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Leukemia is a malignant tumor with high heterogeneity and a complex evolutionary process. It is difficult to resolve the heterogeneity and clonal evolution of leukemia cells by applying traditional bulk sequencing techniques, thus preventing a deep understanding of the mechanisms of leukemia development and the identification of potential therapeutic targets. However, with the development and application of single-cell sequencing technology, it is now possible to investigate the gene expression profile, mutations, and epigenetic features of leukemia at the single-cell level, thus providing a new perspective for leukemia research. In this article, we review the recent applications and advances of single-cell sequencing technology in leukemia research, discuss its potential for enhancing our understanding of the mechanisms of leukemia development, discovering therapeutic targets and personalized treatment, and provide reference guidelines for the significance of this technology in clinical research. [ABSTRACT FROM AUTHOR]

Magonia pubescens is a natural species from the Brazilian cerrado biome. Its fruits and seeds are used in the treatment of seborrheic dermatitis, a common inflammatory skin disease. In this work, the known compounds lapachol, stigmasterol, maniladiol and scopoletin were isolated from hexane and dichloromethane extracts of M. pubescens branches. The aqueous extract of this material was fractioned through a liquid-liquid partition and the obtained fractions were analyzed by UHPLC-MS/MS. The results obtained were compared with data from three databases, leading to the putative identification of 51 compounds from different classes, including flavonoids, saponins and triterpenes. The cytotoxicity of aqueous fractions was assayed against breast cancer (MDA-MB-231) and leukemia (THP-1 and K562) cells. The best activity was observed for fraction AE3 against MDA-MB-231 cells (IC50 30.72 µg.mL−1). [ABSTRACT FROM AUTHOR]

Naphthylisoquinoline (NIQ) alkaloids are rising as a promising class of secondary metabolites with pharmaceutical potential. NF-κB has already been recognized as a significant modulator of cancer proliferation and drug resistance. We have previously reported the mechanisms behind the cytotoxic effect of dioncophylline A, an NIQ monomer, in leukemia cells. In the current study, we have investigated the cytotoxic effect of jozimine A2, an NIQ dimer, on leukemia cells in comparison to a second, structurally unsymmetric dimer, michellamine B. To this end, molecular docking was applied to predict the binding affinity of the dimers towards NF-κB, which was then validated through microscale thermophoresis. Next, cytotoxicity assays were performed on CCRF-CEM cells and multidrug-resistant CEM/ADR5000 cells following treatment. Transcriptome analysis uncovered the molecular networks affected by jozimine A2 and identified the cell cycle as one of the major affected processes. Cell death modes were evaluated through flow cytometry, while angiogenesis was measured with the endothelial cell tube formation assay on human umbilical vein endothelial cells (HUVECs). The results indicated that jozimine A2 bound to NF-κB, inhibited its activity and prevented its translocation to the nucleus. In addition, jozimine A2 induced cell death through apoptosis and prevented angiogenesis. Our study describes the cytotoxic effect of jozimine A2 on leukemia cells and explains the interactions with the NF-κB signaling pathway and the anticancer activity. [ABSTRACT FROM AUTHOR]

Background: Reverse transcription quantitative polymerase chain reaction (RT-qPCR) can accurately detect relative gene expression levels in biological samples. However, widely used reference genes exhibit unstable expression under certain conditions. Methods and results: Here, we compared the expression stability of eight reference genes (RPLP0, RPS18, RPL13, EEF1A1, β-actin, GAPDH, HPRT1, and TUBB) commonly used in liproxstatin-1 (Lip-1)-treated K562 cells using RNA-sequencing and RT-qPCR. The expression of EEF1A1, ACTB, GAPDH, HPRT1, and TUBB was considerably lower in cells treated with 20 μM Lip-1 than in the control, and GAPDH also showed significant downregulation in the 10 μM Lip-1 group. Meanwhile, when we used geNorm, NormFinder, and BestKeeper to compare expression stability, we found that GAPDH and HPRT1 were the most unstable reference genes among all those tested. Stability analysis yielded very similar results when geNorm or BestKeeper was used but not when NormFinder was used. Specifically, geNorm and BestKeeper identified RPL13 and RPLP0 as the most stable genes under 20 μM Lip-1 treatment, whereas RPL13, EEF1A1, and TUBB were the most stable under 10 μM Lip-1 treatment. TUBB and EEF1A1 were the most stable genes in both treatment groups according to the results obtained using NormFinder. An assumed most stable gene was incorporated into each software to validate the accuracy. The results suggest that NormFinder is not an appropriate algorithm for this study. Conclusions: Stable reference genes were recognized using geNorm and BestKeeper but not NormFinder. Overall, RPL13 and RPLP0 were the most stable reference genes under 20 μM Lip-1 treatment, whereas RPL13, EEF1A1, and TUBB were the most stable genes under 10 μM Lip-1 treatment. [ABSTRACT FROM AUTHOR]

In order to study the chemical constituents from Carpesium cernuum and their inhibitory effects on leukemia cells in vitro. The chemical constituents from ethyl acetate fraction of C. cernuum were isolated and purified by silica gel column chromatography, Sephadex LH-20 column chromatography and macroporous adsorption resin, and their structures were identified by means of various spectroscopic techniques such as 1H NMR, 13C NMR and MS. The inhibitory effects of compounds 1-10 on leukemia cells (K562, HEL) in vitro were determined by MTT assay. The results were as follows: (1) Eleven compounds were isolated and identified as 2, 9-epoxy-5, 9-dihydroxy-8-angeloyloxy-11-methoxymethyl-4(15)-germacraen-6, 12-olide (1), cardivin D (2), cernuumolide I (3), cernuumolide J (4), 8-hydroxy-9, 10-diisobutyryloxythymol (5), (2E, 6Z, 10E, 12R)-7-［(acetyloxy)methyl］-3, 11, 15-trimethylhexadeca-2, 6, 10, 14-tetraene-1, 12-diol (6), 9, 10-dihydroxyoctadecanoate (7), 1, 6-dihydroxy-8-hydroxymethyl-anthraquinone (8), emodin (9), 4-megastigmen-3, 9-dione (10), β-sitosterol (11). Among them, Compound 1 was identified as a new compound, compounds 5, 7-10 were isolated from Carpesium for the first time, compounds 2, 5-10 were isolated from C. cernuum for the first time. (2) The results of activity test showed that cardivin D (2), cernuumolide I (3) and cernuumolide J (4) had good inhibitory effects on leukemia cells in vitro. The IC50 of compounds 2-4 against K562 cells and HEL cells were (2.27 ± 0.46), (5.53 ± 0.41), (3.90 ± 0.80) μmol·L-1 and (1.84 ± 0.14), (2.36 ± 0.90), (2.31 ± 1.17) μmol·L-1, respectively. The study enriches the chemical constituents of C. cernuum, and provides a material basis for the development of anti-leukemia drugs.

