Uniform Widespread Nuclear Phosphorylation of Histone H2AX Is an Indicator of Lethal DNA Replication Stress.
Fiche publication
Date publication
mars 2019
Journal
Cancers
Auteurs
Membres identifiés du Cancéropôle Est :
Dr TORA Laszlo, Pr WEISS Etienne, Dr OULAD-ABDELGHANI Mustapha
Tous les auteurs :
Moeglin E, Desplancq D, Conic S, Oulad-Abdelghani M, Stoessel A, Chiper M, Vigneron M, Didier P, Tora L, Weiss E
Lien Pubmed
Résumé
Phosphorylated histone H2AX (γ-H2AX), a central player in the DNA damage response (DDR), serves as a biomarker of DNA double-strand break repair. Although DNA damage is generally visualized by the formation of γ-H2AX foci in injured nuclei, it is unclear whether the widespread uniform nuclear γ-H2AX (called pan-nuclear) pattern occurring upon intense replication stress (RS) is linked to DDR. Using a novel monoclonal antibody that binds exclusively to the phosphorylated C-terminus of H2AX, we demonstrate that H2AX phosphorylation is systematically pan-nuclear in cancer cells stressed with RS-inducing drugs just before they die. The pan-nuclear γ-H2AX pattern is abolished by inhibition of the DNA-PK kinase. Cell death induction of cancer cells treated with increasing combinations of replication and kinase (ATR and Chk1) inhibitory drugs was proportional to the appearance of pan-nuclear γ-H2AX pattern. Delivery of labeled anti-γ-H2AX Fabs in stressed cells demonstrated at a single cell level that pan-nuclear γ-H2AX formation precedes irreversible cell death. Moreover, we show that H2AX is not required for RS-induced cell death in HeLa cells. Thus, the nuclear-wide formation of γ-H2AX is an incident of RS-induced cell death and, thus, the pan nuclear H2AX pattern should be regarded as an indicator of lethal RS-inducing drug efficacy.
Mots clés
H2AFX gene, H2AX phosphorylation, cancer cells, cell death, chemotherapy, histone variant, knock-out, monoclonal antibody, pan-nuclear pattern, replication stress, γ-H2AX
Référence
Cancers (Basel). 2019 Mar 13;11(3):