 80%/100% for CD14, 100%/81% for CD64, 100%/58% for CD15/CD33, and 89%/97% for CD36/CD64. Conclusion The co-expression of LILRB1/LILRB4 outperformed other myelomonocytic markers as a highly sensitive and specific marker for monocytes at all stages of maturation and could reliably distinguish M-AML from NM-AML. LILRB4 additionally represents a novel therapeutic target for treating M-AML.

Objetivo: Descrever um caso de um paciente pediátrico que apresentou linfo-histiocitose hemofagocítica (LHH) associada à leucemia monocítica aguda pós-quimioterapia, com hemofagocitose causada pelas próprias células leucêmicas. Descrição do caso: Em um hospital universitário do Sul do Brasil, uma menina de três anos foi diagnosticada com leucemia monocítica aguda com cariótipo normal. Após receber protocolo quimioterápico, atingiu remissão seis meses depois do início do tratamento, recaíndo quatro meses após com um cariótipo complexo envolvendo ambos os cromossomos, 8p e 16q. A medula óssea mostrava-se infiltrada por células blásticas vacuolizadas com aspecto monocítico, com evidências de hemofagocitose. A criança apresentou um declínio clínico progressivo e dois meses após a recaída foi a óbito. Comentários: A LHH é uma condição inflamatória rara e agressiva caracterizada por citopenias, hepatoesplenomegalia, febre e hemofagocitose na medula óssea, linfonodos, baço e fígado. A LHH associada a doenças malignas, embora seja uma condição rara, é potencialmente fatal. A paciente deste caso apresentou cinco dos oito critérios estabelecidos para o diagnóstico de LHH. A evolução do cariótipo do paciente, independentemente do perfil do diagnóstico, pareceu ser secundária ao tratamento da leucemia monocítica aguda, sendo que a instabilidade citogenética pode ter influenciado o comportamento atípico observado nas células leucêmicas. Este é um dos raros casos de LHH em uma criança com leucemia monocítica aguda. Objective: To describe the case of a child who presented hemophagocytic lymphohistiocytosis (HLH) associated with acute monocytic leukemia after chemotherapy, with hemophagocytosis caused by leukemic cells. Case description: In a university hospital in Southern Brazil, a 3-yearold female was diagnosed with acute monocytic leukemia with normal karyotype. The chemotherapy regimen was initiated, and she achieved complete remission six months later, relapsing after four months with a complex karyotype involving chromosomes 8p and 16q. The bone marrow showed vacuolated blasts with a monocytic aspect and evidence of hemophagocytosis. The child presented progressive clinical deterioration and died two months after the relapse. Comments: HLH is a rare and aggressive inflammatory condition characterized by cytopenias, hepatosplenomegaly, fever, and hemophagocytosis in the bone marrow, lymph nodes, spleen, and liver. Although rare, malignancy-associated HLH (M-HLH) is fatal. The patient in this case report met five out of the eight established criteria for HLH. The evolution of the patient’s karyotype, regardless of the diagnostic profile, seemed secondary to the treatment for acute monocytic leukemia. In this case, the cytogenetic instability might have influenced the abnormal behavior of leukemic cells. This is a rare case of HLH in a child with acute monocytic leukemia.

