title: Multiple microRNAs rescue from Ras-induced senescence by inhibiting p21(Waf1/Cip1).
abstract: Overexpression of Ras(G12V) in primary cells induces a permanent growth arrest called oncogene-induced senescence (OIS) that serves as a fail-safe mechanism against malignant transformation. We have performed a genome-wide small interfering RNA (siRNA) screen and a microRNA (miRNA) screen to identify mediators of OIS and show that siRNA-mediated knockdown of p21(Waf1/Cip1) rescues from Ras(G12V)-induced senescence in human mammary epithelial cells (HMECs). Moreover, we isolated a total of 28 miRNAs that prevented Ras(G12V)-induced growth arrest, among which all of the miR-106b family members were present. In addition, we obtained a number of hits, miR-130b, miR-302a, miR-302b, miR302c, miR-302d, miR-512-3p and miR-515-3p with seed sequences very similar to miR-106b family members. We show that overexpression of all these miRNAs rescues HMECs from Ras(G12V)-induced senescence by prevention of Ras(G12V)-induced upregulation of p21(Waf1/Cip1). Our results establish an important role for the cell cycle inhibitor p21(Waf1/Cip1) in growth control of HMECs and extend the repertoire of miRNAs that modulate the activity of this tumour suppressor.
authors.affiliation: Blizard Institute of Cell and Molecular Science, Barts and The London School of Medicine and Dentistry, London, UK.
authors.forename: V
authors.initials: V
authors.lastname: Borgdorff
authors.forename: M E
authors.initials: ME
authors.lastname: Lleonart
authors.forename: C L
authors.initials: CL
authors.lastname: Bishop
authors.forename: D
authors.initials: D
authors.lastname: Fessart
authors.forename: A H
authors.initials: AH
authors.lastname: Bergin
authors.forename: M G
authors.initials: MG
authors.lastname: Overhoff
authors.forename: D H
authors.initials: DH
authors.lastname: Beach
mesh_terms: D000818:Animals; D001483:Base Sequence; D002453:Cell Cycle / Q000235:genetics; D016922:Cellular Senescence; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000172:deficiency* / Q000235:genetics*; D055785:Gene Knockdown Techniques; D006801:Humans; D042361:Mammary Glands, Human / Q000166:cytology / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics*; D034741:RNA, Small Interfering / Q000235:genetics; D015854:Up-Regulation; D018631:ras Proteins / Q000378:metabolism*
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D035683:MicroRNAs; D034741:RNA, Small Interfering; D018631:ras Proteins