OBJECTIVE: To investigate the influence and mechanism of atorvastatin on glycolysis of adriamycin resistant acute promyelocytic leukemia (APL) cell line HL-60/ADM. METHODS: HL-60/ADM cells in logarithmic growth phase were treated with different concentrations of atorvastatin, then the cell proliferation activity was measured by CCK-8 assay, the apoptosis was detected by flow cytometry, the glycolytic activity was checked by glucose consumption test, and the protein expressions of PTEN, p-mTOR, PKM2, HK2, P-gp and MRP1 were detected by Western blot. After transfection of PTEN-siRNA into HL-60/ADM cells, the effects of low expression of PTEN on atorvastatin regulating the behaviors of apoptosis and glycolytic metabolism in HL-60/ADM cells were further detected. RESULTS: CCK-8 results showed that atorvastatin could inhibit the proliferation of HL-60/ADM cells in a concentration-dependent and time-dependent manner (r=0.872, r=0.936), and the proliferation activity was inhibited most significantly when treated with 10 μmol/L atorvastatin for 24 h, which was decreased to (32.3±2.18)%. Flow cytometry results showed that atorvastatin induced the apoptosis of HL-60/ADM cells in a concentration-dependent manner (r=0.796), and the apoptosis was induced most notably when treated with 10 μmol/L atorvastatin for 24 h, which reached to (48.78±2.95)%. The results of glucose consumption test showed that atorvastatin significantly inhibited the glycolytic activity of HL-60/ADM cells in a concentration-dependent and time-dependent manner (r=0.915, r=0.748), and this inhibition was most strikingly when treated with 10 μmol/L atorvastatin for 24 h, reducing the relative glucose consumption to (46.53±1.71)%. Western blot indicated that the expressions of p-mTOR, PKM2, HK2, P-gp and MRP1 protein were decreased in a concentration-dependent manner (r=0.737, r=0.695, r=0.829, r=0.781, r=0.632), while the expression of PTEN protein was increased in a concentration-dependent manner (r=0.531), when treated with different concentrations of atorvastatin for 24 h. After PTEN-siRNA transfected into HL-60/ADM cells, it showed that low expression of PTEN had weakened the promoting effect of atorvastatin on apoptosis and inhibitory effect on glycolysis and multidrug resistance. CONCLUSION Atorvastatin can inhibit the proliferation, glycolysis, and induce apoptosis of HL-60/ADM cells. It may be related to the mechanism of increasing the expression of PTEN, inhibiting mTOR activation, and decreasing the expressions of PKM2 and HK2, thus reverse drug resistance.
Humans ; Atorvastatin/pharmacology* ; PTEN Phosphohydrolase/pharmacology* ; Sincalide/metabolism* ; Drug Resistance, Neoplasm/genetics* ; TOR Serine-Threonine Kinases/metabolism* ; Leukemia, Promyelocytic, Acute/drug therapy* ; Doxorubicin/pharmacology* ; Apoptosis ; RNA, Small Interfering/pharmacology* ; Glycolysis ; Glucose/therapeutic use* ; Cell Proliferation

OBJECTIVE: To investigate the effect of phorbol-12-myristate-13-ace-tate (TPA) on the proliferation and apoptosis of acute promyelocytic leukemia cell line NB4 and its molecular mechanism. METHODS: The effect of different concentrations of TPA on the proliferation of NB4 cells at different time points was detected by CCK-8 assay. The morphological changes of NB4 cells were observed by Wright-Giemsa staining. The cell cycle and apoptosis of NB4 cells after TPA treatment were detected by flow cytometry. The mRNA expressions of NB4 cells after TPA treatment were analyzed by high-throughput microarray analysis and real-time quantitative PCR. Western blot was used to detect the protein expression of CDKN1A, CDKN1B, CCND1, MYC, Bax, Bcl-2, c-Caspase 3, c-Caspase 9, PIK3R6, AKT and p-AKT. RESULTS: Compared with the control group, TPA could inhibit the proliferation of NB4 cells, induce the cells to become mature granulocyte-monocyte differentiation, and also induce cell G₁ phase arrest and apoptosis. Differentially expressed mRNAs were significantly enriched in PI3K/AKT pathway. TPA treatment could increase the mRNA levels of CCND1, CCNA1, and CDKN1A, while decrease the mRNA level of MYC. It could also up-regulate the protein levels of CDKN1A, CDKN1B, CCND1, Bax, c-Caspase 3, c-Caspase 9, and PIK3R6, while down-regulate MYC, Bcl-2, and p-AKT in NB4 cells. CONCLUSION TPA induces NB4 cell cycle arrest in G₁ phase and promotes its apoptosis by regulating PIK3/AKT signaling pathway.
Humans ; Leukemia, Promyelocytic, Acute ; Caspase 3/metabolism* ; Caspase 9/pharmacology* ; Phosphatidylinositol 3-Kinases/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; bcl-2-Associated X Protein/metabolism* ; Cell Line, Tumor ; Cell Division ; Apoptosis ; RNA, Messenger ; Cell Proliferation

