CHARACTERIZATION OF A NEW HUMAN EMBRYONAL RHABDOMYOSARCOMA CELL-LINE,RMS-GR

A human tumor cell line designated RMS-GR was established from an embr yonal rhabdomyosarcoma, The monolayer cells were polygonal, round or s pindle-shaped, The RMS-GR cell line became stable with a doubling time of 42 h, Tumorigenicity of the cells was confirmed by heterotransplan tion into nude mice. Electron microscopic images showed typical cytopl asmic inclusion of aggregated intermediate filaments and myofibril-lik e thin filaments. The expression of desmin, vimentin, actin and human myoglobin was recognized by cytofluorometric analyses, and a large fra ction of CK-MM and small fractions of CK-BB and MCK-1 isoenzymes were found. Chromosomal analysis showed that the modal chromosome number wa s consistently near triploid with structural abnormalities mostly invo lving chromosomes 1, 3 and 8, and additional unidentified markers. No alteration of chromosome 2 was observed. The RMS-GR cell line may prov ide a system to identify genes which are involved in the pathogenic me chanism of rhabdomyosarcomas, and to investigate the modulation of myo genic differentiation.