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AIM:To investigate the effect of decitabine (Dacogen, DAC) on the proliferation and differentia-tion of K562 cells.METHODS:The K562 cells were treated with different concentrations of DAC .The colony formation ability of the cells was detected by the colony formation assay with semi-solid culture .The cell viability was detected with MTT assay.The morphologic features were observed under inverted microscope with Wright ’s staining.The changes of the cell cycle distribution and the expression of CD 11b and CD42b were analyzed with flow cytometry .The protein expression of CDK2, cyclin E1, P27, GATA-1 and PU.1 in the K562 cells was determined by Western blot .RESULTS:DAC signifi-cantly decreased the colony number of the cells and cell viability in a dose-dependent manner .The morphological changes of the cells displayed partial differentiation .After treated the K562 cells with DAC for 72 h, the cell proportion in S phase was obviously decreased , while the cell proportion in G 2/M phase was obviously increased in a dose-dependent manner . After treated the K562 cells with DAC for 7 d, the percentage of CD11b and CD14 positive cells was further elevated , and the protein expression of P27, GATA-1 and PU.1 was increased.However, the protein expression of CDK2 and cyclin E1 was decreased .CONCLUSION:DAC inhibits the proliferation and induces differentiation of the K 562 cells via regulation of cell cycle .
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Objective To enhance the solubility and bioavailability of curcumin (CUR).Methods A novel curcumin nanoparticles were prepared.The CUR-PGD nanoparticles were prepared by the method of ultrasound precipitation combined with high-pressure homogenization using codendrimer PAMAM-co-0.25OEG (PGD) as stabilizer.The stability of CUR-PGD nanoparticles was measured in 0.9% sodium chloride solution,5% glucose, PBS and plasma.Results The drug loading capacity (DL%) of CUR-PGD nanoparticles was 41.2%, the solubility of CUR was increased to 1.5 mg·mL-1 (50 times of CUR bulk powder).The mean diameter of the nanoparticles was 438.0 nm with spherical morphology and the zeta potential was 41.4 mV.The nanoparticles was stable in 0.9% sodium chloride solution,5% glucose, PBS and plasma and there was no hemolytic phenomenon, which meant they were suitable for intravenous administration.The DSC and XRD spectra of CUR-PGD nanoparticles showed that the CUR was presented as crystal morphology in the nanoparticles.The CUR released from nanoparticles was detected in different releasing medium and presented obvious controlled release behavior.Conclusion PGD may be an effective stabilizer for the preparation of CUR-PGD nanoparticles and CUR-PGD nanoparticles are a promising drug delivery system for CUR application in clinic.
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Aim To investigate the effect of bufalin on proliferation and expression of WT1 in K562 cells. Methods The colony number of K562 cell was detec-ted with semi-solid culture assay. The cell cycle was measured by flowcytometry, and the expression of WT1 was observed with immunocytochemistry. Subcutaneous tumor models established by K562 cells in BALB/C nu/nu mice were divided into three groups, including model group, bufalin group and positive control group. After 21 days, the subcutaneous tumors were removed for calculating the inhibitory rate of tumor growth. HE staining and immunohistochemistry were used to ob-serve the morphological changes and the expression of WT1 . Results ① Bufalin could significantly decrease the colony number of K562 cell, arrest it at G0/G1 phase and down-regulate its expression of WT1 in a dose-dependent manner. ② Compared with the model group, the tumor inhibitory rate was much higher, while the volume and the weight were obviously lower in the other two groups. ③Bufalin could induce apop-tosis, necrosis, hemorrhage and fibrosis with HE stai-ning, and down-regulate the expression of WT1. Con-clusion Bufalin could inhibit the proliferation, arrest the cell cycle at G0/G1 phase and down-regulate the expression of WT1 in vitro. Bufalin could inhibit the tumor inhibitory rate, the volume and the weight of the subcutaneous tumors, induce apoptosis, necrosis, hemorrhage and fibrosis with HE staining and down-regulate the expression of WT1 .
