Effect of Scutellarin on Proliferation of Acute Myeloid Leukemia Cells and Its Related Mechanism / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of scutellarin (SCU) on proliferation, cell cycle and apoptosis of acute myeloid leukemia (AML) cells and its related molecular mechanism.@*METHODS@#Human AML HL-60 cells were cultured in vitro. The cells were treated with SCU at the concentration of 0, 2, 4, 8, 16, 32, 64 μmol/L, and the inhibition rate of cell proliferation was detected by CCK-8 method. Then HL-60 cells were treated with SCU at the concentration of 4, 8, 16 μmol/L, and the negative control group (NC group) was set. The cell cycle distribution and apoptosis were detected by flow cytometry, and the expression of cell cycle, apoptosis and JAK2/STAT3 pathway related proteins were detected by Western blot.@*RESULTS@#SCU significantly inhibited the proliferation of HL-60 cells in a concentration- and time-dependent manner(r =0.958,r =0.971). Compared with NC group, the proportion of cells in G0/G1 phase and apoptosis rate of HL-60 cells in 4, 8, 16 μmol/L SCU group were significantly increased, and the proportion of cells in S phase was significantly decreased (P <0.05). The relative protein expression levels of p21, p53, caspase-3 and Bax were significantly increased, while the relative protein expression levels of CDK2, cyclin E and Bcl-2 were significantly decreased (P <0.05). The ratio of p-JAK2/JAK2 and p-STAT3/STAT3 were significantly decreased (P <0.05). The changes of above-mentioned indexes were concentration dependent.@*CONCLUSION@#SCU can inhibit the proliferation of AML cells, induce cell cycle arrest and apoptosis, and its mechanism may be related to the regulation of JAK2/STAT3 signaling pathway.

Preliminary Study on the Effect of Silencing Nucleostemin Com- bined with Rapamycin on Autophagy and Apoptosis of HL-60 Cells / 中国实验血液学杂志

OBJECTIVE@#To investigate the effects of knocking down nucleostemin ( NS) combined with rapamycin (RAPA) on autophagy and apoptosis in HL-60 cells , and to explore its role in HL-60 cells .@*METHODS@#The expression of NS protein was detected using Western blot , after transfection of HL-60 cells was achieved by the recombinant lentviral vector NS -RNAi-GV248 . Flow cytometry was used to detect changes in cells apoptosis after NS silencing/ rapamycin for 24 , 48 hours , and the expressions of NS , LC3 , p62 , BCL-2 and Bax proteins in cells were detected by Western blot.@*RESULTS@#The expression of NS in HL-60 cells was successfully down-regulated by recombinant lentiviral vector. After treatment with rapamycin for 24 and 48 h , the apoptosis rate of cells in each group increased (P < 0.05) , and the apoptosis was more obvious at 48 hours . Compared with the NS silencing group or rapamycin group , after treated with NS down-regulation combined with rapamycin for 48 hours , the apoptosis of HL-60 cells was significantly increased ( P < 0.05 ) , LC3 -II/LC3 -I ratio was significantly increased ( P < 0.05 ) , p62 protein expression was significantly decreased (P < 0.05) , and BCL-2/Bax ratio was significantly decreased ( P < 0.05) .@*CONCLUSION@#NS down-regulation combined with rapamycin can enhance the apoptosis and autophagy of HL-60 cells , and the induction of apoptosis of HL-60 cells may be related to the expression of BCL-2 and Bax proteins .

Effects of circ-SFMBT2 on Proliferation, Migration and Invasion of Acute Myeloid Leukemia Cells by Regulating miR-491-5p/HOXA9 Axis / 中国实验血液学杂志