In order to study the chemical constituents from Carpesium cernuum and their inhibitory effects on leukemia cells in vitro. The chemical constituents from ethyl acetate fraction of C. cernuum were isolated and purified by silica gel column chromatography, Sephadex LH-20 column chromatography and macroporous adsorption resin, and their structures were identified by means of various spectroscopic techniques such as 1H NMR, 13C NMR and MS. The inhibitory effects of compounds 1-10 on leukemia cells (K562, HEL) in vitro were determined by MTT assay. The results were as follows: (1) Eleven compounds were isolated and identified as 2, 9-epoxy-5, 9-dihydroxy-8-angeloyloxy-11-methoxymethyl-4 (15)-germacraen-6, 12-olide (1), cardivin D (2), cernuumolide I(3), cernuumolide J(4), 8-hydroxy-9, 10-diisobutyryloxythymol (5), (2E, 6Z, 10E, 12R)-7-[(acetyloxy)methyl]-3, 11, 15-trimethylhexadeca-2, 6, 10, 14-tetraene-1, 12-diol(6), 9, 10-dihydroxyoctadecanoate(7), 1, 6-dihydroxy-8-hydroxymethyl-anthraquinone (8), emodin (9), 4-megastigmen-3, 9-dione(10), β-sitosterol(11). Among them, Compound 1 was identified as a new compound, compounds 5, 7-10 were isolated from the Carpesium for the first time, compounds 2, 5-10 were isolated from C. cernuum for the first time. (2) The results of activity test showed that cardivin D(2), cernuumolide I(3)and cernuumolide J(4)had good inhibitory effects on leukemia cells in vitro. The IC50 of compounds 2-4 against K562 cells and HEL cells were(2.27 ± 0.46), (5.53 ± 0.41), (3.90 ± 0.80) μmol·L-1 and(1.84 ± 0.14), (2.36 ± 0.90), (2.31 ± 1.17) μmol·L-1, respectively. Thus, the study enriches the chemical constituents of C. cernuum, and provides a material basis for the development of anti-leukemia drugs. [ABSTRACT FROM AUTHOR]

We aim to study the inhibitory effect of alkaline serine protease (ASPNJ) on lymphocytic leukemia Jurkat cells and its related mechanism through examining the expression of membrane proteins or membrane‐associated proteins. MTT assay and trypan blue staining were used to detect the inhibitory effect of ASPNJ on the proliferation and growth of Jurkat cells. Wright‐Giemsa staining was used to observe the effect of ASPNJ on the morphology of Jurkat cells. The effect of ASPNJ on Jurkat cell apoptosis was detected by flow cytometry. Two‐dimensional electrophoresis‐mass spectrometry (2‐DE‐MS) was used to detect and identify the differentially expressed proteins of Jurkat cells treated with ASPNJ (4 μg/mL, 3 h), of which three were selected and verified by Western blot. ASPNJ significantly inhibited the proliferation of leukemia cells (Raji, U937, and Jurkat), caused obvious morphological changes, and induced apoptosis of Jurkat cells. ASPNJ also increased the sensitivity of Jurkat cells to vincristine (VCR). Seven differentially expressed proteins were obtained through 2DE‐MS, of which Peroxiredoxin‐6 (PRDX6), Calcium‐binding protein (CHP1), and 40S ribosomal protein SA (RPSA) were validated. ASPNJ can cause significant toxic effects on Jurkat cells and enhance the effects of VCR. The mechanism of action of ASPNJ on Jurkat cells may be related to differentially expressed proteins such as PRDX6. This study provides a new experimental basis and direction for antileukemia research. [ABSTRACT FROM AUTHOR]

Naphthylisoquinoline (NIQ) alkaloids are rising as a promising class of secondary metabolites with pharmaceutical potential. NF-κB has already been recognized as a significant modulator of cancer proliferation and drug resistance. We have previously reported the mechanisms behind the cytotoxic effect of dioncophylline A, an NIQ monomer, in leukemia cells. In the current study, we have investigated the cytotoxic effect of jozimine A2, an NIQ dimer, on leukemia cells in comparison to a second, structurally unsymmetric dimer, michellamine B. To this end, molecular docking was applied to predict the binding affinity of the dimers towards NF-κB, which was then validated through microscale thermophoresis. Next, cytotoxicity assays were performed on CCRF-CEM cells and multidrug-resistant CEM/ADR5000 cells following treatment. Transcriptome analysis uncovered the molecular networks affected by jozimine A2 and identified the cell cycle as one of the major affected processes. Cell death modes were evaluated through flow cytometry, while angiogenesis was measured with the endothelial cell tube formation assay on human umbilical vein endothelial cells (HUVECs). The results indicated that jozimine A2 bound to NF-κB, inhibited its activity and prevented its translocation to the nucleus. In addition, jozimine A2 induced cell death through apoptosis and prevented angiogenesis. Our study describes the cytotoxic effect of jozimine A2 on leukemia cells and explains the interactions with the NF-κB signaling pathway and the anticancer activity.

The aim of this study was to explore the mechanism of antitumor effect of (E)-6-morpholino-9-(styrylsulfonyl)-9H-purine (6-Morpholino-SPD) and (E)-6-amino-9-(styrylsulfonyl)-9H-purine (6-Amino-SPD). The effects on apoptosis induction, mitochondrial potential, and accumulation of ROS in treated K562 cells were determined by flow cytometry. The RT-PCR method was used to measure the expression of Akt, CA IX, caspase 3, and cytochrome c genes, as well as selected miRNAs. Western blot analysis was used to determine the expression of Akt, cytochrome c, and caspase 3. The results demonstrate the potential of the tested derivatives as effective antitumor agents with apoptotic-inducing properties. In leukemic cells treated with 6-Amino-SPD, increased expression of caspase 3 and cytochrome c genes was observed, indicating involvement of the intrinsic mitochondrial pathway in the induction of apoptosis. Conversely, leukemic cells treated with 6-Morpholino-SPD showed reduced expression of these genes. The observed downregulation of miR-21 by 6-Morpholino-SPD may contribute to the induction of apoptosis and disruption of mitochondrial function. In addition, both derivatives exhibited increased expression of Akt and CA IX genes, suggesting activation of the Akt/HIF pathway. However, the exact mechanism and its relations to the observed overexpression of miR-210 need further investigation. The acceptable absorption and distribution properties predicted by ADMET analysis suggest favorable pharmacokinetic properties for these derivatives. [ABSTRACT FROM AUTHOR]

Pilocarpine is a selective M1/M3 agonist of muscarinic acetylcholine receptor subtypes. Muscarinic acetylcholine receptors are G protein-coupled receptors. These receptors are different drug targets. The aim of the present work was to investigate the effect of pilocarpine on the expression of M3 muscarinic acetylcholine receptor, the AChE activity, IL-8 release response, and proliferation in K562 cells, via muscarinic receptor activation. Human chronic myeloid leukemic cell cultures were incubated with drugs. Proliferation assays were performed by BrdU assay. Expression of M3 muscarinic acetylcholine receptor and apoptosis proteins such as bcl, bax, cyt C, and caspases was assessed with the semiquantitative Western blotting method. Pilocarpine inhibits chronic myeloid cell proliferation and M3 muscarinic acetylcholine receptor protein expression. Pilocarpine increases caspase-8 and -9 expression levels, upregulating the proapoptotic protein Bax and downregulating the expression levels of the antiapoptotic protein Bcl-2. The apoptotic activity of pilocarpine is associated with an increase in AChE activity. M3 muscarinic acetylcholine receptors can activate multiple signal transduction systems and mediate inhibitory effects on chronic myeloid K562 cell proliferation depending on the presence of 1% FBS conditions. This apoptotic effect of pilocarpine may be due to the concentration of pilocarpine and the increase in AChE level. Our results suggest that inhibition of cell proliferation by inducing apoptosis of pilocarpine in K562 cells may be one of the targets. M3 selective agonist may have therapeutic potential in chronic myeloid leukemia. [ABSTRACT FROM AUTHOR]

