Human Chronic Myeloid Leukemia Research Articles

BCAT1 contributes to the development of TKI-resistant CML.

Although most of chronic myeloid leukemia (CML) patients can be effectively treated by the tyrosine kinase inhibitors (TKIs), such as Imatinib, TKI-resistance still occurs in approximately 15-17% of cases. Although many studies indicate that branched chain amino acid (BCAA) metabolism may contribute to the TKI resistance in CML, the detailed mechanisms remains largely unknown. The cell proliferation, colony formation and in vivo transplantation were used to determined the functions of BCAT1 in leukemogenesis. Quantitative real-time PCR (RT-PCR), western blotting, RNA sequencing, BCAA stimulation in vitro were applied to characterize the underlying molecular mechanism that control the leukemogenic activity of BCAT1-knockdown cells. In this report, we revealed that branched chain amino acid transaminase 1 (BCAT1) is highly enriched in both mouse and human TKI-resistant CML cells. Leukemia was almost completely abrogated upon BCAT1 knockdown during transplantation in a BCR-ABLT315I-induced murine TKI-resistant CML model. Moreover, knockdown of BCAT1 led to a dramatic decrease in the proliferation of TKI-resistant human leukemia cell lines. BCAA/BCAT1 signaling enhanced the phosphorylation of CREB, which is required for maintenance of TKI-resistant CML cells. Importantly, blockade of BCAA/BCAT1 signaling efficiently inhibited leukemogenesis both in vivo and in vitro. These findings demonstrate the role of BCAA/BCAT1 signaling in cancer development and suggest that targeting BCAA/BCAT1 signaling is a potential strategy for interfering with TKI-resistant CML.

Progesterone decreases viability and up regulates membrane progesterone receptors expression on the human Chronic Myeloid Leukemia cell line

Progesterone (P4)) has an important effect (activatory or inhibitory) on cell proliferation. Although there is evidence of the impact of progesterone on sex-linked cancers, it can affect other cancer cells expressing P4 receptors (PRs). We evaluated the expression of membrane P4 receptors (mPRs) and the viability in progesterone-treated K562 cells to inspect the possible effects route of progesterone on this (CML) cancer cell line. K562 cells were exposed to various concentrations of progesterone or no exposure for 48 and 72 hours. The percentage of viability and cells that expressed mPRα and mPRβ were evaluated by MTT test and flow cytometry respectively. Progesterone significantly increased the expression of mPRα and especially mPRβ on the surface of K562 cells and significantly decreased their viability (p ≤ 0.05). Progesterone can reduce viability in K562 cells. Our findings showed that progesterone affects its receptor expression on K562 cells. Thus it may influence the performance of K562 cells in addition to its direct effects on these cells (via binding to its receptors).

Ultrasound-assisted extraction of withanolides from Tubocapsicum anomalum: Process optimization, isolation and identification, and antiproliferative activity

Tubocapsicum anomalum, a Chinese medicinal plant rich in anti-tumor withanolides, requires efficient extraction methods. In this paper, an HPLC method was first established for the detection of withanolides, and gradient elution was carried out using a methanol–water solvent system. It was found that the content of withanolides was the highest in the leaves of T. anomalum, followed by the stems and fruits, and almost none in the roots. During the actual picking process, the quantity of leaves collected was relatively small, while the number of stems was the highest. Therefore, the Box-Behnken response surface method was used to optimize the ultrasonic-assisted extraction process of withanolides from the stems of T. anomalum. The optimal extraction conditions were determined as follows: the liquid–solid ratio was 20:1, the extraction solvent was 70 % ethanol, the ultrasonic power was 250 W, the ultrasonic time was 40 min, and the ultrasonic temperature was 50 °C. Under these conditions, the average yields of tubocapsenolide A (Te-A) and tubocapsanolide A (Ta-A) can reach 2.87 ± 0.12 mg/g and 1.18 ± 0.05 mg/g, respectively. We further compared extraction rates of two withanolides from different parts of T. anomalum using ultrasonic and traditional extraction methods. Ultrasonic extraction significantly increased rates, with the highest yields from leaves, followed by stems and fruits. The results show that ultrasonic optimization can improve extraction rate, reduce time, lower costs, enhance quality, and increase yield. Therefore, the optimized ultrasonic-assisted extraction process was adopted to extract the aerial parts of T. anomalum and separate the components. After optimization, the extract underwent several chromatographic separations to isolate eight previously undescribed withanolides (1–8) and two artificial withanolides (9–10), in addition to fifteen known compounds (11–25). Their structures were established through extensive spectroscopic data analysis. The compounds were evaluated for their antiproliferative effects against multiple cancer cell lines, including human hepatocellular carcinoma cells (HepG2, Hep3B, and MHCC97-H), human lung cancer cells (A549), human fibro-sarcoma cancer cells (HT1080), human chronic myeloid leukemia cells (K562), and human breast cancer cells (MDA-MB-231 and MCF7). Compounds 1–3, 5, 7, 11, 13, 15–16, and 22 displayed significant activity with IC50 values of 5.14–19.87 μM. The above results indicate that ultrasonic-assisted extraction technology can be used to obtain new withanolides more efficiently from T. anomalum, thereby enhancing the utilization rate of T. anomalum resources.

