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OBJECTIVE To observe the effect of mannitol on oxidative stress of human kidney tubular epithelial cells(HK-2). METHODS MTT assay was applied to detect HK-2 cell viability after ex?posure to different concentrations(50,100,150,200,250,300,350 and 400 mmol · L-1)of mannitol for 4,10,24,48 and 72 h. DCFH-DA method was used to determine the level of reactive oxygen species (ROS)after HK-2 cells were exposed to mannitol 100 and 250 mmol · L-1 for 4 h. Furthermore,cell morphology and indexes of oxidative stress such as malondialdehyde(MDA) content,superoxide dismutase(SOD )activity and glutathione(GSH) content were observed at different time points. RESULTS HK-2 cell viability decreased by about 50%after being treated with mannitol 250 mmol · L-1 for 72 h (P<0.05). ROS production in mannitol 250 mmol · L-1 treated group (68.7 ± 3.6) was higher than in solvent control group(50.3 ± 4.6)(P<0.05). HK-2 cells exhibited morphological changes after treatment with mannitol 250 mmol · L-1 for 4-72 h,including cell swelling,vacuoles and fall off. After treatment with mannitol 250 mmol · L-1 for 4,10,24,48 ahd 72 h,the MDA content increased signifi?cantly(P<0.05),while the activity of SOD and the content of GSH decreased significantly compared with solvent control group(P<0.05). CONCLUSION Over-production of ROS in HK-2 cells induced by high concentration(250 mmol·L-1)of mannitol may cause lipid peroxidation and injure the ability of an?tioxidation,which may contribute to mannitol induced cytotoxicity.
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[ ABSTRACT] AIM:To observe the effect of the metabolites generated from oxidative deamination of methylamine ( MA) or benzylamine ( BZA ) catalyzed by semicarbazide-sensitive amine oxidase ( SSAO ) on 3T3-L1 adipocytes. METHODS:3T3-L1 preadipocytes were induced to differentiation.SSAO activity was determined by high performance liquid chromatography ( HPLC) at different differentiation time points.MTT assay was applied to detect cell vitality after exposure to different concentrations of MA or BZA.Fluorescence probe DCFH-DA was used to determine the production of reactive oxygen species after incubation of 3T3-L1 adipocytes with MA or BZA.After exposure to 0.5 mmol/L MA or BZA for 4 h, malondialdehyde ( MDA) , total superoxide dismutase ( T-SOD) and glutathione ( GSH) in the adipocytes or prea-dipocytes were measured.RESULTS:SSAO activity increased with the increase in the differentiation days, and reached a maximum at the 8th day.Incubation of the cells with different concentrations of MA or BZA for 4 h did not significantly de-creased the cell vitality (P>0.05).After exposure to 0.5 mmol/L MA or BZA, the reactive oxygen species in adipocytes significantly increased, and were about 3 to 4 times as compared with control group (P0.05 ) .CONCLUSION: MA or BZA induces oxidative stress in the mature adipocytes, which might result from the deamination products catalyzed by SSAO.
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Objective To observe the anti-tumor effect on human multiple myeloma cell lines U266 and KM3 with a combination of varinostat and melphalan in vitro.Methods The cell proliferation of U266 and KM3 was datected with MTT assay when treated them with vorinostat alone and melphalan alone,then calculate their IC50 values respectively.Fixed the concentrations of vorinostator melphalan,the cell proliferation was datected in combination with melphalan/vorinostat in seriesly concentrations by MTr assay.Then to calculate drug combination index(CI).Results The IC50 value of U266 was 5.0-7.5 μmol/L and that of KM3 was 2.5-5.0 μmol/L when treated by vorinostat alone,the IC50 value of U266 was 40-60 μmol/L and that of KM3 was 60-80 μmol/L treated by melphalan alone.When fixed the concentration of vorinostat(in U266 the concentration was 1.25 μmol/L,in KM3 the concentration was 1.0 μ mol/L),Synergism(CI＜0.9)was observed when the concentrations of melphalan were 20 μmol/L,40 μmol/L,60 μ mol/L and 80 μ mol/L in U266,40 μmol/L,60 μmol/L,80 μmol/L and 100 μmol/L in KM3;When fixed the concertration of melphalan (in U266,was 10 μmol/L,in KM3 was 20 μmol/L),synergism(CI＜0.9)was observed when the concentrations of vorinostat were 1.0 μmol/L,2.5 μmol/L,5.0 μmol/L and 7.5 μmol/L in U266,and 1.0 μmol/L,2.5μmol/L,5.0 μmol/L in KM3.An additive effect was observed with the czombination of vorinostat 7.5 μmol/L plus melphalan 20 μmol/L in KM3(CI=0.93).Conclusion Vorinostat had potential anti-myeloma effect alone,and had synergistic anti-tumor effect with melphalan in vitro.