To explore the molecular mechanisms of action underlying the antileukemia activities of darinaparsin, an organic arsenical approved for the treatment of peripheral T–cell lymphoma in Japan, cytotoxicity of darinaparsin was evaluated in leukemia cell lines NB4, U-937, MOLT-4 and HL-60. Darinaparsin was a more potent cytotoxic than sodium arsenite, and induced apoptosis/necrosis in NB4 and HL-60 cells. In NB4 cells exhibiting the highest susceptibility to darinaparsin, apoptosis induction was accompanied by the activation of caspase-8/-9/-3, a substantial decrease in Bid expression, and was suppressed by Boc-D-FMK, a pancaspase inhibitor, suggesting that darinaparsin triggered a convergence of the extrinsic and intrinsic pathways of apoptosis via Bid truncation. A dramatic increase in the expression level of γH2AX, a DNA damage marker, occurred in parallel with G2/M arrest. Activation of p53 and the inhibition of cdc25C/cyclin B1/cdc2 were concomitantly observed in treated cells. Downregulation of c-Myc, along with inactivation of E2F1 associated with the activation of Rb, was observed, suggesting the critical roles of p53 and c-Myc in darinaparsin-mediated G2/M arrest. Trolox, an antioxidative reagent, suppressed the apoptosis induction but failed to correct G2/M arrest, suggesting that oxidative stress primarily contributed to apoptosis induction. Suppression of Notch1 signaling was also confirmed. Our findings provide novel insights into molecular mechanisms underlying the cytotoxicity of darinaparsin and strong rationale for its new clinical application for patients with different types of cancer. [ABSTRACT FROM AUTHOR]

Simple Summary: PARP inhibitors (PARPi) have been administered to treat BRCA1/2-mutated/deficient malignancies. Nevertheless, the resistance to PARPi is emerging in experimental and clinical interventions. Importantly, the resistance originated from diverse mechanisms, therefore requiring tremendous efforts to identify mechanistic aspects and develop combinational therapies to prevent the resistance and/or restore the efficiency of PARPi in cancer cells. Here, we review pre-existing and acquired resistance to PARPi and propose potential therapeutic solutions. The advanced development of synthetic lethality has opened the doors for specific anti-cancer medications of personalized medicine and efficient therapies against cancers. One of the most popular approaches being investigated is targeting DNA repair pathways as the implementation of the PARP inhibitor (PARPi) into individual or combinational therapeutic schemes. Such treatment has been effectively employed against homologous recombination-defective solid tumors as well as hematopoietic malignancies. However, the resistance to PARPi has been observed in both preclinical research and clinical treatment. Therefore, elucidating the mechanisms responsible for the resistance to PARPi is pivotal for the further success of this intervention. Apart from mechanisms of acquired resistance, the bone marrow microenvironment provides a pre-existing mechanism to induce the inefficiency of PARPi in leukemic cells. Here, we describe the pre-existing and acquired mechanisms of the resistance to PARPi-induced synthetic lethality. We also discuss the potential rationales for developing effective therapies to prevent/repress the PARPi resistance in cancer cells. [ABSTRACT FROM AUTHOR]

Previous studies demonstrated that CD4+ T cells can uptake tumor antigenpulsed dendritic cell-derived exosomes (DEXO), which harbor tumor antigen peptide/pMHC I complex and costimulatory molecules and show potent effects on inducing antitumor immunity. However, in preliminary study, CD4+ T cells targeted by leukemia cell-derived exosomes (LEXs) did not show the expected effects in inducing effective anti-leukemia immunity, indicating that LEX is poorly immunogenetic largely due to an inadequate costimulatory capacity. Therefore, LEX-based anti-leukemia vaccines need to be optimized. In this study, we constructed a novel LEX-based vaccine by combining CD4+ T cells with costimulatory molecules gene-modified LEXs, which harbor upregulated CD80 and CD86, and the anti-leukemia immunity of CD80 and CD86 gene-modified LEX-targeted CD4+ T cells was investigated. We used lentiviral vectors encoding CD80 and CD86 to successfully transduced the L1210 leukemia cells, and the expression of CD80 and CD86 was remarkably upregulated in leukemia cells. The LEXs highly expressing CD80 and CD86 were obtained from the supernatants of gene-transduced leukemia cells. Our data have shown that LEX-CD8086 could promote CD4+ T cell proliferation and Th1 cytokine secretion more efficiently than control LEXs. Moreover, CD4+ TLEX-CD8086 expressed the acquired exosomal costimulatory molecules. With acquired costimulatory molecules, CD4+ TLEX-CD8086 can act as APCs and are capable of directly stimulating the leukemia cell antigen-specific CD8+ CTL response. This response was higher in potency compared to that noted by the other formulations. Furthermore, the animal study revealed that the CD4+ TLEXCD8086 significantly inhibited tumor growth and prolonged survival of tumorbearing mice than other formulations did in both protective and therapeutic models. In conclusion, this study revealed that CD4+ TLEX-CD8086 could effectively induce more potential anti-leukemia immunity than LEX-CD8086 alone, suggesting that the utilization of a costimulatory molecule gene-modified leukemia cell-derived exosome-targeted CD4+ T cell vaccine may have promising potential for leukemia immunotherapy. [ABSTRACT FROM AUTHOR]

Previous studies demonstrated that CD4+ T cells can uptake tumor antigen-pulsed dendritic cell-derived exosomes (DEXO), which harbor tumor antigen peptide/pMHC I complex and costimulatory molecules and show potent effects on inducing antitumor immunity. However, in preliminary study, CD4+ T cells targeted by leukemia cell-derived exosomes (LEXs) did not show the expected effects in inducing effective anti-leukemia immunity, indicating that LEX is poorly immunogenetic largely due to an inadequate costimulatory capacity. Therefore, LEX-based anti-leukemia vaccines need to be optimized. In this study, we constructed a novel LEX-based vaccine by combining CD4+ T cells with costimulatory molecules gene-modified LEXs, which harbor upregulated CD80 and CD86, and the anti-leukemia immunity of CD80 and CD86 gene-modified LEX-targeted CD4+ T cells was investigated. We used lentiviral vectors encoding CD80 and CD86 to successfully transduced the L1210 leukemia cells, and the expression of CD80 and CD86 was remarkably upregulated in leukemia cells. The LEXs highly expressing CD80 and CD86 were obtained from the supernatants of gene-transduced leukemia cells. Our data have shown that LEX-CD8086 could promote CD4+ T cell proliferation and Th1 cytokine secretion more efficiently than control LEXs. Moreover, CD4+ TLEX-CD8086 expressed the acquired exosomal costimulatory molecules. With acquired costimulatory molecules, CD4+ TLEX-CD8086 can act as APCs and are capable of directly stimulating the leukemia cell antigen-specific CD8+ CTL response. This response was higher in potency compared to that noted by the other formulations. Furthermore, the animal study revealed that the CD4+ TLEX-CD8086 significantly inhibited tumor growth and prolonged survival of tumor-bearing mice than other formulations did in both protective and therapeutic models. In conclusion, this study revealed that CD4+ TLEX-CD8086 could effectively induce more potential anti-leukemia immunity than LEX-CD8086 alone, suggesting that the utilization of a costimulatory molecule gene-modified leukemia cell-derived exosome-targeted CD4+ T cell vaccine may have promising potential for leukemia immunotherapy.

