Human Chronic Myeloid Leukemia K562 Research Articles

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.

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.

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.

Biological evaluation of combinations of tyrosine kinase inhibitors with Inecalcitol as novel treatments for human chronic myeloid leukemia

BackgroundThe use of tyrosine kinase inhibitors (TKIs) as a treatment for chronic myeloid leukemia (CML) has improved the natural history of the disease and increased the duration of survival. Tyrosine kinase inhibitors represent the success of target therapies that work on molecular targets, although some patients still have therapy failure. Vitamin D has antiproliferative, pro-apoptotic, and anti-angiogenic effects on cells, therefore it can be considered as a potential cancer preventative and treatment agent. Inecalcitol (TX-522) is the 14-epi-analogue of Calcitriol (1,25(OH)2-vitamin D3), and inhibits cancer cell proliferation more effectively than Calcitriol. This study was conducted to evaluate the antiproliferative and synergistic effects of the anticancer drugs Imatinib and Dasatinib in combinations with Inecalcitol on human chronic myeloid leukemia K-562 cells. MethodThe growth inhibitory activities of Inecalcitol, Imatinib, Dasatinib, and different combinations of one of the two drugs (Imatinib and Dasatinib) with Inecalcitol, were determined in vitro using MTT assay against K-562 cell line. ResultsInecalcitol, Imatinib, and Dasatinib showed potent antiproliferative activities against K-562 cells with GI50 values of 5.6 µM, 0.327 µM, and 0.446 nM, respectively. Combinations of Imatinib or Dasatinib with different concentrations of Inecalcitol increased significantly the antiproliferative activities and potencies of both drugs (****p < 0.0001), with optimal GI50 values of 580 pM (Imatinib) and 0.51 pM (Dasatinib). Furthermore, the combination treatments showed synergistic interaction between the antileukemic drugs and Inecalcitol, with combination indices (CI) < 1. ConclusionThe study demonstrated that the human chronic myeloid leukemia K-562 cells were subjected to a synergistic growth inhibitory impact when antileukemic drugs (Imatinib or Dasatinib) were combined with Inecalcitol, therefore, it is recommended that these combinations be viewed as promising novel antileukemic medications and used in place of individual medications with lower dosages and negligible side effects in the treatment of CML.

Design, Synthesis, and Evaluation of a New Series of 2-Pyrazolines as Potential Antileukemic Agents.

In an attempt to identify small molecules for the treatment of leukemia, 12 new pyrazolines (2a-l) were synthesized efficiently. WST-1 assay was performed to examine their cytotoxic features on HL-60 human acute promyelocytic leukemia (APL), K562 human chronic myeloid leukemia (CML), and THP-1 human acute monocytic leukemia cells. Four compounds (2e, 2f, 2g, and 2h) were determined as promising antileukemic agents on HL-60 and K562 cells. IC50 values of compounds 2f, 2h, 2e, 2g, and bortezomib for the HL-60 cell line were found as 33.52, 42.89, 48.02, 62.34, and 31.75 μM, while IC50 values of compounds 2h, 2g, 2f, 2e, and bortezomib for K562 cells were determined as 33.61, 50.23, 57.28, 76.90, and 42.69 μM, respectively. Further studies were carried out to shed light on the mechanism of antileukemic action. According to the data obtained by in vitro experiments, 1-(4-fluorophenyl)-3-(thiophen-3-yl)-5-(4-(4-methylpiperazin-1-yl)phenyl)-2-pyrazoline (2f) and 1-(3-bromophenyl)-3-(thiophen-3-yl)-5-(4-(4-methylpiperazin-1-yl)phenyl)-2-pyrazoline (2h) have proved to be potential antileukemic agents with remarkable cytotoxicity against HL-60 and K562 cells by activation of caspase 3, thereby inducing apoptosis.

8-Hydroxydaidzein Induces Apoptosis and Inhibits AML-Associated Gene Expression in U-937 Cells: Potential Phytochemical for AML Treatment.

