【Objective】 To explore the effects and the possible mechanism of RNA targeting membrane-bound prostaglandin E2 synthase l（mPGES- 1）on proliferation，apoptosis and drug resistance of leukemia cell line K562/A.【Methods】RNA interference was used to inhibit the expression of mPGES-1 of K562/A cells. Four groups were set up as follows：untreated group（K562/A），negative control group after interference（K562/A-NC），group after interference（K562/ A-KD），and group after interference with exogenous PGE2（K562/A-KD+PGE2）.Cell viability was assessed by CCK-8 assay. Cell apoptosis was analyzed by flow cytometry. Concentration of PGE2 was detected by ELISA. Proteins expression was detected by western blot.【Results】The expression of mPGES- 1 in K562/A cells was significantly down- regulated and the synthesis of PGE2 decreased（P < 0.000 1）after RNA interference. After RNA interference，the proliferation of K562/A cells was inhibited and apoptosis increased，and the sensitivity to chemotherapy drugs was enhanced（P < 0.05）. Meanwhile，the expression of β-catenin and MDR1 was decreased（P < 0.01）. Exogenous PGE2 could reverse the effect of RNA interference on proliferation ，apoptosis and drug sensitivity in K562/A cells（P < 0.05），and up-regulate the expression of β-catenin and MDR1（P < 0.01）. XAV939，an inhibitor of β-catenin，could down-regulate the expression of β- catenin and MDR1 in an dose- dependent pattern in K562/A cells（P < 0.05）.【Conclusions】RNA interference of mPGES- 1 could inhibit proliferation，induce apoptosis and reverse drug resistance in K562/A cells. The mechanism was related to reducing the synthesis of PGE2 and thus down- regulating the expression of β- catenin and MDR1. Wnt/β- catenin signal pathway may participate in the regulation of MDR1 by mPGES-1/PGE2.

【Objective】To explore the effects and the possible mechanism of KPT- 8602，a novel selective inhibitor of nuclear export protein （XPO1），on proliferation，cell cycle and apoptosis in human histiocytic lymphoma cell line U937 cells.【Methods】U937 cells were treated with different concentrations of KPT- 8602. Cell viability was assessed by CCK-8 assay. The cell cycle distribution and the apoptosis rate were analyzed by flow cytometry. The proteins expression of XPO1，p-AKT，AKT，Cleaved Caspase-3，p21 were determined by Western blot. Fluorescence microscope was used in observing the intracellular location of XPO1. 【Results】 KPT- 8602 inhibited the growth of U937 cells in a dose- dependent（P<0.001）and time- dependent manner（P<0.001），but normal PBMC were unaffected. 48 h after treatment with KPT-8602，a higher proportion of cells in G1 phase was observed（P<0.001）and the apoptosis rate increased（P=0.016）with drug concentration in U937 cells. XPO1 protein expression of U937 cells was significantly higher than normal PBMC（P=0.003）. 48 h after treatment with KPT- 8602，the protein expression of XPO1 decreased（P=0.011），p-AKT decreased（P=0.011），and Cleaved Caspase- 3 increased（P=0.009）. In addition，the protein expression of p21，the cargo protein of XPO1，increased in both the nuclei and the cytoplasm（P<0.05）after treatment with KPT- 8602. XPO1 decreased in both the nuclei and the cytoplasm under the fluorescence microscope after treatment with KPT- 8602.【Conclusion】KPT- 8602 can inhibit the proliferation of U937 cells，block the cell cycle at G1 phase，and induce cell apoptosis，which may partially be attributed to the down-regulation of XPO1 and inhibition of PI3K/AKT signaling.

[Objective]Examine the expression of microsomal prostaglandin E synthase-1(mPGES-1)and nuclear transcription factor kappa B p65(NF-κB p65)in diffuse large B cell lymphoma(DLBCL),assessing their correlation with clinical variables,prognosis and potential clinical valve.[Methods]The immunohistochemistry was uesd to investigate the expression of mPGES-1 and NF-κB p65 in 83 DLBCL patiens'tissues.The relationship between these two proteins and the clinical variables and prognosis of these patients was evaluated.[Results]The high expression of mPGES-1 and NF-κB p65 were observed in 65.1%(54/83)and 73.5%(61/83)cases of DLBCL,respectively.The expression level of NF-κB p65 was positively correlated with mPGES-1 expression(P<0.05).The expression of these two proteins was found to be significantly associated with B cell lymphoma/leukemia-2 protein(BCL-2),higher expression of Ki67,higher lactate dehydrogenase (LDH),more extranodal lesions,advanced Ann Arbor stage and higher international prognostic index(IPI)score(P<0.05). In addition,NF-κB p65 was related with multiple myeloma oncogene 1(MUM1),pathological type(P<0.05). Both mPGES-1 and NF-κB p65 overexpression was correlated with worse overall survival(OS)while NF-κB p65 was an in-dependent prognostic factor for OS of DLBCL(P<0.05).[Conclusions]mPGES-1 and NF-κB p65 were highly expressed in DLBCL and closely linked with each other. The overexpression of mPGES-1 and NF-κB p65 was correlated with tumor progression and unfavorable prognosis in patients with DLBCL.