OBJECTIVE@#To explore the effects and molecular mechanism of circ-SFMBT2 on the proliferation, migration and invasion of acute myeloid leukemia (AML) cells.@*METHODS@#Bone marrow samples from 35 pediatric AML patients and 35 healthy controls in Henan Provincial Children's Hospital from April 2015 to April 2017 and human bone marrow stromal cell lines (HS-5) and AML cell lines (HL-60, THP-1, U-937 and Kasumi-1) were collected. The expressions of circ-SFMBT2, miR-491-5p and homeobox A9 (HOXA9) in bone marrow samples and cells were detected by RT-qPCR and Western blot. The Pearson method was used to analyze the correlation of circ-SFMBT2, miR-491-5p and HOXA9 mRNA expression levels in bone marrow samples of AML patients. HL-60 cells were cultured in vitro and divided into 5 groups: Control, si-NC, si-circ-SFMBT2, si-circ-SFMBT2+anti-NC and si-circ-SFMBT2+anti-miR-491-5p, HL-60 cells were transfected with si-NC, si-circ-SFMBT2, anti-NC, and miR-491-5p inhibitor with Lipofectamine™ 3000. RT-qPCR and Western blot were performed to detect the expression levels of circ-SFMBT2, miR-491-5p and HOXA9 in cells of each group. The proliferation activity of HL-60 cells in each group was detected by CCK-8 assay at 24, 48 and 72 h after transfection, respectively. The apoptosis rate was detected by flow cytometry. The migration and invasion abilities of cells were detected by Transwell assay. The regulatory roles of circ-SFMBT2, miR-491-5p and HOXA9 in AML cells were verified by dual-luciferase reporter gene assay, RNA pull-down and RNA-binding protein immunoprecipitation (RIP) experiments.@*RESULTS@#The expression levels of circ-SFMBT2 and HOXA9 mRNA were increased in bone marrow samples and cell lines (HL-60, THP-1, U-937 and Kasumi-1) of children with AML (P <0.001), while the expression level of miR-491-5p was significantly decreased (P <0.001). Pearson correlation analysis showed that the expression levels of circ-SFMBT2 and miR-491-5p in bone marrow samples of AML children were negatively correlated (r =-0.905), miR-491-5p was also negatively correlated with HOXA9 mRNA (r =-0.930), while the expression levels of HOXA9 mRNA and circ-SFMBT2 was positively correlated (r =0.911). The overall survival rate of AML children with high expression of circ-SFMBT2 was significantly decreased than those with low expression of circ-SFMBT2 (P <0.05). Silencing of circ-SFMBT2 could greatly up-regulate the expression of miR-491-5p, decrease the expression of HOXA9, inhibit the proliferation, migration and invasion of AML cells, and promote cell apoptosis (P <0.05). Down-regulation of miR-491-5p expression greatly attenuated the inhibitory effects of circ-SFMBT2 silencing on cell proliferation, migration and invasion (P <0.05). Dual-luciferase reporter gene assay, RNA pull-down and RIP experiments confirmed that circ-SFMBT2 could target miR-491-5p and negatively regulate the expression of miR-491-5p in AML, and HOXA9 was the target of miR-491-5p.@*CONCLUSION@#Silencing of circ-SFMBT2 may inhibit the proliferation, migration and invasion of AML cells by regulating the miR-491-5p/HOXA9 axis.

Effects of Methionine Restriction on Proliferation, Cell Cycle, and Apoptosis of Human Acute Leukemia Cells / 中国实验血液学杂志

OBJECTIVE@#To investigate the effects of methionine restriction on proliferation, cell cycle and apoptosis of human acute leukemia cells.@*METHODS@#Cell Counting Kit-8 (CCK-8) assay was used to detect the effect of methionine restriction on HL-60 and Jurkat cells proliferation. The effect of methionine restriction on cell cycle of HL-60 and Jurkat cells was examined by PI staining. Annexin V-FITC / PI double staining was applied to detect apoptosis of HL-60 and Jurkat cells following methionine restriction. The expression of cell cycle-related proteins cyclin B1, CDC2 and apoptosis-related protein Bcl-2 was evaluated by Western blot assay.@*RESULTS@#Methionine restriction significantly inhibited the proliferation of HL-60 and Jurkat cells in a time-dependent manner (HL-60: r =0.7773, Jurkat: r =0.8725), arrested the cells at G2/M phase (P < 0.001), and significantly induced apoptosis of HL-60 and Jurkat cells (HL-60: P < 0.001; Jurkat: P < 0.05). Furthermore, Western blot analysis demonstrated that methionine restriction significantly reduced the proteins expression of Cyclin B1 (P < 0.05), CDC2 (P < 0.01) and Bcl-2 (P < 0.001) in HL-60 and Jurkat cells.@*CONCLUSION@#Acute leukemia cells HL-60 and Jurkat exhibit methionine dependence. Methionine restriction can significantly inhibit the proliferation, promote cell cycle arrest and induce apoptosis of HL-60 and Jurkat cells, which suggests that methionine restriction may be a potential therapeutic strategy for acute leukemia.

