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: 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 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

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 effect of silencing SET gene on the biological characteristics of acute promyelocytic leukemia NB4-R1 cells.

METHODSThe expression vector of pGCSIL containing SET-shRNA were transfected into 293T cells by using other packaging plasmids. The supernatant of the 293T cells was harvested for lentivirus. The SET-shRNA lentiviral vector was transfected into acute promyelocytic leukemia NB4-R1 cells and a stably transfected cell line was established. Real-time quantitative PCR and Western blot were used to assay the silencing efficiency on SET gene and the expression of PP2A. The cell cycle distribution was tested by flow cytometry.

RESULTSThe expression of SET in experimental group statistically decreased as compared with that of the control group. The expression of PP2A was obviously raised at the level of mRNA and protein. The percentage of NB4-R1 cells in G0/G1 phase significantly increased, while the percentage of cells in S phase significantly decreased.

CONCLUSIONThe silencing gene in acute promyelocytic leukemia NB4-R1 cells using SET-shRNA lentiviral vector can increase the expression of PP2A and interfere of the cell cycle in NB4-R1 cells. This study has laid a experimental base for targed therapy of patients with acute promyelocytic leukemia.

Cell Cycle ; Cell Line, Tumor ; Gene Silencing ; Genetic Vectors ; HEK293 Cells ; Histone Chaperones ; genetics ; Humans ; Lentivirus ; Leukemia, Promyelocytic, Acute ; genetics ; pathology ; Protein Phosphatase 2 ; metabolism ; RNA, Messenger ; RNA, Small Interfering ; Transcription Factors ; genetics ; Transfection

OBJECTIVETo explore the effect of RNA interference of human I2PP2A gene on the proliferation and apoptosis of retinoic acid-resistant human acute promyelocytic leukemia (APL) cell line NB4-R1.

METHODSDesigned and constructed a RNA interference lentiviral vector I2PP2A-shRNA which targeted against I2PP2A gene, then transfected it into NB4-R1 via polybrene mediation. The I2PP2A expression levels before and after transfection were detected by qRT-PCR and Western blot, respectively. Meanwhile, the proliferation and apoptosis rates of each group were determined by CCK-8 and flow cytometry assay. The protein expressions of caspase-8 and PARP were detected by Western blot.

RESULTSBoth qRT-PCR and Western blot data showed the I2PP2A expression level was significantly downregulated in the transfection group. The I2PP2A mRNA expression level decreased by (70.0 ± 9.6)% and (64.0 ± 6.2)% respectively, compared with blank control and negative control group, and the I2PP2A protein expression level showed a consistent trend. CCK-8 proliferation assay indicated the NB4-R1 cell proliferation rate in I2PP2A-shRNA transfection group significantly reduced compared to blank control group (P<0.05). Flow cytometry results showed that NB4-R1 apoptosis rate in I2PP2A-shRNA transfection group increased by (6.30 ± 0.67) times and (6.04 ± 0.56) times, respectively (P<0.01). After inhibition of I2PP2A, the total caspase-8 and total PARP expressions decreased by (44.0 ± 3.1)% and (57.0 ± 4.0)%, respectively; Meanwhile, the cleaved caspase-8 (p43) and cleaved PARP (p89) increased by (36.0 ± 2.5)% and (45.0 ± 4.8)%, respectively compared with blank control group (P<0.05).

CONCLUSIONI2PP2A gene silenced by RNA interference could inhibit the proliferation and promote the apoptosis of NB4-R1, which may be regulated through caspase-8-induced exogenous apoptosis pathway.

Apoptosis ; genetics ; Caspase 8 ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; genetics ; Drug Resistance, Neoplasm ; Histone Chaperones ; genetics ; metabolism ; Humans ; Leukemia, Promyelocytic, Acute ; metabolism ; pathology ; RNA Interference ; Transcription Factors ; genetics ; metabolism ; Tretinoin ; pharmacology

This study aims to investigate the effects of small interference RNA (siRNA) targeting PML-RARa mRNA on the activity of the acute promyelocytic leukemia cell line NB4. The proliferation inhibition was evaluated by MTT assay and colony-formation inhibiting test. Apoptosis was determined by flow cytometry after siRNA treatment. The results showed that the cell growth of siRNA treated group was inhibited, and the apoptosis of NB4 could be induced. The siRNA targeting PML-RARα mRNA might be a valid therapy of acute promyelocytic leukemia.
Apoptosis ; Cell Cycle ; Cell Line, Tumor ; Humans ; Leukemia, Promyelocytic, Acute ; genetics ; metabolism ; Oncogene Proteins, Fusion ; genetics ; metabolism ; RNA, Messenger ; genetics ; RNA, Small Interfering ; genetics

