Biological characterization of cells derived from a human breast carcinoma. I. Some characteristics of cells cultivated in vitro prior to and after transplantation into nude mice.

Single cells from a patient (B. E., 65 years) have been isolated by collagenase treatment and cultivated in vitro. The human tumour of the mammary gland showed predominantly simple undifferentiated and also tubular structures. The 5th in vitro passage of these cells was characterized by DNA-distribution pattern, cell doubling time, chromosome number, ultrastructure, hormone and drug sensitivity. Cells of the 5th in vitro passage were i.p. transplanted into nude mice. The characteristics of in vitro cultivated cells (5th in vitro passage) were compared with both ascitic cells (1703/A) and cells of solid tumour material (1703/S) grown in nude mice for several passages (0, 10, 21). DNA-distribution patterns, chromosome numbers and cell doubling times are in good correlation. The number of polyploid cells is increased in ascitic cells. These malignant cells are best able to proliferate in vitro after transplantation into nude mice. Ultrastructure examination of the 21st passage has shown similarity between cultured cells, ascitic cells and cells of solid tumour material grown in nude mice. Virus particles could be observed in cells of solid only. Estrogen binding could be observed in the original tumour material only. All other cell or tissue preparations contained no receptors. Drug sensitivity was changed in the case of Vinblastin, Daunoblastin and Sarkolysin treatment of cells of solid tumour material more than in ascitic cells grown in nude mice. The environment dependence of cells and biological differences between in vivo-in vitro tumours and human neoplasms has to be taken into account when using cells as in vivo or in vitro model systems in experimental and clinical cancer research.