Effect of Inhibiting SIX1 Expression on Drug-resistance of Acute Myeloid Leukemia Cell Line HL-60/ADR Cells / 中国实验血液学杂志

OBJECTIVE@#To establish HL-60 cells and adriamycin resistant HL-60 cells (H-60/ADR) in which the expression of homologous box gene 1 (SIX1) was inhibited, and investigate the effect of inhibiting the expression of SIX1 on the drug resistance.@*METHODS@#Lentivirus was used to transfect HL-60 and HL-60/ADR cells, and the cell lines stably inhibiting the expression of SIX1 were screened by puromycin. CCK-8 assay was used to detect the proliferation ability of cells in each group, apoptosis kit was used to detect the cell apoptosis, and real-time quantitative PCR was used to detect the expression level of drug-resistant related genes.@*RESULTS@#HL-60 and HL-60/ADR stably transfected cell lines with down-regulation of SIX1 expression were successfully constructed. Compared with control group, the inhibition of SIX1 expression significantly inhibited the proliferation of HL-60 and HL-60/ADR cells (P <0.05), increased the apoptosis rate (P <0.05), and the sensitivity of cells to adriamycin increased after inhibition of SIX1 expression.@*CONCLUSION@#Inhibition of SIX1 expression can improve cell sensitivity to adriamycin, and its role in reversing drug resistance may be related to the promotion of apoptosis gene expression.

RBM38 Mediates the Proliferation of Acute Myeloid Leukemia Cells HL-60 by Regulating FZD1 mRNA Stability / 中国实验血液学杂志

OBJECTIVE@#To explore the regulatory function of RNA binding motif protein 38 (RBM38) in human acute myeloid leukemia cells HL-60 and its mechanism.@*METHODS@#The lentivirus carriers of overexpressed and knockdown RBM38 were constructed. After HL-60 cells were transfected, Western blot was used to analyze the expression level of RBM38 in HL-60 cells. The cell proliferation and cycle of HL-60 were detected by CCK-8 assay and flow cytometry assay, respectively. RNA immunoprecipitation coupled real-time PCR (RIP-qPCR) was used to detect the combination of RBM38 with mRNAs. Actinomycin D treatment followed by real-time PCR (AcD-qPCR) was used to detect the effect of RBM38 on the stability of target mRNAs.@*RESULTS@#RBM38 in HL-60 cells was overexpressed or inhibited by lentivirus transduction. Overexpressed RBM38 promoted the cell cycle and proliferation of HL-60, while RBM38 knockdown repressed the two processes. RBM38 showed an interaction with FZD1 mRNA and enhancement of its stability.@*CONCLUSION@#RBM38 can regulate cell proliferation of HL-60 by improving the stability of FZD1 mRNA.

Trdmt1 3'-untranslated region functions as a competing endogenous RNA in leukemia HL-60 cell differentiation

Severe blockage in myeloid differentiation is the hallmark of acute myeloid leukemia (AML). Trdmt1 plays an important role in hematopoiesis. However, little is known about the function of Trdmt1 in AML cell differentiation. In the present study, Trdmt1 was up-regulated and miR-181a was down-regulated significantly during human leukemia HL-60 cell differentiation after TAT-CT3 fusion protein treatment. Accordingly, miR-181a overexpression in HL-60 cells inhibited granulocytic maturation. In addition, our "rescue" assay demonstrated that Trdmt1 3′-untranslated region promoted myeloid differentiation of HL-60 cells by sequestering miR-181a and up-regulating C/EBPα (a critical factor for normal myelopoiesis) via its competing endogenous RNA (ceRNA) activity on miR-181a. These findings revealed an unrecognized role of Trdmt1 as a potential ceRNA for therapeutic targets in AML.