Acute myeloid leukemia (AML) is the most common and aggressive blood cancer in adults. In particular, significant unmet medical needs exist for effective treatment strategies for acute myelomonocytic leukemia (M4) and acute monocytic leukemia (M5) AML subtypes. Antibody–drug conjugates (ADC) are a promising drug class for AML therapy, as demonstrated by the FDA-approved anti-CD33 ADC, gemtuzumab ozogamicin (Mylotarg). However, CD33 is expressed in normal hematopoietic stem cells, highlighting the critical need to identify AML-specific targets to minimize the risk of potential adverse effects. We have demonstrated that the leukocyte immunoglobulin-like receptor subfamily B4 (LILRB4) is expressed at significantly higher levels on monocytic M4 and M5 AML cells than on normal counterparts. Here, we test whether LILRB4 is a promising ADC target to kill monocytic AML cells while sparing healthy counterparts. To this end, we generated ADCs from a humanized anti-LILRB4 mAb and the antimitotic payload, monomethyl auristatin F. The conjugates constructed were characterized and evaluated for LILRB4-specific cell killing potency, toxicity to progenitor cells, pharmacokinetics, and therapeutic efficacy. Our ADC linker technology platform efficiently generated homogeneous anti-LILRB4 ADCs with defined drug-to-antibody ratios. The homogeneous anti-LILRB4 ADCs demonstrated the capacity for LILRB4-mediated internalization, suitable physicochemical properties, and high cell killing potency against LILRB4-positive AML cells. Importantly, our data indicate that these ADCs spare normal progenitor cells. One of our homogeneous conjugates exerted a remarkable therapeutic effect and no significant toxicity in a xenograft mouse model of disseminated human AML. Our findings highlight the clinical potential of anti-LILRB4 ADCs in monocytic AML therapy.

Protozoan parasites of the genus Leishmania are the causative agents of leishmaniasis, a spectrum of a disease that threatens public health worldwide. Although next-generation therapeutics are urgently needed, the early stage of the drug discovery process is hampered by very low hit rates from intracellular Leishmania phenotypic high-throughput screenings. Designing and applying a physiologically relevant in vitro assay is therefore in high demand. In this study, we characterized the infectivity, morphology, and drug susceptibility of different Leishmania and host cell infection combinations. Primary bone marrow-derived macrophage (BMDM) and differentiated human acute monocytic leukemia (THP-1) cells were infected with amastigote or promastigote forms of Leishmania amazonensis and Leishmania donovani. Regardless of host cell types, amastigotes were generally well phagocytosed and showed high infectivity, whereas promastigotes, especially those of L. donovani, had predominantly remained in the extracellular space. In the drug susceptibility test, miltefosine and sodium stibogluconate (SSG) showed varying ranges of activity with 14 and &gt, 10-fold differences in susceptibility, depending on the host-parasite pairs, indicating the importance of assay conditions for evaluating antileishmanial activity. Overall, our results suggest that combinations of Leishmania species, infection forms, and host cells must be carefully optimized to evaluate the activity of potential therapeutic compounds against Leishmania.

Herein we present a female patient aged 61 with Philadelphia negative acute lymphoblastic leukaemia demonstrating near haploid karyotype and abnormal TP53 expression at diagnosis, who relapsed with lineage switch as Acute Monocytic Leukemia post allogeneic stem cell transplantation. Molecular analysis established that both neoplasms were derived from the same founder clone. The leukemic lineage switch phenomenon has recently re-attracted interest as mechanism of leukemic evasion post treatment with chimeric antigen receptor T-cells but there is paucity of data on its presence post allograft or following novel antibody treatments such as Inotuzumab Ozogamicin or Blinatumomab. Our proposition for cancer research is that near haploidy in ALL could be linked to leukemic stem cell plasticity evading stem cell transplantation and other immunotherapy approaches.