8-hydroxydaidzein (8-OHD) is a compound derived from daidzein, known for its anti-inflammatory and anti-proliferative properties in K562 human chronic myeloid leukemia (CML) cells. However, its effects on acute myeloid leukemia (AML) cells have not been fully understood. To investigate its potential anti-AML mechanism, we employed an integrated in vitro-in silico approach. Our findings demonstrate that 8-OHD suppresses the expression of CDK6 and CCND2 proteins and induces cell apoptosis in U-937 cells by activating Caspase-7 and cleaving PARP-1. Microarray analysis revealed that 8-OHD downregulates differentially expressed genes (DEGs) associated with rRNA processing and ribosome biogenesis pathways. Moreover, AML-target genes, including CCND2, MYC, NPM1, FLT3, and TERT, were downregulated by 8-OHD. Additionally, molecular docking software predicted that 8-OHD has the potential to interact with CDK6, FLT3, and TERT proteins, thereby reducing their activity and inhibiting cell proliferation. Notably, we discovered a synergic pharmacological interaction between 8-OHD and cytarabine (Ara-C). Overall, this study provides insights into the therapeutic applications of 8-OHD in treating AML and elucidates its underlying mechanisms of action.

Cytotoxic and apoptotic effects of chemically synthesized silver nanoparticles loaded with recombinant Staphylococcus LukS-PV toxin.

Chronic myeloid leukemia (CML) accounts for approximately 15% of leukemias. LukS-PV, a Panton-Valentine leucocidin (PVL) component, is secreted by Staphylococcus aureus. Silver nanoparticles have increasingly been used for different purposes, most notably for drug delivery and anticancer agents. In this work, the cytotoxicity effect of recombinant LukS-PV protein, chemically synthesized AgNPs, and recombinant LukS-PV protein-loaded silver nanoparticles was investigated on human Chronic myeloid leukemia K562 cells and human normal embryonic kidney HEK293 cells. Cell apoptosis was investigated by staining with Annexin V/propidium iodide. The recombinant LukS-PV protein-loaded silver nanoparticles exhibited dose-dependent cytotoxicity and induced apoptosis in the K562 cells but had little effect on normal HEK293 cells. After 24h of exposure to recombinant LukS-PV protein-loaded silver nanoparticles (IC50 concentration), flow cytometry showed that 31.17% of K562 cells were apoptotic. These results indicate that recombinant LukS-PV protein-loaded silver nanoparticles maybe are a potential chemotherapeutic agent candidate against K562 cells. Hence, silver nanoparticles could be used as drug carriers for toxin release to cancer cells.

Amsacrine downregulates BCL2L1 expression and triggers apoptosis in human chronic myeloid leukemia cells through the SIDT2/NOX4/ERK/HuR pathway

Accumulating evidence indicates that the anticancer activity of acridine derivatives is mediated through the regulation of anti-apoptotic and pro-apoptotic BCL2 protein expression. Therefore, we investigated whether the cytotoxicity of amsacrine with an acridine structural scaffold in human chronic myeloid leukemia (CML) K562 cells was mediated by BCL2 family proteins. Amsacrine induced apoptosis, mitochondrial depolarization, and BCL2L1 (also known as BCL-XL) downregulation in K562 cells. BCL2L1 overexpression inhibited amsacrine-induced cell death and mitochondrial depolarization. Amsacrine treatment triggered SIDT2-mediated miR-25 downregulation, leading to increased NOX4-mediated ROS production. ROS-mediated inactivation of ERK triggered miR-22 expression, leading to increased HuR mRNA decay. As HuR is involved in stabilizing BCL2L1 mRNA, downregulation of BCL2L1 was noted in K562 cells after amsacrine treatment. In contrast, amsacrine-induced BCL2L1 downregulation was alleviated by restoring ERK phosphorylation and HuR expression. Altogether, the results of this study suggest that amsacrine triggers apoptosis in K562 cells by inhibiting BCL2L1 expression through the SIDT2/NOX4/ERK-mediated downregulation of HuR. Furthermore, a similar pathway also explains the cytotoxicity of amsacrine in CML MEG-01 and KU812 cells.