The aim of this study was to explore the mechanism of antitumor effect of (E)-6-morpholino-9-(styrylsulfonyl)-9H-purine (6-Morpholino-SPD) and (E)-6-amino-9-(styrylsulfonyl)-9H-purine (6-Amino-SPD). The effects on apoptosis induction, mitochondrial potential, and accumulation of ROS in treated K562 cells were determined by flow cytometry. The RT-PCR method was used to measure the expression of Akt, CA IX, caspase 3, and cytochrome c genes, as well as selected miRNAs. Western blot analysis was used to determine the expression of Akt, cytochrome c, and caspase 3. The results demonstrate the potential of the tested derivatives as effective antitumor agents with apoptotic-inducing properties. In leukemic cells treated with 6-Amino-SPD, increased expression of caspase 3 and cytochrome c genes was observed, indicating involvement of the intrinsic mitochondrial pathway in the induction of apoptosis. Conversely, leukemic cells treated with 6-Morpholino-SPD showed reduced expression of these genes. The observed downregulation of miR-21 by 6-Morpholino-SPD may contribute to the induction of apoptosis and disruption of mitochondrial function. In addition, both derivatives exhibited increased expression of Akt and CA IX genes, suggesting activation of the Akt/HIF pathway. However, the exact mechanism and its relations to the observed overexpression of miR-210 need further investigation. The acceptable absorption and distribution properties predicted by ADMET analysis suggest favorable pharmacokinetic properties for these derivatives.

Spin probes can be used to monitor biological membranes, including the penetration of different molecules into cells. The aim of the present studies was an investigation of the endocytosis process of two spin labels—2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO) and 4-hydroxy-TEMPO (TEMPOL)—into yeast cells and a leukemia cell line (HL-60, ATCC CCL-240) by Electron Spin Resonance (ESR). The ESR method is helpful for the direct detection of free radicals. The cell incubation and endocytosis of spin probes were carried out at 310 K. In contrast, the ESR measurements of yeast cells and a leukemia cell line with spin probes were at 240 K. Spectral differentiation was observed; hence, the spin probes present in suspension and attached to the cell membrane could be distinguished. The ESR signal changes of spin probes depended on spin probe concentration, cell number, and type of cell (healthy/cancerous). Additionally, the effect of external factors (oxygen and vitamin C) on the ESR signal decay of spin markers in the cell solution was established. The experimental results prove that the spin probes (TEMPO and TEMPOL) could scavenge free radicals inside the cell. At the same time, the mechanism of spin probe interaction in suspension was determined based on the measurements at low temperatures. [ABSTRACT FROM AUTHOR]

Hydroxytyrosol (HT), the main representative of polyphenols of olive oil, has been described as one of the most powerful natural antioxidants, also showing anti-inflammatory, antimicrobial, cardioprotective and anticancer activity in different type of cancers, but has been little studied in hematological neoplasms. The objective of this work was to evaluate the anticancer potential of HT in acute human leukemia T cells (Jurkat and HL60) and the anti-inflammatory potential in murine macrophages (Raw264.7). For this, cytotoxicity tests were performed for HT, showing IC50 values, at 24 h, for Jurkat, HL60 and Raw264.7 cells, of 27.3 µg·mL−1, 109.8 µg·mL−1 and 45.7 µg·mL−1, respectively. At the same time, HT caused cell arrest in G0/G1 phase in both Jurkat and HL60 cells by increasing G0/G1 phase and significantly decreasing S phase. Apoptosis and cell cycle assays revealed an antiproliferative effect of HT, decreasing the percentage of dividing cells and increasing apoptosis. Furthermore, HT inhibited the PI3K signaling pathway and, consequently, the MAPK pathway was activated. Inflammation tests revealed that HT acts as an anti-inflammatory agent, reducing NO levels in Raw264.7 cells previously stimulated by lipopolysaccharide (LPS). These processes were confirmed by the changes in the expression of the main markers of inflammation and cancer. In conclusion, HT has an anticancer and anti-inflammatory effect in the cell lines studied, which were Raw264.7, Jurkat, and HL60, and could be used as a natural drug in the treatment of liquid cancers, leukemias, myelomas and lymphomas. [ABSTRACT FROM AUTHOR]

Ultrasound single-beam acoustic tweezer system has attracted increasing attention in the field of biomechanics. Cell biomechanics play a pivotal role in leukemia cell functions. To better understand and compare the cell mechanics of the leukemia cells, herein, we fabricated an acoustic tweezer system in-house connected with a 50-MHz high-frequency cylinder ultrasound transducer. Selected leukemia cells (Jurkat, K562, and MV-411 cells) were cultured, trapped, and manipulated by high-frequency ultrasound single beam, which was transmitted from the ultrasound transducer without contacting any cells. The relative deformability of each leukemia cell was measured, characterized, and compared, and the leukemia cell (Jurkat cell) gaining the highest deformability was highlighted. Our results demonstrate that the high-frequency ultrasound single beam can be utilized to manipulate and characterize leukemia cells, which can be applied to study potential mechanisms in the immune system and cell biomechanics in other cell types. [ABSTRACT FROM AUTHOR]

Many quinazoline derivatives with pharmacological properties, such as anticancer activity, have been synthesized. Fourteen quinazoline derivatives bearing a substituted sulfonamide moiety (4a–n) were previously synthesized and fully characterized. These compounds exerted antiproliferative activity against cell lines derived from solid tumors. Herein, the antileukemic activities of these compounds (4a–n) against two different leukemia cell lines (Jurkat acute T cell and THP-1 acute monocytic) were investigated. Our investigation included examining their activity in vivo in a zebrafish embryo model. Remarkably, compounds 4a and 4d were the most potent in suppressing cell proliferation, with an IC50 value range of 4–6.5 µM. Flow cytometry analysis indicated that both compounds halted cell progression at the G2/M phase and induced apoptosis in a dose-dependent manner. RT-PCR and Western blot analyses also showed that both compounds effectively induced apoptosis by upregulating the expression of proapoptotic factors while downregulating that of antiapoptotic factors. In vivo animal toxicity assays performed in zebrafish embryos indicated that compound 4d was more toxic than compound 4a, with compound 4d inducing multiple levels of teratogenic phenotypes in zebrafish embryos at a sublethal concentration. Moreover, both compounds perturbed the hematopoiesis process in developing zebrafish embryos. Collectively, our data suggest that compounds 4a and 4d have the potential to be used as antileukemic agents. [ABSTRACT FROM AUTHOR]

An interaction between acute myeloid leukemia (AML) cells and endothelial cells in the bone marrow seems to play a critical role in chemosensitivity on leukemia treatment. The endothelial niche reportedly enhances the paracrine action of the soluble secretory proteins responsible for chemoresistance in a vascular endothelial growth factor A (VEGF-A)/VEGF receptor 2 (VEGFR-2) signaling pathway–dependent manner. To further investigate the contribution of VEGF-A/VEGFR-2 signaling to the chemoresistance of AML cells, a biochemical assay system in which the AML cells were cocultured with human endothelial EA.hy926 cells in a monolayer was developed. By coculture with EA.hy926 cells, this study revealed that the AML cells resisted apoptosis induced by the anticancer drug cytarabine. SU4312, a VEGFR-2 inhibitor, attenuated VEGFR-2 phosphorylation and VEGF-A/VEGFR-2 signaling–dependent endothelial cell migration; thus, this inhibitor was observed to block VEGF-A/VEGFR-2 signaling. Interestingly, this inhibitor did not reverse the chemoresistance. When VEGFR-2 was knocked out in EA.hy926 cells using the CRISPR–Cas9 system, the cytarabine-induced apoptosis of AML cells did not significantly change compared with that of wild-type cells. Thus, coculture-induced chemoresistance appears to be independent of VEGF-A/VEGFR-2 signaling. When the transwell, a coculturing device, separated the AML cells from the EA.hy926 cells in a monolayer, the coculture-induced chemoresistance was inhibited. Given that the migration of VEGF-A/VEGFR-2 signaling–dependent endothelial cells is necessary for the endothelial niche formation in the bone marrow, VEGF-A/VEGFR-2 signaling contributes to chemoresistance by mediating the niche formation process, but not to the chemoresistance of AML cells in the niche. • Coculture with endothelial cells inhibits the drug-induced apoptosis of AML cells. • The chemoresistance is not reversed by the inhibition or knockout of VEGFR-2. • The VEGFR-2 pathway is dispensable for endothelial cells-induced AML chemoresistance. [ABSTRACT FROM AUTHOR]