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[ ABSTRACT] AIM:To observe the effects of total saponins of Panax ginseng ( TSPG) on the promotion of hema-topoiesis and to explore the underlying mechanism in treating aplastic anemia ( AA) in a mouse model.METHODS:For preparation of AA model, BALB/c mice were exposed to sublethal dose of 5.0 Gyγradiation, followed by transplantation of lymphocytes from DBA/2 donor mice.The experiment was divided into 6 groups, including normal control group, AA model group, TSPG treatment groups with low, medium and high doses, and positive control group with cyclosporine A ( CsA) .Both TSPG and CsA were administered by gastrogavage.After 15 d treatment, the peripheral hemogram was test-ed, the cytokine contents in serum were measured, and bone marrow semisolid culture of colony-forming assay was conduc-ted for determining hematopoietic progenitor cells.The protein levels of extracellular signal-regulated kinase 1/2 ( ERK1/2) and its phosphorylation status in the bone marrow cells were determined.RESULTS:Curative effect of TSPG in trea-ting AA mice was satisfactory.Peripheral counts of white blood cells and platelet, and concentration of hemoglobin in TSPG groups with medium and high doses were significantly higher than those in model control.TSPG increased the colony num-bers of CFU-E, BFU-E, CFU-GM and CFU-MK derived from hematopoietic progenitor cells.Meanwhile, up-regulation of the phosphorylated ERK1/2, decreased contents of Th1 cytokines and increased contents of Th2 cytokines in the serum were observed.CONCLUSION:TSPG possess the dual efficacies on the promotion of hematopoiesis and immunoregulation in AA mice by regulating the expression of Th1/Th2/Th17 cytokines and increasing the phosphorylation of ERK1/2.
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Aim To observe mesenchymal stem cell differentiation into osteoblast induced by TSPG, and explore how TSPG enhances the promotion of hemato-poiesis of osteoblast differentiation from mesenchymal stem cell. Methods MSCs were cultured by TSPG combined with osteoinductive medium. The cellular vi-ability of proliferation was detected with MTT assay. The content of alkaline phosphatase in the cultural su-pernatant was tested with pNPP assay. The ability of MSCs to form calcium nodes was also observed after a-lizarin red stain. The protein expression of RUNX2 was analyzed with Western blot. The content of cytokines associated with hematopoiesis was tested with Elisa as-say. The ability of promoting hematopoiesis was detec-ted with hematopoietic colony forming assay. Results Both MTT and pNPP assay showed that optical den-sity ( OD) values were increased in response to TSPG treatment in a dose-dependent manner. The mineraliza-tion formation ability was enhanced with TSPG-treat-ment. Meanwhile, the expression of RUNX2 protein was up-regulated in TSPG-treated cell. Moreover, the content of cytokines associated with hematopoiesis and the number of hematopoietic progenitor colony were in-creased by TSPG-treatment compared with the control group. Conclusion TSPG could induce MSCs differ-entiation in to osteoblast and enhance the effect of oste-oblast differentiation from MSCs on promoting hemato-poiesis.
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Aim To investigate the effect of resveratrol on proliferation and differentiation in K562 cells. Methods K562 cells were treated with different con-centrations of resveratrol for 6d. The colony number of K562 cells was detected with semi-solid culture assay. Expression of GATA-1 and PU. 1 in K562 cells was re-spectively measured with immunocytochemistry and Western blot. Expression of differentiation related anti-gen, CD11b, CD14 and CD42b, was measured with flowcytometry on K562 cells. Results Resveratrol could significantly decrease the colony number of K562 cells in a dose-dependent manner, and enhance the ex-pression of GATA-1,PU. 1,CD11b, CD14 and CD42b in K562 cells. Conclusion Resveratrol could inhibit the proliferation and induce differentiation of K562 cells via up-regulating the expression of GATA-1 and PU. 1 protein.
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Objective To investigate the influence of ionic strength on the stability of the methotrexate-loaded dendrimer nanoparticles. Methods The influences of different ions (Na+,Cl-) and different concentrations of sodium chloride on the stability of the nanoparticles were studied. The particle size was measured by dynamic light scattering(DLS) and drug-loading content was determined by high-performance liquid chromatography (HPLC) in order to evaluate the stability. Results The Cl- was finally verified to play an important role in stabilizing the nanoparticles and the effective concentration of the sodium chloride was recommended to be below 1. 80% . Conclusion The recommended concentration (less than 1. 80% ) of the sodium chloride significantly improves the stability of the nanoparticles and benefits for long term storage.