Association of kinesin family member 2A with increased disease risk, deteriorative clinical characteristics, and shorter survival profiles in acute myeloid leukemia

This study aimed to explore the correlation of kinesin family member 2A (KIF2A) expression with disease risk, clinical characteristics, and prognosis of acute myeloid leukemia (AML), and investigate the effect of KIF2A knockdown on AML cell activities in vitro. Bone marrow samples were collected from 176 AML patients and 40 healthy donors, and KIF2A expression was measured by real-time quantitative polymerase chain reaction. Treatment response, event-free survival (EFS), and overall survival (OS) were assessed in AML patients. In vitro, KIF2A expression in AML cell lines and CD34+ cells (from healthy donors) was measured, and the effect of KIF2A knockdown on AML cell proliferation and apoptosis in HL-60 and KG-1 cells was detected. KIF2A expression was greater in AML patients compared to healthy donors, and receiver operating characteristic curve indicated that KIF2A expression predicted increased AML risk (area under curve: 0.793 (95%CI: 0.724-0.826)). In AML patients, KIF2A expression positively correlated with white blood cells, monosomal karyotype, and high risk stratification. Furthermore, no correlation of KIF2A expression with complete remission or hematopoietic stem cell transplantation was found. Kaplan-Meier curves showed that KIF2A expression was negatively correlated with EFS and OS. In vitro experiments showed that KIF2A was overexpressed in AML cell lines (KG-1, HL-60, ME-1, and HT-93) compared to CD34+ cells, moreover, cell proliferation was reduced but apoptosis was increased by KIF2A knockdown in HL-60 and KG-1 cells. In conclusion, KIF2A showed potential to be a biomarker and treatment target in AML.

Alternative Splicing Analysis of LACTB Gene and Expression Characteristics of Different Transcripts in Leukemia Cell Lines / 中国实验血液学杂志

OBJECTIVE@#To detect the expression of different transcripts of lactamase β（LACTB) gene in leukemic cell lines.@*METHODS@#NCBI website and DNAstar software were used to detect the Bioinformatics analysis of LACTB. The expression of different transcripts of LACTB gene in leukemic cell lines (THP-1, HL60, K562, U937, Jurkat and Raji) was detected by reverse transcription PCR (RT-PCR), DNA and clone sequencing; the expression of different transcripts of LACTB gene in leukemic cell lines was detected by Quantitative Real-time PCR.@*RESULTS@#There were a variety of splicing isomers in LACTB, and it could produce a variety of protein isomers with conserved N-terminal and different C-terminal, moreover, there were many splice isoforms of LACTB in leukemia cell lines, and there were different expression patterns in different cell lines, including XR1, V1, V2 and V3. The expression of total LACTB showed high in HL60 cells, while low in Raji cells, and the difference was statistically significant (P<0.05). The V1 was high expression in U937 cells but low in Raji cells, and the difference was statistically significant (P<0.05). V2 was high expression in HL60 cells but lowly in Raji cells, and the difference was statistically significant (P<0.05). The expression of V3 was low in THP-1 cells, which was significantly different as compared with that in normal bone marrow (P<0.05).@*CONCLUSION@#The reaserch found that there are many splice isomers of LACTB in leukemic cell lines, and there are different expression patterns in different cell lines.

Effect of Competitive Antagonist of Transmembrane Glutamine Flux V-9302 on Apoptosis of Acute Myeloid Leukemia Cell Lines HL-60 and KG-1 / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of V-9302 (an antagonist of transmembrane glutamine flux) on the proliferation and apoptosis of acute myeloid leukemia cells HL-60 and KG-1.@*METHODS@#HL-60 and KG-1 cells at logarithmic phase were treated by different concentrations of V-9302. CCK-8 assay was used to detect the proliferation of the cells. Annexin V-FITC / PI double staining flow cytometry was used to detect the apoptosis of HL-60 and KG-1 cells. The expressions of BAX, BCL-2 and Caspase3 were detected by RT-qPCR and Western blot.@*RESULTS@#V-9302 could significantly inhibit the growth of HL-60 and KG-1 cells. The concentration of V-9302 at 10, 20 μmol/L could significantly promote the apoptosis of HL-60 and KG-1 cells(P<0.05). The results of apoptosis related gene detection showed that when V-9302 was applied to HL-60 and KG-1 cell lines at 10 and 20 μmol/L, the expression levels of Pro-apoptotic protein genes BAX and Caspase3 in HL-60 and KG-1 were significantly higher than those in control group (P<0.05), while the expression level of anti-apoptotic protein gene BCL-2 was significantly lower than that in the control group (P<0.05). The results of Western blot were basically consistent with that of RT-qPCR.@*CONCLUSION@#Competitive antagonist of transmembrane glutamine flux V-9302 can significantly promote the apoptosis of acute myeloid leukemia cell lines HL-60 and KG-1.

