title: Molecular mechanisms of asymmetric divisions in mammary stem cells.
abstract: Stem cells have the remarkable ability to undergo proliferative symmetric divisions and self-renewing asymmetric divisions. Balancing of the two modes of division sustains tissue morphogenesis and homeostasis. Asymmetric divisions of Drosophila neuroblasts (NBs) and sensory organ precursor (SOP) cells served as prototypes to learn what we consider now principles of asymmetric mitoses. They also provide initial evidence supporting the notion that aberrant symmetric divisions of stem cells could correlate with malignancy. However, transferring the molecular knowledge of circuits underlying asymmetry from flies to mammals has proven more challenging than expected. Several experimental approaches have been used to define asymmetry in mammalian systems, based on daughter cell fate, unequal partitioning of determinants and niche contacts, or proliferative potential. In this review, we aim to provide a critical evaluation of the assays used to establish the stem cell mode of division, with a particular focus on the mammary gland system. In this context, we will discuss the genetic alterations that impinge on the modality of stem cell division and their role in breast cancer development.
authors.affiliation: Department of Experimental Oncology, European Institute of Oncology, Milan, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Santoro
authors.affiliation: Department of Experimental Oncology, European Institute of Oncology, Milan, Italy.
authors.forename: Thalia
authors.initials: T
authors.lastname: Vlachou
authors.affiliation: Department of Experimental Oncology, European Institute of Oncology, Milan, Italy.
authors.forename: Manuel
authors.initials: M
authors.lastname: Carminati
authors.affiliation: Department of Experimental Oncology, European Institute of Oncology, Milan, Italy piergiuseppe.pelicci@ieo.eu marina.mapelli@ieo.eu.
authors.forename: Pier Giuseppe
authors.initials: PG
authors.lastname: Pelicci
authors.affiliation: Department of Experimental Oncology, European Institute of Oncology, Milan, Italy piergiuseppe.pelicci@ieo.eu marina.mapelli@ieo.eu.
authors.forename: Marina
authors.identifier: 0000-0001-8502-0649
authors.initials: M
authors.lastname: Mapelli
mesh_terms: D000818:Animals; D060049:Asymmetric Cell Division / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics; D019070:Cell Lineage; D004330:Drosophila / Q000235:genetics; D029721:Drosophila Proteins / Q000235:genetics; D006801:Humans; D042361:Mammary Glands, Human / Q000166:cytology* / Q000502:physiology; D051379:Mice; D008938:Mitosis / Q000235:genetics; D009369:Neoplasms / Q000209:etiology; D009474:Neurons / Q000502:physiology; D012679:Sense Organs / Q000166:cytology / Q000502:physiology; D055153:Stem Cell Niche; D013234:Stem Cells / Q000502:physiology*
chemical_list: D029721:Drosophila Proteins
keywords: asymmetric cell division assays; asymmetric cell divisions; breast cancer; mammary stem cells