Clusterin is, in its major form, a secreted heterodimeric disulfide-linked glycoprotein (75-80 kDa). It was first linked to cell death in the rat ventral prostate after androgen deprivation. Recent studies have demonstrated that overexpression of clusterin in prostatic cells protects them against tumor necrosis factor-␣ (TNF␣)-induced apoptosis. However the details of this survival mechanism remain undefined. Here, we investigate how clusterin prevents cells from undergoing TNF␣-induced apoptosis. We established a double-stable prostatic cell line for inducible clusterin by using the Tet-On gene expression system. We demonstrated that 50% of the cells overexpressing clusterin escaped from TNF␣-and actinomycin D-induced cell death. Moreover we demonstrated that the incubation of MLL cells with conditioned medium containing the secreted clusterin or the supplementation of purified clusterin in the extracellular medium decreased the TNF␣-induced apoptosis significantly. This extracellular action implicates megalin, the putative membrane receptor for clusterin to mediate survival. Indeed clusterin overexpression up-regulated the expression of megalin and induced its phosphorylation in a dose-dependent manner. We interestingly showed that clusterin overexpression is associated with the up-regulation of the phosphorylation of Akt. Activated Akt induced the phosphorylation of Bad and caused a decrease of cytochrome c release. These results enable us to pinpoint one mechanism by which secreted clusterin favors survival in androgen-independent prostate cancer cells, implicating its receptor megalin and Akt survival pathway.Clusterin, also known as testosterone-repressed message-2, is overexpressed in the rat prostate during castration-induced programmed cell death (1). Clusterin overexpression reaches a maximum 3-4 days post-castration and coincides with the onset of massive cell death (2). The clusterin level also rises in various tissues during cell death responses (3-5). As clusterin is present during apoptosis, it was initially viewed as a cell death inducer, but other studies suggest that clusterin overproduction occurs in resistant cells (6, 7). Thus, clusterin has been described as an anti-apoptotic factor, and it has also been implicated in prostate cancer progression to androgen independence (8). Miyake et al. (9) have demonstrated that the overexpression of clusterin in human androgen-responsive prostate cancer cells LNCaP by stable transfection rendered them highly resistant to androgen ablation, and the introduction of antisense testosterone-repressed message-2 oligodeoxynucleotide therapy in the Shionogi tumor model induces apoptosis and tumor regression. Moreover small interference RNA-mediated clusterin gene silencing in osteosarcoma and prostate cancer induces significant reduction of cellular growth and increases cellular apoptosis (10, 11).Clusterin is a sulfated glycoprotein encoded by a single gene. It has two known isoforms obtained by alternative splicing (12). The first isoform, secretory clusteri...

Objective To isolate new cDNAs corresponding to genes whose expression is increased during castrationinduced rat prostate apoptosis. Materials and methods Differential display of mRNAs from 3-day castrated and normal rat ventral prostates was used to identify differentially expressed clones. Northern blots were hybridized to con®rm the positive regulation of the candidates and to follow the change in their expression in the involuting rat prostate, and in thymocytes of dexamethazone-treated rats. Results Five cDNAs were cloned: one encoding ribosomal protein L7, one coding for the insulin-like growth factor binding protein-3 (IGFBP-3), and three whose products are unknown. After castration, all ®ve genes had expression kinetics that closely paralleled the proportion of prostatic epithelial cells undergoing apoptosis. The gene encoding L7 and two of the unknown genes were also upregulated in glucocorticoid-induced programmed death in thymocytes.In addition to the IGFBP-3 gene, those coding for proteins IGFBP-4, -5 and -6 were also overexpressed in the involuting prostate of androgen-deprived rats. Conclusion Five new genes were identi®ed that are upregulated during castration-induced rat prostate apoptosis, three of which are potentially involved in the common intracellular pathway leading to programmed cell death.

The early identification of bacteremia is critical for ensuring appropriate treatment of nosocomial infections in intensive care unit (ICU) patients. The aim of this study was to use flow cytometric data of myeloid cells as a biomarker of bloodstream infection (BSI). An eight-color antibody panel was used to identify seven monocyte and two dendritic cell subsets. In the learning cohort, immunophenotyping was applied to (1) control subjects, (2) postoperative heart surgery patients, as a model of noninfectious inflammatory responses, and (3) blood culture-positive patients. Of the complex changes in the myeloid cell phenotype, a decrease in myeloid and plasmacytoid dendritic cell numbers, increase in CD14+CD16+ inflammatory monocyte numbers, and upregulation of neutrophils CD64 and CD123 expression were prominent in BSI patients. An extreme gradient boosting (XGBoost) algorithm called the “infection detection and ranging score” (iDAR), ranging from 0 to 100, was developed to identify infection-specific changes in 101 phenotypic variables related to neutrophils, monocytes and dendritic cells. The tenfold cross-validation achieved an area under the receiver operating characteristic (AUROC) of 0.988 (95% CI 0.985–1) for the detection of bacteremic patients. In an out-of-sample, in-house validation, iDAR achieved an AUROC of 0.85 (95% CI 0.71–0.98) in differentiating localized from bloodstream infection and 0.95 (95% CI 0.89–1) in discriminating infected from noninfected ICU patients. In conclusion, a machine learning approach was used to translate the changes in myeloid cell phenotype in response to infection into a score that could identify bacteremia with high specificity in ICU patients.

Prostate cancer develops from clones that are already present as early as thirty-five years of age, when circulating concentrations of androgens are high. The progression of the disease is low and the cancer is diagnosed at a more advanced age. Prostate cancer evolves from an androgen dependant stage to stage where it escapes from all anti-androgenic treatments. The patient usually dies within two years following the diagnosis of advanced cancer. Therefore, it is of great interest to develop new therapies for androgen independent prostate cancer. The androgen independent evolution of prostate cancer is a complex phenomenon at the cellular and molecular levels. It includes an increased sensitivity to growth factors, the control of proliferation pathways, apoptotic and survival pathways as well as the control of angiogenesis. Epidemiological studies have also suggested that certain vitamins or phyto-oestrogens could protect against prostate cancer development. The present review attempts to present an overview of the fundamental research in cellular signalling which could be interesting as target for the treatment of androgen independent prostate cancer. Also the potential interest of non-androgenic steroids was reviewed for the same goal.