Effect of MiR-96 on Cell Invasion and Apoptosis in Pediatric Acute Myeloid Leukemia via Regulating MYB / 中国实验血液学杂志

OBJECTIVE@#To analyze the relationship of the expression of transcription factor MYB targeted regulation by miR-96 to cell invasion and apoptosis in pediatric acute myeloid leukemia (AML).@*METHODS@#A total of 65 children with AML in The 928 Hospital of PLA Joint Logistics Support Forces from January 2017 to November 2019 were selected, including 35 cases diagnosed as primary AML and 30 cases as complete remission AML. Thirty children with immune thrombocytopenia were selected as control group. The clinical characteristics were analyzed and compared between the two groups. The levels of miR-96 and MYB in peripheral blood samples were detected by qRT-PCR and compared between the two groups. The miR-96 mimics and its negative control (NC), inhibitor-miR-96 and its NC transfected HL60 cells induced by liposome (Lipofectamine 2000), respectively, Then the expression levels of MYB were detected with Western blot and compared among four HL60 cell groups. The invasion ability of four HL60 cell groups were detected with Transwell assay. The cell proliferation ability of four HL60 cell groups were detected with MTT at 24 h, 48 h, and 72 h, respectively. The apoptosis rates of four HL60 cell groups were detected with flow cytometry.@*RESULTS@#Compared with control group, the level of miR-96 in AML children were higher, but MYB lower (P0.05). The promotion of over-expression level of miR-96 on the invasion ability of HL 60 cells was confirmed by Transwell assay. MTT assay showed that miR-96 could promote the proliferation of HL60 cells, inhibit the apoptosis of HL60 cells, and the effect was time-dependent manner (r=0.804). The inhibition of miR-96 on HL60 cells apoptosis was also confirmed with flow cytometry.@*CONCLUSION@#MiR-96 has significant negative effect on invasion and apoptosis of AML cells by targeting regulation MYB, and it might be a potential novel strategy for pediatric AML treatment.

The Influence of Glutamic Pyruvate Transaminase 2 to Biological Characteristics of Acute Myeloid Leukemia Cell HL-60 / 中国实验血液学杂志

OBJECTIVE@#To investigate the influence of GPT2（glutamic pyruvate transaminase 2）to biological characteristics of human acute myeloid leukemia cell line HL-60.@*METHODS@#The expression of GPT2 in hematological tumor and AML cell was detected. The lentvirus-mediated of short-hairpin RNA (shRNA) was constricted, and the knock-down efficiency of HL-60 in AML cell after infected by lentvirus-mediated was detected by Western blot and Q-PCR. CCK-8 assay and soft agar colony formation assay were used to detect the effect of GPT2 gene deletion to the cell proliferation potential. Fluorescence activated cell sorting(FACS) was used to analyze the effect of gene deletion to the cell cycle and Caspase 3/7 Activity Assay Kit was used to analyze the effect of GPT2 gene deletion to the cell apoptosis.@*RESULTS@#GPT2 showed mRNA high expression in AML patients. CCK-8, soft agar assay, and Caspase 3/7 Activity Assay Kit results showed that compared with shCtrl group, the cells in shGPT2-1、shGPT2-2、shGPT2-3 group showed the slowing down on proliferation, decreasing on colony ability, and the apoptosis of the cells was increasing significantly. FACS showed that GPT2 gene was related to the cycle of HL-60 cell.@*CONCLUSION@#GPT2 appears to involve the proliferation, cycle distribution and apoptosis of AML cell HL-60. The deletion of GPT gene can lead to the inhibitation of cells proliferation and increase apoptosis.

Inhibitory Effect of PKC412 Against Human Acute Leukemia Cell Line HL-60 Cells / 中国实验血液学杂志

