Mutational signatures reveal the role of RAD52 in p53-independent p21-driven genomic instability

Research output: Contribution to journalJournal articleResearchpeer-review

Panagiotis Galanos, George Pappas, Alexander Polyzos, Athanassios Kotsinas, Ioanna Svolaki, Nickolaos N Giakoumakis, Christina Glytsou, Ioannis S Pateras, Umakanta Swain, Vassilis L Souliotis, Alexandros G Georgakilas, Nicholas Geacintov, Luca Scorrano, Claudia Lukas, Jiri Lukas, Zvi Livneh, Zoi Lygerou, Dipanjan Chowdhury, Claus Storgaard Sørensen, Jiri Bartek & 1 others Vassilis G Gorgoulis

BACKGROUND: Genomic instability promotes evolution and heterogeneity of tumors. Unraveling its mechanistic basis is essential for the design of appropriate therapeutic strategies. In a previous study, we reported an unexpected oncogenic property of p21WAF1/Cip1, showing that its chronic expression in a p53-deficient environment causes genomic instability by deregulation of the replication licensing machinery.

RESULTS: We now demonstrate that p21WAF1/Cip1can further fuel genomic instability by suppressing the repair capacity of low- and high-fidelity pathways that deal with nucleotide abnormalities. Consequently, fewer single nucleotide substitutions (SNSs) occur, while formation of highly deleterious DNA double-strand breaks (DSBs) is enhanced, crafting a characteristic mutational signature landscape. Guided by the mutational signatures formed, we find that the DSBs are repaired by Rad52-dependent break-induced replication (BIR) and single-strand annealing (SSA) repair pathways. Conversely, the error-free synthesis-dependent strand annealing (SDSA) repair route is deficient. Surprisingly, Rad52 is activated transcriptionally in an E2F1-dependent manner, rather than post-translationally as is common for DNA repair factor activation.

CONCLUSIONS: Our results signify the importance of mutational signatures as guides to disclose the repair history leading to genomic instability. We unveil how chronic p21WAF1/Cip1expression rewires the repair process and identifies Rad52 as a source of genomic instability and a candidate therapeutic target.

Original languageEnglish
Article number37
JournalGenome Biology (Online Edition)
Volume19
Pages (from-to)1-18
ISSN1474-7596
DOIs
Publication statusPublished - 2018

    Research areas

  • Break-induced replication (BIR), Genomic instability, P21, Rad52, Single nucleotide substitution (SNS), Single strand annealing (SSA), Translesion DNA synthesis (TLS)

Number of downloads are based on statistics from Google Scholar and www.ku.dk


No data available

ID: 194519470