OBJECTIVE: To investigate the transcriptional regulation of transcription factor MZF-1 on acute monocytic leukemia-related gene MLAA-34. METHODS: The effect of MZF-1 on the transcriptional activity of MLAA-34 gene promoter was analyzed by luciferase reporter gene detection system and site-directed mutation technique. The EMSA and ChIP assay were used to verify whether MZF-1 directly and specifically binds to the core region of MLAA-34 promoter. The over-expression vector and interference vector of MZF-1 were constructed to transfect U937 cells, and RT-PCR and Western blot were used to detect the transcription and expression changes of MLAA-34 gene. RESULTS: The transcription factor MZF-1 had a regulatory effect on MLAA-34 gene expression, and the relative luciferase activity was decreased after MZF-1 binding point mutation (P<0.01). EMSA and ChIP experiments demonstrated that MZF-1 could directly bind to MLAA-34 promoter and play a regulatory role. In the over-expression test, the increase of MZF-1 could up-regulate the expression of MLAA-34 (P<0.05). In the interference test, the decrease of MZF-1 could down-regulate the expression of MLAA-34 (P<0.05). CONCLUSION Transcription factor MZF-1 can bind to the transcriptional regulatory region on the promoter of MLAA-34 gene and promote the transcription of MLAA-34 gene in acute monocytic leukemia.
Antigens, Neoplasm ; genetics ; Apoptosis Regulatory Proteins ; genetics ; Gene Expression Regulation, Neoplastic ; Genes, Reporter ; Hepatocyte Nuclear Factor 1-alpha ; Humans ; Kruppel-Like Transcription Factors ; metabolism ; Leukemia, Monocytic, Acute ; Promoter Regions, Genetic ; Transcription, Genetic

OBJECTIVETo investigate the effect of CXCR4 gene on the proliferation, adhesion, invasion and tumorigenicity of a human monocytic leukemic cell line SHI-1.

METHODSThe lentivirus vector silencing the expression of CXCR4 was constructed for infection of SHI-1 cells silencing expression of CXCR4 in SHI-1 cells. The expression of CXCR4, MMP-2 and MMP-9 was detected by real time PCR. The expression of CXCR4 on membrane of SHI-1 cells was detected by flow cytometry. The SHI-1 cell proliferation ability was detected by MTT. The co-culture system of the leukemia cells and bone marrow stromal cells was used to detect the adhesion and migration ability of leukemia cells. SHI-1 cells were inoculated subcutaneously in nude mice to investigate the growth ability in vivo.

RESULTSAfter SHI-1 cells were infected by lentivirus silencing expression of CXCR4, the expression of CXCR4 mRNA in SHI-1 CXCR-4i cells decreased by 76% as compared with expression of SHI-1/NC of negative control virus, the expression of CXCR4 on membrane of SHI-1/CXCR4i obviously downregulated; the expression of MMP-2 and MMP-9 in SHI-1/CXCRi cells also declined by 63% and 62% respectively; the proliferation ability of SHI-1/CXCR4i in vitro did not obviously changed, but the adhesion and trans-matrigel invasion ability significantly decreased, the SHI-1/CXCR4i cells could not form neoplasm subcutaneously in mice, but the SHI-1 and SHI-1/NC cells could form neoplasm subcutaneously in mice, and there was no significant difference in volumn of neoplasm mass.

CONCLUSIONThe silencing expression of CXCR4 can decline the adhesion and migration ability of SHI-1 cells, and can completely suppress the formation of neoplasm subcutaneously, so the CXCR4 may serve as a target for treating leukemia.

Animals ; Cell Adhesion ; Cell Line, Tumor ; Cell Proliferation ; Coculture Techniques ; Humans ; Lentivirus ; Leukemia, Monocytic, Acute ; pathology ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Mesenchymal Stromal Cells ; Mice ; Mice, Nude ; Neoplasm Invasiveness ; RNA Interference ; RNA, Messenger ; Receptors, CXCR4 ; genetics ; Signal Transduction