No abstract available.
Antineoplastic Agents/*adverse effects/*therapeutic use ; Bone Marrow Cells/metabolism ; Humans ; Karyotyping ; Leukemia, Myeloid, Acute/*chemically induced/*diagnosis/genetics ; Leukemia, Promyelocytic, Acute/*drug therapy ; Male ; Middle Aged ; Oncogene Proteins, Fusion/genetics ; Remission Induction ; Tretinoin/therapeutic use

In general, a 2-yr disease-free duration is recommended before kidney transplantation (KT) in end-stage renal disease (ESRD) patients who also have acute leukemia. However, the optimal disease-free interval has not been specified for all subtypes of acute leukemia. Among these subtypes, acute promyelocytic leukemia (APL) shows a favorable prognosis and low relapse rate compared to other types of leukemia. We here report KT after complete remission (CR) of APL in an ESRD patient. Irreversible kidney injury developed in a 23-yr-old man with APL. First, we induced CR and subsequently performed KT 7 months after the achievement of CR. The patient's clinical course after KT was favorable, without allograft rejection or relapse of APL up to1 yr after KT. On the basis of our clinical experience, it is suggested that a long wait may not be necessary before KT in patients with ESRD and APL.
Adult ; Antineoplastic Agents/therapeutic use ; Arsenicals/therapeutic use ; Bone Marrow Cells/pathology ; Humans ; Kidney Failure, Chronic/*therapy/ultrasonography ; *Kidney Transplantation ; Leukemia, Promyelocytic, Acute/*diagnosis/drug therapy ; Male ; Oxides/therapeutic use ; Receptors, Retinoic Acid/genetics/metabolism ; Remission Induction

OBJECTIVETo study the expression profile of microRNAs in acute promyelocytic leukemia (APL) cells during differentiation.

METHODSDifferentiation of APL cell line NB4 cells was induced by all-trans retinoic acid (ATRA) and arsenic trioxide (As2O3). Morphological and immunological assay was performed by Wright-Giemsa staining and flow-cytometric analysis of CD11b surface expression. During in vitro NB4 differentiation induced by ATRA and As2O3, microRNA expression profiles (miR-15b, miR-16, miR-34a, miR-107, miR-124a, miR-146, miR-155, miR-181a, miR-223, miR-342, let7c) were detected by real time RT-PCR, and the relative expression level of microRNAs were quantitatively analyzed by using 2(-ΔΔCt), and compared with that of control group. Meanwhile, the microRNA expression profiles were also detected in 15 newly diagnosed APL patients and 15 complete remission (CR) APL cases by real time RT-PCR, and the relative expression level of microRNA was quantitated by using 2(-ΔCt), and compared with that of control group (newly diagnosed APL as control group). These data were expressed as x(-) ± s, and differences between groups were examined using t test. P < 0.05 was considered statistically significant.

RESULTSThe expression levels of miR-15b, miR-16, miR-107, miR-223 and miR-342 in NB4 differentiation group were obviously up-regulated (3.40, 4.22, 5.41, 20.03 and 5.29 folds higher in ATRA treated NB4 cells than that of control group respectively, and 3.62, 2.49, 2.58, 4.27 and 1.94 folds higher in AS2O3 treated NB4 cells than that of control group respectively), except for miR-15b, the expression levels of miR-16, miR-107, miR-223 and miR-342 in ATRA treated group was significantly higher than that in As2O3 treated group. The relative expression levels of miR-15b, miR-16, miR-107, miR-181a, miR-223 and miR-342 were 0.4137, 0.6367, 0.1260, 0.0522, 0.6611, 0.0280 in APL CR group, and 0.0751, 0.2022, 0.0425, 0.3064, 0.1733, 0.0090 in newly diagnosed APL group, respectively. The expression level of miR-15b, miR-16, miR-107, miR-223 and miR-342 in APL CR group were significantly upregulated compared with that of newly diagnosed APL groups (P < 0.05), while the expression level of miR-181a was significantly downregulated (P < 0.05).

CONCLUSIONSpecific expression of microRNA profiles is a key contributing factor in the differentiation of APL.

Arsenicals ; pharmacology ; Cell Differentiation ; drug effects ; Humans ; Leukemia, Promyelocytic, Acute ; genetics ; metabolism ; MicroRNAs ; genetics ; metabolism ; Oxides ; pharmacology ; RNA, Messenger ; genetics ; Tretinoin ; pharmacology ; Tumor Cells, Cultured