OBJECTIVETo investigate the effects of shRNA targeting mPGES-1 on tumorigenicity of human acute leukemia K562 cells in nude mice in vivo and its mechanisms.

METHODSFor experiment 3 groups including KD group(expression of mPGES-1 in K562 cells was down-regulated by shRNA), CON (cells without any treatment) and NC group (cells treated with nonspecific-sequence shRNA) were set-up. Western blot was used to test the expression of β-catenin and cyclinD1 in cells. Then the cells of 3 groups were implanted into BALB/c nude mice subcutaneously to establish murine xenograft model. The growth state of the mice and the size of the xenograft tumor were recorded. HE staining was used to observe the morphology of xenograft tumor. Expressions of β-catenin and cyclinD1 in xenograft tumor were detected by immunohistochemical staining.

RESULTSIn vitro the expression of β-catenin and cyclinD1 in KD group were lower than the CON group and NC group (P<0.05). In vivo the tumor volume and weight of KD group were significant smaller than the other two groups (P<0.01). HE staining showed that tissues in the KD group were relatively looser in arrangement with smaller cell nucleus and less cytoplasm. The expression of β-catenin and cyclinD1 in the KD group were remarkable weak as compared with that in CON group and NC group (P<0.05).

CONCLUSIONDown-regulating the expression of mPGES-1 by shRNA may significantly inhibit the tumorigenicity of K562 cells in nude mice in vivo and its mechanism may be related with the inhibition of expression of β-catenin and cyclinD1.

OBJECTIVETo investigate the clinical significance of bone marrow morphological differences in the differential diagnosis of megaloblastic anemia (MM) and refractory anemia (R4).

METHODSA total of 60 anemia patients selected from our hospital between April 2004 and April 2015 were divided into MA group (30 cases) and RA group (30 cases) in accordance with their clinical diagnosis. Clinical manifestations, results of bone marrow morphology test, blood examination, peripheral blood smear, erythroid megaloblastic variability rate and nucleated red blood cell level in the 2 groups were compared and analyzed.

RESULTSIncidence of fever, hemorrhage, digestive reaction, splenomegaly and fatigue as well as hemoglobin level, platelets and white blood cell counts in patients of MA group were similar to those of RA group, there was no statistically significant difference between 2 groups (P>0.05). The percentages of dysplastic hematopoiesis in erythroid cells, granulocytic cells, magakaryoajtic cells, the PAS-positive rate and red blood cell distribution in the MA patients were obviously lower than those in the RA patients, while the erythroid megaloblastic variability rate (90%) in MA group was obviously higher than that in RA patients (10%) and with statistically significant difference (P<0.05). The percentage of immature red blood cells was similar between MA group (53.33%) and RA group (60.00%), without significant difference (P>0.05).

CONCLUSIONMost of clinical manifestations and peripheral blood smear results are consistent in MA patients and RA patients, bone marrow morphology detection in RA group should be focused on lymphocytoid micromegakaryocytes, while the erythroid megaloblastic cell body is the focus in MA group, PAS can be used as a diagnostic criteria.

Anemia, Megaloblastic ; diagnosis ; Anemia, Refractory ; diagnosis ; Bone Marrow ; pathology ; Diagnosis, Differential ; Erythrocyte Count ; Humans ; Leukocyte Count ; Megakaryocytes ; cytology

To investigate the effect of a microsomal prostaglandin E synthase-1 (mPGES-1) inhibitor MK886 on cell cycle of the human acute myeloid leukemia HL-60 cells. HL-60 cells were treated with different concentration of MK886 (10, 25, 50 µmol/L) for 24 h. Flow cytometry, Western blot and ELISA were used to measure cell cycle, cyclin D1, mPGES-1, PGE(2), Akt, P-Akt and C-MYC. The results indicated that after treated with MK886, the percentage of HL-60 cells decreased in G(0)/G(1) phase and increased in S phase, and expressions of mPGES-1, cyclin D1, P-Akt and C-MYC and synthesis of PGE(2) decreased significantly. It is concluded that MK886 can arrest HL-60 cells in G(0)/G(1) phase, the mechanism of which is possibly associated to inhibition of mPGES-1 expression, reduction of PGE(2) synthesis, suppression of Akt phosphorylation and C-MYC expression, down-regulation of cyclin D1 expression.
Cell Cycle ; drug effects ; HL-60 Cells ; Humans ; Indoles ; pharmacology ; Intramolecular Oxidoreductases ; antagonists & inhibitors ; Leukemia ; metabolism ; pathology ; Prostaglandin-E Synthases

