Transcriptional activation of the c-myc oncogene in the T-47D mammary cancer cells by conditioned media from embryonic mouse fibroblasts (BALB/c-3T3). Effect of the antiestrogen ICI 164,384.
The effects of the conditioned medium (CM) of embryonic mouse fibroblast (BALB/c-3T3) cells (clone A31) on the mRNA of the c-myc oncogene of the hormone-dependent T-47D mammary cancer cells were explored. After 6h incubation a significant stimulation of c-myc expression was observed with a 10% v/v concentration of CM, and the effect was even higher using a CM concentration of 30% v/v. It is suggested that this action of CM could be related to the stimulatory effect on proliferation and DNA synthesis induced by the CM, as was recently demonstrated for the T-47D cells. It was also observed that the antiestrogen ICI 164,384 (5 x 10(-6) M) can inhibit the stimulatory action of CM on c-myc expression. It is concluded that the fibroblast mouse embryonic cells contain and secrete factor(s) involved in the mechanism of proliferation of human hormone-dependent mammary cancer cells.
Pasqualini
J R
JR
C.N.R.S. Steroid Hormone Research Unit, Foundation for Hormone Research, Paris, France.
Chen
T A
TA
Maloche
C
C
Chetrite
G
G
Valentin
E
E
Allfrey
V
V
D016475:3T3 Cells; D000818:Animals; D015152:Blotting, Northern; D017077:Culture Media, Conditioned; D004305:Dose-Response Relationship, Drug; D004622:Embryo, Mammalian; D004958:Estradiol / Q000031:analogs & derivatives* / Q000494:pharmacology; D004965:Estrogen Antagonists / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D016259:Genes, myc / Q000187:drug effects; D007700:Kinetics; D008325:Mammary Neoplasms, Experimental / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D053284:Polyunsaturated Alkamides; D016271:Proto-Oncogene Proteins c-myc / Q000096:biosynthesis*; D015533:Transcriptional Activation / Q000187:drug effects
D017077:Culture Media, Conditioned; D004965:Estrogen Antagonists; D053284:Polyunsaturated Alkamides; D016271:Proto-Oncogene Proteins c-myc; D004958:Estradiol; C051781:ICI 164384