Background: Pancreatic métastases from renal cell carcinoma (RCC) are clinically rare but highly resectable. The aim of this article is to identify patients who profit from pancreatic resection of RCC despite the invasiveness of the surgery. Methods: Between January 1996 and December 2007, data from 744 patients were collected in a prospective pancreatic surgery database, and patients with metastasis into the pancreas from RCC were identified. Results: Resective surgery was performed in 14 patients with metastasis to the pancreas from RCC. Most patients were clinically asymptomatic. The median interval between primary treatment of RCC and occurrence of pancreatic metastasis was 94 months (range 32–158). The morbidity rate was 42.8%. Patients with a metastasis size <2.5 cm had a much better survival after resection (100 months) than those with a metastasis size >2.5 cm (44 months). Moreover, the number of métastases predicts the survival after resection. Conclusions: In patients with pancreatic métastases from RCC who have only limited disease, complete resection of all lesions can be successfully performed with a low rate of complications. Thus, patients with a history of RCC should be monitored for more than 10 years after nephrectomy to detect recurrence. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Background: Pancreatic cancer is one of the leading causes of cancer-related death. Using DNA gene expression analysis based on a custom made Affymetrix cancer array, we investigated the expression pattern of both primary and established pancreatic carcinoma cell lines. Methods: We analyzed the gene expression of 5 established pancreatic cancer cell lines (AsPC-1, BxPC-3, Capan-1, Capan-2 and HPAF II) and 5 primary isolates, 1 of them derived from benign pancreatic duct cells. Results: Out of 1,540 genes which were expressed in at least 3 experiments, we found 122 genes upregulated and 18 downregulated in tumor cell lines compared to benign cells with a fold change > 3. Several of the upregulated genes (like Prefoldin 5, ADAM9 and E-cadherin) have been associated with pancreatic cancer before. The other differentially regulated genes, however, play a so far unknown role in the course of human pancreatic carcinoma. By means of immunohistochemistry we could show that thymosin [β-10 (TMSB10), upregulated in tumor cell lines, is expressed in human pancreatic carcinoma, but not in non-neoplastic pancreatic tissue, suggesting a role for TMSB10 in the carcinogenesis of pancreatic carcinoma. Conclusion: Using gene expression profiling of pancreatic cell lines we were able to identify genes differentially expressed in pancreatic adenocarcinoma, which might contribute to pancreatic cancer development. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Background: Metastases to the pancreas are rare, accounting for less then 2 % of all pancreatic malignancies. However, both the benefit of extended tumor resection and the ideal oncological approach have not been established for such cases; therefore, we evaluated patients with metastasis to the pancreas who underwent pancreatic resection. Methods: Between 1994 and 2012, 676 patients underwent pancreatic surgery in our institution. We retrospectively reviewed patients’ medical records according to survival, and surgical and non-surgical complications. Student’s t-test and the log-rank test were used for statistical analysis. Results: Eighteen patients (2.7 %) received resection for pancreatic metastases (12 multivisceral resections and 6 standard resections). The pancreatic metastases originated from renal cell carcinoma (n = 10), malignant melanoma (n = 2), neuroendocrine tumor of the ileum (n = 1), sarcoma (n = 1), colon cancer (n = 1), gallbladder cancer (n = 1), gastrointestinal stromal tumor (n = 1), and non-small cell lung cancer (n = 1). The median time between primary malignancy resection to metastasectomy was 83 months (range, 0–228 months). Minor surgical complications (Grade I-IIIa) occurred in six patients (33.3 %) whereas major surgical complications (Grade IIIb-V) occurred in three patients (16.6 %). No patients died during hospitalization. The median follow-up was 76 months (range, 10–165 months). One-year, 3-year and 5-year survival for standard resection versus multivisceral resection was 83, 50, and 56 % versus 83, 66, and 50, respectively. Twelve patients died after a median of 26 months (range, 5–55 months). Conclusions: A surgical approach with curative intent is justified in select patients suffering from metastases to the pancreas and offers good long-term survival. The resection of pancreatic metastases of different tumor types was associated with favorable morbidity and mortality when compared with resection of the primary pancreatic malignancies. Our findings also demonstrated that multivisceral resection was feasible, with acceptable long term outcomes, even though morbidity rates tended to be higher after multivisceral resection than after standard resection.