MLAA-34 is a novel leukemia-associated gene closely related to the carcinogenesis of acute monocytic leukemia (AML). MLAA-34 over expression has been observed to inhibit apoptosis in vitro. JAK2/STAT3 pathway plays an important role in cell proliferation, differentiation and inhibition of apoptosis in number of cancers. However, the relationship and interaction between MLAA-34 and JAK2/STAT3 has never been investigated in AML. This study investigates and reports a novel relationship between MLAA-34 and JAK2/STAT3 pathway in AML both in vitro and in vivo. We constructed MLAA-34 knockdown vector and transfected U937 cells to observe its apoptotic activities in relation to JAK2/STAT3 signaling pathway in vitro and then in vivo in mouse model. Levels of expression of MLAA-34 and JAK2/STAT3 and its downstream targets were also measured in AML patients and a few volunteers. We found that MLAA-34 knockdown increased U937 apoptosis in vitro and inhibited tumor growth in vivo. Components of the canonical JAK2/STAT3 pathway or its downstream targets, including c-myc, bcl-2, Bax, and caspase-3, were shown to be involved in the carcinogenesis of AML. We also found that the JAK2/STAT3 pathway positively regulated MLAA-34 expression. We additionally identified a STAT3 binding site in the MLAA-34 promoter where STAT3 binds directly and activates MLAA-34 expression. In addition, MLAA-34 was found to form a complex with JAK2 and was enhanced by JAK2 activation. Correlation of MLAA-34 and JAK2/STAT3 was further confirmed in AML patients. In conclusion, MLAA-34 is a novel regulator for JAK2/STAT3 signaling, and in turn, is regulated by this interaction in a positive feedback loop. Thus we report a novel model of interaction mechanism between MLAA-34 and JAK2/STAT3 which can be utilized as a potential target for a novel therapeutic approach in AML.

Background In this study, we aimed to investigate the effect of DNA methyltransferase 1 gene (DNMT1) expression on leukemia cell proliferation. Methods Following stimulation with interferon-α (IFN-α) or methylation inhibitor for three days, we evaluated changes in the DNMT1 expression levels, cell proliferation activity, and Bcl-2-Associated X Protein (BAX) expression levels in the chronic myelogenous leukemia cell line K562 and the acute monocytic leukemia cell line THP-1. Results DNMT1 expression levels and cell proliferation activity decreased in K562 and THP-1 cells, whereas BAX expression levels increased. Conclusions These results suggest that the enzymatic activity of DNMT1 promotes the proliferation of tumor cells and that tumor cell proliferation can be suppressed by inhibiting DNMT1 enzymatic activity. Furthermore, because DNA methylation is associated with apoptosis, a process critical to cell growth and injury in leukemia, assessing DNMT1expression levels might help in treatment decisions for leukemia patients.

CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Maytenus distichophylla is a medicinal species used in Northeast of Brazil. The hexane (HE), chloroform (CE), ethyl acetate (EAE) and methanol (ME) extracts and compounds from its roots were evaluated for their protective activity against Staphylococcus aureus and Candida albicans. The cytotoxicity for chronic myeloid leukemia (K562), acute monocytic leukemia (THP-1), and peripheral blood mononuclear cells of normal individuals (PBMC) cells was established by MTT method using etoposide as standard. The in vivo toxicity of samples was determined using Caenorhabditis elegans model. From HE and CE were isolated: friedelan-3-one (1), b-sitosterol (2), 3-oxo-olean-9(11),12-diene (3), a mixture of pristimerin (4) and 11a-hydroxylup-20(29)-en-3-one (5), 30-hydroxylup-20(29)-en-3-one (6), friedelane-3,7-dione (7), tingenone (8) and triacylglycerol (9). The structures of 1-9 were confirmed by spectral data. All samples reduced the viability of S. aureus and present no effect against C. albicans. The HE, CE, mixture of 4/5 and 8 reduced 75% of S. aureus viability. Cytotoxic effect for K562 and THP-1 cells was caused by compounds 1, 2 and 8. All samples displayed selectivity for leukemic cells and low toxicity to PBMC cells, suggesting their potential as anticancer agents. Extracts and compounds were non-toxic to L1 larvae of C. elegans. However, most of them reduced significantly young adult worm’s survival, being considered as potential nematicides.

A highly efficient and milder protocol for the syntheses of novel series of 2-aminothiazoles bearing 5-methylisoxazoline and pyridine-piperazine hybrid molecules has been developed. The target compounds 13a-e were screened for their in vitro cytotoxicity activity against various tumor cell lines including MCF-7 (human breast adenocarcinoma), HCT-116 (colorectal carcinoma), Jurkat (human Tcell leukemia) and THP-1 (human acute monocytic leukemia). The bioactive assay showed most of the new compounds exhibited promising results in comparison with the parental Sunitinib. The synthesized compounds could well be used in the future as lead anticancer drugs in drug development studies. The synthesized compounds were fully characterized by IR, 1H NMR, 13C NMR, elemental analysis and mass spectral data.

