ESTABLISHMENT AND CHARACTERIZATION OF A PATIENT-DERIVED CANCER MODEL OF UNDIFFERENTIATED PLEOMORPHIC SARCOMA

Background: Undifferentiated pleomorphic sarcoma (UPS) is a pleomorphic variant of undifferentiated, aggressive, and heterogeneous mesenchymal malignancy. Patient-derived cancer models comprise an invaluable preclinical tool for developing novel therapeutic strategies, although owing to the diversity in UPS, multiple cell lines are required for research of this disease. Therefore, we aimed to establish novel patient-derived xenografts (PDXs) from the tumor tissue of a patient with UPS, along with a cell line from an established PDX. Methods: The biological characteristics of the established cell line such as morphology, growth rate, colony formation capacity, and immunohistochemical characteristics were determined. Proteomic features were assessed by mass spectrometry. Results: The tumor tissues of PDXs showed a similar histological appearance to that of primary tumor tissue. The cells grew at a sufficient rate for conventional experiments. The cells exhibited colony-forming ability and expressed a typical marker of UPS. The mass spectrometric protein expression profiling revealed a unique spectrum of functions from the original tumor tissue, through patient-derived xenograft, to the cell line. The use of the established xenograft and cell line will facilitate our understanding of the molecular mechanisms underlying poor prognosis of UPS, and will contribute to the development of novel therapeutic strategies.