Targeting cyclin B1 inhibits proliferation and sensitizes breast cancer cells to taxol

Background Cyclin B1, the regulatory subunit of cyclin-dependent kinase 1 (Cdk1), is essential for the transition from G2 phase to mitosis. Cyclin B1 is very often found to be overexpressed in primary breast and cervical cancer cells as well as in cancer cell lines. Its expression is correlated with the malignancy of gynecological cancers. Methods In order to explore cyclin B1 as a potential target for gynecological cancer therapy, we studied the effect of small interfering RNA (siRNA) on different gynecological cancer cell lines by monitoring their proliferation rate, cell cycle profile, protein expression and activity, apoptosis induction and colony formation. Tumor formation in vivo was examined using mouse xenograft models. Results Downregulation of cyclin B1 inhibited proliferation of several breast and cervical cancer cell lines including MCF-7, BT-474, SK-BR-3, MDA-MB-231 and HeLa. After combining cyclin B1 siRNA with taxol, we observed an increased apoptotic rate accompanied by an enhanced antiproliferative effect in breast cancer cells. Furthermore, control HeLa cells were progressively growing, whereas the tumor growth of HeLa cells pre-treated with cyclin B1 siRNA was strongly inhibited in nude mice, indicating that cyclin B1 is indispensable for tumor growth in vivo. Conclusion Our data support the notion of cyclin B1 being essential for survival and proliferation of gynecological cancer cells. Concordantly, knockdown of cyclin B1 inhibits proliferation in vitro as well as in vivo. Moreover, targeting cyclin B1 sensitizes breast cancer cells to taxol, suggesting that specific cyclin B1 targeting is an attractive strategy for the combination with conventionally used agents in gynecological cancer therapy

Feilke revisited : 60 Stellenbesuche

Weitere Hrsg.: Thorsten Pohl, Sara Rezat, Torsten Steinhoff, Martin SteinseiferAnlässlich des 60. Geburtstags des Linguisten und Sprachdidaktikers Helmuth Feilke wurden Wegbegleiterinnen und Wegbegleiter gebeten, einzelne Stellen in seinen wissenschaftlichen Schriften erneut zu besuchen. Entstanden sind pointierte Kommentare, kurze wissenschaftliche Abhandlungen und Analysen, Varianten auch des kritischen und kontroversen Nach- und Weiterdenkens und Ansätze zur Neu- oder Re-Kontextualisierung. Je nach wissenschaftlicher Vita der Autorinnen und Autoren kann es sich um Stellen handeln, deren Rezeption zeitlich weit zurückliegt, oder um Passagen, die ganz aktuelle Fragen der eigenen Forschungsarbeit tangieren. Abgesehen davon, dass ein kurzes Format für die Beiträge gewählt und die Autorinnen und Autoren gebeten wurden, die ausgewählte Stelle knapp zu verorten und zu erläutern, war die Bearbeitungsform gänzlich freigestellt. So sind Texte in einer Bandbreite von pointierten Kommentaren, kurzen wissenschaftlichen Abhandlungen und Analysen, Varianten des Nach- und Weiterdenkens, Ansätze zur Neu- oder Re-Kontextualisierung bis hin zu Formen des kritischen Hinterfragens und der kontroversen Auseinandersetzung entstanden

Mytilid mussels: global habitat engineers in coastal sediments

International audienceDense beds of mussels of the family Mytilidae occur worldwide on soft-bottoms in cold and warm temperate coastal waters and have usually been considered hot spots of biodiversity. We examined intertidal mussel beds at four distant locations around the globe with the same sampling method, to find out whether this “hot spot” designation holds universally. We studied species assemblages within the matrices of byssally interconnected mussels engineered by in the North Sea, by mixed and at the southern Chilean coast, by in the Yellow Sea and by at the coast of southern Australia. In all cases, species assemblages inside mussel beds were significantly different from those outside with many species being restricted to one habitat type. However, species richness and diversity were not generally higher in mussel beds than in ambient sediments without mussels. In the North Sea () and at the Chilean coast (, ), mussel beds have markedly higher species numbers and diversities than surrounding sediments, but this was not the case for mussel beds in Australia () and the Yellow Sea () where numbers of associated species were only slightly higher and somewhat lower than in adjacent sediments, respectively. In conclusion, although soft bottom mytilid mussels generally enhance habitat heterogeneity and species diversity at the ecosystem level, mussel beds themselves are not universal centres of biodiversity, but the effects on associated species are site specific