Lactogenic hormones increase epidermal growth factor messenger RNA content of mouse mammary glands.
Epidermal growth factor (EGF) is known to stimulate mammary epithelial proliferation, has been identified in milk and is expressed in lactating mammary epithelia. This study examined hormonal control of EGF mRNA in mammary glands of mice. Prepro-EGF mRNA (4.7 kb) was detected during lactation (and increased significantly during this period), whereas a smaller EGF-like RNA (.5 kb) was at highest levels in mammary glands of virgin and pregnant mice. The 4.7 kb RNA was polyadenylated, whereas .5 kb RNA was not. In mammary gland organ cultures from steroid-primed mice, the combinations of insulin + hydrocortisone and insulin + prolactin + hydrocortisone increased both prepro-EGF and beta-casein mRNA expression. When hydrocortisone was present there was a decrease in mammary gland content of EGF-like RNA (.5 kb band). We conclude that prepro-EGF mRNA expression in mouse mammary tissue is under the control of the lactogenic hormones prolactin and hydrocortisone.
Fenton
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Endocrinology-Reproductive Physiology Program, University of Wisconsin, Madison 53706.
Sheffield
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LG
D000375:Aging; D000818:Animals; D002364:Caseins / Q000235:genetics; D015342:DNA Probes; D004815:Epidermal Growth Factor / Q000235:genetics*; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D008321:Mammary Glands, Animal / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D051379:Mice; D008815:Mice, Inbred Strains; D009924:Organ Culture Techniques; D010052:Ovariectomy; D011374:Progesterone / Q000494:pharmacology*; D011498:Protein Precursors / Q000235:genetics*; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D012741:Sexual Maturation
D002364:Caseins; D015342:DNA Probes; D011498:Protein Precursors; D012333:RNA, Messenger; C042652:epidermal growth factor precursor; D011374:Progesterone; D004958:Estradiol; D004815:Epidermal Growth Factor