This study was aimed to investigate the effect of MK886, a mPGES-1 inhibitor, on apoptosis and drug resistance of leukemia HL-60/A cell line. Expression of mPGES-1 was assayed by QT-PCR and Western blot. The effect of MK886 on HL-60/A cell proliferation was assayed by CCK-8 method, and flow cytometry was used to detect cell apoptosis. The expression of Akt and P-Akt was detected by Western blot. PGE2 was measured by ELISA. Effect of MK886 (10 µmol/L) on the chemotherapeutic sensitivity of HL-60/A cells and expression of mdr-1 mRNA and P170 protein were investigated too. The results indicated the expression of mPGES-1 was higher in HL-60/A cells. MK886 inhibited HL-60/A cell proliferation and induced apoptosis in a time- and concentration-dependent manner. Expression of mPGES-1 and P-Akt and synthesis of PGE2 decreased significantly. MK886 reduced expression of mdr-1 and P170 protein and enhanced the sensitivity of HL-60/A cells to chemotherapeutic drugs. It is concluded that MK886 can inhibit HL-60/A cell proliferation, induce apoptosis and enhance sensitivity to chemotherapeutic drugs, the mechanism of which possibly associates to down-regulation of mPGES-1/PGE2 synthesis, reduction P-Akt expression and decreasing mdr-1 and P170 protein expression.
Apoptosis ; drug effects ; Cell Proliferation ; drug effects ; Drug Resistance, Neoplasm ; drug effects ; Gene Expression Regulation, Leukemic ; HL-60 Cells ; Humans ; Indoles ; pharmacology

To observe the expression of cyclin D1, hTERT, and telomerase activity in MNC, HL-60, HL-60A and to explore their effects on leukemogenesis and drug-resistance, normal human peripheral blood mononuclear cells, HL-60 cells sensitive to adriamycin and HL-60A cells resistant to adriamycin were investigated. The cell cycle was analyzed by flow cytometry, and the apoptosis was analyzed by Annexin V-FITC(+) PI staining. Expressions of cyclin D1 and hTERT were determined by real-time PCR and Western blot. Telomerase activity was detected by TRAP-ELISA. The results indicated that the percentage of MNC, HL-60 and HL-60A in S phase was (10.21 + 2.11)%, (44.93 + 3.00)%, and (51.38 + 1.10)% respectively; the percentage of apoptosis cells was (16.14 + 2.13)%, (7.53 + 0.92)%, (4.15 + 0.96)% respectively; the expression of mRNA and protein for cyclin D1 and hTERT increased; the telomerase activities of HL-60 and HL-60A were higher (p = 0.000), whereas the difference between HL-60 and HL-60A was no statistically significant (p = 0.232); positive correlation between cyclin D1, hTERT and telomerase activity had been found (p < 0.01). It is concluded that the cells of S phase increased while the apoptotic cells decreased in HL-60 and HL-60A, especially in HL-60A, which may be due to the up-regulation of cyclin D1, hTERT and telomerase activity.
Cell Cycle ; Cyclin D1 ; metabolism ; HL-60 Cells ; Humans ; Leukemia ; metabolism ; Telomerase ; metabolism

This study was aimed to clarify whether valproic acid (VPA) induces apoptosis of leukemia HL-60 cell line and its possible mechanism. The effect of different concentrations and treatment time of VPA on HL-60 cell proliferation was assayed by cytotoxicity test (CCK-8 method) and fluorescence microscopy, and flow cytometry was used to detect cell apoptosis. The expressions of telomerase subunit h-tert mRNA and apoptosis-related protein as well as caspase-3 activity were detected by real time-quantitative PCR, Western blot and ELISA respectively. The results indicated that VPA inhibited proliferation of HL-60 cells and induced cell apoptosis in a dose dependent manner (r = -0.87). The expressions of anti-apoptotic protein BCL-2 and h-tert mRNA were significantly decreased while the pro-apoptotic protein BAX and caspase-3 activity increased after treatment with VPA. The apoptosis rate of HL-60 cell was negatively correlated with expression of h-tert mRNA. It is concluded that VPA can inhibit leukemia HL-60 cell proliferation and induce apoptosis. The VPA displays anti-leukemia activity possibly through reducing h-tert mRNA and BCL-2 protein expression, increasing BAX expression and activity of caspase-3.
Apoptosis ; drug effects ; Caspase 3 ; metabolism ; HL-60 Cells ; Humans ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Telomerase ; metabolism ; Valproic Acid ; pharmacology ; bcl-2-Associated X Protein ; metabolism