Proteomic Dynamics of Multidrug Resistance Mechanisms in Lucena 1 Cell Line.

The Lucena 1 cell line, derived from the human chronic myeloid leukemia cell line K562 under selective pressure of vincristine supplementation, exhibits multidrug resistance (MDR). This study aims to explore and elucidate the underlying mechanisms driving MDR in the Lucena 1 cell line. A proteomic analysis comparing K562 and Lucena 1 revealed qualitative differences, with a focus on the ATP-dependent efflux pump, Translocase ABCB1, a key contributor to drug resistance. Tubulin analysis identified two unique isoforms, Tubulin beta 8B and alpha chain-like 3, exclusive to Lucena 1, potentially influencing resistance mechanisms. Additionally, the association of Rap1A and Krit1 in cytoskeletal regulation and the presence of STAT1, linked to the urea cycle and tumor development, offered insights into Lucena 1's distinctive biology. The increased expression of carbonic anhydrase I suggested a role in pH regulation. The discovery of COP9, a tumor suppressor targeting p53, further highlighted the Lucena 1 complex molecular landscape. This study offers new insights into the MDR phenotype and its multifactorial consequences in cellular pathways. Thus, unraveling the mechanisms of MDR holds promise for innovating cancer models and antitumor targeted strategies, since inhibiting the P-glycoprotein (P-gp)/ABCB1 protein is not always an effective approach given the associated treatment toxicity.

Glutathione determines chronic myeloid leukemia vulnerability to an inhibitor of CMPK and TMPK

Bcr-Abl transformation leads to chronic myeloid leukemia (CML). The acquirement of T315I mutation causes tyrosine kinase inhibitors (TKI) resistance. This study develops a compound, JMF4073, inhibiting thymidylate (TMP) and cytidylate (CMP) kinases, aiming for a new therapy against TKI-resistant CML. In vitro and in vivo treatment of JMF4073 eliminates WT-Bcr-Abl-32D CML cells. However, T315I-Bcr-Abl-32D cells are less vulnerable to JMF4073. Evidence is presented that ATF4-mediated upregulation of GSH causes T315I-Bcr-Abl-32D cells to be less sensitive to JMF4073. Reducing GSH biosynthesis generates replication stress in T315I-Bcr-Abl-32D cells that require dTTP/dCTP synthesis for survival, thus enabling JMF4073 susceptibility. It further shows that the levels of ATF4 and GSH in several human CML blast-crisis cell lines are inversely correlated with JMF4073 sensitivity, and the combinatory treatment of JMF4073 with GSH reducing agent leads to synthetic lethality in these CML blast-crisis lines. Altogether, the investigation indicates an alternative option in CML therapy.

Overcoming flumatinib resistance in chronic myeloid leukaemia: Insights into cellular mechanisms and ivermectin's therapeutic potential.

