TY - JOUR A1 - Nietzer, Sarah A1 - Baur, Florentin A1 - Sieber, Stefan A1 - Hansmann, Jan A1 - Schwarz, Thomas A1 - Stoffer, Carolin A1 - Häfner, Heide A1 - Gasser, Martin A1 - Waaga-Gasser, Ana Maria A1 - Walles, Heike A1 - Dandekar, Gudrun T1 - Mimicking metastases including tumor stroma: a new technique to generate a three-dimensional colorectal cancer model based on a biological decellularized intestinal scaffold JF - Tissue Engineering Part C-Methods N2 - Tumor models based on cancer cell lines cultured two-dimensionally (2D) on plastic lack histological complexity and functionality compared to the native microenvironment. Xenogenic mouse tumor models display higher complexity but often do not predict human drug responses accurately due to species-specific differences. We present here a three-dimensional (3D) in vitro colon cancer model based on a biological scaffold derived from decellularized porcine jejunum (small intestine submucosa+mucosa, SISmuc). Two different cell lines were used in monoculture or in coculture with primary fibroblasts. After 14 days of culture, we demonstrated a close contact of human Caco2 colon cancer cells with the preserved basement membrane on an ultrastructural level as well as morphological characteristics of a well-differentiated epithelium. To generate a tissue-engineered tumor model, we chose human SW480 colon cancer cells, a reportedly malignant cell line. Malignant characteristics were confirmed in 2D cell culture: SW480 cells showed higher vimentin and lower E-cadherin expression than Caco2 cells. In contrast to Caco2, SW480 cells displayed cancerous characteristics such as delocalized E-cadherin and nuclear location of beta-catenin in a subset of cells. One central drawback of 2D cultures-especially in consideration of drug testing-is their artificially high proliferation. In our 3D tissue-engineered tumor model, both cell lines showed decreased numbers of proliferating cells, thus correlating more precisely with observations of primary colon cancer in all stages (UICC I-IV). Moreover, vimentin decreased in SW480 colon cancer cells, indicating a mesenchymal to epithelial transition process, attributed to metastasis formation. Only SW480 cells cocultured with fibroblasts induced the formation of tumor-like aggregates surrounded by fibroblasts, whereas in Caco2 cocultures, a separate Caco2 cell layer was formed separated from the fibroblast compartment beneath. To foster tissue generation, a bioreactor was constructed for dynamic culture approaches. This induced a close tissue-like association of cultured tumor cells with fibroblasts reflecting tumor biopsies. Therapy with 5-fluorouracil (5-FU) was effective only in 3D coculture. In conclusion, our 3D tumor model reflects human tissue-related tumor characteristics, including lower tumor cell proliferation. It is now available for drug testing in metastatic context-especially for substances targeting tumor-stroma interactions. KW - Multicenter randomized-trial KW - Carcinoma cells KW - Tissue KW - Fluorouracil KW - Matrix KW - 1st-line treatment KW - Beta-catenin KW - Invasion KW - 5-Fluorouracil KW - Fibroblasts Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-188202 VL - 22 IS - 7 ER - TY - THES A1 - Ceteci, Fatih T1 - Analysis of the role of the E-(Epithelial) Cadherin in murine lung tumorigenesis T1 - Aanlyse der Rolle des E-(Epithelischer) Cadherin in der Lunge Tumorigenesis N2 - Beim humanen nichtkleinzelligen Bronchialkarzinom ist die schrittweise Progression vom gutartigen Tumor zur malignen Metastasierung weitestgehend ungeklärt. In einem transgenen Mausmodell für das humane nichtkleinzellige Bronchialkarzinom, in dem in Lungenepithelzellen eine onkogene Mutante der Proteinkinase C-RAF exprimiert wird, können einzelne Schritte im Prozess der malignen Progression entschlüsselt werden. Die durch C-RAF induzierten Adenome zeichnen sich durch eine hohe genomische Stabilität in den Tumorzellen, durch starke interzelluläre Adhäsionskontakte zwischen den Tumorzellen und das Fehlen einer malignen Progression aus. Hier wurde demzufolge untersucht, ob die Auflösung der E-Cadherin-vermittelten Zellkontakte zwischen den einzelnen Tumorzellen eine Metastasierung auslösen könnte. Es wurden zwei genetische Ansätze verfolgt, um die Rolle der Tumorzelladhäsion im C-RAF Modell zu bewerten, die konditionelle Eliminierung des E-Cadheringens Cdh1 sowie die regulierbare transgene Expression von dominant-negativem E-Cadherin. Die Auflösung der E-Cadherin-vermittelten Zelladhäsion führte zur Neubildung von Tumorgefäßen, welche in der frühen Phase der Gefäßbildung durch Wiederherstellung des Zellkontakts reversibel war. Die vaskularisierten Tumore wuchsen schneller, bildeten invasive Fronten aus und führten zur Ausbildung von Mikrometastasen. Es konnte gezeigt werden, dass Beta-Catenin für die Induktion der Angiogenesefaktoren VEGF-A und VEGF-C in Lungentumorzellinien des Menschen und der Maus essentiell war. Lungentumorzellen aus den in situ Tumoren mit aufgelösten E-Cadherin-vermittelten Zellkontakten exprimierten Gene endodermaler und anderer Zellabstammung, was epigenetische Reprogrammierung in Tumorzellen als den Mechanismus bei der malignen Progression vermuten lässt. N2 - Steps involved in the progression of non-small cell lung cancer (NSCLC) to metastasis are poorly understood. Expression of oncogenic C-RAF in lung epithelial cells has yielded a model for non-small cell lung cancer (NSCLC). The induced adenomas are characterised by high genomic stability, a lack of tumor progression and pronounced cell-cell contacts raising the question whether disruption of E-cadherin complexes would promote progression to metastasis. Two genetic approaches were used to evaluate the role of adherens junctions in a C-RAF driven mouse model for NSCLC: conditional ablation of the Cdh1 gene and expression of dominant negative (dn) E-cadherin. Disruption of E-cadherin function caused massive formation of intratumoral vessels that was reversible in the early phase of induction. Vascularized tumors grew more rapidly, developed invasive fronts and gave rise to micrometastasis. ß-catenin was identified as a critical effector of E-cadherin disruption leading to up-regulation of angiogenic inducers (VEGF-A and VEGF-C) in mouse and human lung tumor cell lines. In vivo, lung tumor cells with disrupted E-cadherin expressed ß-catenin target genes of endodermal and other lineages suggesting that reprogramming may be involved in metastatic progression. KW - E-cadherin KW - Beta-catenin KW - C-RAF KW - VEGF KW - Metastasis KW - E-cadherin KW - Beta-catenin KW - C-RAF KW - VEGF KW - Metastasis KW - E-cadherin KW - Beta-catenin KW - C-RAF KW - VEGF KW - Metastasis Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-29396 ER -