title: Plk2 regulates mitotic spindle orientation and mammary gland development.
abstract: Disruptions in polarity and mitotic spindle orientation contribute to the progression and evolution of tumorigenesis. However, little is known about the molecular mechanisms regulating these processes in vivo. Here, we demonstrate that Polo-like kinase 2 (Plk2) regulates mitotic spindle orientation in the mammary gland and that this might account for its suggested role as a tumor suppressor. Plk2 is highly expressed in the mammary gland and is required for proper mammary gland development. Loss of Plk2 leads to increased mammary epithelial cell proliferation and ductal hyperbranching. Additionally, a novel role for Plk2 in regulating the orientation of the mitotic spindle and maintaining proper cell polarity in the ductal epithelium was discovered. In support of a tumor suppressor function for Plk2, loss of Plk2 increased the formation of lesions in multiparous glands. Collectively, these results demonstrate a novel role for Plk2 in regulating mammary gland development.
authors.affiliation: Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Villegas
authors.forename: Elena B
authors.initials: EB
authors.lastname: Kabotyanski
authors.forename: Amy N
authors.initials: AN
authors.lastname: Shore
authors.forename: Chad J
authors.initials: CJ
authors.lastname: Creighton
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Westbrook
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Rosen
mesh_terms: D000818:Animals; D016764:Cell Polarity / Q000235:genetics*; D002478:Cells, Cultured; D004848:Epithelium / Q000378:metabolism / Q000502:physiology; D005260:Female; D018507:Gene Expression Regulation, Developmental; D008321:Mammary Glands, Animal / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D016513:Mice, SCID; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000502:physiology*; D008941:Spindle Apparatus / Q000235:genetics*
chemical_list: D017346:Protein Serine-Threonine Kinases; C444640:serum-inducible kinase
keywords: Mammary gland development; Plk2; Spindle orientation