Gene amplification in human cells knocked down for RAD54
Ruiz-Herrera Moreno, Aurora (Universitat Autònoma de Barcelona. Departament de Biologia Cel·lular, de Fisiologia i d'Immunologia)
Smirnova, Alexandra (Università di Pavia. Dipartimento di Genetica e Microbiologia "Adriano Buzzati-Traverso")
Khouriauli, Lela (Università di Pavia. Dipartimento di Genetica e Microbiologia "Adriano Buzzati-Traverso")
Nergadze, Solomon G. (Università di Pavia. Dipartimento di Genetica e Microbiologia "Adriano Buzzati-Traverso")
Mondello, Chiara (Istituto di Genetica Molecolare (Pàvia, Itàlia))
Giulotto, Elena (Università di Pavia. Dipartimento di Genetica e Microbiologia "Adriano Buzzati-Traverso")
Universitat Autònoma de Barcelona. Institut de Biotecnologia i de Biomedicina "Vicent Villar Palasí"

Date:	2011
Abstract:	Background: In mammalian cells gene amplification is a common manifestation of genome instability promoted by DNA double-strand breaks (DSBs). The repair of DSBs mainly occurs through two mechanisms: non-homologous end-joining (NHEJ) and homologous recombination (HR). We previously showed that defects in the repair of DSBs via NHEJ could increase the frequency of gene amplification. In this paper we explored whether a single or a combined defect in DSBs repair pathways can affect gene amplification. Results: We constructed human cell lines in which the expression of RAD54 and/or DNA-PKcs was constitutively knocked-down by RNA interference. We analyzed their radiosensitivity and their capacity to generate amplified DNA. Our results showed that both RAD54 and DNA-PKcs deficient cells are hypersensitive to γ-irradiation and generate methotrexate resistant colonies at a higher frequency compared to the proficient cell lines. In addition, the analysis of the cytogenetic organization of the amplicons revealed that isochromosome formation is a prevalent mechanism responsible for copy number increase in RAD54 defective cells. Conclusions: Defects in the DSBs repair mechanisms can influence the organization of amplified DNA. The high frequency of isochromosome formation in cells deficient for RAD54 suggests that homologous recombination proteins might play a role in preventing rearrangements at the centromeres.
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; Versió publicada
Published in:	Genome integrity, Vol. 2, N. 5 (March 2011) , p. 1-10, ISSN 2041-9414

DOI: 10.1186/2041-9414-2-5
PMID: 21418575

10 p, 2.1 MB

Additional file 1 2 p, 9.5 KB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Health sciences and biosciences > Institut de Biotecnologia i de Biomedicina (IBB)
Articles > Published articles