Chronic myeloid leukaemia (CML) is a haematological malignancy characterized by the constitutive tyrosine kinase activity of the BCR-ABL1 fusion protein. Flumatinib, a second-generation tyrosine kinase inhibitor, has exhibited superior clinical efficacy compared to its precursor, imatinib. However, with increased clinical use, resistance to flumatinib has emerged as a significant challenge. To investigate the mechanisms of flumatinib resistance in CML, we induced the human CML cell line K562 using a flumatinib concentration gradient method invitro, successfully establishing a flumatinib-resistant K562/FLM cell line. This cell line exhibited cross-resistance to imatinib and doxorubicin, but remained sensitive to the antiparasitic agent ivermectin, which possesses antitumoural effects. Through cellular experimentation, we explored the resistance mechanisms, which indicated that K562/FLM cells evade flumatinib cytotoxicity by enhancing autophagy, increasing the expression of membrane transport proteins, particularly P-glycoprotein, ABCC1 and ABCC4, as well as enhancing phosphorylation of p-EGFR, p-ERK and p-STAT3 proteins. Moreover, it was found that ivermectin effectively suppressed the expression of autophagy and transport proteins in K562/FLM cells, reduced the activity of the aforementioned phosphoproteins, and promoted apoptotic cell death. Collectively, the increased autophagy, higher expression of drug-efflux proteins and hyperactivation of the EGFR/ERK/STAT3 signalling pathway were identified as pivotal elements promoting resistance to flumatinib. The significant effects of ivermectin might offer a novel therapeutic strategy to overcome flumatinib resistance and optimize the treatment outcomes of CML.

Asciminib, a novel allosteric inhibitor of BCR-ABL1, shows synergistic effects when used in combination with imatinib with or without drug resistance.

In the treatment of chronic myeloid leukemia (CML), resistance to BCR-ABL inhibitors makes it difficult to continue treatment and is directly related to life expectancy. Therefore, asciminib was introduced to the market as a useful drug for overcoming drug resistance. While combining molecular targeted drugs is useful to avoid drug resistance, the new BCR-ABL inhibitor asciminib and conventional BCR-ABL inhibitors should be used as monotherapy in principle. Therefore, we investigated the synergistic effect and mechanism of the combination of asciminib and imatinib. We generated imatinib-resistant cells using the human CML cell line K562, examined the effects of imatinib and asciminib exposure on cell survival using the WST-8 assay, and comprehensively analyzed genetic variation related to drug resistance using RNA-seq and real-time PCR. A synergistic effect was observed when imatinib and asciminib were combined with or without imatinib resistance. Three genes, GRRP1, ESPN, and NOXA1, were extracted as the sites of action of asciminib. Asciminib in combination with BCR-ABL inhibitors may improve the therapeutic efficacy of conventional BCR-ABL inhibitors and prevent the development of resistance. Its dosage may be effective even at minimal doses that do not cause side effects. Further verification of this mechanism of action is needed. Additionally, cross-resistance between BCR-ABL inhibitors and asciminib may occur, which needs to be clarified through further validation as soon as possible.

HIF-2α inhibition disrupts leukemia stem cell metabolism and impairs vascular microenvironment to enhance chronic myeloid leukemia treatment

Leukemic stem cells (LSCs) in chronic myeloid leukemia (CML) contribute to treatment resistance and disease recurrence. Metabolism regulates LSCs, but the mechanisms remain elusive. Here, we show that hypoxia-inducible factor 2α (HIF-2α) is highly expressed in LSCs in mouse and human CML and increases after tyrosine kinase inhibitor (TKI) treatment. Deletion of HIF-2α suppresses disease progression, reduces LSC numbers, and enhances the efficacy of TKI treatment in BCL-ABL-induced CML mice. Mechanistically, HIF-2α deletion reshapes the metabolic profile of LSCs, leading to increased production of reactive oxygen species (ROS) and apoptosis in CML. Moreover, HIF-2α deletion decreases vascular endothelial growth factor (VEGF) expression, thereby suppressing neovascularization in the bone marrow of CML mice. Furthermore, pharmaceutical inhibition of HIF-2α by PT2399 attenuates disease progression and improves the efficacy of TKI treatment in both mouse and human CML. Overall, our findings highlight the role of HIF-2α in controlling the metabolic state and vascular niche remodeling in CML, suggesting it is a potential therapeutic target to enhance TKI therapy.

Nutrient-sensitizing drug repurposing screen identifies lomerizine as a mitochondrial metabolism inhibitor of chronic myeloid leukemia.