KOENZİM Q0 İNSAN KRONİK MYELOİD LÖSEMİ K562 HÜCRELERİNİN PROLİFERASYONUNU ENGELLER VE MAPK VE AKT SİNYAL YOLAKLARINI MODÜLE EDER

Objective: This study evaluated the antiproliferative and pro-apoptotic effects of coenzyme Q0 (CoQ0) in human chronic myeloid leukemia K562 cell line. Material and Method: The cytotoxic effect of CoQ0 on human chronic myeloid leukemia cell line, K562 was determined by MTT test. The activity of caspase-3, expression of proteins involved in apoptosis, MAPK and AKT signaling pathways were determined with enzymatic assay and western blot analysis, respectively. Result and Discussion: Results showed that CoQ0 inhibited cell viability of K562 cells at 5 μM and higher concentrations and Bax protein expression was significantly decreased at 12.5 μM concentration of CoQ0. However, CoQ0 did not significantly affect caspase 3 activity and Bcl-2 protein expression. p-c-Raf (Ser259) protein expression was significantly decreased at 12.5 μM of CoQ0. Treatment with 10 μM of CoQ0 induced significantly phosphorylation of p38 MAPK and 12.5 μM CoQ0 caused a nonsignificant decrease in p-ERK1/2 protein expression in K562 cell line. Interestingly, in K562 cells, phosphorylation of Akt (Ser473) was diminished at 12.5 μM of CoQ0, with no change observed in p-Akt (Thr308) protein expression among groups. In conclusion, CoQ0 inhibited cell proliferation and suppressed phosphorylation of c-Raf (Ser259), Akt (Ser473), but not ERK1/2 in K562 cells. There is still a need for new insights into the anticancer mechanisms of CoQ0 and develop treatment strategies for chronic myeloid leukemia.

Role of Calcium-Activated Potassium Channels in Proliferation, Migration and Invasion of Human Chronic Myeloid Leukemia K562 Cells.

Calcium-activated potassium channels (KCa) are important participants in calcium signaling pathways due to their ability to be activated by an increase in intracellular free calcium concentration. KCa channels are involved in the regulation of cellular processes in both normal and pathophysiological conditions, including oncotransformation. Previously, using patch-clamp, we registered the KCa currents in the plasma membrane of human chronic myeloid leukemia K562 cells, whose activity was controlled by local Ca2+ entry via mechanosensitive calcium-permeable channels. Here, we performed the molecular and functional identification of KCa channels and have uncovered their role in the proliferation, migration and invasion of K562 cells. Using a combined approach, we identified the functional activity of SK2, SK3 and IK channels in the plasma membrane of the cells. Selective SK and IK channel inhibitors, apamin and TRAM-34, respectively, reduced the proliferative, migratory and invasive capabilities of human myeloid leukemia cells. At the same time, the viability of K562 cells was not affected by KCa channel inhibitors. Ca2+ imaging showed that both SK and IK channel inhibitors affect Ca2+ entry and this could underlie the observed suppression of pathophysiological reactions of K562 cells. Our data imply that SK/IK channel inhibitors could be used to slow down the proliferation and spreading of chronic myeloid leukemia K562 cells that express functionally active KCa channels in the plasma membrane.

Combination of chemotherapy and gaseous signaling molecular therapy: Novel β-elemene nitric oxide donor derivatives against leukemia.

This study aimed to design and synthesize active hybrids of β-elemene and nitric oxide (NO) donor pharmacophore as potential agents for treating leukemia. Derivatives reported herein exerted better inhibitory effects against human chronic myeloid leukemia K562 cells compared to β-elemene (IC50 > 100 μM). The most potent compound 18f showed an IC50 value of 0.53 μM against K562 cells, as well as a high NO release level in vitro. In the K562 xenograft tumor mice model, compound 18f effectively inhibited the growth of the tumor, with a significant inhibition rate of 73.18%. After treatment with compound 18f, the body weight of mice did not decrease, indicating that it possessed good safety profile. All these proved that compound 18f was an excellent potential agent against leukemia.

PHYTOCHEMICAL CONSTITUENTS AND ANTILEUKEMIC EFFECTS OF JUNIPERUS OXYCEDRUS EXTRACT

Aim: Many genetic and environmental factors can be effective in the process of cancerization. Preventing the progression of leukemia may be possible by controlling the pathways involving mechanisms such as apoptosis and autophagy. When the literature is examined, there are studies showing the effects of various types of juniper on various cancer cell lines, including human chronic myeloid leukemia cells, but the signal pathways in which they act are not fully known. In this study, the anticancer effects of Juniperus oxycedrus extract on K-562 human chronic myeloid leukemia cells were investigated. Method: After the cells were treated with the Juniperus oxycedrus extract, cytotoxicity and gene expression analyzes were performed. Changes in the expression of Akt, the member of the PI3K/Akt/mTOR signaling pathway; caspase 3, which is one of the main effective genes in the pathways regulating apoptosis; and the apoptosis suppressor BCL-2 gene, which is an oncogene, were investigated. Results: According to the MTT test results, Juniperus oxycedrus extract showed over approximately 50% cell viability in K-562 cells at all doses. The most appropriate dose of Juniperus oxycedrus fruit extract in this research was determined as 50 µg/ mL considering cell viability. After the gene expression analysis, it was observed that Akt expression increased 1.092 times, BCL-2 expression decreased approximately 0.3 times, and caspase 3 expression increased 1.2 times. Conclusions: Constituents of Juniperus oxycedrus plant may have apoptotic effects on chronic myeloid leukemia cells.

