The role of c-FLIP splice variants in urothelial tumours

Deregulation of apoptosis is common in cancer and is often caused by overexpression of anti-apoptotic proteins in tumour cells. One important regulator of apoptosis is the cellular FLICE-inhibitory protein (c-FLIP), which is overexpressed, for example, in melanoma and Hodgkin's lymphoma cells. Here, we addressed the question whether deregulated c-FLIP expression in urothelial carcinoma impinges on the ability of death ligands to induce apoptosis. In particular, we investigated the role of the c-FLIP splice variants c-FLIPlong (c-FLIPL) and c-FLIPshort (c-FLIPS), which can have opposing functions. We observed diminished expression of the c-FLIPL isoform in urothelial carcinoma tissues as well as in established carcinoma cell lines compared with normal urothelial tissues and cells, whereas c-FLIPS was unchanged. Overexpression and RNA interference studies in urothelial cell lines nevertheless demonstrated that c-FLIP remained a crucial factor conferring resistance towards induction of apoptosis by death ligands CD95L and TRAIL. Isoform-specific RNA interference showed c-FLIPL to be of particular importance. Thus, urothelial carcinoma cells appear to fine-tune c-FLIP expression to a level sufficient for protection against activation of apoptosis by the extrinsic pathway. Therefore, targeting c-FLIP, and especially the c-FLIPL isoform, may facilitate apoptosis-based therapies of bladder cancer in otherwise resistant tumours

Evaluation of Brain Nuclear Medicine Imaging Tracers in a Murine Model of Sepsis-Associated Encephalopathy

PURPOSE: The purpose of this study was to evaluate a set of widely used nuclear medicine imaging agents as possible methods to study the early effects of systemic inflammation on the living brain in a mouse model of sepsis-associated encephalopathy (SAE). The lipopolysaccharide (LPS)-induced murine systemic inflammation model was selected as a model of SAE. PROCEDURES: C57BL/6 mice were used. A multimodal imaging protocol was carried out on each animal 4 h following the intravenous administration of LPS using the following tracers: [(99m)Tc][2,2-dimethyl-3-[(3E)-3-oxidoiminobutan-2-yl]azanidylpropyl]-[(3E)-3-hyd roxyiminobutan-2-yl]azanide ([(99m)Tc]HMPAO) and ethyl-7-[(125)I]iodo-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carbox ylate ([(125)I]iomazenil) to measure brain perfusion and neuronal damage, respectively; 2-deoxy-2-[(18)F]fluoro-D-glucose ([(18)F]FDG) to measure cerebral glucose uptake. We assessed microglia activity on another group of mice using 2-[6-chloro-2-(4-[(125)I]iodophenyl)-imidazo[1,2-a]pyridin-3-yl]-N-ethyl-N-methyl -acetamide ([(125)I]CLINME). Radiotracer uptakes were measured in different brain regions and correlated. Microglia activity was also assessed using immunohistochemistry. Brain glutathione levels were measured to investigate oxidative stress. RESULTS: Significantly reduced perfusion values and significantly enhanced [(18)F]FDG and [(125)I]CLINME uptake was measured in the LPS-treated group. Following perfusion compensation, enhanced [(125)I]iomazenil uptake was measured in the LPS-treated group's hippocampus and cerebellum. In this group, both [(18)F]FDG and [(125)I]iomazenil uptake showed highly negative correlation to perfusion measured with ([(99m)Tc]HMPAO uptake in all brain regions. No significant differences were detected in brain glutathione levels between the groups. The CD45 and P2Y12 double-labeling immunohistochemistry showed widespread microglia activation in the LPS-treated group. CONCLUSIONS: Our results suggest that [(125)I]CLINME and [(99m)Tc]HMPAO SPECT can be used to detect microglia activation and brain hypoperfusion, respectively, in the early phase (4 h post injection) of systemic inflammation. We suspect that the enhancement of [(18)F]FDG and [(125)I]iomazenil uptake in the LPS-treated group does not necessarily reflect neural hypermetabolism and the lack of neuronal damage. They are most likely caused by processes emerging during neuroinflammation, e.g., microglia activation and/or immune cell infiltration

Description of Isotherms of Two-Component Non-Electrolyte Solution Adsorption onto Solids with Structural Heterogeneity of Adsorbents Taken into Consideration

The concepts of Stoeckli as well as those of Wojsz and Rozwadowski have been adopted for describing adsorption from two-component non-electrolyte liquid mixtures at solid adsorbents taking into account structural heterogeneity of the adsorbent. Some new global adsorption equations have been obtained and verified on the basis of experimental data