Background: Pancreatic métastases from renal cell carcinoma (RCC) are clinically rare but highly resectable. The aim of this article is to identify patients who profit from pancreatic resection of RCC despite the invasiveness of the surgery. Methods: Between January 1996 and December 2007, data from 744 patients were collected in a prospective pancreatic surgery database, and patients with metastasis into the pancreas from RCC were identified. Results: Resective surgery was performed in 14 patients with metastasis to the pancreas from RCC. Most patients were clinically asymptomatic. The median interval between primary treatment of RCC and occurrence of pancreatic metastasis was 94 months (range 32–158). The morbidity rate was 42.8%. Patients with a metastasis size <2.5 cm had a much better survival after resection (100 months) than those with a metastasis size >2.5 cm (44 months). Moreover, the number of métastases predicts the survival after resection. Conclusions: In patients with pancreatic métastases from RCC who have only limited disease, complete resection of all lesions can be successfully performed with a low rate of complications. Thus, patients with a history of RCC should be monitored for more than 10 years after nephrectomy to detect recurrence. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

No description available.

Background: Pancreatic cancer is one of the leading causes of cancer-related death. Using DNA gene expression analysis based on a custom made Affymetrix cancer array, we investigated the expression pattern of both primary and established pancreatic carcinoma cell lines. Methods: We analyzed the gene expression of 5 established pancreatic cancer cell lines (AsPC-1, BxPC-3, Capan-1, Capan-2 and HPAF II) and 5 primary isolates, 1 of them derived from benign pancreatic duct cells. Results: Out of 1,540 genes which were expressed in at least 3 experiments, we found 122 genes upregulated and 18 downregulated in tumor cell lines compared to benign cells with a fold change > 3. Several of the upregulated genes (like Prefoldin 5, ADAM9 and E-cadherin) have been associated with pancreatic cancer before. The other differentially regulated genes, however, play a so far unknown role in the course of human pancreatic carcinoma. By means of immunohistochemistry we could show that thymosin [β-10 (TMSB10), upregulated in tumor cell lines, is expressed in human pancreatic carcinoma, but not in non-neoplastic pancreatic tissue, suggesting a role for TMSB10 in the carcinogenesis of pancreatic carcinoma. Conclusion: Using gene expression profiling of pancreatic cell lines we were able to identify genes differentially expressed in pancreatic adenocarcinoma, which might contribute to pancreatic cancer development. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Pancreatic ductal adenocarcinoma (PDAC) has an extremely poor prognosis. To improve the prognosis, novel molecular markers and targets for earlier diagnosis and adjuvant and/or neoadjuvant treatment are needed. Recent advances in human genome research and high-throughput molecular technologies make it possible to cope with the molecular complexity of malignant tumors. With DNA array technology, mRNA expression levels of thousand of genes can be measured simultaneously in a single assay. As several studies using microarrays in PDAC have already been published, this review attempts to compare the published data and therefore to validate the results. In addition, the applied techniques are discussed in the context of pancreatic malignancies. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Pancreatic stellate cells (PSCs) constitute important cells of the pancreatic microenvironment and their close interaction with cancer cells is important in pancreatic cancer. It is currently not known whether PSCs accumulate genetic alterations that contribute to tumor biology. Our aim was to analyze genetic alterations in cancer associated PSCs. PSC DNA was matched to DNA isolated from pancreatic cancer patients’ blood (n = 5) and analyzed by Next-Generation Sequencing (NGS). Bioinformatic analysis was performed using the GATK software and pathogenicity prediction scores. Sanger sequencing was carried out to verify specific genetic alterations in a larger panel of PSCs (n = 50). NGS and GATK analysis identified on average 26 single nucleotide variants in PSC DNA as compared to the matched blood DNA that could be visualized with the Integrative Genomics Viewer. The absence of PDAC driver mutations (KRAS, p53, p16/INK4a, SMAD4) confirmed that PSC isolations were not contaminated with cancer cells. After filtering the variants, using different pathogenicity scores, ten genes were identified (SERPINB2, CNTNAP4, DENND4B, DPP4, FGFBP2, MIGA2, POLE, SNRNP40, TOP2B, and ZDHHC18) in single samples and confirmed by Sanger sequencing. As a proof of concept, functional analysis using control and SERPINB2 knock-out fibroblasts revealed functional effects on growth, migration, and collagen contraction. In conclusion, PSC DNA exhibit a substantial amount of single nucleotide variants that might have functional effects potentially contributing to tumor aggressiveness.