OBJECTIVE@#To explore the effects and mechanisms of PKC412 inhibitor on proliferation and apoptosis of HL-60 cell line.@*METHODS@#CCK-8 assay was used to detect the effect of PKC412 on the proliferation of HL-60 cells at different concentrations; Wright-Giemsa staining was used to estimated the effect of PKC412 on the apoptosis of HL-60 cells; the mRNA expression of BCL-2 and P53 genes was detected by qRT-PCR, the expression of BCL-2 and P53 proteins was detected by Western blot. HL-60 cells were injected into mouse caudal vein to construct acute myeloid leukemia model, PKC412 was administered to tail vein for 31.25 nmol/kg, normal saline was injected into the same site of the mice as control group, and the inhibitory effect of PKC412 on HL-60 cells in mice was observed. ELISA assay was used to detect the effect of PKC412 on the inflammatory factors of TNF-α and TGF-β in tumor mice.@*RESULTS@#PKC412 could inhibit the proliferation of HL-60 cell, which was in a dose dependent manner(r=0.9973) (IC50 was 0.31 μmol/L), and induce apoptosis of HL-60 cells. After HL-60 cell was treated by PKC412 for 48 h the expression of BCL-2 gene was down regulated(0.417±0.044 vs 0.933±0.033, t=9.347, P0.05) as compared with control group. And the expression of BCL-2 protein was decreased, while the expression of P53 protein was increased. PKC412 could inhibited the growth of HL-60 tumor cells in vivo, the survival rate of mice after administration was 50% and the weight was increased as compared with that in control group(18.02±0.403 g vs 16.44±0.562 g, t=2.272, P=0.0356). The secretion of TNF-α and TGF-β cytokine in serum and spleen cells in PKC412 group was significantly lower than that in control group (P<0.05).@*CONCLUSION@#PKC412 can induce apoptosis of HL-60 cells by inhibiting the expression level of BCL-2 gene, PKC412 administration in vivo can inhibit the growth of the tumors.

NCTD Retards AML HL60 Cell Proliferation via Targeting Hedgehog/SOX2 axis / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of norcantharidin (NCTD) to proliferation of leukemia cells through disrupting key regulators of sonic Hedgehog (SHH) pathway and its downstream transcription factor SOX2.@*METHODS@#CCK8 was used to detected the HL60 and NB4 cells after inhibited by NCTD, SMO and GLI1 inhibitor for 24 hours. Expression level of SMO, GLI1 and SOX2 in HL60 cells with NCTD treatment was detected by immunoblot. HL60 cells were transfected with pcDNA3.1 plasmid expressing GLI1 or SOX2. Empty vector and pcDNA3. 1-EGFP were divided into negative and positive control group, respectively. The expression of exogenous GLI1 or SOX2 in HL60 cells was confirmed by immunoblot, and growth curve of HL60 cell was checked by CCK8. Proliferation of genetic modified HL60 cells treated by various dose of NCTD was detected.@*RESULTS@#NCTD, SMO/GLI1 inhibitors could inhibit the proliferation of NB4 and HL60 cells in a dose-dependent manner. Compared with solvent (DMSO)-treated control group, NCTD remarkably decreased protein level of SMO, GLI1 and SOX2. GLI1 and SOX2 were overexpressed in HL60 cells as compared with pcDNA3.1 empty vector-transfected group. Growth curve demonstrated significant proliferative advantage of GLI1/SOX2-transfected cells. CCK8 assay indicated that GLI1/SOX2-overexpressed HL60 cells were more resistant to NCTD treatment.@*CONCLUSION@#NCTD attenuates HL60 proliferation via targeting the Hedgehog/SOX2 axis.

MiR-218 Targeting Bmi-1 Inhibits Proliferation of Acute Promyelocytic Leukemia Cells / 中国实验血液学杂志

OBJECTIVE@#To explore the molecular mechanism by which miR-218 targeting Bmi-1 inhibits the proliferation of acute promyelocytic leukemia (APL) cells.@*METHODS@#APL cell line HL-60 was transfected by miR-218 and RNA-negative control sequences, respectively. The expression of miR-218 in cells was detected by real-time fluorescence quantitative PCR. The effect of transfected miR-218 on the proliferation of APL cells was detected by MTT assay. Cell apoptosis was detected by flow cytometry. The regulation effect of miR-218 on Bmi-1 expression was determined by Western blot. The correlation of miR-218 expressions with Bmi-1 was analyzed by Spearman test. The targeted relationship between miR-218 and Bmi-1 was verified by luciferase assay.@*RESULTS@#MTT assay showed that the proliferation of HL-60 cells in vitro was inhibited by high expression miR-218 significantly. Flow cytometry showed that the G1 and G2 phase cells increased while the S phase cells decreased after transfected by miR-218. Western blot showed that the level of Bmi-1 protein in HL-60 cells decreased significantly after transfection of miR-218 (P＜0.05). Spearman correlation analysis showed that the mRNA level of miR-218 negatively correlated with the protein content of Bmi-1 (r=-0.326, P＜0.01). Luciferase assay indicated that Bmi-1 could targeted on miR-218 directly.@*CONCLUSION@#miR-218 can inhibit the proliferation, metastasis and invasion of APL cells, which can be related with the down-regulated of Bmi-1.

