Establishment and characterization of a new osteogenic cell line (MOS-J) from a spontaneous C57BL/6J mouse osteosarcoma

In this paper we describe the establishment and characterization of a transplantable cell line derived from a spontaneously occurring chondroblastic osteosarcoma in a C57BL/6J mouse. The tumor line, MOS-J, forms solid tumors when injected intramuscularly into immunocompetent syngeneic hosts, mimicking endochondral bone development. These transplantable tumors have the capacity to destroy and invade existing bone and invade vessels in close proximity to the tumor. In culture, MOS-J cells form layers of pleomorphic cells with high mitotic activity. These cells have marked alkaline phosphatase activity and form calcified foci in vitro that stain with alizarin red. MOS-J cells also promote osteoclast development in vitro from normal bone marrow cells. These characteristics indicate the potential utility of the MOS-J osteosarcoma cell line as a model for studies of human osteosarcoma and bone biology.