Somatic cell hybridization of human tumor samples

Human intraspecific hybrids were formed between tumor cells isolated from both primary and metastatic tumors and a tissue culture adapted cell line, D98OR, a HeLa derivative which is thioguanine and ouabain resistant. Five different tumor types in all were attempted: renal cell carcinoma, colon adenocarcinoma, melanoma, chrondrosarcoma, and hepatocarcinoma. The tumor tissue was either (1) immediately dissociated and fused, or (2) frozen and later thawed, dissociated, and fused. Two different PEG concentrations were used. The results reported here demonstrate that: (1) hybrid tumor cell lines can be made from several types of cancer, (2) unfrozen tumor tissue fused with D98OR by exposure to 50% PEG appears optimal, (3) chromosome loss, as determined by flow cytometry studies of hybrid DNA content, is minimal, and (4) hybrids have characteristics consistent with derivation from tumor cells rather than derivation from the nonmalignant cells of a tumor.