The biology of corticotropin-releasing factor (CRF) finds increasing interest in the scientific community because of the neuromodulatory actions of CRF on brain functions such as learning, anxiety, feeding, and locomotion. Additional actions on immunumodulation and apoptosis have recently been discovered. All actions of CRF are mediated by G protein-coupled receptors, which trigger different, sometimes opposite actions in different regions of the central nervous system. The CRF system exhibits considerable plasticity by the involvement of numerous different ligands, splice variants, and transductional couplings. The generation of multiple splice variants is facilitated by the intron exon structure of the CRF receptor genes.
To investigate galectin-8 expression patterns in normal urothelium and bladder cancer specimens and to elucidate its prognostic value.162 samples of non-muscle-invasive transitional cell carcinoma, 25 samples of muscle-invasive transitional cell carcinoma and 10 samples of normal urothelium were investigated by immunohistochemistry using tissue microarrays. Complete patient and tumor characteristics were compared with galectin-8 staining patterns. The likelihood of tumor recurrence and progression was analyzed based on a 3-year follow-up.Loss of galectin-8 was associated with the likelihood of tumor recurrence in univariate (p < 0.05) and multivariate analyses (p < 0.01). No significance was observed for tumor progression. Patients whose specimens showed weak galectin-8 expression had a shorter recurrence-free interval (42 vs. 12 months; p < 0.01, log-rank test). All of the 10 normal urothelium samples showed high galectin-8 expression. Decreased staining was found to be associated with higher tumor stages and grades (p < 0.0001, one-way ANOVA). A significant difference was found comparing normal urothelium with any tumor stage (p < 0.01), pTa vs. pT1 tumors (p < 0.05) and non-muscle-invasive vs. muscle-invasive tumors (p < 0.0001).Loss of galectin-8 might be an early step in the development of malignant lesions of the bladder and is a significant independent predictor of recurrence.
474 Background: Rho GDP dissociation inhibitor 2 (ARHGDIB) is an important mediator of cellular signaling. The expression of ARHGDIB correlates with tumor growth and metastasis in a variety of non genitourinary cancers, however the role of ARHGDIB in renal cell cancer (RCC) has not yet been evaluated. Methods: Tissue samples from 106 patients undergoing surgery for RCC were obtained. The expression of ARHGDIB mRNA in normal kidney tissue and in corresponding cancer tissue was analyzed by means of quantitative real time PCR. Differences in mRNA expression levels were assessed using paired two-sample tests. Associations of relative mRNA expression levels and clinicopathological parameters were statistically analyzed using an univariate logistic regression model. Relative mRNA expression levels in healthy renal tissue compared to cancerous tissue from the same kidney was assessed using a paired t-test. Results: When comparing 74 tissues from kidney tumors with adjacent histologically normal appearing paired tissues, mRNA expression of ARHGDIB was significantly higher in the tumor tissue (p < 0.001). Paired analysis did not only show significantly higher mRNA expression levels for ARHGDIB over all RCC but also for the subgroup with clear cell RCC (ccRCC). The mRNA expression of ARHGDIB was also more pronounced in ccRCC when compared with papillary RCC (p < 0.001). When looking at clinicopathological parameters in univariate logistic regression analysis ccRCC was significantly associated with nodal involvement (p = 0.03) and also with tumor grade (p = 0.05). For all RCC there was no association with clinicopathological parameters. A bivariate Cox regression model, adjusted for metastatic status (p = 0.001), tumor diameter (p = 0.043), state of advanced disease (p = 0.030) and lymph node metastasis (p = 0.006) identified ARHGDIB mRNA expression as a candidate positive prognosticator for RFS. Conclusions: Increased ARHGDIB mRNA expression is significantly associated with RCC tissues. Higher relative expression observed within tumor tissues represents a candidate prognosticator for better RFS of patients.
414 Background: Significance of Urocortin (Ucn or UcnI), Ucn2, Ucn3, and their receptors, Corticotropin Releasing Factor Receptor 1 and 2 (CRFR1 and CRFR2), and the binding protein, Corticotropin-Releasing Hormone-Binding Protein (CRHBP) in oncology is growing rapidly. Recently we found that the UCN system may also be a relevant structure in renal cell cancer. Here we investigate whether CRHBP CGI methylation occurs in cc-RCC and whether its methylation is associated with clinicopathological parameters of patients. Methods: Tumoral tissues of 109 patients with renal cell cancer and their corresponding normal tissues have been used. Combined bisulfite restriction analysis (COBRA) for detection of relative degree of CpG island (CGI) methylation and pyrosequencing have been performed. Results: We found an approximately five-fold increase in mean methylation of the CRHBP CGI for tumor tissues (p < 0.00005). Higher DNA methylation of the CRHBP CGI showed a positive correlation with advanced disease as well (p = 0.024). Conclusions: To our knowledge we report for the first time the CGI methylation of CRHBP in clear cell renal cell carcinoma indicating a contribution of epigenetic alteration of CRHBP to RCC tumorigenesis. Moreover, our results suggest CRHBP as a potential molecular marker for assessment of progression and aggressiveness of tumors.