6,7-Dimethoxycoumarin Influences the Erythroid Differentiation of Human Chronic Myelogenous Leukemia K562 Cells through Regulating FOXO3/p27 Signal Pathway.

Objective To study the pharmacological activity and the mechanism of action of natural compounds derived from 6,7-dimethoxycoumarin on the differentiation of human chronic myeloid leukemia K562 cells. Methods We use MTT assay (Sigma-Aldrich, USA) to detect cell viability; use flow cytometry to analyze DNA content for cell cycle analysis; use benzidine staining to synthesize hemoglobin to determine K562 cell differentiation; use western blot analysis and qPCR to detect the expression levels of FOX03, P27, CDK4, and their phosphorylation; and use the AOBS laser scanning confocal system (Leica, Wetzlar, Germany) to analyze and quantify the number of positive green spots. The statistical methods used are one-way analysis of variance (ANOVA) and Dunnett's test to analyze within and between groups. Results In order to explore the effect of 6,7-dimethoxycoumarin on the differentiation of K562 cell erythrocytes, it was concluded that 6,7-dimethoxycoumarin promotes the differentiation of K562 cell erythrocytes; the proliferation of K562 cells was detected by MTT method, and the results showed that 6,7-dimethoxycoumarin can inhibit the proliferation of K562 cells; to evaluate the effect of 6,7-dimethoxycoumarin on the proliferation of K562 cells, the results showed that 6,7-dimethoxycoumarin increased the expression of FOXO3, P27, CDK4, and CDK65, and decreased the phosphorylation of CDK4 and CDK6 proteins. To further explore the effect of knocking out FOXO3 on cell differentiation, the results show that 6,7-dimethoxycoumarin can reduce the differentiation and proliferation of K562 cells by increasing the expression of FOXO3. Conclusion This study extended the understanding of the pharmacological activity of 6,7-dimethoxycoumarin and may provide a potential new target for the treatment of chronic myelogenous leukemia. However, we still need to further study the specific molecular capabilities of 6.7 dimethylcoumarin to understand their possible capture mechanism.

Aberrant Expressional Profiling of Small RNA by Cold Atmospheric Plasma Treatment in Human Chronic Myeloid Leukemia Cells.

Small RNAs (sRNAs), particularly microRNAs (miRNAs), are functional molecules that modulate mRNA transcripts and have been implicated in the etiology of various types of cancer. Cold atmospheric plasma (CAP) is a physical technology widely used in the field of cancer treatment after exhibiting extensive lethality on cancer cells. However, few studies have reported the exact role of miRNAs in CAP-induced anti-cancer effects. The aim of the present study was to determine whether miRNAs are involved in CAP-induced cytotoxicity by using high-throughput sequencing. Our research demonstrated that 28 miRNAs were significantly changed (17 upregulated and 11downregulated) following 24 h of treatment with a room-temperature argon plasma jet for 90 s compared with that of the untreated group in human chronic myeloid leukemia K562 cells. GO enrichment analysis revealed that these target genes were related to cell organelles, protein binding, and single-organism processes. Furthermore, KEGG pathway analysis demonstrated that the target genes of differentially expressed miRNAs were primarily involved in the cAMP signaling pathway, AMPK signaling pathway, and phosphatidylinositol signaling system. Taken together, our study demonstrated that CAP treatment could significantly alter the small RNA expression profile of chronic myeloid leukemia cells and provide a novel theoretical insight for elucidating the molecular mechanisms in CAP biomedicine application.

