Proteomic identification of aldo-keto reductase AKR1B10 induction after treatment of colorectal cancer cells with the proteasome inhibitor bortezomib.

Targeting the ubiquitin-proteasome pathway with the proteasome inhibitor bortezomib has emerged as a promising approach for the treatment of several malignancies. The cellular and molecular effects of this agent on colorectal cancer cells are poorly characterized. This study investigated the antiproliferative effect of bortezomib on colorectal cancer cell lines (Caco-2 and HRT-18). In order to define the proteins potentially involved in the mechanisms of action, proteome profiling was applied to detect the proteins altered by bortezomib. The in vitro efficacy of bortezomib as a single agent in colorectal cancer cell lines was confirmed. Proteome profiling with two-dimensional PAGE followed by mass spectrometry revealed the up-regulation of the major inducible isoform of heat shock protein 70 (hsp72) and lactate dehydrogenase B in both cell lines, as well as the induction of aldo-keto reductase family 1 member B10 (AKR1B10) in HRT-18 cells. Both AKR1B10 and hsp72 exert cell-protective functions. This study shows for the first time a bortezomib-induced up-regulation of AKR1B10. Small interfering RNA-mediated inhibition of this enzyme with known intracellular detoxification function sensitized HRT-18 cells to therapy with the proteasome inhibitor. To further characterize the relevance of AKR1B10 for colorectal tumors, immunohistochemical expression was shown in 23.2% of 125 tumor specimens. These findings indicate that AKR1B10 might be a target for combination therapy with bortezomib.

The incidence and outcome of severe brain trauma - Design and first results of an epidemiological study in an urban area.

Epidemiological data on the incidence, the prehospital and hospital care and the outcome of traumatic brain injury in Germany are scarce. It is therefore difficult to estimate the importance of this injury with respect to magnitude as well as effectiveness and efficiency of therapeutic concepts. We therefore planned a study that was supposed to provide population based epidemiological data in the field of severe brain trauma from the site of the accident until discharge from hospital. All 90.000 prehospital emergencies that were cared for by emergency physicians in Cologne from January 1990 until December 1996 were screened for identification of severe brain trauma. Their clinical course was reviewed using standard records and patients were included if they had their accident within the city of Cologne and fullfilled the final inclusion criteria of GCS /=3. 650 eligible patients were identified of whom 530 had complete datasets (follow-up 80 %). Univariate statistical analysis was performed for all relevant variables. The main study endpoints were incidence and outcome of severe brain trauma. The annual incidence of severe brain trauma in Cologne (1 mio. inhabitants) was 93. The average age was 39 years and 71 % of the patients were male. The average prehospital GCS was 6.8, the average prehospital Trauma Score was 8.3 points. 49 % of the study population suffered from multiple injuries. The overall mortality rate was 46,6 %. 60 % of deaths occurred within the prehospital setting. The incidence of severe brain trauma in Cologne in this study was significantly lower compared to what could be expected from the litera-ture. The overall mortality was high, especially the high prehospital death rate is striking.