Expression of Prooncogenic Nuclear Receptor 4A (NR4A)-Regulated Genes β1-Integrin and G9a Inhibited by Dual NR4A1/2 Ligands

TL;DR

This study shows that dual NR4A1/2 ligands inhibit the expression of β1-integrin and G9a genes, which are regulated by NR4A1 and NR4A2 in colon cancer cells.

Contribution

The study identifies dual NR4A1/2 ligands as inhibitors of NR4A-regulated genes and reveals shared and unique gene regulation by these receptors.

Findings

DIM-3,5 compounds inhibit NR4A1- and NR4A2-regulated gene expression by displacing nuclear factors from gene promoters.

NR4A1 and NR4A2 regulate both common and unique genes in SW480 colon cancer cells.

Functional analysis shows that differentially expressed genes converge on shared pathways and gene ontology terms.

Abstract

Bis-indole-derived compounds including 1,1-bis(3′-indolyl)-1-(3,5-disubstitutedphenyl)methane (DIM-3,5) analogs bind both orphan nuclear receptors 4A1 (NR4A1) and NR4A2, and DIM-3,5 compounds act as dual receptor inverse agonists and inhibit both NR4A1- and NR4A2-regulated responses. Chromatin immunoprecipitation assays show that β1-integrin and the methyltransferase gene G9a are regulated by both NR4A1 and NR4A2 acting as cofactors for Sp1- and Sp4-dependent gene expression. DIM-3,5 treatment results in the loss of one or more of these nuclear factors from the β1-integrin and G9a promoters. Single-cell and RNAseq analyses show that both receptors regulate common (<10%) and unique genes in SW480 colon cancer cells; however, functional enrichment analysis of the differentially expressed genes converges to several common pathways and gene ontology terms.

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