The in vitro antibacterial effect of a synthetic new peptide NJP9-A originated from natural marine invertebrates and its cytotoxicity, selectivity and one possible mechanism of action on human leukemia cells were investigated. NJP9-A showed significant bacteriostasis against Staphylococcus aureus (including methicillin-resistant S. aureus), and had a very low hemolysis efficiency on the human red blood cells. NJP9-A selectively bound to and inhibited the proliferation of leukemia cells, but had almost no inhibitory effect on the proliferation of HEK293 and HUVEC cells. The underlying mechanism of NJP9-A's anti-leukemia cell effect may involve changing the expression of PIK3R1 (PI3K p85 regulatory subunit 1), and the corresponding PI3K signal transduction pathway. NJP9-A inhibits Gram-positive bacteria and is cytotoxic to leukemia cells. The underlying mechanism of NJP9-A's anti-leukemia cell effect is still unclear, but it may be related to the alteration of PIK3R1 expression. [ABSTRACT FROM AUTHOR]

To explore the molecular mechanisms of action underlying the antileukemia activities of darinaparsin, an organic arsenical approved for the treatment of peripheral T–cell lymphoma in Japan, cytotoxicity of darinaparsin was evaluated in leukemia cell lines NB4, U-937, MOLT-4 and HL-60. Darinaparsin was a more potent cytotoxic than sodium arsenite, and induced apoptosis/necrosis in NB4 and HL-60 cells. In NB4 cells exhibiting the highest susceptibility to darinaparsin, apoptosis induction was accompanied by the activation of caspase-8/-9/-3, a substantial decrease in Bid expression, and was suppressed by Boc-D-FMK, a pancaspase inhibitor, suggesting that darinaparsin triggered a convergence of the extrinsic and intrinsic pathways of apoptosis via Bid truncation. A dramatic increase in the expression level of γH2AX, a DNA damage marker, occurred in parallel with G2/M arrest. Activation of p53 and the inhibition of cdc25C/cyclin B1/cdc2 were concomitantly observed in treated cells. Downregulation of c-Myc, along with inactivation of E2F1 associated with the activation of Rb, was observed, suggesting the critical roles of p53 and c-Myc in darinaparsin-mediated G2/M arrest. Trolox, an antioxidative reagent, suppressed the apoptosis induction but failed to correct G2/M arrest, suggesting that oxidative stress primarily contributed to apoptosis induction. Suppression of Notch1 signaling was also confirmed. Our findings provide novel insights into molecular mechanisms underlying the cytotoxicity of darinaparsin and strong rationale for its new clinical application for patients with different types of cancer.

Leukemia is a malignant tumor with high heterogeneity and a complex evolutionary process. It is difficult to resolve the heterogeneity and clonal evolution of leukemia cells by applying traditional bulk sequencing techniques, thus preventing a deep understanding of the mechanisms of leukemia development and the identification of potential therapeutic targets. However, with the development and application of single-cell sequencing technology, it is now possible to investigate the gene expression profile, mutations, and epigenetic features of leukemia at the single-cell level, thus providing a new perspective for leukemia research. In this article, we review the recent applications and advances of single-cell sequencing technology in leukemia research, discuss its potential for enhancing our understanding of the mechanisms of leukemia development, discovering therapeutic targets and personalized treatment, and provide reference guidelines for the significance of this technology in clinical research., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Xie, An, Yang, Wang, Guo, Luo, Huang and Sun.)

Efforts to overcome multidrug resistance in cancer have led to the development of several novel strategies including photodynamic therapy (PDT). PDT is based on the use of photosensitizers (PSs) photoactivation, which causes the formation of reactive oxygen species that can induce cell death. In the last decade, the development of new PSs has been significantly accelerated. Recently, acridine-3,6-dialkyldithiourea hydrochlorides (AcrDTUs) have been investigated as a new group of PSs and we have shown that PDT/AcrDTUs caused cell death of mouse leukemic cells L1210. In this study, we investigated the efficacy of PDT/AcrDTUs for the treatment of L1210/VCR cells as a model of chemoresistant cells (overexpressing P-glycoprotein, P-gp). The photoactivation (365 nm, 1.05 J/cm2) increased the cytotoxicity of AcrDTUs 10-15 times. Inhibition of P-gp (verapamil) has been shown to have no significant effect on the accumulation of propyl-AcrDTU (the most potent derivative) in L1210/VCR cells. The intracellular distribution of this acridine derivative has been studied. Prior to irradiation of the resistant cells, propyl-AcrDTU was sequestered mainly in the cytosol, partly in the mitochondria, and, unlike in the sensitive cells, the AcrDTU was not found in the lysosomes. PDT with 1 µM propyl-AcrDTU induced cell shrinkage and "ladder DNA" formation, and although a drastic decrease of the intracellular ATP level was observed at the same time, there was no increase in extracellular LDH activity. AIF in the nucleus can induce DNA fragmentation and we have actually observed a mitochondrio-nuclear translocation of AIF. We concluded that AcrDTUs are photocytotoxic against L1210/VCR cells and that mitochondria play an important role in cell death induced by PDT. [ABSTRACT FROM AUTHOR]

Spin probes can be used to monitor biological membranes, including the penetration of different molecules into cells. The aim of the present studies was an investigation of the endocytosis process of two spin labels—2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO) and 4-hydroxy-TEMPO (TEMPOL)—into yeast cells and a leukemia cell line (HL-60, ATCC CCL-240) by Electron Spin Resonance (ESR). The ESR method is helpful for the direct detection of free radicals. The cell incubation and endocytosis of spin probes were carried out at 310 K. In contrast, the ESR measurements of yeast cells and a leukemia cell line with spin probes were at 240 K. Spectral differentiation was observed; hence, the spin probes present in suspension and attached to the cell membrane could be distinguished. The ESR signal changes of spin probes depended on spin probe concentration, cell number, and type of cell (healthy/cancerous). Additionally, the effect of external factors (oxygen and vitamin C) on the ESR signal decay of spin markers in the cell solution was established. The experimental results prove that the spin probes (TEMPO and TEMPOL) could scavenge free radicals inside the cell. At the same time, the mechanism of spin probe interaction in suspension was determined based on the measurements at low temperatures.

