Difference in growth factor requirements of rat 3Y1 cells among growth in mass culture, clonal growth in low density culture, and stimulation to enter S phase in resting culture

Abstract

A semiserum-free medium was developed for monolayer culture of rat 3Y1 fibroblastic cells. The main components of the developed medium added to Dulbecco's modified Eagle's medium (DMEM) were insulin, transferrin, epidermal growth factor, poly-D-lysine, bovine albumin, oleic acid, and bovine alpha-globulin. In this medium, 3Y1 cells grew in mass culture at much the same rate as in DMEM supplemented with 10% fetal bovine serum (FBS), and colonies, albeit of smaller sizes, did form. Virally transformed derivatives of 3Y1 (simian virus 40-3Y1, polyoma virus-3Y1 and adenovirus type 12-3Y1) also formed colonies in the semiserum-free medium. When trypsinized 3Y1 cells were seeded with the medium lacking alpha-globulin, neither growth in the mass culture nor clonal growth in the low density culture (clonal growth) occurred. In this case, cell spreading was inhibited by albumin, and this inhibition was overcome by adding alpha-globulin or treating dishes with serum. When albumin was excluded from the semiserum-free medium, clonal growth did not occur, whereas growth in mass culture and stimulation of DNA synthesis in the resting mass culture (stimulation of DNA synthesis) were not so drastically affected. When oleic acid was removed, growth in mass culture was inhibited considerably, but no considerable effect was seen on clonal growth or on stimulation of DNA synthesis. In the absence of insulin, stimulation of DNA synthesis was inhibited more markedly than when other components were removed, but such was not the case with growth in mass culture and clonal growth.

Rat cells infected with anemia-inducing Friend leukemia virus contain integrated replication-competent but not defective proviral genomes.

“…The Fischer rat cell line 3Y1 (which H. Hanafusa kindly provided) has been described (18), as has the establishment, growth conditions, and characterization of FLV-transformed cell lines G-1, G-2, and G-3 (19); 5-86 (2); and SQ-A (16). Cells were maintained in Glasgow minimum essential medium (GIBCO) supplemented with 10% fetal calf serum, penicillin, and streptomycin.…”

IV-1 Growth Factors

“…Murakami et al (1981) established a serum-free medium for plasmacytoma cells. Okuda, Kajiwara and Kimura (1983) detected different growth factor requirements for the mass culture, clonal culture, and stimulation of resting culture in rat 3Y1 cells. Hoshi et al (1983) also detected different requirements for growth factors and hormones in normal and transformed human fibroblasts.…”