Human acute premyeloid leukemia cell cDNA expression library was constructed to screen acute premyeloid leukemia tumor antigen. Total RNA and purified mRNA were extracted from human premyeloid cell line NB4. First and second strands of cDNA were synthesized by reverse transcription. After blunting, the cDNA fragments were ligated with EcoR I adapters. Then the cDNAs were digested with Xho I, and less than 400 bp cDNA fragment was removed by Sephacryl-S400 spin column, the remaining were ligated with lambdaZAP vector. The recombinants were packaged in vitro, and a small portion of packaged phage was used to infect E. coli XL1-Blue-MRF' for titration. The recombinants were examined by color selection. In order to evaluate the size of cDNA inserts and the diversity of library, the pBK-CMV phagemid was excised from the ZAP express vector by using ExAssist helper phage with XLOLR strain, and then the pBK-CMV phagemid was digested by Xho I and EcoR I. The results showed that the NB4 cell line cDNA library consisting of 1.65 x 10(6) recombinant bacteriophages was constructed with the recombinant ratio of 99.6%. The average length of the recombinant exogenous inserts was about 1.7 kb. It was concluded that the constructed cDNA library are deserved to screen target clones.
Bacteriophages/genetics ; DNA, Complementary/*biosynthesis ; *DNA, Neoplasm/biosynthesis ; DNA, Recombinant/biosynthesis ; *Gene Library ; Genetic Vectors ; Leukemia, Promyelocytic, Acute/*genetics ; Leukemia, Promyelocytic, Acute/metabolism ; Leukemia, Promyelocytic, Acute/pathology ; RNA-Directed DNA Polymerase/metabolism ; Transcription, Genetic/genetics

Objective: Most acute promyelocytic leukemia cases are characterized by the PML-RARa fusion oncogene and low white cell counts in peripheral blood. Methods: Based on the frequent overexpression of miR-125-family miRNAs in acute promyelocytic leukemia, we examined the consequence of this phenomenon by using an inducible mouse model overexpressing human miR-125b. Results: MiR-125b expression significantly accelerates PML-RARa-induced leukemogenesis, with the resultant induced leukemia being partially dependent on continued miR-125b overexpression. Interestingly, miR-125b expression led to low peripheral white cell counts to bone marrow blast percentage ratio, confirming the clinical observation in acute promyelocytic leukemia patients. Conclusion This study suggests that dysregulated miR-125b expression is actively involved in disease progression and pathophysiology of acute promyelocytic leukemia, indicating that targeting miR-125b may represent a new therapeutic option for acute promyelocytic leukemia.
Animals ; Humans ; Leukemia, Promyelocytic, Acute/metabolism* ; Mice ; MicroRNAs/genetics* ; Oncogene Proteins, Fusion/therapeutic use*

The high expression of tissue factor (TF) is related to the coagulation disorder in acute leukemia. TF in blood circulation is mainly expressed in cells, microparticles (MP) and alternatively spliced human tissue factor (asHTF). To elucidate the role of TF in the coagulation disorder of acute myeloid leukemia (AML), RT-PCR was performed on 6 common AML cell lines NB4, HL-60, Kasumi-1, U937, K562 and THP-1. The results showed that only NB4 and U937 cells expressed baseline full-length TF and asHTF which were proved by sequencing. The flow cytometric detection, TF activity and TF antigen tests in NB4 and U937 cells revealed that the asHTF was expressed in trace amount and almost had no activity, while the TF antigen and activity in microparticles were significantly higher than that in asHTF. It is concluded that asHTF may play an unimportant role in the coagulation disorder of AML. Microparticle associated tissue factor (MP-TF) is the predominant source of TF activity released from AML cells.
Alternative Splicing ; HL-60 Cells ; Humans ; Leukemia, Promyelocytic, Acute ; genetics ; metabolism ; Thromboplastin ; genetics ; metabolism ; Tumor Cells, Cultured ; U937 Cells

