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BACKGROUND:Nowadays, growth factors are commonly used to induce bone marrow mesenchymal stem cells. However, this is a high-cost method with a great amount of growth factors. In addition, the chondrogenic potential of bone marrow mesenchymal stem cells wil decrease significantly with increasing times of culture. OBJECTIVE:To observe the directed differentiation of bone marrow mesenchymal stem cells co-cultured with human synovial fluid. METHODS:Human bone marrow mesenchymal stem cells were isolated and cultured by adherence screening method. The synovial fluid of the knee was aspirated from healthy volunteers by aseptic operation. Passage 3 human bone marrow mesenchymal stem cells were co-cultured with the fol owing media:synovial fluid+complete medium;synovial fluid+bone marrow mesenchymal stem cells+complete medium;bone marrow mesenchymal stem cells+complete medium. The morphology and growth of the cells were observed under an inverted microscope every day. At days 7, 14 and 21 of induction, toluidine blue staining and immunocytochemical staining were performed. RESULTS AND CONCLUSION:After co-culture with human synovial fluid, human bone marrow mesenchymal stem cells proliferated slowly, and varied from fusiform to oval or polygonal;toluidine blue and col agen II staining were positive. These findings indicate that the synovial fluid has a positive role in the chondrogenic differentiation of bone marrow mesenchymal stem cells. The synovial fluid may contain substances that promote the chondrogenic differentiation of bone marrow mesenchymal stem cells.
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Aim To investigate apoptosis induced by 3,3'-diethyl-9-methylthia-carbocyanine iodide(DMTCCI) , an inhibitor of DNA primase found in our previous study, and the mechanism of DMTCCI in human myelogenous leukemia HL-60 cells. Methods HL-60 cells were cultured in RPMI-1640 medium and treated with different concentrations of DMTCCI. MTT assay was used to detect growth inhibition.Flow cytometry and DNA ladders were used to detect apoptosis. Western blotting was used to observe the expression of survivin, Bcl-xL, Bad, Bax, Bcl-2, caspase-9, caspase-3, caspase-6, PARP, DFF45 and lamin B protein. Caspase-3 activity was measured by ApoAlert Caspase-3 Assay Kit. Results DMTCCI inhibited proliferation of human leukemia HL-60 cells with IC50 value of 0. 24 μmol · L-1. The results of flow cytometry and DNA ladders showed that DMTCCI could induce apoptosis of HL-60 cells. The expression levels of protein survivin and Bcl-xL were down-regulated, Bad and Bax were up-regulated,while Bcl-2 protein had no change in response to DMTCCI treatment in HL-60 cells. Treatment of HL-60cells with DMTCCI induced the proteolytic cleavage of caspase-9, caspase-3, caspase-6, PARP, DFF45and lamin B protein. Caspase-3 activity apparently increased at 3 h and reached a peak at 12 h after exposure to 1 μmol · L-1 of DMTCCI in HL-60 cells. Conclusion DMTCCI inhibited proliferation and induced apoptosis of human leukemia HL-60 cells. Bcl-2 family proteins, survivin and caspases family proteins might playa role in the apoptosis process induced by DMTCCI.
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Aim The aim of this study is to determine effect of ST2325 on HER2/neu tyrosine kinase signal pathway and cell cycle in breast cancer BT474 cells. Methods Protein expression was detected with immunoblot analysis. Cell cycle distribution was examined using flow cytometry.Results ST2325 inhibited tyrosine phosphorylation of HER-2/neu in a dose-dependent manner with half maximal inhibition occurring at a concentration of 8.7 ?mol?L -1 without reduced HER-2/neu receptor protein expression. Activation of MAPK and AKT, downstream molecules of HER-2/neu-mediated signal transduction pathway was inhibited following exposure to ST2325. After BT474 cells were treated with different concentrations of ST2325 for 24 h, the results of flow cytometry analysis showed cell cycle arrest in G 1 phase. Western blot assay showed up-regulation of p27 protein expression and decrease of hyperphosphorylated Rb and cyclin D1 protein expression.Conclusions ST2325 inhibits HER2 tyrosine kinase phosphorylation and induces G 1 arrest in BT474 cells. Cell cycle arrest in G 1 is associated with p27 up-regulation, decrease of cyclin D1 protein and hyperphosphorylated Rb.
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Cyclins, CDKs and CKIs in cell cycle play important roles in maintaining cell cycle and regulation of the process cell cycle. Many endogenous and extraneous inhibitors have effects on cell cycle by modulating functions of cyclins, CDKs and CKIs. Several highlighted points in the researches of cell cycle and related proteins, inhibitors were reviewed, including the latest advances on their applications in cancer therapy.
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Object To study the inhibitory effect of Anti-EB Virus Liquor (AEVL) on EB (Epstein-Barr) virus antigen expression and its cytotoxicity. Methods The effect of AEVL on Raji cell early antigen (EA) expression and B 95-8 cell virus capsid antigen (VCA) expression was assayed by indirect fluorescent technique; the cytotoxicity on nasopharyngeal carcinoma CNE 2 cells was determined by MTT method. Results At the non-toxic concentration, AEVL had markedly inhibitory effect on Raji cell EB-virus, IC 50 was 0.667 mg/mL and showed powerfully inhibitory effect on B 95-8 cell EB-virus VCA expression, IC 50 was 0.89 mg/mL; and it had strongly inhibitory effect on B 95-8 cell EB virus VCA expression stimulated by sodium n-butyric acid, IC 50 was 1.4 mg/mL. The IC 50 of AEVL on human nasopharyngeal carcinoma CNE 2 cell was 7.57 mg/mL. Conclusion AEVL could inhibit EB virus antigen expression and have cytotoxicity on nasopharyngel carcinoma cells at high concentration.