Chromatin Regulates Genome Targeting with Cisplatin

Area of Science:

• Molecular Biology
• Cancer Research
• Genetics

Background:

• Cisplatin derivatives induce DNA lesions (DNA-Pt) and activate DNA damage responses.
• Visualizing DNA-Pt within cells at high resolution remains challenging.

Purpose of the Study:

• To develop a high-resolution method for visualizing DNA-Pt in cells.
• To investigate the role of chromatin and HDAC inhibition in cisplatin-induced DNA damage responses.

Main Methods:

• Utilized a novel azide-containing cisplatin derivative (APPA) and click chemistry for DNA-Pt labeling.
• Employed a cellular pre-extraction protocol for enhanced visualization.
• Investigated the effects of SAHA (HDAC inhibitor) and cisplatin cotreatment on DNA-Pt localization and cellular responses.

Main Results:

• Developed a method to visualize DNA-Pt with high resolution using APPA and click chemistry.
• SAHA treatment induced DNA-Pt clustering, colocalizing with RAD18 and PCNA.
• SAHA and cisplatin cotreatment promoted Polη accumulation, synergistic PCNA mono-ubiquitination, and apoptosis in a RAD18-dependent manner.

Conclusions:

• Chromatin plays a role in regulating the targeting of cisplatin derivatives.
• SAHA enhances cisplatin efficacy by promoting DNA-Pt clustering and activating specific DNA repair pathways.
• The developed visualization strategy offers new insights into cisplatin-induced DNA damage and cellular responses.