Neuroendokrine Neoplasmen der Bauchspeicheldrüse (PanNEN) sind eine seltene und vielfältige Form von Krebs. PanNENs umfassen hochgradige PanNECs und NETG3 PanNETs, sowie die öfter diagnostizierten NETG1 und NETG2 PanNETs. Hochgradige PanNENs weisen eine schlechte Prognose auf, und sind histologisch schwierig zu diagnostizieren. In dieser Studie wird eine auf Methylierung basierende Klassifizierung vorgestellt, die PanNETs von PanNECs unterscheidet und die zugrunde liegende Komplexität in Bezug auf molekularen Merkmalen und den Ursprungszellen der PanNENs aufzeigt. Zuerst wurden PanNENs auf Grundlage ihrer Methylierungsprofile gruppiert, wodurch sich die PanNETs und PanNECs in zwei Gruppen A und B aufteilten. Während Tumore der Gruppe B häufig Veränderungen in KRAS, TP53 und SMAD4 aufweisen, umfasst das Mutationsspektrum von Gruppe A Veränderungen in klassischen PanNEN-Genen wie MEN1, DAXX, ATRX und VHL. Darüber hinaus ist Gruppe A durch chromosomale Aberrationen geprägt, während Gruppe B eine signifikante fokale Deletion des RB1-Lokus aufweist. Anhand von Methylierungsprofilen von alpha-, beta-, duktalen und azinären Pankreaszellen sowie von Expressionsmustern normaler Zelltyp Markergene innerhalb der Tumore folgt, dass die PanNETs alpha-, beta- und intermediär-ähnliche Tumore endokrinen Ursprungs sind, während die PanNECs azinäre Tumore vermutlich exokrinen Ursprungs sind. Ausprägung des Azinuszellenprofils und Expression des SOX9-Proteins in Gruppe B sind vergleichbar mit denen des duktalen Adenokarzinoms der Pankreas (PDAC), einer Tumorentität mit nachgewiesen exokrinen Zellursprung. Insgesamt ergeben die neuen Erkenntnisse dieser Arbeit ein umfassendes Profil, das PanNET- und PanNEC-Tumore genetisch und epigenetisch eindeutig charakterisiert. Weiterhin liefert diese Arbeit starke Beweise für die aufkommende, aber unbewiesene Theorie des exokrinen Ursprungs von PanNECs und somit einen neuen Ansatz für die Behandlung dieser seltenen, aber oft tödlichen Krankheit. / Pancreatic Neuroendocrine Neoplasm (PanNEN) is a rare form of cancer comprising a heterogeneous set of high-grade tumors PanNECs and NETG3, in addition to the more commonly diagnosed NETG1 and NETG2 PanNETs. High-grade PanNENs display poor prognosis among patients and remains challenging to diagnose histologically. This study presents a methylation-based classification, which precisely distinguishes PanNETs and PanNECs, exposing the complexity evident in molecular and tumor cell-of-origin features of PanNENs. My work establishes distinct PanNEN subgroups based on methylation profiles. The PanNETs and PanNECs were separated into two groups: Group A and Group B, respectively. While Group B tumors are enriched for recurring alterations in KRAS, TP53 and SMAD4, the mutational spectrum of Group A encompasses alterations in classical PanNEN genes including MEN1, DAXX, ATRX and VHL. Recurring whole chromosomal aberrations are evident in Group A tumors, in contrast to Group B tumors, which reveal a significant focal deletion of the RB1 locus. Using methylation profiles of normal pancreatic cell types, in addition to expression patterns of normal cell type marker genes within tumors, the study concluded that the PanNET tumors are alpha-like, beta-like, and intermediate-like tumors of endocrine origin, while PanNECs of Group B are acinar-like tumors with a potential exocrine origin. The proportion of acinar-cell methylation profile and expression of SOX9 protein in Group B tumors are comparable to Pancreatic Ductal adenocarcinoma (PDAC), a tumor entity of exocrine cell-of-origin. Together, the novel findings of this thesis establish a comprehensive profile distinctly characterizing PanNET and PanNEC tumors at the genetic and epigenetic molecular level. Importantly, this work provides strong evidence for the emerging yet unproven theory of an exocrine origin of PanNECs, offering a new approach for treating patients with this rare but often fatal disease.

