Assays for Validating Histone Acetyltransferase Inhibitors

Area of Science:

• Biochemistry
• Molecular Biology
• Cancer Therapeutics

Background:

• Lysine acetyltransferases (KATs) regulate gene expression and chromatin dynamics through protein acetylation.
• KATs, like CBP/p300, are crucial in cancer development and are investigated as therapeutic targets.
• Developing specific and potent KAT inhibitors requires robust validation assays.

Purpose of the Study:

• To outline a pipeline of three in vitro methods for validating novel histone acetyltransferase inhibitors (HATi).
• To provide rigorous assessment of HATi specificity, potency, and mechanism of action.

Main Methods:

• A test tube HAT assay using recombinant HATs and histones, measuring site-specific acetylation via immunoblotting.
• A Chromatin Hyperacetylation Inhibition (ChHAI) assay using immunoblotting to screen for HATi effects in a cellular context.
• Chromatin Immunoprecipitation-quantitative PCR (ChIP-qPCR) to assess HATi impact on histone acetylation at specific genomic regions.

Main Results:

• The HAT assay quantifies direct inhibition of KAT activity.
• The ChHAI assay confirms HATi efficacy in a cellular environment by monitoring histone hyperacetylation.
• ChIP-qPCR elucidates the genomic targets and regulatory effects of HATi.

Conclusions:

• The combined pipeline of HAT assay, ChHAI assay, and ChIP-qPCR offers comprehensive validation for novel HAT inhibitors.
• This approach is essential for advancing the development of KAT-targeted cancer therapies.