Actualités
Séminaires

Valéria NAIM

CNRS UMR 9019 Paris-Saclay

Intégrité du génome et cancer

Gustave Roussy, Villejuif

"Understanding genome instability from S-phase to mitosis"

contact : Eric JULIEN (Inserm/CNRS)

Replication stress resulting from slowing or stalling of DNA replication forks is a major driver of genome instability during cancer initiation and progression. DNA replication can be challenged as a consequence of oncogene activation or by agents that interfere with DNA synthesis, such as the ones used in chemotherapy. To accomplish genome duplication and prevent chromosomal instability, cells have evolved mechanisms that protect, stabilize and/or restart replication forks while delaying cell cycle progression, which avoids entering mitosis with under-replicated DNA. Over the last years, however, work from several laboratories including ours has shown that cells can progress into mitosis with under-replicated DNA. This led to the identification of mechanisms, mediated by the Fanconi anemia (FA) and Homologous Recombination (HR) repair pathways, that promote post-replication repair and rescue of under-replicated DNA in mitosis, allowing cells to divide and continue proliferating. I will discuss how these findings have advanced our understanding of the link between replication stress and genome instability; I will present a molecular pathway that connects mitochondrial stress and functions of FA proteins in genome maintenance; finally, I will show that mechanisms involved in mitotic rescue of under-replicated DNA may represent promising targets to selectively kill cancer cells that sustain intrinsically high levels of replication stress.