In chronic myeloid leukemia (CML), the persistence of leukemic stem cells (LSCs) after treatment with tyrosine kinase inhibitors (TKIs), such as imatinib, can lead to disease relapse. It is known that therapy-resistant LSCs rely on oxidative phosphorylation (OXPHOS) for their survival and that targeting mitochondrial respiration sensitizes CML LSCs to imatinib treatment. However, current OXPHOS inhibitors have demonstrated limited efficacy or have shown adverse effects in clinical trials, highlighting that identification of clinically safe oxidative pathway inhibitors is warranted. We performed a high-throughput drug repurposing screen designed to identify mitochondrial metabolism inhibitors in myeloid leukemia cells. This identified lomerizine, a US Food and Drug Administration (FDA)-approved voltage-gated Ca2+ channel blocker now used for the treatment of migraines, as one of the top hits. Transcriptome analysis revealed increased expression of voltage-gated CACNA1D and receptor-activated TRPC6 Ca2+ channels in CML LSCs (CD34+CD38-) compared with normal counterparts. This correlated with increased endoplasmic reticulum (ER) mass and increased ER and mitochondrial Ca2+ content in CML stem/progenitor cells. We demonstrate that lomerizine-mediated inhibition of Ca2+ uptake leads to ER and mitochondrial Ca2+ depletion, with similar effects seen after CACNA1D and TRPC6 knockdown. Through stable isotope-assisted metabolomics and functional assays, we observe that lomerizine treatment inhibits mitochondrial isocitrate dehydrogenase activity and mitochondrial oxidative metabolism and selectively sensitizes CML LSCs to imatinib treatment. In addition, combination treatment with imatinib and lomerizine reduced CML tumor burden, targeted CML LSCs, and extended survival in xenotransplantation model of human CML, suggesting this as a potential therapeutic strategy to prevent disease relapse in patients.

A Carbon 21 Steroidal Glycoside with Pregnane Skeleton from Cynanchum atratum Bunge Promotes Megakaryocytic and Erythroid Differentiation in Erythroleukemia HEL Cells through Regulating Platelet-Derived Growth Factor Receptor Beta and JAK2/STAT3 Pathway.

Erythroleukemia is a rare form of acute myeloid leukemia (AML). Its molecular pathogenesis remains vague, and this disease has no specific therapeutic treatments. Previously, our group isolated a series of Carbon 21 (C-21) steroidal glycosides with pregnane skeleton from the root of Cynanchum atratum Bunge. Among them, we found that a compound, named BW18, can induce S-phase cell cycle arrest and apoptosis via the mitogen-activated protein kinase (MAPK) pathway in human chronic myeloid leukemia K562 cells. However, its anti-tumor activity against erythroleukemia remains largely unknown. In this study, we aimed to investigate the anti-erythroleukemia activity of BW18 and the underlying molecular mechanisms. Our results demonstrated that BW18 exhibited a good anti-erythroleukemia activity in the human erythroleukemia cell line HEL and an in vivo xenograft mouse model. In addition, BW18 induced cell cycle arrest at the G2/M phase and promoted megakaryocytic and erythroid differentiation in HEL cells. Furthermore, RNA sequencing (RNA-seq) and rescue assay demonstrated that overexpression of platelet-derived growth factor receptor beta (PDGFRB) reversed BW18-induced megakaryocytic differentiation in HEL cells, but not erythroid differentiation. In addition, the network pharmacology analysis, the molecular docking and cellular thermal shift assay (CETSA) revealed that BW18 could inactivate Janus tyrosine kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway, which might mediate BW18-induced erythroid differentiation. Taken together, our findings elucidated a novel role of PDGFRB in regulating erythroleukemia differentiation and highlighted BW18 as an attractive lead compound for erythroleukemia treatment.

Indirubin, an Active Component of Indigo Naturalis, Exhibits Inhibitory Effects on Leukemia Cells via Targeting HSP90AA1 and PI3K/Akt Pathway.

