Long-term cultivation of human mammary carcionoma: proliferation and differential biochemical properties of the cultured cells.

Human mammary carcinoma cell cultures proliferated from primary explants in Eagle's essential medium (MEM) supplemented with insulin, fetal calf serum (FCS) and/or human alpha-a1-antitrypsin. Human mammary carcinoma cells differed from normal mammary epithelial cells by the following catalytic activities: a. Thymidine uptake into the carcinoma cells was 6 to 10 fold greater, whereas thymidine conversion to CO2 was half to one fifth that of normal cells. b. The nucleolytic activity patterns of the mammary carcinoma cells preferred polycytydylic acid and double helical polynucleotides, whereas those of the normal mammary cells preferred polyuridylic acid and had no effect on double helical polynucleotides. c. The polymerase activity most evident in mammary carcinoma cells is a hybrid-dependent DNA polymerase which is guided by the ribo-strand of the template poly (rA) . poly(dT). In contrast the all-ribo template poly (rA) . poly(rU) showed little activity. d. There was slight or statistically non-significant difference between the amino acid composition of material cleaved from mammary carcinoma cells prepared from tumor tissues and from cells cultivated 10 months in vitro. e. There was no difference between the molar proportions of the carbohydrate components of the cell membrane from fresh tumor tissue and long term in vitro cultivated cells. f. The granules from long term in vitro cultured mammary carcinoma cells contained high collagenolytic, caseinolytic, fibrinolytic and esterolytic activities.