Chromatin Regulates Genome Targeting with Cisplatin

Angewandte Chemie - International Edition

4 years ago

Chromatin Regulates Genome Targeting with Cisplatin

Valérie Bergoglio, Emmanouil Zacharioudakis, Blerta Xhemalce, Raphaël Rodriguez, Alexandra Bartoli, Kyle M. Miller, Poonam Agarwal, Nathan Abell, Lavaniya Kunalingam

Cisplatin derivatives can form various types of DNA lesions (DNA-Pt) and trigger pleiotropic DNA damage responses. Here, we report a strategy to visualize DNA-Pt with high resolution, taking advantage of a novel azide-containing derivative of cisplatin we named APPA, a cellular pre-extraction protocol and the labeling of DNA-Pt by means of click chemistry in cells. Our investigation revealed that pretreating cells with the histone deacetylase (HDAC) inhibitor SAHA led to detectable clusters of DNA-Pt that colocalized with the ubiquitin ligase RAD18 and the replication protein PCNA. Consistent with activation of translesion synthesis (TLS) under these conditions, SAHA and cisplatin cotreatment promoted focal accumulation of the low-fidelity polymerase Polη that also colocalized with PCNA. Remarkably, these cotreatments synergistically triggered mono-ubiquitination of PCNA and apoptosis in a RAD18-dependent manner. Our data provide evidence for a role of chromatin in regulating genome targeting with cisplatin derivatives and associated cellular responses. Treatment of cancer cells with cisplatin derivatives and a histone deacetylase inhibitor leads to the production of clusters of platinated DNA lesions that synergistically activate translesion synthesis and apoptosis signaling. These findings provide evidence for a role of chromatin in regulating genome targeting with cisplatin derivatives and associated cellular responses.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/anie.201701144