DNA Damage Signaling-Induced Cancer Cell Reprogramming as a Driver of Tumor Relapse

Area of Science:

• Cancer Biology
• Epigenetics
• DNA Damage Response

Background:

• The DNA damage response (DDR) is recognized for its role in suppressing tumor formation.
• However, the intricate mechanisms by which DDR influences cancer progression remain incompletely understood.

Purpose of the Study:

• To investigate the role of DDR signaling in epigenetic modifications and its impact on tumorigenesis.
• To explore the potential of targeting DDR-induced epigenetic changes for cancer therapy.

Main Methods:

• Genetic-lineage tracing experiments in mice.
• In situ labeling approaches.
• Analysis of DNA methylation and gene expression, including OCT4, Myc, and macroH2A.

Main Results:

• DDR signaling triggers epigenetic events leading to the activation of pro-tumorigenic genes and the pluripotency gene OCT4.
• Loss of DNA methylation is an initial step in OCT4 reactivation, further promoted by oncogenes like Myc and reduced macroH2A.
• DDR-induced OCT4 reactivation confers chemoresistance and drives tumor relapse in both mouse models and human cancers.
• OCT4 deletion effectively reverses chemoresistance and delays tumor relapse.

Conclusions:

• DDR plays a previously unrecognized tumor-promoting role through cancer cell reprogramming via OCT4 reactivation.
• Targeting DDR-induced epigenetic reprogramming and OCT4 offers novel therapeutic strategies for overcoming chemoresistance and preventing cancer relapse.