title: Autocrine growth hormone prevents lactogenic differentiation of mouse mammary epithelial cells.
abstract: We have examined the expression, postnatal ontogeny, and localization of mouse GH (mGH) and its relative expression during pregnancy, lactation, and weaning in the mouse. mGH mRNA and protein was expressed predominantly in the epithelial component of the mammary gland, and maximal expression was observed during the pubertal period. Autocrine mGH expression dramatically decreased during late pregnancy and lactation. Concordantly, autocrine mGH expression is repressed during forced differentiation of mouse HC11 mammary epithelial cells in culture. Forced expression of mGH in HC11 cells abrogated lactogenic differentiation as indicated by reduced expression of beta-casein and reduced expression and loss of lateral epithelial localization of E-cadherin. Forced expression of mGH in mouse mammary epithelial cells increased cell survival and proliferation and consequently increased the size of mammary acinar-like structures formed in three-dimensional Matrigel. Thus, autocrine mGH expression in the mouse mammary epithelial cell is maximal at puberty and prevents mammary epithelial cell differentiation. Autocrine GH will therefore participate in mammary morphogenic processes at puberty.
authors.affiliation: Institute of Molecular and Cell Biology, Singapore
authors.forename: Svetlana
authors.initials: S
authors.lastname: Mukhina
authors.forename: Dongxu
authors.initials: D
authors.lastname: Liu
authors.forename: Ke
authors.initials: K
authors.lastname: Guo
authors.forename: Mireille
authors.initials: M
authors.lastname: Raccurt
authors.forename: Sahra
authors.initials: S
authors.lastname: Borges-Bendris
authors.forename: Hichem C
authors.initials: HC
authors.lastname: Mertani
authors.forename: Peter E
authors.initials: PE
authors.lastname: Lobie
mesh_terms: D000818:Animals; D017209:Apoptosis; D002454:Cell Differentiation; D049109:Cell Proliferation; D004847:Epithelial Cells / Q000166:cytology; D005260:Female; D013006:Growth Hormone / Q000235:genetics / Q000502:physiology*; D008297:Male; D008321:Mammary Glands, Animal / Q000166:cytology* / Q000254:growth & development; D051379:Mice; D009024:Morphogenesis; D012333:RNA, Messenger / Q000032:analysis; D011986:Receptors, Somatotropin / Q000235:genetics / Q000502:physiology
chemical_list: D012333:RNA, Messenger; D011986:Receptors, Somatotropin; D013006:Growth Hormone