OBJECTIVE: To investigate the expression of peptidylarginine deiminase 4 (PADI4) during the process of differentiation into granulocyte of NB4 cells induced by all-trans-retinoic acid (ATRA) and whether PADI4 is involved in the inflammatory cytokines expression. METHODS: Granulocyte differentiation model of NB4 cells induced by ATRA was established. The cell morphology changes were observed by Wright-Giemsa staining. The expression of cell differentiation marker CD11b was analyzed by flow cytometry. The mRNA and protein expression of PADI4 was detected by RT-PCR and Western blot, respectively. The expression of tumor necrosis factor (TNF) α and interleukin (IL) 1β was analyzed by ELISA, and also examined with the knockdown of PADI4 expression by siRNA. RESULTS: After NB4 cells induced by ATRA, the cytoplasm increased and the ratio of nuclear to cytoplasmic was reduced. Nuclear dented, and rod-shaped nucleus, lobulated phenomenon increased (P<0.05). Flow cytometry analysis results showed that the cell surface molecule CD11b expression increased (P<0.01). RT-PCR and Western blot showed the expression of PADI4 increased at both transcriptional and translational levels during the process of the differentiation. ELISA showed TNF-α and IL-1β secretion increased in differentiated macrophages, while they could be inhibited by PADI4-specific siRNA. CONCLUSION During the differentiation into granulocyte of NB4 cells induced by ATRA, PADI4 expression increased. Furthermore, PADI4 appeared to play a critical role in inflammatory cytokines secretion.
Cell Differentiation ; Cell Line, Tumor ; Cytokines/metabolism* ; Granulocytes ; Humans ; Leukemia, Promyelocytic, Acute ; Protein-Arginine Deiminase Type 4/metabolism* ; Tretinoin/pharmacology*

OBJECTIVERecent studies have suggested that there is a close relation between microRNA and acute leukemia (AL). The aim of this study was to investigate and better understand the classification and diagnosis of AL as well as pathogenesis and prognosis of this disease.

METHODSA total of 93 children with AL and and 12 cases of idiopathic thrombocytopenic purpura (as control group) were enrolled in this study. Microarray chip analysis of their bone marrow samples was conducted to evaluate the microRNA profiles. Quantitative real-time PCR was performed for validating the abnormal expression of microRNA.

RESULTSThe microRNA expression profiles were different between acute granulocytic leukemia and acute lymphoblastic leukemia and also between the three subtypes (M1, M2 and M3) of acute granulocytic leukemia according to FAB classification based on leukemic cell differentiation. These three subtypes of leukemia could be identified by unsupervised hierarchical cluster analysis of microRNA expression and had specific up-regulation of miR-335, miR-126 and miR-125b, respectively. However, in the M2 and M3 subtypes with positive AML1-ETO and PML-RARα, respectively, which have a better prognosis, the expressions of miR-126 and miR-125b were significantly higher than those with negative AML1-ETO and PML-RARα. Further more, miR-335 and miR-146 were up-regulated in acute granulocytic leukemia observed in this study, which are different from those reported for adult patients.

CONCLUSIONSmicroRNA cascade may serve as new biomarkers for the classification and diagnosis of pediatric AL. It is also suggested that there might be different pathogenesis and prognosis between AL types related to specific expression and regulation of microRNA.

Adolescent ; Child ; Child, Preschool ; Female ; Gene Expression Profiling ; Humans ; Infant ; Leukemia, Myeloid ; classification ; genetics ; metabolism ; Leukemia, Myeloid, Acute ; genetics ; metabolism ; Leukemia, Promyelocytic, Acute ; genetics ; metabolism ; Male ; MicroRNAs ; genetics ; metabolism ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; genetics ; metabolism