Hydroxytyrosol (HT), the main representative of polyphenols of olive oil, has been described as one of the most powerful natural antioxidants, also showing anti-inflammatory, antimicrobial, cardioprotective and anticancer activity in different type of cancers, but has been little studied in hematological neoplasms. The objective of this work was to evaluate the anticancer potential of HT in acute human leukemia T cells (Jurkat and HL60) and the anti-inflammatory potential in murine macrophages (Raw264.7). For this, cytotoxicity tests were performed for HT, showing IC50 values, at 24 h, for Jurkat, HL60 and Raw264.7 cells, of 27.3 µg·mL−1, 109.8 µg·mL−1 and 45.7 µg·mL−1, respectively. At the same time, HT caused cell arrest in G0/G1 phase in both Jurkat and HL60 cells by increasing G0/G1 phase and significantly decreasing S phase. Apoptosis and cell cycle assays revealed an antiproliferative effect of HT, decreasing the percentage of dividing cells and increasing apoptosis. Furthermore, HT inhibited the PI3K signaling pathway and, consequently, the MAPK pathway was activated. Inflammation tests revealed that HT acts as an anti-inflammatory agent, reducing NO levels in Raw264.7 cells previously stimulated by lipopolysaccharide (LPS). These processes were confirmed by the changes in the expression of the main markers of inflammation and cancer. In conclusion, HT has an anticancer and anti-inflammatory effect in the cell lines studied, which were Raw264.7, Jurkat, and HL60, and could be used as a natural drug in the treatment of liquid cancers, leukemias, myelomas and lymphomas.

Many quinazoline derivatives with pharmacological properties, such as anticancer activity, have been synthesized. Fourteen quinazoline derivatives bearing a substituted sulfonamide moiety (4a–n) were previously synthesized and fully characterized. These compounds exerted antiproliferative activity against cell lines derived from solid tumors. Herein, the antileukemic activities of these compounds (4a–n) against two different leukemia cell lines (Jurkat acute T cell and THP-1 acute monocytic) were investigated. Our investigation included examining their activity in vivo in a zebrafish embryo model. Remarkably, compounds 4a and 4d were the most potent in suppressing cell proliferation, with an IC50 value range of 4–6.5 µM. Flow cytometry analysis indicated that both compounds halted cell progression at the G2/M phase and induced apoptosis in a dose-dependent manner. RT-PCR and Western blot analyses also showed that both compounds effectively induced apoptosis by upregulating the expression of proapoptotic factors while downregulating that of antiapoptotic factors. In vivo animal toxicity assays performed in zebrafish embryos indicated that compound 4d was more toxic than compound 4a, with compound 4d inducing multiple levels of teratogenic phenotypes in zebrafish embryos at a sublethal concentration. Moreover, both compounds perturbed the hematopoiesis process in developing zebrafish embryos. Collectively, our data suggest that compounds 4a and 4d have the potential to be used as antileukemic agents.

Silibinin is the main biologically active component of silymarin extract and consists of a mixture 1:1 of two diastereoisomeric flavonolignans, namely silybin A (1a) and silybin B (1b), which we call here silybins. Despite the high interest in the activity of this flavonolignan, there are still few studies that give due attention to the role of its stereochemistry and, there is still today a strong need to investigate in this area. In this regard, here we report a study concerning the radical scavenger ability and the antiproliferative activity on different cell lines, both of silybins and phosphodiester-linked silybin dimers. An efficient synthetic strategy to obtain silybin dimers in an optical pure form (6aa, 6ab and 6bb) starting from a suitable building block of silybin A and silybin B, obtained by us from natural extract silibinin, was proposed. New dimers show strong antioxidant properties, determined through hydroxyl radical (HO●) scavenging ability, comparable to the value reported for known potent antioxidants such as quercetin. A preliminary screening was performed by treating cells with 10 and 50 μM concentrations for 48 h to identify the most sensitive cell lines. The results show that silibinin compounds were active on Jurkat, A375, WM266, and HeLa, but at the tested concentrations, they did not interfere with the growth of PANC, MCF-7, HDF or U87. In particular, both monomers (1a and 1b) and dimers (6aa, 6ab and 6bb) present selective anti-proliferative activity towards leukemia cells in the mid-micromolar range and are poorly active on normal cells. They exhibit different mechanisms of action in fact all the cells treated with the 1a and 1b go completely into apoptosis, whereas only part of the cells treated with 6aa and 6ab were found to be in apoptosis.

Synthesis of molecular hybrids, obtained by combination of two or more pharmacophoric groups of different bioactive substances in order to produce more efficient drugs, is now a frequently used approach in medicinal chemistry. Following this strategy, we synthetized a library of 3-methylidene-1-tosyl-2,3-dihydro-1,8-naphthyridin-4(1H)-ones, combining a 1,8-naphthyridin-4-one motif with an exo-methylidene bond conjugated with a carbonyl group, pharmacophoric units that are present in many natural, biologically active compounds with anticancer potential. We reasoned that such bifunctional conjugates may have enhanced cytotoxic activity. The title compounds were synthesized in a four step reaction sequence. β-Ketophosphonate, obtained from methyl N-tosylnicotinate and diethyl methylphosphonate, was reacted with various aldehydes giving 3-diethoxyphosphoryl-2,3-dihydro-1,8-naphthyridin-4(1H)-ones as keto-enol tautomers. Later, these compounds were transformed into 3-methylidene-1-tosyl-2,3-dihydro-1,8-naphthyridin-4(1H)-ones applying the Horner-Wadsworth-Emmons methodology. Then, the cytotoxicity of the new compounds was assessed on two cancer cell lines, promyelocytic leukemia HL-60 and breast cancer adenocarcinoma MCF-7, and for comparison, on human umbilical vein endothelial cells HUVEC. The most active and selective analog, 2-ethyl-3-methylidene-1-tosyl-2,3-dihydro-1,8-naphthyridin-4(1H)-one 4 a was chosen for more detailed studies on HL-60 cell line, to determine molecular mechanisms of its anticancer activity. It was shown that 4 a strongly inhibited proliferation and induced apoptosis which could be attributed to its ability to cause DNA damage., (© 2023 Wiley‐VCH GmbH.)

The studies concerned the expression of sulfurtransferases and cystathionine beta-synthase in six human leukemia cell lines: B cell acute lymphoblastic leukemia-B-ALL (REH cells), T cell acute lymphoblastic leukemia-T-ALL (DND-41 and MOLT-4 cells), acute myeloid leukemia—AML (MV4-11 and MOLM-14 cells), and chronic myeloid leukemia—CML (K562 cells). Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis were performed to determine the expression of thiosulfate sulfurtransferase, 3-mercaptopyruvate sulfurtransferase, gamma-cystathionase, and cystathionine beta-synthase on the mRNA and protein level. Interestingly, we found significant differences in the mRNA and protein levels of sulfurtransferases and cystathionine beta-synthase in the studied leukemia cells. The obtained results may contribute to elucidating the significance of the differences between the studied cells in the field of sulfur compound metabolism and finding new promising ways to inhibit the proliferation of various types of leukemic cells by modulating the activity of sulfurtransferases, cystathionine beta-synthase, and, consequently, the change of intracellular level of sulfane sulfur as well as H2S and reactive oxygen species production.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL/Apo2L) is a highly selective and promising anticancer agent due to its specific apoptosis-inducing effect on tumor cells, rather than most normal cells. TRAIL is currently under investigation for use in the treatment of leukemia. However, the resistance of leukemic cells to TRAIL-induced apoptosis may limit its efficacy. The mechanisms of leukemic cell resistance to antitumor immunity remains a topical issue. In this work, we have found an increase in the resistance to TRAIL-induced cell death in human leukemia THP-1 cells, which was caused by differentiation into a macrophage-like phenotype in high-density culture in vitro. Stressful conditions, manifested by the inhibition of cell growth and the activation of cell death in high-density culture of THP-1 cells, induced the appearance of cells adhered to culture dishes. The THP-1ad cell line was derived by selection of these adhered cells. The genetic study, using STR and aCGH assays, has shown that THP-1ad cells were derived from THP-1 cells due to mutagenesis. The THP-1ad cells possessed high proliferative potential and a macrophage-like immunophenotype. The adhesion of THP-1ad cells to the extracellular matrix was mediated by αVβ5 integrin. The cytokine production, as well as the rise of intracellular ROS and NO activities by LPS in THP-1ad cell culture, were characteristic of macrophage-like cells. The THP-1ad cells were found to appear to increase in resistance to TRAIL-induced cell death in comparison with THP-1 cells. The mechanism of the increase in TRAIL-resistance can be related to a decrease in the expression of death receptors DR4 and DR5 on the THP-1ad cells. Thus, the macrophage-like phenotype formation with the maintenance of a high proliferative potential of leukemic cells, caused by stress conditions in high-density cell cultures in vitro, can induce an increase in resistance to TRAIL-induced cell death due to the loss of DR4 and DR5 receptors. The possible realization of these events in vivo may be the reason for tumor progression.

