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 - JOUR A1 - Rudel, Thomas A1 - Mehlitz, Adrian T1 - Modulation of host signaling and cellular responses by Chlamydia JF - Cell Communication and Signaling N2 - Modulation of host cell signaling and cellular functions is key to intracellular survival of pathogenic bacteria. Intracellular growth has several advantages e.g. escape from the humoral immune response and access to a stable nutrient rich environment. Growth in such a preferred niche comes at the price of an ongoing competition between the bacteria and the host as well as other microbes that compete for the very same host resources. This requires specialization and constant evolution of dedicated systems for adhesion, invasion and accommodation. Interestingly, obligate intracellular bacteria of the order Chlamydiales have evolved an impressive degree of control over several important host cell functions. In this review we summarize how Chlamydia controls its host cell with a special focus on signal transduction and cellular modulation. KW - Chlamydia KW - Invasion KW - Inclusion KW - Type III secretion KW - Tarp KW - Inc KW - Signaling KW - Trafficking Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-97225 UR - http://www.biosignaling.com/content/11/1/90 ER -