Distinct mechanisms for opposite functions of homeoproteins Cdx2 and HoxB7 in double-strand break DNA repair in colon cancer cells

Autor: Isabelle Gross, Jean-Noël Freund, Isabelle Duluc, Elisabeth Martin, Christine Soret, Marie Vanier, Françoise Dantzer, Claire Domon-Dell
Přispěvatelé: Freund, Jean-Noël, Equipe 1 'Emergence des Cellules Souches & Initiation Tumorale' (Groupe 2 : Hématopoïse et Leucémogenèse Humaines) (SMART - Inserm U1113), Interface de Recherche Fondamentale et Appliquée en Cancérologie (IRFAC - Inserm U1113), Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre Paul Strauss : Centre Régional de Lutte contre le Cancer (CRLCC)-Fédération de Médecine Translationelle de Strasbourg (FMTS)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre Paul Strauss : Centre Régional de Lutte contre le Cancer (CRLCC)-Fédération de Médecine Translationelle de Strasbourg (FMTS), Biotechnologie et signalisation cellulaire (BSC), Université de Strasbourg (UNISTRA)-Institut de recherche de l'Ecole de biotechnologie de Strasbourg (IREBS)-Centre National de la Recherche Scientifique (CNRS), Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg (UNISTRA)
Rok vydání: 2015
Předmět:
Zdroj: Cancer Letters
Cancer Letters, 2016, 374 (2), pp.208-215. ⟨10.1016/j.canlet.2016.02.026⟩
ISSN: 1872-7980
0304-3835
DOI: 10.1016/j.canlet.2016.02.026⟩
Popis: Homeobox genes, involved in embryonic development and tissues homeostasis in adults, are often deregulated in cancer, but their relevance in pathology is far from being fully elucidated. In colon cancers, we report that the homeoproteins HoxB7 and Cdx2 exhibit different heterogeneous patterns, Cdx2 being localized in moderately altered neoplasic glands in contrast to HoxB7 which predominates in poorly-differentiated areas; they are coexpressed in few cancer cells. In human colon cancer cells, both homeoproteins interact with the DNA repair factor KU70/80, but functional studies reveal opposite effects: HoxB7 stimulates DNA repair and cell survival upon etoposide treatment, whereas Cdx2 inhibits both processes. The stimulatory effect of HoxB7 on DNA repair requires the transactivation domain linked to the homeodomain involved in the interaction with KU70/80, whereas the transactivation domain of Cdx2 is dispensable for its inhibitory function, which instead needs the homeodomain to interact with KU70/80 and the C-terminal domain. Thus, HoxB7 and Cdx2 respectively use transcription-dependent and -independent mechanisms to stimulate and inhibit DNA repair. In addition, in cells co-expressing both homeoproteins, Cdx2 lessens DNA repair activity through a novel mechanism of inhibition of the transcriptional function of HoxB7, whereby Cdx2 forms a molecular complex with HoxB7 and prevents it to recognize its target in the chromatin. These results point out the complex interplay between the DSB DNA repair activity and the homeoproteins HoxB7 and Cdx2 in colon cancer cells, making the balance between these factors a determinant and a potential indicator of the efficacy of genotoxic drugs.
Databáze: OpenAIRE
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