title: Functional Role of the microRNA-200 Family in Breast Morphogenesis and Neoplasia.
abstract: Branching epithelial morphogenesis is closely linked to epithelial-to-mesenchymal transition (EMT), a process important in normal development and cancer progression. The miR-200 family regulates epithelial morphogenesis and EMT through a negative feedback loop with the ZEB1 and ZEB2 transcription factors. miR-200 inhibits expression of ZEB1/2 mRNA, which in turn can down-regulate the miR-200 family that further results in down-regulation of E-cadherin and induction of a mesenchymal phenotype. Recent studies show that the expression of miR-200 genes is high during late pregnancy and lactation, thereby indicating that these miRs are important for breast epithelial morphogenesis and differentiation. miR-200 genes have been studied intensively in relation to breast cancer progression and metastasis, where it has been shown that miR-200 members are down-regulated in basal-like breast cancer where the EMT phenotype is prominent. There is growing evidence that the miR-200 family is up-regulated in distal breast metastasis indicating that these miRs are important for colonization of metastatic breast cancer cells through induction of mesenchymal to epithelial transition. The dual role of miR-200 in primary and metastatic breast cancer is of interest for future therapeutic interventions, making it important to understand its role and interacting partners in more detail.
authors.affiliation: Stem Cell Research Unit, Department of Medical Faculty, Biomedical Center, University of Iceland, Vatnsmyrarvegi 16, 101 Reykjavík, Iceland. byh1@hi.is.
authors.forename: Bylgja
authors.initials: B
authors.lastname: Hilmarsdottir
authors.affiliation: Stem Cell Research Unit, Department of Medical Faculty, Biomedical Center, University of Iceland, Vatnsmyrarvegi 16, 101 Reykjavík, Iceland. eib13@hi.is.
authors.forename: Eirikur
authors.initials: E
authors.lastname: Briem
authors.affiliation: Stem Cell Research Unit, Department of Medical Faculty, Biomedical Center, University of Iceland, Vatnsmyrarvegi 16, 101 Reykjavík, Iceland. jon.bergthorsson@gmail.com.
authors.forename: Jon Thor
authors.initials: JT
authors.lastname: Bergthorsson
authors.affiliation: Stem Cell Research Unit, Department of Medical Faculty, Biomedical Center, University of Iceland, Vatnsmyrarvegi 16, 101 Reykjavík, Iceland. magnuskm@hi.is.
authors.forename: Magnus Karl
authors.initials: MK
authors.lastname: Magnusson
authors.affiliation: Stem Cell Research Unit, Department of Medical Faculty, Biomedical Center, University of Iceland, Vatnsmyrarvegi 16, 101 Reykjavík, Iceland. tgudjons@hi.is.
authors.forename: Thorarinn
authors.initials: T
authors.lastname: Gudjonsson