Human hybrid tumor cells: observations on their production and clinical effects.

: Human hybrid tumor cells have been produced by fusing cells from freshly harvested tumor specimens with cells from a cultured human tumor line, D98OR. Fusions were performed with cells from 67 tumors and continuously growing hybrid lines were obtained from 16 (24%). A successful fusion usually produced 1 or 2 hybrid lines, but four easily fusable tumors produced from 6 to 26 lines. The parent cells and hybrids were analyzed by flow cytometry. Hybrids appeared to retain a high percentage of parental deoxyribonucleic acid. Ten patients participated in a clinical study in which they received intradermal immunization with semiautologous hybrids and Corynebacterium parvum as adjuvant. The only side effect was slight local tenderness at the injection sites. No tumor regressions occurred. Skin testing with parental and hybrid cells was performed prior to and following immunization with hybrids. Delayed cutaneous hypersensitivity was often achieved for hybrids but not for autologous tumor cells.