Altering the Cleaving Effector in Chimeric Molecules that Target RNA Enhances Cellular Selectivity.

Area of Science:

• Molecular Biology
• Chemical Biology
• RNA Therapeutics

Background:

• Small molecules targeting RNA are valuable research tools and potential therapeutics.
• Selective degradation of specific RNA molecules is a key goal in drug discovery.
• Cancer-associated RNAs, such as c-Jun mRNA and pre-miR-372, are important therapeutic targets.

Purpose of the Study:

• To investigate factors influencing the degradation of c-Jun mRNA and pre-miR-372.
• To determine if RNA structural features can direct selective small-molecule-mediated cleavage.
• To explore the potential of altering cleaving modules for targeted RNA degradation.

Main Methods:

• Utilized small molecules designed to bind specific RNA structures.
• Employed different cleaving effector moieties: bleomycin A5 for oxidative cleavage and RNase L via RiboTACs.
• Assessed RNA degradation in cancer cells based on the attached cleaving module and RNA sequence context.

Main Results:

• Bleomycin A5 selectively cleaved pre-miR-372, which possesses AU pairs and contiguous purines.
• RNase L-based RiboTACs selectively cleaved c-Jun mRNA, which contains unpaired pyrimidines.
• RNA structural context dictates the efficacy of different small-molecule-mediated degradation strategies.

Conclusions:

• The choice of cleaving effector moiety can be programmed to achieve selective RNA degradation.
• RNA sequence and structure surrounding the binding site are critical for determining cleavage specificity.
• This strategy offers a predictable approach for developing RNA-targeting small-molecule therapeutics.