ESTABLISHMENT AND CHARACTERIZATION OF A CELL-LINE (NB-YK) DERIVED FROM A TRANSPLANTABLE RAT NEPHROBLASTOMA

A new cell line, designated NB-YK, was established from a transplantab le rat nephroblastoma (NB-Y) which was derived from a spontaneous neph roblastoma in an aged Fischer 344 rat. NB-YK grew in a piling-up and n oncohesive pattern on the plastic surface and formed colonies in a sof t agar. The main cell type of NB-YK represented morphology of mesenchy mal phenotype and most of the cells contained several secretory granul es in their cytoplasm. Immunocytochemically the cells were positive fo r vimentin, cytokeratin, and laminin. Coexpression of vimentin and cyt okeratin in the cells was confirmed by the one-dimensional gel electro phoresis and immunoblotting for intermediate filament proteins. NB-YK cells were tumorigenic and produced fibrosarcoma-like tumor when inocu lated subcutaneously or intraperitoneally into syngeneic rats and nude mice. NB-YK seems to be a useful model for studying biological proper ties of nephroblastoma.