title: Estrogen treatment in vivo increases keratinocyte growth factor expression in the mammary gland.
abstract: Proliferation and differentiation of mammary epithelia are regulated by the combined action of systemic hormones and locally derived paracrine growth factors. Keratinocyte growth factor (KGF) is a potential candidate stromal factor that may participate in the hormonal control of stromal/epithelial interactions. In this study, we have examined the in vivo effect of 17beta-estradiol (E) treatment on KGF expression in mammary glands of peripubertal (5-week-old) and mature (11-week-old) mice. Mice received subcutaneous injections of hormone after which KGF mRNA levels were assayed by ribonuclease protection analysis of mammary gland RNA. E treatment caused a dose- and time-dependent increase in KGF mRNA levels in intact mice from both age groups. Neither 17alpha-estradiol nor progesterone injection affected KGF mRNA levels. Comparison of the relative expression of KGF in parenchyma-free fat pads and in intact glands demonstrated that the basal and E-dependent KGF mRNA levels did not require the presence of mammary epithelium. ELISA assay of KGF tissue content demonstrated that concomitantly with an up-regulation of mRNA, E treatment also increased KGF protein in mammary glands from peripubertal and mature mice. These data show that E treatment stimulates both KGF mRNA and protein expression in mammary stroma in vivo and raises the possibility that KGF has a role in E-regulated mammary gland development.
authors.affiliation: Department of Molecular and Integrative Physiology and Kansas Cancer Institute, University of Kansas Medical Center, Kansas City, Kansas 66160-7810, USA.
authors.forename: V K
authors.initials: VK
authors.lastname: Pedchenko
authors.forename: W
authors.initials: W
authors.lastname: Imagawa
mesh_terms: D000367:Age Factors; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D051526:Fibroblast Growth Factor 10; D051523:Fibroblast Growth Factor 7; D005346:Fibroblast Growth Factors; D006133:Growth Substances / Q000235:genetics / Q000378:metabolism*; D008321:Mammary Glands, Animal / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D010052:Ovariectomy; D012333:RNA, Messenger / Q000378:metabolism*; D013997:Time Factors; D015854:Up-Regulation
chemical_list: C496454:Fgf7 protein, mouse; D051526:Fibroblast Growth Factor 10; D006133:Growth Substances; D012333:RNA, Messenger; D051523:Fibroblast Growth Factor 7; D004958:Estradiol; D005346:Fibroblast Growth Factors