This research intended to predict the active ingredients and key target genes of Indigo Naturalis in treating human chronic myeloid leukemia (CML) using network pharmacology and conduct the invitro verification. The active components of Indigo Naturalis and the corresponding targets and leukemia-associated genes were gathered through public databases. The core targets and pathways of Indigo Naturalis were predicted through protein-protein interaction (PPI) network, gene ontology (GO) function, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Next, after intersecting with leukemia-related genes, the direct core target gene of Indigo Naturalis active components was identified. Subsequently, HL-60 cells were stimulated with indirubin (IND) and then examined for cell proliferation using CCK-8 assay and cell cycle, cell apoptosis, and mitochondrial membrane potential using flow cytometry. The content of apoptosis-associated proteins (Cleaved Caspase 9, Cleaved Caspase 7, Cleaved Caspase 3, and Cleaved parp) were detected using Western blot, HSP90AA1 protein, and PI3K/Akt signaling (PI3K, p-PI3K, Akt, and p-Akt) within HL-60 cells. A total of 9 active components of Indigo Naturalis were screened. The top 10 core target genes (TNF, PTGS2, RELA, MAPK14, IFNG, PPARG, NOS2, IKBKB, HSP90AA1, and NOS3) of Indigo Naturalis active components within the PPI network were identified. According to the KEGG enrichment analysis, these targets were associated with leukemia-related pathways (such as acute myeloid leukemia and CML). After intersecting with leukemia-related genes, it was found that IND participated in the most pairs of target information and was at the core of the target network; HSP90AA1 was the direct core gene of IND. Furthermore, the in-vitro cell experiments verified that IND could inhibit the proliferation, elicit G2/M-phase cell cycle arrest, enhance the apoptosis of HL-60 cells, reduce mitochondrial membrane potential, and promote apoptosis-related protein levels. Under IND treatment, HSP90AA1 overexpression notably promoted cell proliferation and inhibited apoptosis. Additionally, IND exerted tumor suppressor effects on leukemia cells by inhibiting HSP90AA1 expression. IND, an active component of Indigo Naturalis, could inhibit CML progression, which may be achieved via inhibiting HSP90AA1 and PI3K/Akt signaling expression levels.

Evaluation of multidrug resistance in tumors using 99mTc-doxorubicin

Doxorubicin (DOX) is a potent chemotherapeutic agent used as the first-choice drug in treating different types of cancer, such as leukemia, lymphoma, and breast cancer, among others. However, the development of multidrug resistance represents a significant obstacle to the successful treatment of tumors. In this study, we assessed whether labeled DOX could be uptaken by susceptible and multidrug-resistant cell lines and by tumors in vivo in animals. The efficiency of DOX labeling was maintained at around 90% in this work. To evaluate the effect of 99mTc-DOX on cells expressing active P-glycoprotein (Pgp), we utilized cultured human chronic myeloid leukemia K562 cells and the resistant counterpart Lucena 1 cells. Lucena 1 cell line showed overexpression of Pgp that was not observed in K562. Our results suggested that the resistance to labeled or unlabeled DOX can be reversed by Pgp inhibition and can be easily detected. In conclusion, administering 99mTc-DOX into mice enables the differentiation between multidrug-resistant tumors in a non-invasive way and the evaluation of tumor resistance and possible chemosensitizers.

Abstract 2307: State-transition modeling of blood transcriptome predicts disease evolution and treatment response in chronic myeloid leukemia (CML)