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ObjectiveTo investigate the gene expressions of TAZ and Wnt/β-catenin on the postosteogenic cells of mesenchymal stem cells(MSC)in multiple myeloma(MM)patients and to explore the potential therapeutic target of multiple myeloma bone disease (MBD).MethodsBone marrow mononuclear cells MNC from MM and controls were isolated,cultured,expanded and then induced to osteogenic differentiation.Realtime quantitative RT-PCR was employed to detect the osteogenic markers (TAZ,Wnt/β-catenin,OPN,OC,ALP and Cbf α1); and alizarin red staining for mineral deposition.The mRNA expressions of TAZ and Wnt/β-catenin in the two groups were analysed.ResultsAlizarin red staining was positive and the red calcium nodules were appeared on the post-osteogenic cells of MSC.The mRNA expressions of OC,ALP and Cbf α1 were 2.0958±0.5665,2.6670±0.3847,0.8463±0.3473,respectively,on the post-osteogenic cells of MSC in the experimental groups,which were significantly higher than those of pre-osteogenic cells(1.3487±0.9291,1.1452±0.6054,0.4439±0.2945) (t =2.171,6.709,2.795; all P ＜ 0.05).The mRNA expressions of OPN,OC,ALP and Cbf α1 were 2.1096±0.8267,2.8991±0.3531,4.3045±0.2844,1.3273±0.4075,respectively,on the post-osteogenic cells of MSC in the controls,which were significantly higher than those of pre-osteogenic cells (1.2200±0.9091,0.8780±0.3927,1.9161±0.2684,0.6736±0.2513) (t =2.289,12.103,25.134,4.411; all P ＜ 0.05).The mRNA expressions of OPN,OC,ALP,Cbf α1 were 1.2710±0.5636,2.0958±0.5665,2.6670± 0.3847,0.8463+0.3473,respectively,on the post-osteogenic cells of MSC in the experimental groups,which were significantly lower than those of control groups(2.1096 ±0.8267,2.8991 ±0.3531,4.3045±0.2844,1.3273±0.4075) (t =-2.650,-3.805,-10.822,-2.841; all P ＜ 0.05).The mRNA expression of TAZ and β-catenin were 2.2315±1.0723 and 0.5801±0.2159 on the post-osteogenic cells of MSC in MM patients,which were significantly lower than those of control groups (4.4140±0.8325,0.9516±0.2920) (t =±5.085,-3.235;both P ＜ 0.05).ConclusionThe gene expressions of OPN,OC,ALP and Cbf α1,the osteogenesis related genes,are increased in post-osteogenic cells of MSC,which showed the MSC have been successfully induced to osteoblasts.Comparing with control groups,the osteogenic potential of MSC in MM patients is lower.Based on the above research,TAZ and Wnt/β-catenin may present a novel target for the future therapy of MBD.
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Objective To investigate the reversal effect of Topo Ⅱα-shRNA and Topo Ⅱβ-shRNA on Topo Ⅱ gene in K562/AS2 cells. Methods Three pieces of Topo Ⅱα-shRNA and three pieces of Topo Ⅱβ-shRNA were designed,synthesized and transfected into K562/AS2 cells by liposome. Expression level of Topo Ⅱα and Topo Ⅱβ mRNA were determined by real time fluorescence quantitative PCR. The expressions of Topo Ⅱα and Topo Ⅱβ protein were assayed with flow cytometer. Results After treated with Topo Ⅱα-shRNA or Topo Ⅱβ-shRN A for 24 hours,the expression level of Topo Ⅱα mRNA and Topo Ⅱβ mRNA protein in K562/AS2 cells decreased at most (78.22±0.01) %,(31.17±1.27) % (P <0.05),and (57.36±0.01)%,(23.98±1.22) % (P <0.05) respectively. Conclusion The expression of Topo Ⅱ gene can be down-regulated after infected with Topo Ⅱ-shRNA in K562/ AS2 cell line.