Pancreatic β-cells have a central function in the regulation of glucose homeostasis by releasing the blood sugar-lowering hormone insulin. Disruption of this process results in diabetes, which has a tremendous impact on the quality of life and requires lifelong treatment. Elucidating the mechanisms of pancreatic progenitor cell differentiation into fully functional β-cells will contribute to identifying the underlying reasons for β-cell dysfunction and to finding a cure for diabetes. Aldh1b1 was identified by our research group as a regulator of pancreas development and β-cell functionality. Aldh1b1 is a mitochondrial enzyme, expressed in all embryonic pancreas progenitors. Its expression is switched off during the process of differentiation and is undetectable in differentiated cells. Functional inactivation of Aldh1b1 in the mouse leads to premature differentiation of progenitor cells in the embryo and dysfunctional β-cells in the adult. However, the enzymatic function of Aldh1b1 in pancreas progenitors and how it ultimately affects β-cell functionality remained to be elucidated. In this study, I analyzed the role of Aldh1b1 in the metabolism of embryonic pancreas progenitor cells and its impact on chromatin structure and gene expression in both, progenitors and postnatal β-cells. Flow cytometry analysis of freshly isolated Aldh1b1 null embryonic pancreas progenitors showed a significant increase in ROS levels as well as a significant decrease in mitochondrial mass, whereas the mitochondrial membrane potential was not affected. To elucidate the impact of Aldh1b1 on cellular metabolism, I conducted metabolic flux experiments and untargeted metabolomics studies using FACS-isolated embryonic pancreas progenitors expanded in a 3D spheroid culture. Analyses following metabolic labeling with either 13C6-Glucose or 13C2-Glutamine showed that the absence of Aldh1b1 lead to an increase of the reductive glutamine metabolism towards citrate, a reaction that channels carbon units into the acetyl-CoA biosynthesis. However, the ACLy-dependent flux towards acetyl-coA synthesis was reduced and this was consistent with reduced expression of ACLy as well as the citrate transporter SLC25a1. A decrease in cellular acetyl-CoA would reduce histone acetylation. Untargeted metabolomics showed an increase in the concentration of S-adenosyl-methionine, suggesting increased DNA and histone methylation. Consistent with these findings, ATAC-Seq analyses on freshly isolated pancreatic progenitors showed reduced chromatin accessibility at genes implicated in chromatin organization, protein acetylation and histone modification. Transcription motif analysis showed that the affected genomic sites were mainly associated with the binding of Klf/Sp and Nrf1 transcription factors. Transcriptome analyses displayed that the expression of genes implicated in progenitor differentiation, ECM organization and transcriptional regulation was affected. Furthermore, transcriptome analyses of early postnatal β-cells uncovered early signs of oxidative stress and increased proliferation, thus providing the basis to explain the β-cell phenotype in Aldh1b1 null mice. I then used organotypic cultures of embryonic pancreata to investigate the connection between high ROS levels and aberrant differentiation in the Aldh1b1 null pancreata. Reducing ROS levels using NAC enabled the reversal of the aberrant transcription factor expression and increased viability of Aldh1b1 null explants, thus identifying high ROS levels as a driving force in this process. To investigate how persisting Aldh1b1 expression would affect progenitor differentiation, I generated ROSA26LSLAldh1b1, an inducible constitutive Aldh1b1 expression line. Progenitors with continuous Aldh1b1 expression avoided the endocrine cell fate, underscoring the importance of timely Aldh1b1 downregulation in the course of β-cell differentiation. Altogether, my work provides strong evidence for the role of Aldh1b1 as a metabolic regulator in the process of progenitor cell differentiation and identifies a link between metabolism and gene regulation through chromatin accessibility during development. Aldh1b1 inactivity causes defects in embryonic progenitor cells as well as postnatal β-cells and could therefore contribute, as genetic risk factor, to the development of hyperglycemia and diabetes later in life. Comprehending the mechanisms underlying the process of pancreas progenitor differentiation as well as the origins of β cell dysfunction should assist in the design of novel therapeutic interventions for diabetes.