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

Objective: To investigate the prognostic significance of interferon regulatory factor 9 (IRF9) expression and identify its role as a potential therapeutic target in acute promyelocytic leukemia (APL) . Methods: The gene expression profile and survival data applied in the bioinformatic analysis were obtained from The Cancer Genome Atlas and Beat acute myeloid leukemia (AML) cohorts. A dox-induced lentiviral system was used to induce the expression of PML-RARα (PR) in U937 cells, and the expression level of IRF9 in U937 cells treated with or without ATRA was examined. We then induced the expression of IRF9 in NB4, a promyelocytic leukemia cell line. In vitro studies focused on leukemic phenotypes triggered by IRF9 expression. Results: ①Bioinformatic analysis of the public database demonstrated the lowest expression of IRF9 in APL among all subtypes of AML, with lower expression associated with worse prognosis. ②We successfully established a PR-expression-inducible U937 cell line and found that IRF9 was downregulated by the PR fusion gene in APL, with undetectable expression in NB4 promyelocytic cells. ③An IRF9-inducible NB4 cell line was successfully established. The inducible expression of IRF9 promoted the differentiation of NB4 cells and had a synergistic effect with lower doses of ATRA. In addition, the inducible expression of IRF9 significantly reduced the colony formation capacity of NB4 cells. Conclusion: In this study, we found that the inducible expression of PR downregulates IRF9 and can be reversed by ATRA, suggesting a specific regulatory relationship between IRF9 and the PR fusion gene. The induction of IRF9 expression in NB4 cells can promote cell differentiation as well as reduce the colony forming ability of leukemia cells, implying an anti-leukemia effect for IRF9, which lays a biological foundation for IRF9 as a potential target for the treatment of APL.
Cell Differentiation ; Humans ; Interferon-Stimulated Gene Factor 3, gamma Subunit/metabolism* ; Leukemia, Myeloid, Acute/drug therapy* ; Leukemia, Promyelocytic, Acute/genetics* ; Oncogene Proteins, Fusion/metabolism* ; Phenotype ; Tretinoin/therapeutic use* ; U937 Cells

OBJECTIVE: To investigate the effect of monoammonium glycyrrhizinate on the stem cell-like characteristics, oxidative stress and mitochondrial function of acute promyelocytic leukemia cells NB4. METHODS: CCK-8 method was used to detect the viability of acute promyelocytic leukemia cells NB4, and the appropriate dose was screened; Cloning method was used to detect the proliferation rate of NB4 cell; Western blot was used to detect the expression of cell cycle-related protein; flow cytometry was used to detect cell apoptosis and sort NB4 stem cells positive (CD133⁺); Stem cell markers (Oct4, ABCG2, Dclk1) were detected by RT-PCR; ROS was detected by fluorescence; The kit was used to detect the level of oxidative stress markers (MDA); The flow cytometry was used to detect the change of mitochondrial membrane potential; Western blot was used to detect the expression of mitochondrial damage index-related proteins (Bax/BCL-2). RESULTS: Compared with the control group, if the concentration of MAG was less than 5 μmol/L, the cell NB4 viability showed no significant difference; if the concentration was higher than 5 μmol/L, the inhibitory effect on the growth of cell NB4 increased and showed significant difference (P<0.05), according to the results of CCK-8 experiment, four groups were set based on the concentration of MAG 0 μmol/L, MAG 5 μmol/L, MAG 10 μmol/L, and MAG 20 μmol/L; compared with the control group (MAG 0 μmol/L), the cells in MAG 5 μmol/L group showed no significant difference, while the proliferation rate, cyclin expression, mitochondrial membrane potential, stem cell CD133⁺ ratio, and marker mRNA level ( Oct4, ABCG2, Dclk1) of NB4 cell were significantly reduced (P<0.05); the apoptosis rate, reactive oxygen species, MDA content and Bax/BCL-2 expression of NB4 cell significantly increased (P<0.05). CONCLUSION Monoammonium glycyrrhizinate has a significant inhibitory effect on acute promyelocytic leukemia cells NB4, which may be related to the regulation of stem cell-like characteristics, oxidative stress and mitochondrial function.
Apoptosis ; Cell Line, Tumor ; Doublecortin-Like Kinases ; Humans ; Intracellular Signaling Peptides and Proteins/metabolism* ; Leukemia, Promyelocytic, Acute ; Mitochondria ; Oxidative Stress ; Protein Serine-Threonine Kinases ; Stem Cells

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*

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*

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

OBJECTIVETo investigate the immunophenotype of leukemia promyelocytes (LP) in bone marrow of patients with acute promyelocytic leukemia (APL) and to explore their characteristics and significance.

