Cancer cell lines represent in vitro models for studying
malignancies, general cell biology, drug discovery and more. Whether they can be considered as exact representative models of the parental
tumors remains uncertain given the acquisition of additional ex vivo changes of the cells and the lack of tissue architecture and stroma. Previously, within the EuroBoNeT consortium, we characterized a collection of bone
sarcoma cell lines on genomic and proteomic level. Here, we address the phenotypical and functional characterization of the unique set of
osteosarcoma cell lines (n=19) in vitro and in vivo. For functional analysis of differentiation capacity, cells were stimulated towards osteoblasts, adipocytes and chondrocytes. Furthermore, all cell lines were injected subcutaneously and intramuscularly into nude mice to assay their in vivo
tumor formation capacity as well as for phenotypical analysis of the
tumors. All formed
tumors were further characterized histologically and immunohistochemically. Out of 19 cell lines, 17 (89%) showed adipogenic differentiation, 13/19 (68%) could differentiate towards osteoblasts and in 6/19 (32%) cell lines chondrogenic differentiation was evident. About half of the cell lines (8/19, 42%) produced
tumors in vivo after subcutaneous and
intramuscular injections. Several cell lines showed invasion into adjacent tissues and one
tumor developed several lung
metastases. The use of cell lines, especially in
cancer research, is of paramount importance. Here, we identify comprehensively characterized
osteosarcoma cell lines, which robustly represent clinical
osteosarcoma providing researchers useful in vitro and in vivo models to study the genetics and functional characteristics of this highly
malignant neoplasm.