In patients at high risk for disseminated candida infections, suppression of bacterial flora and the more common candida pathogens may permit some less pathogenic, but natively resistant candida species, such as C. krusei, to emerge as systemic pathogens.

We demonstrate that PS-341, a small molecule inhibitor of the proteasome, markedly sensitizes resistant prostate, colon, and bladder cancer cells to TNF-like apoptosisinducing ligand (TRAIL)-induced apoptosis irrespective of Bcl-xL overexpression. PS-341 treatment by itself does not affect the levels of Bax, Bak, caspases 3 and 8, c-Flip or FADD, but elevates levels of TRAIL receptors DR4 and DR5. This increase in receptor protein levels is associated with the ubiquitination of the DR5 protein.When PS-341 is combined with TRAIL, the levels of activated caspase 8 and cleaved Bid are substantially increased. In Bax-negative TRAIL-resistant HC-4 colon cancer cells, the combination of PS-341 and TRAIL overcomes the block to activation of the mitochondrial pathway and causes SMAC and cytochrome c release followed by apoptosis. Similarly, murine embryonic fibroblasts lacking Bax undergo apoptosis when exposed to the combination of PS-341 and TRAIL; however, fibroblasts lacking Bak are significantly resistant. Taken together, these findings indicate that PS-341 enhances TRAIL-induced apoptosis by increasing the cleavage of caspase 8, causing Bak-dependent release of mitochondrial proapoptotic proteins.

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Quantitative indicators of biological integrity are needed for streams in the Great Plains of North America, but it was not known whether the index of biotic integrity (IBI) approach would be effective in this semiarid region. Great Plains streams have a depauperate and tolerant ichthyofauna and highly variable physicochemical conditions that may mask the effects of non‐point‐source pollution and stream habitat degradation. We developed an IBI based on fish assemblages by screening metrics for range, responsiveness to human influence, precision, and lack of redundancy; we then tested the IBI's ability to detect anthropogenic effects by validating the index with an independent data set. The IBI was composed of 10 metrics based on species richness and composition, trophic and reproductive guilds, and age structure. These 10 metrics had many significant correlations with substrate and water chemistry variables but had fewer significant correlations with riparian condition and watershed variables. Of the watershed variables, road density had the highest number of significant correlations with final IBI metrics. The IBI was validated by demonstrating its responsiveness to aggregate measures of human influence, site‐level habitat, and water chemistry, and its lack of responsiveness to factors that varied naturally, such as stream size and site elevation. The IBI was also temporally stable within and between years during repeat visits to a subset of sampled reaches. This IBI can be used as a measure of biological integrity for management of prairie streams faced with threats such as introduced species, intensive agriculture, grazing, and coalbed natural gas extraction. Although we developed this IBI based on data from Montana prairie streams only, our IBI can probably serve as a framework for other North American plains streams and our results suggest that the IBI approach may be useful in other semiarid regions of the world.

BackgroundProstate-derived Ets factor (PDEF) is expressed in tissues of high epithelial content including prostate, although its precise function has not been fully established. Conventional therapies produce a high rate of cure for patients with localized prostate cancer, but there is, at present, no effective treatment for intervention in metastatic prostate cancer. These facts underline the need to develop new approaches for early diagnosis of aggressive prostate cancer patients, and mechanism based anti-metastasis therapies that will improve the outlook for hormone-refractory prostate cancer. In this study we evaluated role of prostate-derived Ets factor (PDEF) in prostate cancer.ResultsWe observed decreased PDEF expression in prostate cancer cell lines correlated with increased aggressive phenotype, and complete loss of PDEF protein in metastatic prostate cancer cell lines. Loss of PDEF expression was confirmed in high Gleason Grade prostate cancer samples by immuno-histochemical methods. Reintroduction of PDEF profoundly affected cell behavior leading to less invasive phenotypes in three dimensional cultures. In addition, PDEF expressing cells had altered cell morphology, decreased FAK phosphorylation and decreased colony formation, cell migration, and cellular invasiveness. In contrast PDEF knockdown resulted in increased migration and invasion as well as clonogenic activity. Our results also demonstrated that PDEF downregulated MMP9 promoter activity, suppressed MMP9 mRNA expression, and resulted in loss of MMP9 activity in prostate cancer cells. These results suggested that loss of PDEF might be associated with increased MMP9 expression and activity in aggressive prostate cancer. To confirm results we investigated MMP9 expression in clinical samples of prostate cancer. Results of these studies show increased MMP9 expression correlated with advanced Gleason grade. Taken together our results demonstrate decreased PDEF expression and increased MMP9 expression during the transition to aggressive prostate cancer.ConclusionsThese studies demonstrate for the first time negative regulation of MMP9 expression by PDEF, and that PDEF expression was lost in aggressive prostate cancer and was inversely associated with MMP9 expression in clinical samples of prostate cancer. Based on these exciting results, we propose that loss of PDEF along with increased MMP9 expression should serve as novel markers for early detection of aggressive prostate cancer.

Mitogen-activated protein kinases (MAPKs) are activated by phosphorylation of threonine and tyrosine residues within a signature sequence of T-X-Y by dual-specificity MAPK kinases (MKKs). MKKs are in turn phosphorylated and activated by a family of serine/threonine MKK kinases (47). Extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) (also called stress-activated protein kinase), and p38 (also called RK or CSBP) are distinct classes of MAPKs playing important roles in various cellular events. JNKs are activated by diverse stimuli, including DNA damage, heat shock, bacterial components, inflammatory cytokines, and Fas (31). Activated JNKs play an essential role in the activation of transcriptional factors, such as c-Jun (21), ATF-2 (16), Elk-1 (57), and ets-2 (50). In macrophages, activated JNKs mediate the expression of inducible nitric oxide synthase (6), cyclooxygenase-2 (56), chemokines such as RANTES (23), and cytokines such as tumor necrosis factor alpha (TNF-␣), interleukin-1 (IL-1), and IL-6 (39), all of which not only potently activate host defense mechanisms but also often lead to excessive inflammatory responses in microbial infection.MAPK activation is a reversible process, and an emerging family of dual-specificity protein phosphatases (DSPs) have been shown to inactivate MAPKs through dephosphorylation of both threonine and tyrosine residues that are essential for the enzymatic activity (4). DSPs share two common features: a catalytic domain with significant amino acid sequence homology to a vaccinia virus DSP, VH-1, and an N-terminal region homologous to the catalytic domain of the cdc25 phosphatase (rhodanase homology domain). Among DSP family members, some show highly selective substrate specificity while others efficiently inactivate all three classes of MAPKs. Interestingly, gene expression of many DSPs is significantly induced following stimulation with growth factors, cytokines, or cell stresses, and this induction of MAPK phosphatases (MKPs) may function as a negative feedback mechanism of MAPK activity.In this study, in order to elucidate the regulatory mechanisms of MAPK pathways in macrophages, we screened a cDNA library from a mouse macrophage cell line with a cDNA probe of MKP-1, a known MKP. We isolated a partial cDNA containing the extended active-site sequence motif, (V/L) X(V/I)HCXAG(I/V)SRSXT(I/V)XXAY(L/I)M (where X is any amino acid), conserved in all DSPs (27,35,41). By rescreening the library and extending the cDNA by the method of 5Ј rapid amplification of cDNA ends (5Ј-RACE), we have isolated a full-length cDNA, which we named MKP-M (for MKP isolated from macrophages). It includes an N-terminal

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