The androgen receptor (AR) plays a crucial role in the modulation of prostate cell proliferation and is involved in the development and progression of prostate cancer (PCa). An understanding of the complex regulation of AR provides novel treatment options for PCa. Here, we show (i) that the ubiquitin-like modifier, interferon-stimulated gene 15 (ISG15), and most enzymes involved in ISG15 conjugation were upregulated in tumor samples versus in non-malignant tissues of PCa patients and (ii) that the expression of these components significantly differed between tumors in patients treated with and without androgen ablation. Using PCa cell lines as in vitro models, the specific androgen-mediated, ARdependent regulation of the ISGylation components was confirmed. In addition, the ISGylation system controls AR mRNA and protein expressions, as overexpression of Ube1L as a limiting ISGylation factor in the AR þ androgensensitive PCa cell line, LNCaP, results in significant AR upregulation, accompanied by an increased proliferation even under androgen deprivation. Accordingly, Ube1L knockdown decreased the AR expression. Thus, this study describes for the first time the modulation of AR expression by ISGylation components, which affects the proliferation of PCa cells, thereby providing evidence for a novel function of the ISGylation system in malignant transformation.

During the last decade the knowledge about the molecular mechanisms of the cellular adaption to hypoxia and the function of the “von Hippel Lindau” (VHL) protein in renal cell carcinoma (RCC) has increased, but there exists little information about the overlap and differences in gene/protein expression of both processes. Therefore the aim of this study was to dissect VHL- and hypoxia-regulated alterations in the metabolism of human RCC using ome-based strategies. The effect of the VHL- and hypoxia-regulated altered gene/protein expression pattern on the cellular metabolism was analyzed by determination of glucose uptake, lactate secretion, extracellular pH, lactate dehydrogenase activity, amino acid content and ATP levels. By employing VHL−/VHL+ RCC cells cultured under normoxic and hypoxic conditions, VHL-dependent, HIF-dependent as well as VHL-/HIF-independent alterations in the gene and protein expression patterns were identified and further validated in other RCC cell lines. The genes/proteins differentially expressed under these distinct conditions were mainly involved in the cellular metabolism, which was accompanied by an altered metabolism as well as changes in the abundance of amino acids in VHL-deficient cells. In conclusion, the study reveals similarities, but also differences in the genes and proteins controlled by VHL functionality and hypoxia thereby demonstrating differences in the metabolic switch of RCC under these conditions.

447 Background: The objective of this project is to dissect the von Hippel-Lindau- and hypoxia-regulated alterations in human renal cell carcinoma to define both novel prognostic markers as well as therapeutic targets. Methods: For this, the VHL-negative RCC cell line 786-O next to recently established gain of function VHL transfectants thereof were used as a model system and subsequently cultured under normoxic or hypoxic conditions. Whereas direct effects on the altered energy metabolism were determined by lactate, pyruvate and pH measurements. the resulting effects at the gene/protein expression profiles were determined by comparative cDNA micro array analysis/ 2DE-based proteome analyses, respectively. Some of the differentially expressed genes/proteins were verified by qPCR and/or Western blot analysis in a panel of RCC cell lines. Results: By employing the VHL-/VHL+RCC model system VHL-dependent, HIF-dependent as well as VHL/HIF-independent alterations in the gene and protein expression pattern were found. Some of the differentially expressed genes/proteins were either associated with the loss of VHL function, the hypoxic conditions or both. The genes/proteins defined as differentially expressed under these conditions are mainly involved in the cellular metabolism and predominantly localized in the cytoplasm or mitochondrion. The verification of the differentially expressed genes/proteins by qPCR and Western blot analysis revealed a heterogeneous expression in RCC cells and lesions. One such gene/protein is represented by the glutamine gamma glutamyl transferase (TGM2). Its expression was associated with the loss of VHL and induction of hypoxia. Furthermore, TGM2 might be an important marker for both VHL-independent and/or hypoxia-induced responses. Conclusions: The data demonstrate that VHL functionality and/or hypoxia induce distinct effects on the metabolic switch of RCC.

Karl Studer: Was sind Ihre Aufgaben als Chefärztin der KJPD?Suzanne Erb: Als Chefärztin bin ich gemeinsam mit der Geschäftsleitung die Erfüllung des Leistungsauftrags und für die Umsetzung der Unternehmensstrategie aus medizinisch-fachlicher Sicht verantwortlich. Dieser umfasst bei uns die psychiatrische Versorgung der null-bis 18-jährigen Bevölkerung unserer drei Vertragskantone (in Ergänzung zu den Freipraktizierenden), forensische Tätigkeit, die Weiterbildung sowie Prävention.

Renal cell carcinoma (RCC) is the most common neoplasm in the adult kidney and its incidence is increasing over the last 20 years. Unfortunately, approximately 30 % of patients are diagnosed at a metastatic stage, which is associated with a poor prognosis and a 5-year survival rate of < 10 %. The clear cell RCC, representing approximately 75 % of RCC lesions, is characterized by a frequent inactivation of the Von-Hippel-Lindau protein (pVHL) resulting in the upregulation of the hypoxia-inducible factor 1α (HIF-1α), which consequently induces the transcription of hypoxia-responsive genes, such as the vascular endothelial growth factor receptor (VEGF) thereby inducing angiogenesis. Thus, the inhibition of angiogenesis is a suitable tool for the therapy of advanced clear cell RCC. During the last decade agents targeting tumor angiogenesis include inhibitors of the VEGF receptor pathway and the mammalian target of rapamycin (mTOR) have been successfully applied for the treatment of this disease. Using proteome-based studies and microRNA arrays hypoxia-regulated miRs and proteins in VHL- versus VHL+ RCC have been identified in the absence or presence of the angiogenesis inhibitors sunitinib and axitinib. (i) A differential miR and protein expression profile exhibiting an inverse correlation was found upon hypoxia, which further differed in VHL- versus wild-type VHL RCC cells. (ii) The hypoxia-regulated miRs and proteins in these cell systems were altered by the tyrosine kinase inhibitors (TKI) sunitinib and axitinib treatment. (iii) Functional analysis of the hypoxia-regulated candidate biomarkers and their modulation by both TKI are currently performed. (iv) The differential expression pattern of miRs and proteins under hypoxia as well as in the absence and presence of both TKIs were confirmed by RT-PCR and Western blot analysis. These data were shown for the first time an effect of sunitinib and axitinib on hypoxia-induced alterations in RCC, which not only leads to a better understanding of the mechanisms of action of both TKIs, but also to the define of novel strategies for the targeted treatment of RCC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1799. doi:1538-7445.AM2012-1799