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Updated: Jul 9, 2026
High-throughput Screening for Chemical Modulators of Post-transcriptionally Regulated Genes
Published on: March 3, 2015
A novel high-throughput screening system identifies a small molecule repressive for matrix metalloproteinase-9
Rajesh R Nair1, Hector Avila, Xujun Ma
1Center for Cell Biology and Cancer Research, Albany Medical College, 47 New Scotland Ave., Albany, NY 12208, USA.
Abstract:
Aberrant gene expression is one of the driving forces for cancer progression and is considered an ideal target for chemical intervention. Although emerging bioluminescence reporter systems allow high-throughput searches for small molecules regulatory for gene expression, frequent silencing of reporter genes by epigenetic mechanisms hinders wide application of this drug discovery strategy. Here we report a novel system that directs the integration of a promoter-reporter construct to an open chromosomal location by Flp-mediated homologous recombination, thereby overcoming reporter-gene silencing. Using this system, we have screened more than 8000 compounds in the DIVERSet chemical library for repressors of a matrix metalloproteinase-9 (MMP-9) promoter and identified 5-methyl-2-(4-methylphenyl)-1H-benzimidazole (MPBD) inhibitory for MMP-9 gene expression. Consistent with this effect, MPBD inhibits MMP-9-dependent invasion of UMSCC-1 oral cancer cells, preosteoclast migration, and receptor activator of nuclear factor-kappaB ligand-induced osteoclast activity over concentration ranges that repressed MMP-9 expression. Mechanistic studies indicated that MPBD antagonizes AP-1 function by inhibiting its transactivation activity. We conclude that the Flp-mediated homologous recombination system to direct reporter integration into open chromatin regions represents a novel strategy allowing for the development of high-throughput systems screening for lead compounds targeting aberrant gene expression in cancer.
Insights
We developed a novel Flp-mediated recombination system to overcome reporter gene silencing in cancer drug discovery. This system identified a compound that inhibits matrix metalloproteinase-9 (MMP-9) gene expression and cancer cell invasion.
Area of Science:
- Molecular Biology
- Cancer Research
- Drug Discovery
Background:
- Aberrant gene expression drives cancer progression and is a key target for therapeutic intervention.
- Existing bioluminescence reporter systems for high-throughput screening are often hindered by epigenetic silencing of reporter genes.
Purpose of the Study:
- To develop a novel system for stable reporter gene expression in high-throughput screening for cancer drug discovery.
- To identify small molecules that repress matrix metalloproteinase-9 (MMP-9) gene expression.
Main Methods:
- A novel system was created using Flp-mediated homologous recombination to integrate promoter-reporter constructs into open chromosomal locations, preventing epigenetic silencing.
- Over 8000 compounds from the DIVERSet chemical library were screened for repressors of the MMP-9 promoter.
- Mechanistic studies were performed to elucidate the mode of action of identified compounds.
Main Results:
- The novel system successfully overcame reporter gene silencing, enabling a high-throughput screen of over 8000 compounds.
- 5-methyl-2-(4-methylphenyl)-1H-benzimidazole (MPBD) was identified as an inhibitor of MMP-9 gene expression.
- MPBD demonstrated inhibitory effects on MMP-9-dependent oral cancer cell invasion, preosteoclast migration, and osteoclast activity by antagonizing AP-1 function.
Conclusions:
- The Flp-mediated homologous recombination system provides a robust strategy for stable reporter gene integration, overcoming silencing issues in drug discovery.
- This system facilitates the development of high-throughput screening platforms for identifying lead compounds targeting aberrant gene expression in cancer.
- MPBD represents a promising lead compound for targeting MMP-9 in cancer therapies.
