Cultivation in vitro of cells derived from a human rhabdomyosarcoma

Two cell lines were derived from an embryonal rhabdomyosarcoma. Cells of both lines grew as monolayers in liquid medium and formed colonies in agar medium. Each line consisted of 2 cytologic types resembling those of the original tumor—spindle cells and large multinucleated cells. No myofibrils could be demonstrated in the cells by light or by electron microscopy nor were virus particles detected. Cells of both lines probably contained myosin-ATPase and cells of line #2 contained myoglobin. Chromosome studies of cell line #1 revealed a stem-line of 51 chromosomes with a consistent karyotype. Three passages of cell line #2 were studied, and no evidence of a stem-line was noted. Chromosome counts ranged from 45 to 170, and consistent marker chromosomes in most cells were present in the form of large metacentrics in the C group.