The purpose of this study was to construct a lentiviral vector carrying IK6 gene and to observe the expression of IK6 as well as related biologic feature in THP1 cells, so as to provide an effective method to further investigate the role of this gene in leukemia. The IK6 gene was obtained by using reverse transcription polymerase chain reaction (RT-PCR). Then IK6 was recombined with the pGC-FU vector to construct a recombinant lentiviral vector named pGC-FU-IK6 gene-GFP,which was confirmed by PCR and sequencing. The 293T cells were transfected with pGC-FU- IK6-GFP by using Lipofectamine 2000. After examining the titer of the virus, pGC-FU- IK6-GFP was used to transfect THP1 cells. The transfection efficiency was detected by flow cytometry, and the expression level of mRNA and IK6-GFP fusion protein were confirmed by RT-PCR and Western blot respectively. Then the impact of IK6 on apoptosis and cell cycle was analyzed. The results showed that the IK6 gene was obtained by RT-PCR and connected into the linearized lentiviral vector to successfully constructed target plasmid named pGC-FU-IK6-GFP with Amp resistant. The target plasmid was transfected into 293T cells and the virus titer was 2.0×10(9)TU/ml. Next, THP1 cells were transfected with pGC-FU-IK6-GFP and the efficiency was up to 90%. The detection of the IK6 mRNA and IK6-GFP fusion protein in target cells showed that IK6 could promote target cell clone formation and inhibit apoptosis, but had no significant effect on the cell cycle. It is concluded that virus vector carrying IK6 gene had been successfully constructed and expressed in THP1 stably. Biology studies of target THP1 cell shows that the IK6 is likely to interfere with the function of normal Ikaros protein as tumor suppressor, and it exerts a potential anti-apoptotic effect. Thus, IK6 can promote leukemia cell growth. However, there is no significant effect on the cell cycle. It provides an effective method for exploring the function of IK6 in acute myeloid leukemia.
Apoptosis ; Cell Cycle ; Cell Line, Tumor ; Gene Expression ; Genetic Vectors ; Humans ; Ikaros Transcription Factor ; genetics ; metabolism ; Lentivirus ; genetics ; Leukemia, Monocytic, Acute ; metabolism ; Plasmids ; Transfection

This study was aimed to investigate the clinical features of CD56(+) patients with acute monocytic leukemia (AML-M5) and their prognostic significance. The data of 76 newly-diagnosed patients from our hospital were analyzed retrospectively. Patients were divided into two groups: CD56(+) group (21 patients) and CD56(-) group (55 patients). The clinical features, CR rate, relapse rate, the duration of CR, and survival time of patients between the two groups were compared. The results indicated that the CD56(+) antigen was observed in 21 patients (27.6%), their median age was 51.5 years and with a range 16 - 70 years. Of the 21 CD56(+) patients, the high WBC count was found in 57.1% CD56(+) patients (12/21), but it only in 15% CD56(-) patients (P < 0.05). The extramedullary infiltration was seen in 13 CD56(+) patients, and accounted for 62% (13/21), meanwhile this infiltration was found in 18 CD56(-) patients (18/55) and accounted for 33% (P < 0.05). All cases immunophenotypically highly expressed CD13, CD33, CD64, CD11b, cMPO, CD38, in which only the expression frequency of CD11b was positively related with CD56 (r = 0.59, P < 0.05). The CR rate in CD56(+) group accounted for 60.0%, and had no significant difference in comparison with that in CD56(-) group. In CD56(+) group the relapse rate was 75% (P = 0.042), the mean duration of CR was 5.5 months (95%CI, 3.1 - 8.6, P = 0.002), the median overall survival time was 10.1 months (95%CI, 2.3 - 16.3, P = 0.001). and all these had statistical significance as compared with that in CD56(-) group. It is concluded that CD56(+) AML-M5 patients always complicate with high WBC count and extramedullary infiltration, their CR rate and duration of CR are lower and shorter respectively, their relapse rate and prognosis are high and poor respectively.
Adolescent ; Adult ; Aged ; CD56 Antigen ; metabolism ; Female ; Humans ; Immunophenotyping ; Leukemia, Monocytic, Acute ; diagnosis ; immunology ; Male ; Middle Aged ; Prognosis ; Young Adult

Ebosin is a novel exopolysaccharide produced by Streptomyces sp.139 with remarkable activity against rheumatic arthritis in vivo. In this paper, we reported effects of Ebosin on the inflammatory cytokines including interleukin-1beta (IL-1beta), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNFalpha) in THP-1 cells. With the special fluorogenic peptide as substrates, the enzymatic activities of interleukin-1beta converting enzyme (ICE) and TNFalpha-converting enzyme (TACE) were inhibited by Ebosin separately. Using the real-time reverse transcription polymerase chain reaction (real-time PCR), the mRNA synthesis of the three cytokines were identified decline separately by Ebosin. The secretion quantum of three cytokines in THP-1 cells with Ebosin was lower than that of normal THP-1 cells determined by ELISA assay and Western blotting. All of these results showed that Ebosin has remarkably suppressed synthesis of the three cytokines in THP-1 cells through different pathways. The primary study of Ebosin on anti-inflammation mechanism was promoted developing the new drugs treating rheumatic arthritis.
ADAM Proteins ; metabolism ; ADAM17 Protein ; Anti-Inflammatory Agents ; pharmacology ; Caspase 1 ; metabolism ; Cell Line, Tumor ; Humans ; Interleukin-1beta ; genetics ; metabolism ; Interleukin-6 ; genetics ; metabolism ; Leukemia, Monocytic, Acute ; metabolism ; pathology ; Polysaccharides, Bacterial ; biosynthesis ; pharmacology ; RNA, Messenger ; metabolism ; Streptomyces ; metabolism ; Tumor Necrosis Factor-alpha ; genetics ; metabolism