Effect of High Dose Vitamin C on Proliferation and Apoptosis of Acute Myeloid Leukemia Cells / 中国实验血液学杂志

OBJECTIVE@#To investigate the effects of high dose vitamin C on proliferation and apoptosis of acute myeloid leukemia (AML) cell lines including HL-60, U937 and primary CD34 leukemia cells in AML.@*METHODS@#CD34 cells were sorted by using immunomagnetic cell sorting system, then the primary CD34 leukemia cells, including HL-60 and U937 cell lines were cultured in vitro. Cells in each group were treated with different concentrations of vitamin C, the survival rate of cells was determined by MTT assay, the apoptosis rate of cells was evaluated by Annexin V/PI double staining, the expression of apoptotic proteins-including cleaved caspase 3, cleaved caspase-9 and cleaved PARP were detected by Western blot.@*RESULTS@#The proliferation of HL-60 and U937 cells could be inhibited by high dose vitamin C, which showed a concentration-dependent manner (r=-0.9664; r=-0.9796). HL-60 and U937 cells were treated with different concentrations of vitamin C (8 and 20 mmol/L) for 24 hours, respectively, it was found that with the increasing of vitamin C concentration, cell apoptosis rate was significantly increased (r=0.9905; r=0.9971), and the expression of apoptosis related proteins including cleaved caspase 3, cleaved caspase-9 and cleaved PARP was aslo significantly increased with the increasing of concentration. In addition, it was found that with or without the mutation of TET2, high dose vitamin C could inhibit the proliferation (r=-0.9719; r=-0.9699) and promote the apoptosis (r=0.9998; r=0.9901) of primary CD34 leukemia cells in AML, which showed a dose-dependent manner, but it showed no effect on the proliferation (r=-0.2032) and apoptosis (r=0.1912) of normal CD34 cells.@*CONCLUSION@#High dose vitamin C can inhibit the proliferation and promote the apoptosis of acute myeloid leukemia cells, and selectively kill primary CD34 leukemia cells in AML.

Effects and Mechanism of PARP Inhibitor Olaparib on the Expression of NKG2D Ligands in HL-60 Cells / 中国实验血液学杂志

OBJECTIVE@#To investigate the regulatory effects of Olaparib on natural killer cell activating receptor (NKG2D) ligands expression on human acute myeloid leukemia (AML) cell line HL-60, and to explore the molecular mechanism of Olaparib on HL-60 cells.@*METHODS@#After HL-60 cells in logarithmic growth phase were treated with Olaparib at different concentrations for different times (24, 48 h), the expression of NKG2D ligand on the surface of HL-60 cells was detected by flow cytometry. Western blot was used to dectect the expression of ERK expression in HL-60 cells. The killing effect of NK cells to HL-60 cells was detected by CFSE/PI method.@*RESULTS@#10 μmol/L Olaparib could upregulate the expression of NKG2D ligand on the surface of HL-60 cell at 24 and 48 hours, while 5 μmol/L Olaparib could induce up-regulation of the expression of ULBP-2 and ULBP-3 at 48 hours. Western blot analysis showed that ERK phosphorylation of HL-60 cells was enhanced after treating with Olaparib. The killing effect of NK cells to HL-60 cells could be enhanced by Olaparib, however, ERK inhibitor could suppress the killing effect of NK cells to HL-60 cells.@*CONCLUSION@#Olaparib can upregulate NKG2D ligands expression on the surface of HL-60 cells and enhance the cytotoxicity of NK cell to HL-60 cells. The mechanism may be related to Olaparib promoting ERK phosphorylation expression.