Abstract Chronic myeloid leukemia (CML) is initiated and initially maintained by BCR-ABL which is clinically targeted using tyrosine kinase inhibitors (TKIs). Although TKIs can induce long-term remission, they are frequently not curative. Thus, CML is an ideal system to test our hypothesis that transcriptome-based state-transition models accurately predict cancer evolution and treatment response. We collected time-sequential blood samples from tetracycline-off (Tet-Off) BCR-ABL-inducible transgenic mice that recapitulates human chronic phase CML and wild-type controls. From the transcriptome, we constructed a CML state-space and a three-well leukemogenic potential landscape that describes CML state-transition from health to disease. The potential’s stable critical points were used to define three distinct disease states. The Early state was characterized by anti-CML genes (n=35) that opposed leukemia progression, whereas an expanding number of pro-CML genes characterized the Transition state (n=357) and Late states (n=1,858). Gene modules that were co-regulated at the unstable points in the potential landscape were identified as the drivers of transition between stable disease states. To investigate CML therapies we used two treatments: silencing of BCR/ABL by readministering Tet (Tet-on, Tet-off [TOTO]) which represented a best-case scenario of disease being cured, and TKI (nilotinib) therapy which represents current clinical practice. TOTO returned the diseased mice transcriptomes to a near health state, without reaching it, suggesting partly irreversible transformation. TKI, however, only reverted the transcriptome to an intermediate disease state, without approaching health, and disease relapse occurred soon after treatment. Finally, using only the earliest time-point as initial conditions, our state-transition models accurately predicted both disease progression and treatment response to both therapies for each individual mouse. In conclusion, these results show state-transition analysis is a valuable approach to gain real time insights into CML development, progression and ongoing treatment response that can also be applied to other type of leukemia and cancers in general. We predicted disease evolution and treatment response in a murine model that recapitulates human disease, supporting this as a potentially valuable approach to time clinical intervention even before phenotypic changes become detectable. Citation Format: David E. Frankhouser, Russell C. Rockne, Dandan Zhao, Sergio Branciamore, Lisa Uechi, Denis O'Meally, Yu-Hsuan Fu, Ya-Huei Kuo, Bin Zhang, Guido Marcucci. State-transition modeling of blood transcriptome predicts disease evolution and treatment response in chronic myeloid leukemia (CML) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2307.

Antiproliferative and Apoptosis-Inducing Effects of Ethanolic Extract of Morus Alba Leaves on Human Chronic Myeloid Leukaemia K-562 Cell Lines

The rate of occurrence and prevalence of chronic myeloid leukaemia (CML) are increasing globally, despite it being a rare type of cancer. Morus alba also known as mulberry, has been used in Chinese traditional medicine for a long time to treat various conditions and diseases like hypertension and arthritis. Modern scientific studies have also recognized its medicinal properties, including antioxidant, antidiuretic, antidiabetic, antimicrobial and anticancer. However, its antiproliferative effects on specifically human CML K-562 cell lines remain poorly elucidated. This study aims to determine the antiproliferative effects of M. alba on K-562 cells. In vitro cytotoxicity was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Acridine orange and propidium iodide (AO/PI) dual staining were then employed to assess the method of cell death. The ethanolic extract of M. alba leaves exhibited significant antiproliferative activity, with the lowest maximal half inhibitory concentration (IC50) value observed at 72 hours being 23 µg/mL. Notably, AO/PI staining revealed significant morphological changes, such as membrane blebbing, nuclear fragmentation, and indicator of early apoptosis, and late apoptosis. These results demonstrated that ethanolic extract of M. alba leaves induces apoptotic cell death in K-562 cells. Overall, these findings suggested that ethanolic extract of M. alba leaves exerts potent antiproliferative effects on human CML K-562 cells a in time- and dose-dependent manner.

Anticancer activity features of imidazole-based ionic liquids and lysosomotropic detergents: in silico and in vitro studies.

Long-chain imidazole-based ionic liquids (compounds 2, 4, 9) and lysosomotropic detergents (compounds 7, 3, 8) with potent anticancer activity were synthesized. Their inhibitory activities against neuroblastoma and leukaemia cell lines were predicted by the new in silico QSAR models. The cytotoxic activities of the synthesized imidazole derivatives were investigated on the SK-N-DZ (human neuroblastoma) and K-562 (human chronic myeloid leukaemia) cell lines. Compounds 2 and 7 showed the highest in vitro cytotoxic effect on both cancer cell lines. The docking procedure of compounds 2 and 7 into the NAD+ coenzyme binding site of deacetylase Sirtuin-1 (SIRT-1) showed the formation of protein-ligand complexes with calculated binding energies of -8.0 and - 8.1kcal/mol, respectively. The interaction of SIRT1 with compounds 2, 7 and 9 and the interaction of Bromodomain-containing protein 4 (BRD4) with compounds 7 and 9 were also demonstrated by thermal shift assay. Compounds 2, 4, 7 and 9 inhibited SIRT1 deacetylase activity in the SIRT-Glo assay. Compounds 7 and 9 showed a moderate inhibitory activity against Aurora kinase A. In addition, compounds 3, 4, 8 and 9 inhibited the Janus kinase 2 activity. The results obtained showed that long-chain imidazole derivatives exhibited cytotoxic activities on K562 leukaemia and SK-N-DZ neuroblastoma cell lines. Furthermore, these compounds inhibited a panel of molecular targets involved in leukaemia and neuroblastoma tumorigenesis. All these results suggest that both long-chain imidazole-based ionic liquids and lysosomotropic detergents may be an effective alternative for the treatment of neuroblastoma and chronic myeloid leukemia and merit further investigation.