Downregulation of Smad4 expression confers chemoresistance against imatinib mesylate to chronic myeloid leukemia K562 cells

ABSTRACT Objective: Imatinib mesylate (IM), a tyrosine kinase inhibitor, exhibits clinically prominent effects against chronic myeloid leukemia (CML); however, a few patients have shown resistance to IM treatment, resulting in disease progression. Smad4 is a tumor inhibitor that transduces TGF-β signaling and modulates genomic stability. Previous studies have indicated that decreased Smad4 expression played a bidirectional role in chemosensitivity in many types of cancers. Therefore, this study aims to evaluate the association between IM sensitivity and decreased Smad4 expression in human CML K562 cells. Methods: Bone marrow (BM) samples were acquired from the patients prior to treatment. qRT-PCR, Western Blotting (WB), colony formation assay (CFA), and apoptosis assay were used to detect relevant indices. Results: Smad4 expression was downregulated in the bone marrow and plasma of patients with multidrug-resistant CML as well as IM-resistant K562 (K562R) cells compared with samples collected from CML patients and K562 cells. Smad4 overexpression inhibited IM-treated K562R cell proliferation and augmented apoptosis, whereas Smad4 silencing promoted viability and inhibited apoptosis in IM-treated K562 cells. In addition, Smad4 expression was inversely correlated with laminin subunit gamma 1 (LAMC1) expression. The upregulation or downregulation of LAMC1 expression partially abolished the effect of Smad4 overexpression or silencing on the IM resistance of CML cells. Conclusion: The downregulation of Smad4 expression might induce drug resistance in CML cells and displayed a possible mechanism through which Smad4 modulates CML cell survival and apoptosis upon IM treatment.

8-Hydroxydaidzein Downregulates JAK/STAT, MMP, Oxidative Phosphorylation, and PI3K/AKT Pathways in K562 Cells.

A metabolite isolated from fermented soybean, 8-hydroxydaidzein (8-OHD, 7,8,4′-trihydroxyisoflavone, NSC-678112), is widely used in ethnopharmacological research due to its anti-proliferative and anti-inflammatory effects. We reported previously that 8-OHD provoked reactive oxygen species (ROS) overproduction, and induced autophagy, apoptosis, breakpoint cluster region-Abelson murine leukemia viral oncogene (BCR-ABL) degradation, and differentiation in K562 human chronic myeloid leukemia (CML) cells. However, how 8-OHD regulates metabolism, the extracellular matrix during invasion and metastasis, and survival signaling pathways in CML remains largely unexplored. High-throughput technologies have been widely used to discover the therapeutic targets and pathways of drugs. Bioinformatics analysis of 8-OHD-downregulated differentially expressed genes (DEGs) revealed that Janus kinase/signal transducer and activator of transcription (JAK/STAT), matrix metalloproteinases (MMPs), c-Myc, phosphoinositide 3-kinase (PI3K)/AKT, and oxidative phosphorylation (OXPHOS) metabolic pathways were significantly altered by 8-OHD treatment. Western blot analyses validated that 8-OHD significantly downregulated cytosolic JAK2 and the expression and phosphorylation of STAT3 dose- and time-dependently in K562 cells. Zymography and transwell assays also confirmed that K562-secreted MMP9 and invasion activities were dose-dependently inhibited by 8-OHD after 24 h of treatment. RT-qPCR analyses verified that 8-OHD repressed metastasis and OXPHOS-related genes. In combination with DisGeNET, it was found that 8-OHD’s downregulation of PI3K/AKT is crucial for controlling CML development. A STRING protein–protein interaction analysis further revealed that AKT and MYC are hub proteins for cancer progression. Western blotting revealed that AKT phosphorylation and nuclear MYC expression were significantly inhibited by 8-OHD. Collectively, this systematic investigation revealed that 8-OHD exerts anti-CML effects by downregulating JAK/STAT, PI3K/AKT, MMP, and OXPHOS pathways, and MYC expression. These results could shed new light on the development of 8-OHD for CML therapy.

Green synthesis and characterization of silver and iron nanoparticles using Nerium oleander extracts and their antibacterial and anticancer activities

