The role of ouabain in cell death of vascular endothelial cells ECV304 and the changes of expression of Na+, K(+)-ATPase alpha1, beta1-subunit / 中国应用生理学杂志

<p><b>AIM</b>To study the effect of Na+, K(+)-ATPase inhibition by ouabain on growth and death of vascular endothelial cells ECV304 and involved mechanisms.</p><p><b>METHODS</b>Growth inhibition of ouabain on ECV304 cells was analyzed using MTT assay. The feature of cell death was studied by Hoechst 33342/PI staining, transmission electron microscopy and DNA agarose gel electrophoresis in ECV304 cells treated with ouabain. The mRNA expression of Na+, K(+)-ATPase alpha1, beta1-subunit was examined by reverse transcription PCR (RT-PCR).</p><p><b>RESULTS</b>Ouabain inhibited the growth of ECV304 cells in a dose and time-dependent manner. 10 micromol/L ouabain treated for 24 hours could stimulate the necrosis of ECV304 cells; When treated with 0.1 micromol/L ouabain for 24-48 hours, the cells showed obviously defluxion, the loss of cell-cell contacts, nuclear chromatin condensation, chromatin margination and DNA fragmentation. Na+, K(+)-ATPase alpha1-subunit mRNA expression was significantly up-regulated in ECV304 cells treated with ouabain while the beta1-subunit expression conversely showed a significant decrease.</p><p><b>CONCLUSION</b>Ouabain could up-regulate Na+, K(+)-ATPase alpha1-Subunit expression and reduce beta1-Subunit expression which mediated signal transduction and decreased cell-cell adhesions and induced ECV304 cells death.</p>

Analyzing anti-cancer action mechanisms of dihydroartemisinin using gene chip / 中国中药杂志

<p><b>OBJECTIVE</b>To understand the action mechanisms of artesunate on inhibiting leukaemia cell line K562 on the molecular level.</p><p><b>METHOD</b>The gene chip was used to detect the expression panel of genes of leukaemia cell line K562 treated by dihydroartemisinin. K562 cells were treated with 1 x 10(-5), 4 x 10(-5), 16 x 10(-5), 64 x 10(-5), 256 x 10(-5) mol x L(-1) dihydroartemisinin for 24 h, and then studied the modality changes by invert microscope. The morphological changes of the nucleons were observed by Hoechst33342/PI staining. The cell cycle were examined by flow cytometry analysis (FCM). Total RNA samples were obtained by TRIzol and were reverse transcribed to the cDNA. The cDNA samples were hybridized to our gene chips. Hybridization signal were collected and analyzed following scanning by Gene Pix 4100A.</p><p><b>RESULT</b>The numbers of drift cells were increased and the density of cells was decreased under invert microscope after K562 cells were treated with dihydroartemisinin for 24 h. Morphological changes of cell apoptosis such as karyopyknosis and conglomeration were observed by Hoechst 33342/PI staining. Flow cytometric analysis showed that cells were arrested in G2 phase. There were 13 differentially expressed genes identified. Hybridization analysis showed up-regulation of chk1 and down-regulation of PCNA, cyclinB1, cyclinD1, cyclinE1, cdk4, cdk2, E2F1, DNA-PK, DNA-Topo I, mcl-1, jNK, VEGF in the dihydroartemisinin-treated K562 cells.</p><p><b>CONCLUSION</b>Dihydroartemisinin can Inhibit the leukaemia cell line K562 and exert its anti-cancer effect by altering the expression of these genes involved in cell cycle; dihydroartemisinin may act via apoptosis pathway.</p>