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Objective To investigate sequence variations of 12 miRNA genes in multiple myeloma(MM) in order to find whether sequence variations in miRNA genes are associated with tumorigenesis and discuss the clinical significance of MM associated with miRNA genes mutations. Methods The miRNA gene mutations in 20 cases of MM, 4 MM-derived cell lines and 20 controls were detected by the methods of polymerase chain reaction single stranded conformation polymorphism (PCR-SSCP) and silver staining technique. Both clinical features and laboratory results were analyzed simultaneously. Results The electrophoretic patterns showed a total of three variations in miR-19a, miR-19b and miRNA-335,which were observed in 3 MM cells (15 %, 3/20). We also found variations of miRNA-335 in MM-derived cell lines KM-3and RPMI8226. However, no sequence alteration in the miRNA genes was observed in our set of controls. One of the three MM patients died, and two of them were detected mutations at the terminal stage of the disease.Conclusion A relative high frequency of miRNA gene mutation was found in MM and MM derived cell lines, which suggests possibility of a main mechanism underlying tumorigenesis. And, detecting miRNA gene mutations in MM might be benefit to evaluate the progression and prognosis of disease.
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Objective To construct a recombinant adenovirus vector of Hairpin RNA specific for MRP1 gene and study its inhibition of MRP1 gene expression in K562/AS2 cell line resistant to AS_2O_3 (ATO). Methods A MRP1-specific hairpin RNA recombinant adenovirus vector was constructed and used to infected K562/AS2 cells. Expression level of MRP1 mRNA detected by real-time fluorescent quantitative PCR. MRP1 protein detected by flow cytometry. MTT method was used to detected the cytotoxicity of ATO and etoposide. Results MRP1 mRNA and protein expression level in K562/AS2 cells before and after the pAd-MRPl-shRNA adenovirus infection was (34.70±0.28 vs 4.19±0.03, P <0.05) and (26.40±0.16 vs 10.85±0.37, P<0.05), respectively. RR of K562/AS2 to arsenic trioxide and etoposide was (11.4078±0.3183 fold vs 1.6126±0.3015 fold, P<0.05) and (5.9141 ±0.0149 fold vs 1.7664±0.1038 fold, P <0.05), respectively. The reversal fold of ATO and etoposide was (7.2409±1.3668) and (3.3555±0.1886), respectively. Conclusion Successfully constructed pAd-EGFP-U6-shRNA-MRPl adenovirus vector, the vector of infection K562/SA2 cells can inhibit MRP1 gene expression and reverse the resistance of the ATO and etoposide.
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Objective To investigate the inhibitional effect of MRPI-shRNA on expression of MRP1gene in K56.2/AS2 cells resistant to arsenic trioxide. Methods Three pieces of MRPI-shRNA were designed,synthesized and transfected into K562/AS2 cells with lipesome. Expression level of MRPI mRNA were determined by real time fluorescent quantitative PCR. MRPI protein expression and intracellular accumulation of DNR were assayed with flow cytometry. Results After treated with MRPI-shRNA, the expression level of MRPI mRNA and MRPI protein in K562/AS2 cells decreased significantly(79.1±0.07) % and (62.48±0.86) %,respectively (P <0.05). The intracellular accumulation of DNR increased significantly(P < 0.05). Conclusion MRPI-shRNA can down-regulate the expression of MRPI gene in K562/AS2 cell line.
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AIM:To explore the changes of the subsets and HLA-DR expression of dendritic cells and their concerning cytokine levels in peripheral blood of patients with breast cancer.METHODS:The subsets of the precussors of dendritic cells(pDC)in the peripheral blood of 57 cases of patients with breast cancer before operation and a week or six months after operation and 20 cases of healthy controls were analyzed by four-color FCM.The levels of IL-12p40,IL-10,IFN-? and IL-4 in the plasmas were tested by ELISA.RESULTS:Among 57 cases of patients with breast cancer,2 cases in Ⅲ phase and 4 cases in Ⅳphase expressed deficiency of pDC,the ratios of pDC1/pDC2 in the other cases inⅠ,Ⅱ,Ⅲ,Ⅳ phase were respectively 1.62?0.59,1.41?0.63,0.91?0.32,0.81?0.29 before operation,which were markedly lower than those in controls(1.94?0.44).The ratios of pDC1/pDC2 in the cases inⅠ,Ⅱ,Ⅲ phase were 1.71?0.47,1.52?0.54,1.04?0.36 a week after operation,which were the same as those in pre-operation,but markedly lower than those in controls.The ratios of pDC1/pDC2 in the cases inⅠ,Ⅱ,Ⅲ phase were 1.92?0.72,1.63?0.65,1.28?0.34 six months after operation,which were markedly higher than those in pre-operation,meanwhile,to compare with controls,those were still lower for patients in Ⅱ,Ⅲ phase except in Ⅰphase.No difference between patients and controls in the expression of HLA-DR of pDCs and the levels of IL-12p40,IL-10,IFN-?,IL-4 in plasmas and the ratios of IL-12p40/IL-10,IFN-?/IL-4 was observed.CONCLUSION:The ratios of pDC1/pDC2 in peripheral blood of patients with breast cancer inⅠ-Ⅳ phase are decreased.Parts of patients in Ⅲ,Ⅳ phase are deficiency of pDCs.HLA-DR expression of DCs and the ability of DCs which secret the concerning cytokines do not change as pDC subsets change.pDC subsets improve markedly inⅡ,Ⅲ phase patients and recover to the normal level inⅠphase patients after operation.