Leukemia, a highly malignant form of cancer, relies on early diagnosis for effective treatment and patient survival. Currently, leukemia is diagnosed by manually identifying blood cells through recognizing morphological features using staining techniques. In this work, we achieve rapid, accurate, label-free identification and categorization of four important leukemia cell lines to a subclass level using Raman spectroscopy and an identification model. The flat gold film-covered glass substrates ensure cell intact, good morphology and high-quality Raman spectra. Although the shapes of unstained erythrocytes, K562, U937 and Raji B cells are similar, their spectra are different. The sensitivity, the specificity and the accuracy of the unsupervised identification model (PCA-KMCA) of these four cell lines were 93.75%, 96.67%, and 97.50%, respectively. The accuracy of this model is higher than that of the supervised identification model (LDA-KNN) with an accuracy of 90.62%. Further, the unsupervised identification (PCA-KMCA) of Raji B and Jurkat cells could be greatly achieved, with sensitivity of 96.25%, specificity of 97.50% and accuracy of 96.88%. This method has great potential in the early diagnosis of leukemia, which can help doctors determine treatment plans faster and improve the prognosis of patients. • An unstained method is crucial for the rapid and accurate early diagnosis of diseases. • Different leukemia cell lines were differentiated at the protein level. • Unsupervised classification used Raman spectra to differentiate leukemia cell lines. • Raman spectra differentiated ALL subclasses via unsupervised classification. [ABSTRACT FROM AUTHOR]

Chalcone and thiosemicarbazone have attracted attention due to their easy synthetic procedure and high success in the development of antiviral and antitumor, however, there are few biological data on the evaluation of chalcone-thiosemicarbazone hybrids and their complexation with metal ions. In this sense, the present work reports the synthesis and characterization of the hybrid (Z)-2-((E)-3-(4-chlorophenyl)-1-phenylallylidene)hydrazine-1-carbothioamide (CTCl) and its Zn(II)-complex (CTCl-Zn). The compounds were cell-based evaluated in terms of cytotoxicity against human T-cell lymphotropic virus type 1 (HTLV-1) infected leukemia cells (MT-2) and the experimental data were correlated with molecular docking calculations. The ligand and Zn(II)-complex were easily synthesized with a good yield - 57% and 79%, respectively. The dynamic of E/Z isomers with respect to the imine bond configuration of CTCl was evidenced by 1H NMR experiments in DMSO‑ d 6 , while the X-ray diffraction of CTCl-Zn showed that Zn(II) ion is tetracoordinated to two ligands in a bidentate mode and the metal ion lies on an intermediate geometry between the see-saw and trigonal pyramid. The ligand and complex exhibited low toxicity and the Zn(II)-complex is more cytotoxic than the ligand, with the corresponding IC 50 value of 30.01 and 47.06 μM. Both compounds had a pro-apoptotic effect without the release of reactive oxygen species (ROS) and they can interact with DNA via minor grooves driven by van der Waals forces. A novel Zn(II) complex with a chalcone-thiosemicarbazone was more cytotoxic than the free ligand toward a virus-infected leukemia cell (MT-2), with a pro-apoptotic effect without the release of reactive oxygen species. Both compounds can interact with DNA mainly via minor grooves driven by van der Waals forces. [Display omitted] • A novel Zn(II) complex based on chalcone-thiosemicarbazone hybrid was prepared. • Both compounds exhibited low toxicity in Artemia salina nauplii. • Zn(II) complex is more cytotoxic than ligand in infected leukemia cells. • The complex and ligand interact with DNA via minor groove by van der Waals forces. [ABSTRACT FROM AUTHOR]

Previous studies demonstrated that CD4 + T cells can uptake tumor antigen-pulsed dendritic cell-derived exosomes (DEXO), which harbor tumor antigen peptide/pMHC I complex and costimulatory molecules and show potent effects on inducing antitumor immunity. However, in preliminary study, CD4 + T cells targeted by leukemia cell-derived exosomes (LEXs) did not show the expected effects in inducing effective anti-leukemia immunity, indicating that LEX is poorly immunogenetic largely due to an inadequate costimulatory capacity. Therefore, LEX-based anti-leukemia vaccines need to be optimized. In this study, we constructed a novel LEX-based vaccine by combining CD4 + T cells with costimulatory molecules gene-modified LEXs, which harbor upregulated CD80 and CD86, and the anti-leukemia immunity of CD80 and CD86 gene-modified LEX-targeted CD4 + T cells was investigated. We used lentiviral vectors encoding CD80 and CD86 to successfully transduced the L1210 leukemia cells, and the expression of CD80 and CD86 was remarkably upregulated in leukemia cells. The LEXs highly expressing CD80 and CD86 were obtained from the supernatants of gene-transduced leukemia cells. Our data have shown that LEX-CD8086 could promote CD4 + T cell proliferation and Th1 cytokine secretion more efficiently than control LEXs. Moreover, CD4 + T LEX-CD8086 expressed the acquired exosomal costimulatory molecules. With acquired costimulatory molecules, CD4 + T LEX-CD8086 can act as APCs and are capable of directly stimulating the leukemia cell antigen-specific CD8 + CTL response. This response was higher in potency compared to that noted by the other formulations. Furthermore, the animal study revealed that the CD4 + T LEX-CD8086 significantly inhibited tumor growth and prolonged survival of tumor-bearing mice than other formulations did in both protective and therapeutic models. In conclusion, this study revealed that CD4 + T LEX-CD8086 could effectively induce more potential anti-leukemia immunity than LEX-CD8086 alone, suggesting that the utilization of a costimulatory molecule gene-modified leukemia cell-derived exosome-targeted CD4 + T cell vaccine may have promising potential for leukemia immunotherapy., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Li, Huang, Jiang, Zhao, Wan and Hao.)

