The role of sex steroids in the expression of MMTV in the normal mouse mammary gland.
Infection with the mouse mammary tumor virus (MMTV) is associated with hyperplastic alveolar growth and subsequent tumorigenesis. The role of the sex steroids in the initial phase of this pathological chain of events is investigated in this study. In normal mammary epithelium, progesterone stimulates MMTV RNA expression both in vivo (2.6-fold) and in vitro (2.9-fold); although estradiol is ineffective alone, it does enhance the effect of progesterone (6.8- and 5.7-fold stimulation, respectively). These results suggest that the sex steroids may play an important role in inducing MMTV expression which can then lead to epithelial hyperplasia and, eventually, malignant transformation.
Bradham
B M
BM
Department of Biology, University of South Carolina, Columbia 29208.
Bolander
F F
FF
D000818:Animals; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D006854:Hydrocortisone / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology; D008321:Mammary Glands, Animal / Q000187:drug effects / Q000382:microbiology*; D008324:Mammary Tumor Virus, Mouse / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*; D051379:Mice; D008809:Mice, Inbred C3H; D009924:Organ Culture Techniques; D011374:Progesterone / Q000494:pharmacology*; D011388:Prolactin / Q000494:pharmacology; D012367:RNA, Viral / Q000187:drug effects; D014284:Triiodothyronine / Q000494:pharmacology
D007328:Insulin; D012367:RNA, Viral; D014284:Triiodothyronine; D011374:Progesterone; D004958:Estradiol; D011388:Prolactin; D006854:Hydrocortisone