Loss of susceptibility to apoptosis signals is a crucial step in carcinogenesis. Therefore, sensitization of tumor cells to apoptosis is a promising therapeutic strategy. c-Jun-Nterminal-kinases (JNK) have been implicated in stressinduced apoptosis, but may also contribute to survival signaling. Here we show that CD95-induced apoptosis is augmented by the JNK inhibitor SP600125 and small interfering RNA directed against JNK1/2. SP600125 potently inhibited methyl methane sulfonate-induced phosphorylation of c-Jun, but had minimal effect on apoptosis alone. In contrast, it strongly enhanced CD95-mediated apoptosis in six of eight tumor cell lines and led to a G 2 /M phase arrest in all cell lines. SP600125 enhanced cleavage of caspase 3 and caspase 8, the most upstream caspase in the CD95 pathway. JNK inhibition up-regulates p53 and its target genes p21Cip1/Waf1 and CD95. However, although HCT116 p53 À/À cells and p21 +/+ cells were less sensitive to CD95 stimulation than their p53 +/+ and p21 À/À counterparts, p53and p21 were not involved in the JNK-mediated effect. JunD, which was described to be protective in tumor necrosis factor-induced apoptosis, was not regulated by JNK inhibition on the protein level. When transcription was blocked by actinomycin D, JNK inhibition still enhanced apoptosis to a comparable extent. We conclude that JNK inhibition has antitumor activity by inducing growth arrest and enhancing CD95-mediated apoptosis by a transcription-independent mechanism. (Cancer Res 2005; 65(15): 6780-8)
Objective. In active early rheumatoid arthritis (RA), glucocorticoids are often used for bridging, due to the delayed action of methotrexate. This study was undertaken to compare the effect of 3 bridging strategies, including high-dose and low-dose prednisolone, on radiographic and clinical outcomes.Methods. Adult RA patients from 1 rheumatology hospital and 23 rheumatology practices who presented with moderate/high disease activity were randomized (1:1:1) to receive 60 mg prednisolone (high-dose prednisolone [HDP]) or 10 mg prednisolone (low-dose prednisolone [LDP]) daily (tapered to 0 mg within 12 weeks) or placebo. The 12-week intervention period was followed by 40 weeks of therapy at the physicians' discretion. The primary outcome measure was radiographic change at 1 year measured using the total modified Sharp/van der Heijde score (SHS). Disease activity was assessed with the Disease Activity Score in 28 joints using the erythrocyte sedimentation rate (DAS28-ESR).Results. Of 395 randomized patients (HDP, n = 132; LDP, n = 131; placebo, n = 132), 375 (95%) remained in the modified intention-to-treat analysis. Mean ± SD changes in SHS scores in the 3 groups after 1 year were comparable: mean ± SD 1.0 ± 2.0 units in the HDP group, 1.1 ± 2.2 units in the LDP group, and 1.1 ± 1.5 units in the placebo group. The primary analysis showed no superiority of HDP compared to placebo (estimated difference of the mean change −0.04 [95% confidence interval (95% CI) −0.5, 0.4]). At week 12, the mean DAS28-ESR differed: −0.6 (95% CI −1.0, −0.2) for HDP versus placebo; -0.8 (95% CI −1.2, −0.5) for LDP versus placebo. At week 52, there was no significant difference in DAS28-ESR between the 3 groups (range 2.6-2.8). Serious adverse events occurred similarly often.Conclusion. Short-term glucocorticoid bridging therapy at a high dose showed no benefit with regard to progression of radiographic damage at 1 year.
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