The aim of this study was to explore the effect of different conditions on two-dimensional gel electrophoresis of proteins from human acute promyelocytic leukemia cell line NB4. The 24 cm pH 3-10 linear immobilized pH gradient (IPG) strips were chosen, the isoelectric focusing was carried out by using IPGphor. Then, the second-dimensional SDS-PAGE was performed. After silver staining, the gel was analyzed by ImageMaster 2D Elite. The results showed that low ion intensity sample washing buffer improved the performance of isoelectric focusing. The lysis buffer containing 7 mol/L urea and 40 mmol/L DTT could solubilize the most proteins from NB4 cell line. The rehydration solution containing thiourea and urea increased the low molecular weight protein points to be resolved in the area of basic end. The reasonable sample load and Volt/hour of NB4 were about 100 micro g and 63 200 V/h for the 24 cm pH 3-10 IPG strips. It is concluded that the proteins from NB4 and similar cell line are complicated and affected by many factors, so that, it is very important to select the right methods for sample preparation and the conditions of two-dimensional gel electrophoresis.
Cell Line, Tumor ; Electrophoresis, Gel, Two-Dimensional ; Humans ; Isoelectric Focusing ; Leukemia, Promyelocytic, Acute ; metabolism ; pathology ; Neoplasm Proteins ; analysis

OBJECTIVETo study the effect of embelin on proliferation, differentiation and apoptosis of HL-60 cells and explore its possible mechanism.

METHODSDifferent concentration of embelin were used to treat HL-60 cells. Cell growth curve was analysed by MTT assay, cell apoptosis by Annexin V/PI double staining and JC-1 dye. The differentiation of HL-60 cells was evaluated by expression of CD33, CD34, CD11b and CD14. Bone marrow cells (BMC) from nine patients with acute nonlymphocytic leukemia (ANML) were also studied.

RESULTSEmbelin induced differentiation of HL-60 cells with significant increase of CD14 and CD11b expression at 33.97µmol/L for 3 days (P < 0.01). Embelin induced apoptosis of HL-60 cells in a time- and dose-dependent manner, the apoptosis rates were (9.23 ± 0.05)%, (25.86 ± 0.30)% and (39.03 ± 0.07)% respectively at 339.67 µmol/L of embelin for 12-, 24- and 48-hours treatment (P < 0.05); the apoptosis rates were (0.07 ± 0.03)%, (7.43 ± 0.30)%, (14.01 ± 0.01)%, (25.52 ± 0.03)% and (39.15 ± 0.01)% respectively at 10.19, 33.97, 101.90, 339.67 and 1019.02 µmol/L of embelin for 24-hours culture (P < 0.05). Clusters of differentiation antigen on BMC from three acute promyelocytic leukemia patients showed significant changes at 33.97 µmol/L of embelin treatment for 3 days. Embelin induced apoptosis of BMCs from all the nine ANML patients at 33.97 µmol/L for 24 hour.

CONCLUSIONEmbelin can inhibit proliferation and induce differentiation and apoptosis of HL-60 cells. The mechanism may be related to mitochondrial apoptosis pathway. Embelin at subtoxic concentration doesn't promote leukemia BMC differentiation, but at 339.67 µmol/L induces apoptosis of these cells.

Apoptosis ; drug effects ; Cell Differentiation ; drug effects ; Cell Proliferation ; drug effects ; HL-60 Cells ; Humans ; Leukemia, Promyelocytic, Acute ; metabolism

In order to investigate the role of tryptase in angiogenesis of acute leukemia (AL), the expressions of tryptase and vascular endothelial growth factor (VEGF) in leukemic cells from 61 patients with AL were examined by using immunocytochemical method, and the correlation between tryptase and VEGF was analyzed. The results showed that tryptase positive expression was found in 15 out of 51 patients with acute myeloid leukemia (AML) (M(1) 1/3, M(2) 7/15, M(3) 5/20, M(5) 2/8). Tryptase positive expression was 29.4% in AML. However, none of 10 patients with acute lymphocytic leukemia (ALL) showed tryptase expression. There were no correlations between the amounts of cells with tryptase expression and patient age, WBC count, numbers of blood or marrow myeloblasts and neutrophil POX. VEGF expression was revealed in 41 patients with AML (80.4%) and only 3 with ALL (30%). Significant correlation has been found between the expression of tryptase and that of VEGF in AML-M(2) (r = 0.65, P < 0.05). It is concluded that tryptase appears to be a myeloid-specific marker in AML and may be involved in the angiogenesis of AML-M(2).
Biomarkers, Tumor ; biosynthesis ; Humans ; Immunohistochemistry ; Leukemia, Monocytic, Acute ; metabolism ; pathology ; Leukemia, Myeloid, Acute ; metabolism ; pathology ; Leukemia, Promyelocytic, Acute ; metabolism ; pathology ; Neovascularization, Pathologic ; Tryptases ; biosynthesis ; Vascular Endothelial Growth Factor A ; biosynthesis

