Tumor microenvironment and stroma in intestinal adenocarcinomas and associated metastases in Atlantic salmon broodfish (Salmo salar)

Publication date: Available online 4 July 2019Source: Veterinary Immunology and ImmunopathologyAuthor(s): Håvard Bjørgen, Hege Hellberg, Oskar Mongstad Løken, Gjermund Gunnes, Erling Olaf Koppang, Ole Bendik DaleAbstractAnimal models are invaluable tools in cancer research. In this context, salmon is a promising candidate. Intestinal adenocarcinoma with metastases may be induced as a consequence of a plant-based diet triggering the inflammation – dysplasia- carcinogenesis pathway. Here, we investigate the stroma and the presence and nature of immune cells in such tumors by staining for mast cells, immunohistochemistry for T cells and antigen-presenting cells and in situ hybridization for B cells. In intestinal tumors, substantial amounts of T cells were detected in the stroma, whilst MHC class II+ cells were mainly among the cancerous cells. Ig+ cells were observed primarily in the tumor periphery. Mast cells showed a strong association with stroma. In metastases, scarce amounts of T cells were detected, whilst MHC I and II-reactivity varied, some tumors being completely negative. Ig+ cells were scattered around the metastatic tissue in no particular pattern, but were occasionally observed within clusters of tumor cells. Small numbers of mast cells were detected in the stroma. To the best of our knowledge, this is the first report addressing immune cells in fish tumors. The teleost tumor microenvironment seems comparable to that of mammals, making fish interesting model ...
Source: Veterinary Immunology and Immunopathology - Category: Veterinary Research Source Type: research