A quantitative high-throughput screen identifies potential epigenetic modulators of gene expression.

Area of Science:

• Molecular Biology
• Epigenetics
• Drug Discovery

Background:

• Epigenetic regulation is crucial for development and implicated in cancer.
• Novel compounds targeting epigenetic mechanisms are needed for therapeutic development.

Purpose of the Study:

• To identify novel chemical compounds with epigenetic regulatory activity.
• To validate a cell-based imaging assay coupled with quantitative high-throughput screening (qHTS) for discovering epigenetic modulators.

Main Methods:

• A locus derepression (LDR) assay using a green fluorescent protein (GFP) reporter was screened against a large chemical library (69,137 compounds) via qHTS.
• Active compounds were analyzed for structure-activity relationships, and selected series were counter-screened.
• Assays included histone deacetylase (HDAC) activity, p16 gene reactivation, CDH13 gene expression, and cancer cell viability.

Main Results:

• qHTS identified 411 active compounds, leading to the selection of 6 distinct chemical series.
• Three series (8-hydroxy quinoline, quinoline-8-thiol, 1,3,5-thiadiazinane-2-thione) were confirmed as non-fluorescent and active in the LDR assay.
• One series induced CDH13 gene expression and inhibited lung cancer cell viability at submicromolar concentrations, without affecting HDAC activity or p16 expression.

Conclusions:

• The study successfully identified novel small molecules with potential epigenetic or transcriptional regulatory functions.
• The cell-based imaging assay combined with qHTS is a validated approach for discovering epigenetic modulators.
• One identified compound series shows promise for lung cancer therapy by targeting epigenetic mechanisms.