Promyelocytic leukemia (PML) protein, a tumor suppressor, plays an important role in patients with acute promyelocytic leukemia (APL) receiving arsenic trioxide (AsO) therapy. APL is a M3 subtype of acute myeloid leukemia (AML), which is characterized by expression of PML-RARα (P/R) fusion protein, leading to the oncogenesis. AsO is currently used as the first-line drug for patients with APL, and the mechanism may be:AsO directly binds to PML part of P/R protein and induces multimerization of related proteins, which further recruits different functional proteins to reform PML nuclear bodies (PML-NBs), and finally it degraded by SUMOylation and ubiquitination proteasomal pathway. Gene mutations may lead to relapse and drug resistance after AsO treatment. In this review, we discuss the structure and function of PML proteins; the pathogenesis of APL induced by P/R fusion protein; the involvement of PML protein in treatment of APL patient with AsO; and explain how PML protein mutations could cause resistance to AsO therapy.
Antineoplastic Agents ; therapeutic use ; Arsenic Trioxide ; therapeutic use ; Drug Resistance, Neoplasm ; genetics ; Humans ; Leukemia, Promyelocytic, Acute ; drug therapy ; Mutation ; Oncogene Proteins, Fusion ; metabolism ; Promyelocytic Leukemia Protein ; chemistry ; genetics ; metabolism

OBJECTIVE: To explore the effect of cytokine levels on early death and coagulation function of patients with newly diagnosed acute promyelocytic leukemia (APL). METHODS: Routine examination was performed on 69 newly diagnosed APL patients at admission. Meanwhile, 4 ml fasting venous blood was extracted from the patients. And then the supernatant was taken after centrifugation. The concentrations of cytokines, lactate dehydrogenase (LDH) and ferritin were detected by using the corresponding kits. RESULTS: It was confirmed that cerebral hemorrhage was a major cause of early death in APL patients. Elevated LDH, decreased platelets (PLT) count and prolonged prothrombin time (PT) were high risk factors for early death (P <0.05). The increases of IL-5, IL-6, IL-10, IL-12p70 and IL-17A were closely related to the early death of newly diagnosed APL patients, and the increases of IL-5 and IL-17A also induced coagulation disorder in APL patients by prolonging PT (P <0.05). In newly diagnosed APL patients, ferritin and LDH showed a positive effect on the expression of IL-5, IL-10 and IL-17A, especially ferritin had a highly positive correlation with IL-5 (r =0.867) and IL-17A (r =0.841). Moreover, there was a certain correlation between these five high-risk cytokines, among which IL-5 and IL-17A (r =0.827), IL-6 and IL-10 (r =0.823) were highly positively correlated. CONCLUSION Elevated cytokine levels in newly diagnosed APL patients increase the risk of early bleeding and death. In addition to the interaction between cytokines themselves, ferritin and LDH positively affect the expression of cytokines, thus affecting the prognosis of APL patients.
Humans ; Leukemia, Promyelocytic, Acute/diagnosis* ; Cytokines/metabolism* ; Interleukin-10 ; Interleukin-17/metabolism* ; Interleukin-6/metabolism* ; Interleukin-5/metabolism* ; Blood Coagulation Disorders ; Ferritins ; Tretinoin