Effects of Panax notoginseng saponins on proliferation, apoptosis and cell cycle of K562 cells in vitro and the mechanisms / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of Panax notoginseng saponins (PNS) on the proliferation, apoptosis and cell cycle of K562 cells and explore the molecular mechanisms underlying these effects.</p><p><b>METHODS</b>PNS-induced growth inhibition of K562 cells was detected by MTT assay; the cell apoptosis was evaluated by AO/EB staining and Annexin V-FITC/ PI staining; flow cytometry was used to detect cell cycle changes in the treated cells. The mRNA expressions of the molecules in mTOR signaling pathway were examined by RT-PCR, and the cellular expressions of cleaved caspeas-3, cyclin D1 and major proteins in mTOR signaling pathway were detected using Western blotting.</p><p><b>RESULTS</b>MTT assay showed that treatment with 100-800 µg/mL PNS significantly inhibited the proliferation, promoted the cell apoptosis, and caused cell cycle arrest in G0/G1 phase in K562 cells. Western blotting revealed increased protein expression of cleaved caspase-3 and decreased expression of cyclin D1 in PNS-treated cells, in which the proteins expressions of mTOR, p-mTOR, p-p70S6K and p-4E-BP 1 and the mRNA expression of mTOR were all decreased.</p><p><b>CONCLUSION</b>PNS can inhibit the proliferation, induce apoptosis and cause cell cycle arrest in K562 cells possibly by up-regulating cleaved caspase 3 and down-regulating cyclin D1 and mTOR signaling pathway.</p>

Lentivirus-mediated stable Fas gene silencing in human umbilical cord-derived mesenchymal stem cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To construct a lentivirus-mediated vector for RNA interference (RNAi) of Fas and establish a human umbilical cord-derived mesenchymal stem cells (UC-MSCs) line with stable Fas gene silencing.</p><p><b>METHODS</b>Four short hairpin RNA sequences targeting the coding region of human Fas mRNA were designed. The synthesized oligonucleotides were ligated with the lentivirus vectors harvested from BamHI and EcoRI double digestion of LV3 recombinant vector. The recombinant lentivirus vectors were transfected into the packaging cells 293T, and the lentivirus titers were determined. Cultured UC-MSCs were infected with the lentivirus, and real-time PCR and Western blotting were used to detect the expressions of Fas mRNA and protein in the transfected cells.</p><p><b>RESULTS</b>Restriction digestion and DNA sequencing showed that the lentiviral vectors were successfully constructed, and the titer of lentivirus reached 3 × 10⁸ TU/ml in the packaging cells. Real-time PCR and Western blot demonstrated significantly suppressed Fas gene expression in UC-MSCs after infection with the recombinant lentivirus.</p><p><b>CONCLUSION</b>Lentivirus-mediated RNAi can effectively inhibit Fas gene expression in cultured UC-MSCs.</p>

A feature selection algorithm design and its implementation in intrusion detection system / 西安交通大学学报·英文版

Objective: Present a new features selection algorithm. Methods: based on rule induction and field knowledge. Results: This algorithm can be applied in catching dataflow when detecting network intrusions, only the sub-dataset including discriminating features is catched. Then the time spend in following behavior patterns mining is reduced and the patterns mined are more precise. Conclusion: The experiment results show that the feature subset catched by this algorithm is more informative and the dataset's quantity is reduced significantly.