Objective: The aim of the present study was to screen the anticancer activity of Atractylis flava Desf in butanolic extract (AFBE). In addition, we attempted to investigate the gene expression levels of seven relevant genes involved in the pathways leading to toxicity: oxidative stress (NCF1, OPA1, SDHA), inflammation (TNFα), apoptotic balance (PDCD4, BCL2, CASP8) and the measurement of caspase-3 activity on the acute monocytic leukemia cell line THP-1. Material and Methods: The cell viability was assessed using Trypan blue exclusion, alamarBlue® and WST-1 assays. The gene expression levels were tested by RT-qPCR. Activity of caspase-3 activity was performed using the EnzChek® Caspase-3 Assay kit to confirm the induction of apoptosis on tumor cells. Results: We observed significant growth inhibitory activity of the AFBE extract on the acute monocytic leukemia cell line THP-1. Moreover, the gene expression analysis showed that the plant extract caused statistically significant downregulation of selected genes compared to the untreated cells. Caspase-3 activity in the treated cells was significantly elevated. Conclusion: The presents study states that the butanolic extract of Atractylis flava Desf showed a significant cytotoxic effect against THP-1 cells. Our results suggest that the AFBE may be beneficial for the treatment and prevention of cancer. Key words: Atractylis flava Desf, Gene expression, RT-qPCR, Apoptosis, THP-1.

Surface enhanced Raman spectroscopy (SERS) was used to quantify leukemia cells spiked in control cells. The novelty of the technique lies in preparing cell lysates by ultrasound sonication and mixing with silver nanoparticles which allow reproducible interaction of biomolecules and nanoparticles. The SERS spectra of these mixtures not only exhibit enhanced bands of intracellular proteins and nucleic acids, but also spectral variations for accurate cell identification. Here, samples from an acute monocytic leukemia cell line, THP-1, and control monocytes from three donors served as the in vitro model system for leukemia. For quantitative analysis, seven mixtures containing different percentile amounts of leukemia lysates and lysates from control monocytes were prepared ranging from 0% to 100% and SERS spectra were measured. The more intense spectral contributions of proteins relative to nucleic acids correlated with the larger cytoplasm to nucleus ratio of leukemia cells than control monocytes. The experimental SERS spectra were fitted by a non-negative least squares (NNLS) algorithm to calculate the percentile amounts of each of the cell types and to determine their contributions to the mixtures. Even in a mixture with control monocytes (360 μl), a small amount (5 μl) of leukemia cells was detected, which represents 10% of leukemia cells considering their twofold larger diameter and eightfold larger volume. As this value is well below the threshold of 20% blast cells for leukemia diagnosis, this approach is very promising for both qualitative and quantitative analysis of human cell mixtures. This study demonstrates the potential of SERS and NNLS fitting as a rapid method for diagnosis of acute monocytic leukemia in human blood or bone marrow samples because only a single spectrum is required.

Chemical investigation of a bioactive methanolic extract of the fruiting bodies of Piptoporus betulinus led to the isolation of five previously undescribed lanostane triterpenoids named piptolinic acids A−E, as well as five known lanostane triterpenoids. Their structures were elucidated on the basis of 1D and 2D NMR spectroscopic and HRESIMS analysis. Piptolinic acid A with an unusual moiety (3-hydroxy-4-methoxycarbonyl-3-methylbutyryloxy) at C-3 exhibited comparable cytotoxic activity against human promyelocytic leukemia cell line HL-60 (IC 50 = 1.77 μM) and human acute monocytic leukemia cell line THP-1 (IC 50 = 8.21 μM) to those of positive control, fluorouracil (IC 50 = 6.38 and 4.41 μM, respectively).