Background: Pancreatic cancer is one of the most deadly malignancies with insufficient therapeutic options and poor outcome. Cancer stem cells (CSCs) are thought to be responsible for progression and therapy resistance. We investigated the potential of pancreatic cell lines for CSC research by analyzing to what extent they contain CSC populations and how representative these are compared to clinical tissue. Methods: Six pancreatic cancer cell lines were analyzed by flow cytometry for CD326, CD133, CD44, CD24, CXCR4 and ABCG2. Subsequently, 70 primary pancreatic tissues were evaluated for CD326, CD133 and CD44 by immunohistochemistry. Results: All the cell lines but one showed a stable expression pattern throughout biological replicates. Marker expression in clinical tissue of CD44 distinguished normal patients from pancreatic carcinoma patients with a sensitivity of 50% at 80% specificity and metastasized from nonmetastasized carcinomas with 69% sensitivity at 100% specificity. Conclusions: Our results indicate a link between elevated CD44 expression, malignancy and metastasis of pancreatic tissue. Furthermore, individual pancreatic cell lines show a substantial amount of cells with CSC properties which is comparable with interpatient variability detected in primary tissue. These pancreatic cancer cell lines could thus serve for urgently needed pharmacological CSC in vitro research.

The fact that urothelial carcinomas (UC) often contain areas with different histologic grades has been recently shown to bear some prognostic relevance. Here we examined the prognostic significance of a grading system considering tumor heterogeneity in muscle-invasive bladder carcinomas. 151 UC treated by radical cystectomy were included. According to the World Health Organization/International Society of Urological Pathology (WHO/ISUP) classification, histologic grade was low-grade (LG) in 8 and high-grade (HG) in 143 cases. 65 HG tumors which focally harbored LG areas were assigned to mixed-type (MT) carcinomas. Mean follow-up was 50 months. While the WHO/ISUP classification showed no significant correlation with disease-specific survival (p = 0.3995 by log-rank test), stratification into LG/MT and HG tumors had a significant prognostic relevance (p = 0.0404). Nodal status was identified as the only independent prognostic factor (p = 0.0001 by multivariate analysis). In this respect, stratification into LG/MT and HG tumors missed the level of statistical significance by a norrow margin (p = 0.07 by multivariate analysis), but it turned out better than tumor category (p = 0.08). In conclusion, a grading system considering tumor heterogeneity may improve the predictive power of the WHO/ISUP classification in muscle-invasive UC of the urinary bladder. Although the two-tired grading system proposed in this study was not identified as an independent prognostic factor, it may help to obtain additional prognostic information on patients with advanced bladder cancer treated by radical cystectomy.

AIM:To investigate the prognostic role of genomic stability and copy number alterations (CNAs) pancreatic neuroendocrine tumors (PanNETs). METHODS:A high-resolution array-based comparative genomic hybridization approach was utilized in order to investigate and quantify chromosomal aberrations in a panel of 37 primary PanNET and 11 metastatic samples. DNA samples were extracted from formalinfixed and paraffin-embedded tumor specimen. Genomic findings were correlated with histopathological and immunohistochemical data. Moreover, the dataset was subjected to employing an unsupervised hierarchical clustering analysis approach utilizing Euclidean distance and average linkage and associations between genomically defined tumor groups and recurrent CNAs or clinicopathological features of the study group were assessed. RESULTS:Numerous chromosomal aberrations were recurrently detected in both, primary tumor samples and metastases. Copy number gains were most frequently observed at 06p22.2-p22.1 (27.1%), 17p13.1 (20.8%), 07p21.3-p21.2 (18.8%), 09q34.11 (18.8%). Genomic losses were significantly less frequent and the only recurrent aberration affected 08q24.3 (6.3%). Moreover, we detected a high degree of genomic heterogeneity between primary tumors and metastatic lesions. Unsupervised hierarchical clustering of loci affected by CNAs in more than 3 primary tumor samples revealed two genetically distinct tumor groups as well as two chromosomal clusters of genomic imbalances indicating a small subset of tumors with common molecular features (13.5%). Aberrations affecting 6p22.2-22.1, 8q24.3, 9q34.11 and 17p13.1 (P = 0.011; 0.003; 0.003; 0.001), were significantly associated with a poorer survival prognosis. CONCLUSION:This study suggests that several frequent CNAs in numerous candidate regions are involved in the pathogenesis and metastatic progression of Pan-NET. Gebauer N et al . Chromosomal aberrations in PanNETs (PanNETs). Analysis of recurrent genomic amplifications delineated two independent clusters of genomic aberrations as well as two patient groups characterized by significantly overlapping cytogenetic features. Copy number alterations affecting chromosomes 6, 8, 9 and 17 were shown to be associated with survival. A high degree of genomic heterogeneity between primary tumor samples and metastatic lesions demonstrates the need for a more focused molecular and cytogenetic characterization in the light of upcoming targeted therapy approaches. PanNETs appear to be genetically distinct from other types of neuroendocrine tumors.

Background: RFA of pancreatic cancer has been demonstrated to be feasible and safe, and data exist showing a positive impact on survival. The aim was to investigate whether an immune reaction is activated after locally advanced pancreatic cancer (LAPC) ablation. Methods: Peripheral Blood samples were obtained preoperatively and in post-operative days 3-30 from patients treated with RFA for LAPC. Evaluated parameters were: cells [CD4+, CD8+ and Double negative lymphocytes, T-Reg, Monocytes, myeloid and plasmocytoid Dendritic cells (mDC and pDC)] and cytokines (IL-6, SDF-1, IL-1b, TNF-a, IFN-g, VEGF, RANTES, TGF-b). Results: Ten patients were enrolled. CD4+ and CD8+ count decreased at day 3, and returned to baseline at day 30, while CD8+ terminal effector memory lymphocytes increased at day 30. The median levels of T-Regs stayed baseline. mDC decreased at day 3 but returned to baseline by day 30. pDC decreased at day 3 and stayed low level at day 30. IL-6 significantly increased at day 3 and returned to baseline at day 30. VEGF levels stayed baseline. Decrease of TGF-b and increase of IFN-g seen at day 3 persisted at day 30. Conclusion: Our study provides the first experimental evidence of an immune systemic reaction to RFA in LAPC, supported by the early significant increase of IL-6 proinflammatory chemokine and lack of activation of immunosuppressive lymphocytes, monocytes and pDC. Further studies are needed to provide experimental evidence of antitumor response and its clinical impact.