Background: Drug resistance is a major problem in ovarian cancer. Triggering apoptosis using death ligands such as tumour necrosis factor-related apoptosis inducing ligand (TRAIL) might overcome chemoresistance. Methods: We investigated whether acquired cisplatin resistance affects sensitivity to recombinant human (rh) TRAIL alone or in combination with cisplatin in an ovarian cancer cell line model consisting of A2780 and its cisplatin-resistant subline CP70. Results: Combining cisplatin and rhTRAIL strongly enhanced apoptosis in both cell lines. CP70 expressed less caspase 8 protein, whereas mRNA levels were similar compared with A2780. Pre-exposure of particularly CP70 to cisplatin resulted in strongly elevated caspase 8 protein and mRNA levels. Caspase 8 mRNA turnover and protein stability in the presence or absence of cisplatin did not differ between both cell lines. Cisplatin-induced caspase 8 protein levels were essential for the rhTRAIL-sensitising effect as demonstrated using caspase 8 small-interfering RNA (siRNA) and caspase-8 overexpressing constructs. Cellular FLICE-inhibitory protein (c-FLIP) and p53 siRNA experiments showed that neither an altered caspase 8/c-FLIP ratio nor a p53-dependent increase in DR5 membrane expression following cisplatin were involved in rhTRAIL sensitisation. Conclusion: Cisplatin enhances rhTRAIL-induced apoptosis in cisplatin-resistant ovarian cancer cells, and induction of caspase 8 protein expression is the key factor of rhTRAIL sensitisation. © 2011 Cancer Research UK All rights reserved.
DOCUMENT
Background: In the Netherlands, the distinction between Bachelor degree and diploma nursing educational levels remains unclear. The added value of Bachelor degree nurses and how they develop professionally after graduation are subject to debate. Objectives: The aim of this study is to investigate whether Bachelor degree nurses have higher critical thinking skills than diploma nurses do and whether there is a positive relationship between higher critical thinking skills and self-efficacy beliefs. Outcomes might provide instruments that are helpful in positioning of nursing levels in education and practice. Participants: Questionnaire data were used of a sample of 95 registered mental health staff nurses (62 diploma nurses and 33 Bachelor degree nurses). Methods: First, ANOVAwas performed to testwhether the two groupswere comparablewith respect to elements of work experience. Second, t-tests were conducted to compare the two groups of nurses on self-efficacy, perceived performance and critical thinking outcomes. Third, relationships between the study variables were investigated. Finally, structural equation modelling using AMOS was applied to test the relationships. Results: The hypothesis that Bachelor degree nurses are better critical thinkers than diploma nurseswas supported (pb0.01). Years in function turned out to be positively related to self-efficacy beliefs (pb0.01). No significant relation was found between the level of education and self-efficacy beliefs. Conclusions: The results of this study support career development and facilitate more efficient positioning of nursing levels.
DOCUMENT
BACKGROUND: Glucocorticoids (GCs) control expression of a large number of genes via binding to the GC receptor (GR). Transcription may be regulated either by binding of the GR dimer to DNA regulatory elements or by protein-protein interactions of GR monomers with other transcription factors. Although the type of regulation for a number of individual target genes is known, the relative contribution of both mechanisms to the regulation of the entire transcriptional program remains elusive. To study the importance of GR dimerization in the regulation of gene expression, we performed gene expression profiling of livers of prednisolone-treated wild type (WT) and mice that have lost the ability to form GR dimers (GRdim).RESULTS: The GR target genes identified in WT mice were predominantly related to glucose metabolism, the cell cycle, apoptosis and inflammation. In GRdim mice, the level of prednisolone-induced gene expression was significantly reduced compared to WT, but not completely absent. Interestingly, for a set of genes, involved in cell cycle and apoptosis processes and strongly related to Foxo3a and p53, induction by prednisolone was completely abolished in GRdim mice. In contrast, glucose metabolism-related genes were still modestly upregulated in GRdim mice upon prednisolone treatment. Finally, we identified several novel GC-inducible genes from which Fam107a, a putative histone acetyltransferase complex interacting protein, was most strongly dependent on GR dimerization.CONCLUSIONS: This study on prednisolone-induced effects in livers of WT and GRdim mice identified a number of interesting candidate genes and pathways regulated by GR dimers and sheds new light onto the complex transcriptional regulation of liver function by GCs.
DOCUMENT