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AIM: To explore the characters of fibroblast-like (F-L) cells cultured from granunocyte clony stimunating factor (G-CSF)-mobilized peripheral blood cell (PBC) harvests. METHODS: The adherent cells in the PBC harvests were cultured for 2 week in the mediums of RPMI-1640/L-DMEM/G-CSF or interleukin-3 (IL-3) plus RPMI-1640, the cultured F-L cells were analyzed by flow cytometry (FC). RESULTS: The adherent non-confluent F-L cells obtained from the four groups were similar in their phenotypes: CD33+, CD11c+, CD64+, CD14+, CD45+, HLA-DR+, CD86+, CD34-, CD38-, CD3-, CD19-, CD56-, CD29-, CD44-, CD105-. The F-L cells are similar to monocytes except CD38-and were distinct from dendritic cells (DC) or mesenchymal stem cells (MSC). CONCLUSION: The cultured F-L cells are macrophages rather than DC or MSC. G-CSF, rhIL-3 enhances their numbers.
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AIM: To establish a arsenic trioxide (As 2O 3 )-resistant leukemic cell line to explore the mechanism of resistance to As 2O 3, and the relationship between the resistant cell line and the multidrug resistance was also investigated. METHODS: The arsenic trioxide (As 2O 3 )-resistant leukemic cell line was established by exposing the cells to the increasing concentration of As 2O 3. MTT assay was used to detect the cytotoxicity. Cell cycle was detected by PI assay. Flow Cytometry was used to detect the P-glycoprotein on the surface of the cells, the intracellular concentration of DNR, and the immuetype of the cells. RESULTS: The cell doublings time and the cell cycle of the arsenic trioxide (As 2O 3 )-resistant leukemic cell line, K562/AS2, is similar to that of K562. The relative resistant fold of K562/AS2 to As 2O 3, DNR, VP16 and Ara-C was 7.4, 2.9, 3.8 and 1.1, respectively. The relative resistant fold of multidrug resistant cell line, K562/ A02, to As 2O 3, DNR, VP16 and Ara-C was 0.8?94?2.5 and 0.9, respectively. The fluorescence of the P-glycoprotein on the surface or of the DNR inside the cells detected was not significantly different between the K562 and the K562/AS2 cell lines. CONCLUSIONS: A cell line, K562/AS2, resistant to clinical achieving level (2 ?mol/L) of As 2O 3 has been established. The relative resistant fold of K562/ AS2 to As 2O 3 is about 7.4 fold to the parent K562 line sensitive to As 2O 3. Partial resistance of K562/AS2 to DNR and VP16 is observed , the mechanism of which is unrelated to the P-gp, the expression product of multidrug resistance gene 1 (mdr1).
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AIM: To investigate the effect of CD_8+ cells from aplastic anemia (AA) patients and its histamine type II (H_2) receptors on the growth of normal CFU-Mk. METHODS: The effects of CD_8+ cells and/or cimetidine, on normal human CFU-Mk growth were studied by using CFU-Mk assay. RESULTS: The CD_8+ cells from the perpheral blood of AA patients significantly suppressed the growth of normal allogeneic CFU-Mk. This inhibitory effect was blocked by cimetidine at concentration of 1.0?10~-5 mol/L. 1.0?10~-5 mol/L cimitidine alone didn't inhibit the growth of normal CFU-Mk. CONCLUSION: H_2 receptor antagonist cimitidine abolishes the suppressive effect of AA patients CD_8+ cells on the growth of normal CFU-Mk.