Synthetic essentiality of chromatin remodelling factor CHD1 in PTEN-deficient cancer

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Synthetic lethality and collateral lethality are established strategies for identifying cancer therapeutic targets, particularly in cancers with tumor suppressor gene deletions.
• Screening mutually exclusive deletion patterns in cancer genomes offers a novel approach to discover synthetic-lethal interactions.

Purpose of the Study:

• To identify 'synthetic-essential' genes that are occasionally deleted but essential in the context of specific tumor suppressor deficiencies.
• To validate these synthetic-essential genes as potential therapeutic targets in cancers with specific tumor suppressor deficiencies.

Main Methods:

• Screening of mutually exclusive deletion patterns in cancer genomes.
• Depletion studies of the chromatin helicase DNA-binding factor CHD1 in PTEN-deficient prostate and breast cancer cell lines.
• Mechanistic studies investigating the PTEN-GSK3β-CHD1-β-TrCP pathway and its role in CHD1 degradation and TNF-NF-κB gene network activation.

Main Results:

• The study identified CHD1 as a putative synthetic-essential gene in PTEN-deficient cancers.
• CHD1 depletion significantly suppressed proliferation, survival, and tumorigenic potential in PTEN-deficient prostate and breast cancers.
• PTEN deficiency leads to CHD1 stabilization, activating the pro-tumorigenic TNF-NF-κB pathway via histone modification.

Conclusions:

• A novel PTEN pathway in cancer involving CHD1 regulation and its impact on the TNF-NF-κB network was elucidated.
• This study provides a framework for discovering 'trackable' therapeutic targets in cancers with specific tumor suppressor deficiencies, highlighting CHD1 as a promising target in PTEN-deficient tumors.