Generation of a new xenogenic transplantation model for the analysis of undifferentiated pleomorphic sarcoma: NOS in mice

e21505 Background: Undifferentiated pleomorphic sarcoma, NOS (not otherwise specified) formerly known as MFH comprise about 15-20% of all soft tissue sarcomas (STS) in adults. This kind of sarcoma is characterized by low response to radiation or chemotherapy. Thus, surgery with the aim of R0-resection is still the cornerstone for a curative treatment regimen. However, surgery is not always possible. In the recent past, many efforts have been undertaken to refine chemotherapeutic options and to develop new drugs for targeted therapies, such as mTOR-inhibtors or tyrosine kinase inhibitors. Yet, the hoped break through is still lacking. In addition, the further development of entity-based new drugs is difficult due to the low incidence of STS and suitable reproducible animal models. Here, we present a new xenogenic transplantation model of a pleomorphic sarcoma in mice. Methods: After intraoperative resection of the sarcoma, a sarcoma-derived cell line was established. These cultured cells were injected s.c. (1x10E6 cells) in immunocompromised NOD/SCID γc-/- mice and in humanized NOD/SCID γc-/- mice. Results: Tumor growth was reproducibly seen after four to six weeks. When resected after 12 weeks, the xenogenic tumor presented the same histological and morphological characteristics as the original tumor. Tumor infiltrating lymphocytes were detected by immunhistochemical staining. Conclusions: This new xenogenic transplantation model can serve as a basis for the evaluation of manifold questions within the fields of oncology, tumor genetics and tumor immunology.