To investigate the effects of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor simvastatin (SV) on proliferation, apoptosis and the PI3K/AKT signaling pathway in human acute monocytic leukemia cell line SHI-1. SHI-1 cells were incubated with different concentrations of SV (5, 10, 15 µmol/L). Otherwise, SHI-1 cells without any treatment were used as control. Cells in different groups were collected at 24, 48 and 72 h after incubation for further detection. MTT method was used to assay the growth inhibition rate and flow cytometry was used to detect the early stage apoptosis ratio. The human PI3K-AKT Signaling Pathway RT(2) Profiler(TM) PCR Array was used to detect the expression of 84 genes involved in PI3K-AKT signaling. The results indicated that the SV inhibited the proliferation and inducted the apoptosis of SHI-1 cells in time- and dose-dependent manners significantly. The growth inhibition rates of SHI-1 cells treated with 15 µmol/L SV for 24, 48 and 72 h were 26.82, 47.09 and 63.92, respectively; and their early stage apoptosis ratios were 5.75, 13.25 and 15.59, respectively. Compared with the control group, expression levels of 39 genes were changed in the group of 15 µmol/L SV at 48 h, among them 26 genes were down-regulated and 13 genes were up-regulated. It is concluded that the SV can inhibit proliferation and induce apoptosis of SHI-1 cells, and the mechanism may be associated with the changes of gene expression level in PI3K-AKT signaling pathway regulated by SV.
Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Down-Regulation ; Gene Expression Regulation, Leukemic ; Humans ; Leukemia, Monocytic, Acute ; metabolism ; Phosphatidylinositol 3-Kinases ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Signal Transduction ; drug effects ; Simvastatin ; pharmacology

The purpose of this study was to investigate the effect of simvastatin (SIM) on proliferation and apoptosis of acute monocytic leukemia cell line SHI-1 and its mechanism. Experiments were divided into control and test groups (5 µmol/L, 10 µmol/L, 20 µmol/L SIM groups). The growth inhibitory rate of SHI-1 cells was detected using methyl thiazolyl tetrazolium (MTT) method. The cell cycle distribution and apoptotic rate were measured by using flow cytometry. The expression of BCL-2, caspase-3 mRNA were determined by reverse transcription polymerase chain reaction (RT-PCR). The expression of BCL-2, caspase-3 protein levels were analyzed by Western blot. The results demonstrated that SIM inhibited the growth of SHI-1 cells in time- and does-dependent manners. Cell cycle analysis showed that SHI-1 cells significantly arrested in S phase (p < 0.05) after treating with SIM for 48 hours, as compared with control group. 5 µmol/L SIM in test group significantly blocked cell cycle progression, but can not induce apoptosis. The expressions of BCL-2 mRNA and protein were down-regulated and caspase-3 mRNA and protein were up-regulated along with the increase of SIM concentration (p < 0.05). It is concluded that SIM is able to inhibit proliferation and induce apoptosis of SHI-1 cells, the mechanism may be associated with downregulating the expression of apoptosis-related gene BCL-2, upregulating the expression of caspase-3.
Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Gene Expression Regulation, Leukemic ; Humans ; Leukemia, Monocytic, Acute ; pathology ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Simvastatin ; pharmacology

OBJECTIVETo study the effect of matrix metalloproteinase 2 (MMP-2), membrane type 1 MMP (MT1-MMP) and tissue inhibitor of metalloproteinase 2 (TIMP-2) expressions on the in vitro invasive capacity of acute monocytic leukemia SHI-1 cells.

METHODSSHI-1, NB4, K562, M937 and THP-1 human leukemia cell lines were cultured in vitro. The mRNA and protein expressions of TIMP-2, MMP-2 and MT1-MMP in different cells were detected by quantitative RT-PCR and western blot. A retroviral vector carrying human TIMP-2 cDNA was constructed and transfected into SHI-1 cells. Three subclone cells (S1, S2 and S3) were screened by G418 and selected by limiting dilution. RNA interference (RNAi) was used to knock down the expression of MMP-2, MT1-MMP and TIMP-2. Cell invasion capacity was performed through a reconstituted human basement membrane assays. Zymography was used to analyze the expression of MMP-2 in the supernatant of co-culture.