Bioassay-guided isolation of anti-leukemic steroids from Aglaia abbreviata by inducing apoptosis

The strategy of bioactivity-guided isolation is widely used to obtain active compounds as quickly as possible. Thus, the inhibitory effects on human erythroleukemia cells (HEL) were applied to guide the isolation of the anti-leukemic compounds from Aglaia abbreviata. As a result, 19 compounds (16 steroids, two phenol derivatives, and a rare C12 chain nor-sesquiterpenoid), including 13 new compounds, were isolated and identified based on spectroscopic data analysis, single-crystal X-ray diffraction data, and electronic circular dichroism (ECD) calculations. Among them, 9 steroids exhibited good selective anti-leukemic activity against HEL and K562 (human chronic myeloid leukemia cells) cells with IC50 values between 2.29 ± 0.18 μM and 19.58 ± 0.13 μM. Notably, all the active compounds had relatively lower toxicity on the normal human liver cell line (HL-7702). Furthermore, five compounds (1, 4, 8, 10, and 19) displayed good anti-inflammatory effects, with IC50 values between 7.15 ± 0.16 and 27.1 ± 0.37 μM. An α,β-unsaturated ketone or a 5,6Δ double bond was crucial for improving anti-leukemic effect from the structure–activity relationship analysis. The compound with the most potential, 14 was selected for the preliminary mechanistic study. Compound 14 can induce apoptosis and cause cell cycle arrest. The expression of the marker proteins, such as PARP and caspase 3, were notably effected by this compound, thus inducing apoptosis. In conclusion, our investigation implied that compound 14 may serve as a potential anti-leukemia agent.

Cell-penetrating peptide and cationic liposomes mediated siRNA delivery to arrest growth of chronic myeloid leukemia cells in vitro

Gene silencing through RNA interference (RNAi) is a promising therapeutic approach for a wide range of disorders, including cancer. Non-viral gene therapy, using specific siRNAs against BCR-ABL1, can be a supportive or alternative measure to traditional chronic myeloid leukemia (CML) tyrosine kinase inhibitor (TKIs) therapies, given the prevalence of clinical TKI resistance. The main challenge for such approaches remains the development of the effective delivery system for siRNA tailored to the specific disease model.The purpose of this study was to examine and compare the efficiency of endosomolytic cell penetrating peptide (CPP) EB1 and PEG2000-decorated cationic liposomes composed of polycationic lipid 1,26-bis(cholest-5-en-3-yloxycarbonylamino)-7,11,16,20-tetraazahexacosane tetrahydrochloride (2Х3) and helper lipid 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) for anti-bcr-abl siRNA delivery into the K562 human CML cell line. We show that both EB1 and 2Х3-DOPE-DSPE-PEG2000 (0.62 % mol.) liposomes effectively deliver siRNA into K562 cells by endocytic mechanisms, and the use of liposomes leads to more effective inhibition of expression of the targeted gene (BCR-ABL1) and cancer cell proliferation. Taken together, these findings suggest that PEG-decorated cationic liposomes mediated siRNA delivery allows an effective antisense suppression of certain oncogenes, and represents a promising new class of therapies for CML.