Medicinal plants can be used as reducing agents in the preparation of metal nanoparticles by green synthesis because of the chemotherapeutic and anti-infectious properties of natural compounds. Therefore, this paper reports the green synthesis of silver and iron nanoparticles from leaf and flower extracts of Nerium oleander and their capacity as anticancer and antimicrobial agents. Nanoparticle manufacturing and structural characterization of silver and iron nanoparticles are reported. The formation of nanoparticles is characterized by scanning electron microscopy with energy dispersive X-ray spectroscopy, UV-Vis and Fourier transform infrared (FTIR) spectroscopy. Nanoparticles formation was also investigated the surface charge, particle size, and distribution using zeta sizer analysis by DLS. Green synthesis of silver and iron nanoparticles using N. oleander showed different levels of selective cytotoxicity against K562 (human chronic myeloid leukemia cells) in low concentrations and were not cytotoxic to the HUVEC (human umbilical vein endothelial cells) in the same concentrations. Silver nanoparticles showed antibacterial activity against multidrug pathogens, while iron nanoparticles failed to show such activity. Results of the present research demonstrate the potential use of green synthesized nanoparticles in various biomedicine and pharmaceuticals fields in the future.

Preliminary study on the effect of B7H3 interaction with fibronectin on apoptosis of human chronic myeloid leukemia cells

目的探讨B7H3和纤维连接蛋白（FN）相互作用对人慢性髓性白血病细胞系K562细胞凋亡的影响。方法采用流式细胞术检测K562细胞中B7H3分子的表达，构建B7H3过表达细胞。采用免疫共沉淀技术检测B7H3与FN的相互作用。添加外源FN后，通过细胞实验检测细胞黏附和细胞凋亡的变化。Western blot法检测凋亡相关蛋白及PI3K/AKT信号通路的变化。结果① K562细胞低表达B7H3分子，慢病毒转染后得到稳定表达B7H3的细胞系K562 OE-B7H3及其对照细胞系K562 NC-B7H3细胞。②B7H3与FN之间存在相互作用（P＝0.036）。③B7H3与FN的相互作用促进细胞黏附（P<0.05），抑制细胞凋亡（P<0.05）。④B7H3与FN相互作用激活PI3K/AKT信号通路（P<0.05）。结论B7H3与FN相互作用促进了细胞黏附，可能通过激活PI3K/AKT信号通路抑制K562细胞的凋亡。

New potential antiproliferative monophosphoester 2-aminoethyl dihydrogen phosphate in K-562 and K-562 MDR+ leukemia cells

The main obstacle in the treatment of cancer patients has been resistance to multiple drugs, leading to the need to develop molecules with a higher specificity target. The liposomal formulation DODAC/2-AEH2P has antitumor potential, inducing apoptosis in several tumor types. Human chronic myeloid leukemia K-562 and K-562 Lucena (MDR+) cells were treated with the DODAC carrier and the liposomal formulation 2-AEH2P. Viability, cell cycle phases, apoptosis, marker expression and mitochondrial potential were analyzed. Significant reduction in viability was observed for all treatments. Changes in the distribution of the cell cycle phases and expression of markers involved in the apoptosis pathways were observed. Reduction of the mitochondrial electrical potential mediated by Bcl-2, being regulated by the reduction of the MTCH2 protein linked to the progression of myeloid leukemia and an increase in the pro-apoptotic proteins Bad and Bax, dependent on p53. This study demonstrated a significant therapeutic potential through apoptotic effects in leukemic cells, regardless of the molecular resistance profile (MDR+).

Iso-suillin-induced DNA damage leading to cell cycle arrest and apoptosis arised from p53 phosphorylation in A549 cells

Extensive investigations have revealed that iso-suillin, a secondary metabolite isolated from Suillus flavus, could induce cell cycle arrest and apoptosis in human chronic myeloid leukemia K562 cells, human hepatocellular carcinoma SMMC-7721 cell line, and human small cell lung cancer H446 cell line in vitro.In the present study, human lung cancer A549 cells were used to reveal the mechanism of iso-suillin's effects on lung adenocarcinoma, which were detected both in vitro and in vivo.Results showed that iso-suillin potently inhibited A549 cell proliferation through an early G1 arrest. Iso-suillin also induced A549 cell apoptosis in vitro. Phosphorylation of p53 at serines 15 and 20 may be one of the pivotal factors for cell cycle arrest and apoptosis after treatment of iso-suillin in A549 cells.Moreover, in an A549 xenograft model, tumor growth and progression could be inhibited by iso-suillin. Body weight change and some vital organs toxicity was also roughly examined, no significant toxic effects of iso-suillin were shown (at a dose of 5 mg/kg for each administration).The in vitro and in vivo anti-tumor effects implied that iso-suillin may act as a tumor growth inhibitor, and its induction of p53 phosphorylation is pivotal for cell cycle arrest and apoptosis in A549 cells.