RESULTSThe expressions of MMP-2, MT1-MMP and TIMP-2 in SHI-1 cells were higher than that in other leukemic cells at both mRNA and protein levels (P < 0.05). The amount of proMMP-2 and activated MMP-2 in the conditioned media from SHI-1 cells co-cultured with bone marrow stromal cells (BMSCs) was more than that from other cells (P < 0.05). The in vitro invasive capacity of SHI-1 cells were higher than that of other cells (P < 0.05). The mRNA levels of TIMP-2 were increased by about 3 fold, 2 fold and 1.5 fold in S1, S2 and S3 cells, respectively (P < 0.05), while the protein levels were by about 2.6 fold, 1.5 fold and 1.3 fold than that of SHI-1 cells, respectively (P < 0.01). The invasion rates of subclone cells demonstrated a 1.5 - 2.5 fold' elevation (P < 0.05) and activated MMP-2 from their supernatants increased by 1.5 - 2.0 fold (P < 0.01). The knock-down efficiency of siRNA was 85% to 98%. The down-regulation of TIMP-2, MMP-2 and MT1-MMP decreased the invasion rates of SHI-1 cells by 60% - 70%, 50% - 60% and 40% - 50%, respectively (P < 0.05). No activated MMP-2 in the supernatants from any knock-down cells could be found.

CONCLUSIONSSHI-1 cells constitutively overexpress MMP-2, MT1-MMP and TIMP-2 at both mRNA and protein levels. After co-cultured with BMSCs the SHI-1 cells increased MMP-2 activation and cell invasion. An increase of TIMP-2 expression in SHI-1 cells reflects an activating effect on cells invasion and MMP-2 activation.

Coculture Techniques ; Humans ; Leukemia, Monocytic, Acute ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinases, Membrane-Associated ; RNA, Messenger

The purpose of this study was to explore the effect of epigallocatechin-3-galate (EGCG) on acute monocytic leukemia cell line U937 and its relevant mechanism. The viability of U937 cells were assayed by SRB method. The cell cycle of U937 cells was analyzed by flow cytometry. The mRNA and protein expression of p16 gene were detected by RT-PCR and Western blot, respectively. Methylation level of U937 cells was analyzed by n-MSP. The mRNA expression of DNA methyltransferase 1 (DNMT1), DNMT3A and DNMT3B genes were analyzed by RT-PCR. The results showed that EGCG could inhibit the growth of U937 cells significantly in dose-and time-dependent manners (r=0.71), and induce the G0/G1 arrest of U937 cells in dose-dependent manner. EGCG could up-regulate the mRNA and protein expression of P16 gene in U937 cells in dose-dependent manner. EGCG could down-regulate the methylation level of p16 gene in U937 cells in dose-dependent manner. EGCG could down-regulate the mRNA expression of DNMT3A, DNMT3B genes, while did not influence the mRNA expression of DNMT1 gene. It is concluded that EGCG can up-regulate the mRNA and protein expression of p16 gene by demethylation or/and by inhibiting DNMT3A and DNMT3B genes, leading, in turn, to G0/G1 arrest and growth inhibition of U937 cells.
Catechin ; analogs & derivatives ; pharmacology ; Cell Proliferation ; drug effects ; DNA (Cytosine-5-)-Methyltransferase 1 ; DNA (Cytosine-5-)-Methyltransferases ; metabolism ; DNA Methylation ; Gene Expression Regulation, Leukemic ; Genes, p16 ; Humans ; Leukemia, Monocytic, Acute ; genetics ; U937 Cells

The aim of this study was to investigate the expression levels of genes psma6 and slc25a4 in bone marrow of patients with acute monocytic leukemia and their correlation with clinical features and prognosis. The expression levels of genes psma6 and slc25a4 in AML-M5 leukemia cells, normal blood cells and non-leukemia cells were detected by real-time quantitative RT-PCR and compared each other. The expression levels of psma6-encoding protein P27K was assayed by using immunohistochemistry method. The results showed that the expression levels of psma6 mRNA in AML-M5 leukemia cells was lower than that in non AML-M5 leukemia cells, non-leukemia cells and normal blood cells. The results obtained by immunohistochemistry assay were consistent with above-mentioned results. The expression level of psma6 in AML-M5 patients with complete remission was higher than that in AML-M5 patients without remission. The expression level of P27K protein in AML-M5 and AL correlated to leukocyte count in peripheral blood and LDH content. The overexpression of slc25a4 mRNA was found in AML-M5, but there was no significant difference in slc25a4 mRNA expression between the patients with complete remission and those without remission. It is concluded that the expression level of psma6 is probably a new prognostic indicator of acute monocytic leukemia, slc25a4 may be a novel gene of antigen associated with acute monocytic leukemia.
Adenine Nucleotide Translocator 1 ; genetics ; metabolism ; Adult ; Bone Marrow ; metabolism ; Female ; Humans ; Leukemia, Monocytic, Acute ; genetics ; metabolism ; Male ; Proteasome Endopeptidase Complex ; genetics ; metabolism