The prodrug approach, as well as the development of specific systems able to deliver a chemotherapeutic agent in the target site, decreasing the side effects often associated with its administration, are still a challenging. In this context, both methotrexate drug molecules (MTX) and biotin ligand moieties, whose receptors are overexpressed on the surface of several cancer cells, were loaded on halloysite nanotubes (HNTs) to develop nanomaterial based on multifunctional and "smart" delivery systems. To highlight the crucial role played by biotin, carrier systems based on HNTs and MTX were also synthetized. In detail, several approaches were envisaged: i) a supramolecular interaction between the clay and the drug; ii) a covalent grafting of the drug onto the HNTs external surface and, iii) a combination of both approaches. The nanomaterials obtained were characterized by thermogravimetric analysis, FT-IR, and UV- vis spectroscopies, DLS and ζ−potential measurements and the morphologies were imaged by HAADF/STEM investigations. Kinetic release experiments at different pH conditions were also performed. Finally, as a proof-of-concept application of our pro-drug delivery systems based on HNTs in cancer therapy, the cytotoxic effects were evaluated on acute myeloid leukemia cell lines, HL60 and its multidrug resistance variant, HL60R. The obtained results showed that both the MTX prodrug system and the biotinylated ones played a crucial role in the biological activity and, they are promising agents for the cancer treatments. [Display omitted] • Methotrexate (MTX) was both loaded and grafted on halloysite nanotubes (HNTs). • Different approaches allowed to obtained innovative HNTs based prodrugs. • An active targeting system based on biotin was also developed. • The nanomaterials showed enhanced antitumoral activity on two leukemia cell lines. [ABSTRACT FROM AUTHOR]

Simple Summary: The mechanisms of leukemic cell resistance to antitumor immunity remains a topical issue. In this work, we found an increase in TRAIL-resistance of human acute myeloid leukemia cells THP-1 in high-density populations in vitro. The results obtained show that a macrophage-like phenotype of the acute myeloid leukemia cells, caused by stressful conditions in high-density culture, can increaser resistance to TRAIL-induced apoptosis, while retaining proliferative potential. The mechanism of the increase in TRAIL-resistance can be related to a decrease in the expression of death receptors DR4 and DR5. The possible realization of these events in vivo may be the reason for tumor progression. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL/Apo2L) is a highly selective and promising anticancer agent due to its specific apoptosis-inducing effect on tumor cells, rather than most normal cells. TRAIL is currently under investigation for use in the treatment of leukemia. However, the resistance of leukemic cells to TRAIL-induced apoptosis may limit its efficacy. The mechanisms of leukemic cell resistance to antitumor immunity remains a topical issue. In this work, we have found an increase in the resistance to TRAIL-induced cell death in human leukemia THP-1 cells, which was caused by differentiation into a macrophage-like phenotype in high-density culture in vitro. Stressful conditions, manifested by the inhibition of cell growth and the activation of cell death in high-density culture of THP-1 cells, induced the appearance of cells adhered to culture dishes. The THP-1ad cell line was derived by selection of these adhered cells. The genetic study, using STR and aCGH assays, has shown that THP-1ad cells were derived from THP-1 cells due to mutagenesis. The THP-1ad cells possessed high proliferative potential and a macrophage-like immunophenotype. The adhesion of THP-1ad cells to the extracellular matrix was mediated by αVβ5 integrin. The cytokine production, as well as the rise of intracellular ROS and NO activities by LPS in THP-1ad cell culture, were characteristic of macrophage-like cells. The THP-1ad cells were found to appear to increase in resistance to TRAIL-induced cell death in comparison with THP-1 cells. The mechanism of the increase in TRAIL-resistance can be related to a decrease in the expression of death receptors DR4 and DR5 on the THP-1ad cells. Thus, the macrophage-like phenotype formation with the maintenance of a high proliferative potential of leukemic cells, caused by stress conditions in high-density cell cultures in vitro, can induce an increase in resistance to TRAIL-induced cell death due to the loss of DR4 and DR5 receptors. The possible realization of these events in vivo may be the reason for tumor progression. [ABSTRACT FROM AUTHOR]

The studies concerned the expression of sulfurtransferases and cystathionine beta-synthase in six human leukemia cell lines: B cell acute lymphoblastic leukemia-B-ALL (REH cells), T cell acute lymphoblastic leukemia-T-ALL (DND-41 and MOLT-4 cells), acute myeloid leukemia—AML (MV4-11 and MOLM-14 cells), and chronic myeloid leukemia—CML (K562 cells). Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis were performed to determine the expression of thiosulfate sulfurtransferase, 3-mercaptopyruvate sulfurtransferase, gamma-cystathionase, and cystathionine beta-synthase on the mRNA and protein level. Interestingly, we found significant differences in the mRNA and protein levels of sulfurtransferases and cystathionine beta-synthase in the studied leukemia cells. The obtained results may contribute to elucidating the significance of the differences between the studied cells in the field of sulfur compound metabolism and finding new promising ways to inhibit the proliferation of various types of leukemic cells by modulating the activity of sulfurtransferases, cystathionine beta-synthase, and, consequently, the change of intracellular level of sulfane sulfur as well as H2S and reactive oxygen species production. [ABSTRACT FROM AUTHOR]

Aim: To synthesize new analogues of ponatinib and evaluate anti-leukemia cells and cytotoxicity. Methodology & results: The inhibitory activity of compounds 13a and 13c against K562 and HL60 cells was comparable to that of ponatinib (IC 50  = 0.74, 0.88 vs 0.64 nM and 0.59, 0.77 vs 0.39 nM, respectively). Compounds 13a and 40b were 34- and 77-fold more potent than ponatinib against KG1a cells (IC 50  = 0.091 and 0040 vs 3.6 μM, respectively). Compounds 13a , 13c and 40b also decreased the Abl protein level in the K562 cells, inhibited colony formation in MCF-7 cells and inhibited cell migration in B16BL6 cells. Compound 13a showed low cytotoxicity in 293 cells. Conclusion: Compound 13a was the best lead compound.

Silibinin is the main biologically active component of silymarin extract and consists of a mixture 1:1 of two diastereoisomeric flavonolignans, namely silybin A ( 1a ) and silybin B ( 1b ), which we call here silybins. Despite the high interest in the activity of this flavonolignan, there are still few studies that give due attention to the role of its stereochemistry and, there is still today a strong need to investigate in this area. In this regard, here we report a study concerning the radical scavenger ability and the antiproliferative activity on different cell lines, both of silybins and phosphodiester-linked silybin dimers. An efficient synthetic strategy to obtain silybin dimers in an optical pure form ( 6aa , 6ab and 6bb ) starting from a suitable building block of silybin A and silybin B, obtained by us from natural extract silibinin, was proposed. New dimers show strong antioxidant properties, determined through hydroxyl radical (HO ● ) scavenging ability, comparable to the value reported for known potent antioxidants such as quercetin. A preliminary screening was performed by treating cells with 10 and 50 μM concentrations for 48 h to identify the most sensitive cell lines. The results show that silibinin compounds were active on Jurkat, A375, WM266, and HeLa, but at the tested concentrations, they did not interfere with the growth of PANC, MCF-7, HDF or U87. In particular, both monomers ( 1a and 1b ) and dimers ( 6aa , 6ab and 6bb ) present selective anti-proliferative activity towards leukemia cells in the mid-micromolar range and are poorly active on normal cells. They exhibit different mechanisms of action in fact all the cells treated with the 1a and 1b go completely into apoptosis, whereas only part of the cells treated with 6aa and 6ab were found to be in apoptosis.

This article described the synthesis and biological investigation of a series of symmetric diarylpentanoids, characterized by a dienone moiety and by a different pattern of substitution on the two phenyl rings. The series of compounds 1a-p were tested against drug-sensitive CCRF-CEM and multidrug-resistant CEM/ADR5000 cells to evaluate their cytotoxic profile, and all the diarypentanoids revealed to be active against both the leukemia cell lines, with the best activity shown by compound 1o that showed a submicromolar activity against both CCRF-CEM and CEM/ADR5000 cell lines (EC 50 =0.54 and 0.25 μM, respectively)., (© 2021 Wiley-VHCA AG, Zurich, Switzerland.)