Effects of Apigenin and Apigenin- Loaded Nanogel on Induction of Apoptosis in Human Chronic Myeloid Leukemia Cells

Background: Diet plays an important role in cancer prevention. Apigenin, a flavonoid with thechemical formula C15H10O5, is abundantly present in vegetables. Vegetarian foods containing flavonoids are rich sources of bioactive compounds. Flavonoids have been utilized in herbal treatment. Nanogels are drug delivery systems based on polymers and are used in tissue engineering and for drug delivery. This study was conducted to compare the effects of apigenin and a nanodrug on the viability of the K562 cell line of chronic myeloid leukemia at different durations under laboratory conditions. Materials and Methods: Chitosan was first dissolved in 1% acetic acid, and ethylene dichloride EDC and NHS were added to the solution. Then, the nanodrug was prepared by loading apigenin into stearate–chitosan nanogel (scs nanogel), and its physical and morphological characteristics were evaluated by TEM, DLS, and FTIR. Trypan blue staining, MTT assay, and flow cytometry were used to analyze the effects of various concentrations of apigenin and apigenin-loaded chitosan–stearate nanogel (APG–SCS) at 24, 48, and 72 h after they were applied to the K562 cell line. Results: The diameter of the nanodrug particles was measured using DLS and confirmed by TEM. The K562 cells treated with APG–SCS and with apigenin exhibited significant differences compared with the control (P < 0.05). Apoptosis was detected by flow cytometry. Conclusion: This study showed that the toxic effects of apigenin and the nanodrug improved with increasing concentrations and exposure durations compared to those in the control.The toxic effect of apigenin loaded into the stearate-chitosan nanogel was greater than apigenin, and the toxic effects of both materials were greater compared to the control under laboratory conditions.[GMJ.2018;7:e1008]

Recognition of Phosphatidylserine Externalisation on Human Chronic Myeloid Leukaemia (K562) Cells Induced by Chrysanthemum morifolium Methanol Extract

Chrysanthemum morifolium is one of the common plants used in traditional Chinese herbal medicine and currently being discovered as an invaluable source for treatment of cancerous diseases. Conventional approach to leukaemia treatment such as chemotherapeutic agents results in good overall survival (OS) in patients but issues of multi-drug resistance (MDR) and disease heterogeneity can make chemotherapy less effective. Thus there is a constant need for alternative therapeutic strategy such as developing new anti-cancer drug from natural products. The present study is carried out mainly to detect phosphatidylserine externalisation as an apoptosis indicator on human chronic myeloid leukaemia (K562) cells induced by Chrysanthemum morifolium methanol extract. K562 cells were treated with indicated IC50 values of bud and flower methanol crude extracts for 24 hours. Phase contrast microscope was used to observe morphological changes in K562 cells post-treatment. Annexin V-FITC/PI apoptosis assay via flow cytometry was done to investigate apoptosis phenomena by detecting phosphatidylserine (PS) externalisation in treated K562 cells. Morphological observations using phase contrast microscopy showed distinct apoptotic characteristics in K562 cells treated with both bud and flower methanol extracts. Annexin V-FITC/PI assay demonstrated a significantly high apoptotic cell population and apoptotic rate (p <0.05) in treated K562 cells compared to control cells. The study outcomes presented promising anti-cancer ability for Chrysanthemum morifolium.

P-Terphenyl and Diphenyl Ether Derivatives from the Marine-Derived Fungus Aspergillus candidus HM5-4.

Two undescribed p-terphenyl derivatives, asperterphenylcins A-B (1-2), and two undescribed diphenyl ether derivatives, asperdiphenylcins A-B (3-4), together with three previously described p-terphenyl derivatives-4″-deoxyterprenin (5), terphenyllin (6), and 3″-hydroxyterphenyllin (7)-were obtained from the solid-rice culture of the marine-derived fungus Aspergillus candidus HM5-4, which was isolated from sponges from the South China Sea. Their structures were elucidated by HRESIMS data and NMR spectroscopic analysis. Compound 1 showed a strong inhibitory effect on Neoscytalidium dimidiatum, with an inhibition circle diameter of 31.67 ± 2.36 mm at a concentration of 10.0 µg/disc. Compounds 5 and 7 displayed cytotoxic activity against human chronic myeloid leukemia cells (K562), human liver cancer cells (BEL-7402), human gastric cancer cells (SGC-7901), human non-small cell lung cancer cells (A549) and human HeLa cervical cancer cells, with IC50 values ranging from 3.32 to 60.36 µM, respectively. Compounds 2, 6 and 7 showed potent inhibitory activity against α-glucosidase, with IC50 values of 1.26 ± 0.19, 2.16 ± 0.44 and 13.22 ± 0.55 µM, respectively.