Childhood sarcomas and lymphomas. Characterization of new cell lines and search for type‐C virus

Four cell lines were derived from childhood malignancies: rhabdomyosarcoma, sarcoma, lymphosarcoma and an American Burkitt's lymphoma. Cells of the four lines formed tumors in immunosuppressed newborn hamsters. The tumors had a microscopic appearance like that of the tumors from which the cell lines were derived. No virus‐like particles were detected by electron microscopy in the cell lines after treatment with bromodeoxyuridine; no hamster type‐C virus expression was present in cell lines derived from the hamster tumors. Chromosome constitution and in vitro growth properties of the cell lines were studied as was the fibrinolytic function of the sarcoma lines.