Polyphenolic extracts of walnut (Juglans regia) green husk containing juglone inhibit the growth of HL-60 cells and induce apoptosis

BACKGROUND: Juglone is a naphthoquinone currently obtained by chemical synthesis with biological activities including antitumor activity. Additionally, juglone is present in the green husk of walnut, which suggests evaluating the effect of GH extracts on carcinogenic cell lines. RESULTS: Walnut green husk ethanolic extract was obtained as 169.1 mg juglone/100 g Green Husk and antioxidant activity (ORAC) of 44,920 µmol Trolox Equivalent/100 g DW Green Husk. At 1 µM juglone in HL-60 cell culture, green husk extract showed an antiproliferative effect, but pure juglone did not; under these conditions, normal fibroblast cells were not affected. A dose-dependent effect on mitochondrial membrane potential loss was observed. Apoptosis of HL-60 was detected at 10 µM juglone. Despite high ORAC values, neither purified juglone nor the extract showed protective effects on HL-60 cells under oxidative conditions. CONCLUSIONS: Green husk extract generates an antiproliferative effect in HL-60 cells, which is related to an induction of the early stages of apoptosis and a loss of mitochondrial membrane potential. The normal cells were not affected when juglone is present at concentrations of 1 µM, while at higher concentrations, there is loss of viability of both cancerous and healthy cells.

microRNA-146a Promotes Growth of Acute Leukemia Cells by Downregulating Ciliary Neurotrophic Factor Receptor and Activating JAK2/STAT3 Signaling

PURPOSE: Acute leukemia (AL) is classified as acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). This study aimed to investigate the effect of miR-146a on childhood AL and its underlying molecular mechanisms. MATERIALS AND METHODS: Bone marrow samples were obtained from 39 AL children and 10 non-cancer controls. The expressions of miR-146a and ciliary neurotrophic factor receptor (CNTFR) were detected by quantitative real-time polymerase chain reaction (qRT-PCR) in ALL and AML pediatric patients, as well as ALL (Jurkat) and AML (HL-60) cells. Correlations between miR-146a and clinical indicators were explored. A targeting relationship between miR-146a and CNTFR was detected by dual luciferase reporter gene assay. Cell proliferation, apoptosis, migration, and invasion of Jurkat and HL-60 cells were measured by MTT assay, flow cytometry, and transwell assay, respectively. LIF expression was detected by qRT-PCR in Jurkat and HL-60 cells. The expression of p-JAK2, JAK2, p-STAT3, and STAT3 in HL-60 cells was measured by Western blot. RESULTS: miR-146a was increased in ALL and AML pediatric patients, while CNTFR was decreased. miR-146a expression was associated with immunophenotype, karyotype, fusion gene, and SIL-TAL1. CNTFR was a target gene of miR-146a. miR-146a could promote cell proliferation, migration, and invasion, as well as inhibit cell apoptosis in Jurkat and HL-60 cells by downregulating CNTFR. Meanwhile, miR-146a inhibited the expression of LIF and activated JAK2/STAT3 pathway by downregulating CNTFR. CONCLUSION: miR-146a could promote the proliferation, migration, and invasion and inhibit the apoptosis of AL Jurkat and HL-60 cells by downregulating CNTFR and activating the JAK2/STAT3 pathway.

Adenanthin Induces Differentiation of Acute Promyelocytic Leukemia Cells by Targeting Peroxiredoxin III / 中国实验血液学杂志

OBJECTIVE@#To investigate the differentiation of acute promyelocytic leukemia (APL) cells induced by adenosine targeting Prx III.@*METHODS@#HL-60 cells were divided into four groups: control group, all-trans retinoic acid (ATRA) group, adenanthin group and ATRA+adenanthin group. Cell morphologic changes were observed under optical microscope. The influence of adenanthin on the differentiation of HL-60 was observed by nitro blue tetrazolium chloride (NBT) test. Cell surface differentiation antigens CD11b expression was measured by flow cytometry. The protein expression of Prx III was detected by immunohistochemical assay.@*RESULTS@#Adenanthin could induce the differentiation of HL-60 cells; the NBT reduction positive rate in ATRA+adenanthin group was significantly higher than that in ATRA group and adenanthin group (P＜0.05). The percentage of CD11b positive cells in ATRA+adenanthin group (43.62％±1.38％) was higher than that in adenanthin group (28.15％±1.78％), ATRA group (36.72％±1.33％) and control group (7.99％±1.78％) (P＜0. 05). The content of Prx Ⅲ protein in adenanthin group was significantly higher than that in control group and ATRA group (P＜0.05).@*CONCLUSION@#Adenanthin and ATRA have a synergistic effect on the differentiation and maturation of HL-60 cells, and its mechanism may be related with regulation of Prx III expression.