METHODSThe immunophenotypes of leukemia cells in 43 patients with APL were analyzed by means of 4 color immunophenotypes; the cell population in which CD45 strength localized at 10(2) and the SSC strength locatized at 10(2) was defined as R3, the cell population in which CD45 strength localized at 10(3) and the SSC strength localized at 10(2) was defined as R5, moreover the ratio of positive cells >80% was defined as strong positive expression, the ratio of positive cells between 20%-80% was difined as weak positive expression, the ratio of positive cells <20% was difined as negative by gating method of CD45/SSC.

RESULTSThere was a abnormal cell population (R3) in 79.07% cases; the immunophenotypes of R3 was cheracteried by high SSC, weaker expression of CD45, the rate of CD38, CD9 and CD13 all was 100%, moreover their bright expression (>80%) was 86.05%, 90.70% and 86.05%, respectively; the positive expression rate of CD33, CD117 and CD64 was 97.67%, 95.35% and 83.80% respectively, moreover thier bright expression was 84.04%, 69.77% and 30.23% respectively; the CD15 was weakly expressed in 39.53% cases, the CD34 and HLA-DR were weakly expression in 16.28% and 6.98% cases respectively. All the cases did not express CD116. There were 2 cell populations (R3 and R5) in 20.93% cases, the immunophenotypic features of R3 were cosistant with above mentioning, while the immunophenotypes of R5 were lower than those of R3 SSC; the fluorescence intensity of CD45 was higher, but lower than that in normal lymphycytes, the positive rate of CD9, CD13, MPO was 100%, moreover thier fluorescence intensity was high; they did not expressed CD123, CD25, CD22, CD4, CD64 and CD14. Thereby it can be concluded that the typical immunophenotypes is characterized by CD13(+) CD9(+) CD38(+) CD33(+) CD117(+) CD64(+) CD11b(-) CD34(-) HLA-DR(-) in APL. There was a special immunophenotype in the APL with basophilic granules. Conclusoin: APL has a characteristic immunophenotypic profile, whose typical immunophenotype is characterized by CD13(+) CD9(+) CD38(+) CD33(+) CD117(+) CD64(+) CD11b(-) CD34(-) HLA-DR(-). The special immunophenotype exists in the APL with basophilic granules. Flow cytometric immunophenotyping may be a useful for rapid recognition of APL and has significant for prognosis.

Antigens, CD ; metabolism ; Cell Count ; Flow Cytometry ; Granulocyte Precursor Cells ; classification ; HLA-DR Antigens ; metabolism ; Humans ; Immunophenotyping ; Leukemia, Promyelocytic, Acute ; classification ; immunology ; Leukocyte Common Antigens ; metabolism ; Prognosis

OBJECTIVETo investigate the effect of human umbilical cord-derived mesenchymal stem cells (UC-MSC) on the differentiation of leukemic cells.

METHODSThe co-culture system of UC-MSC with acute promyelocytic leukemic cell line NB4 cells was constructed in vitro,and the differentiation status of the leukemic cells was assessed by cell morphology,nitroblue tetrazolium reduction test,and cell surface differentiation marker CD11b.

RESULTSUC-MSC induced the granulocytic differentiation of NB4 cells. When UC-MSC and a small dose of all-trans retinoic acid were applied together,the differentiation-inducing effect was enhanced in an additive manner. Interleukin (IL)-6Ra neutralization attenuated differentiation and exogenous IL-6-induced differentiation of leukemic cells.

CONCLUSIONUC-MSC can promotd granulocytic differentiation of acute promyelocytic leukemia cells by way of IL-6 and presented additive effect when combined with a small dose of all-trans retinoic acid.

Cell Differentiation ; Cell Line, Tumor ; Humans ; Interleukin-6 ; metabolism ; Leukemia, Promyelocytic, Acute ; pathology ; Mesenchymal Stromal Cells ; metabolism ; Tretinoin ; pharmacology ; Umbilical Cord ; cytology