Genome-Wide CRISPR Screen Reveals PIK3CA Inhibition Enhances Lipid Nanoparticle-Mediated siRNA Delivery

Area of Science:

• Biotechnology
• Genomics
• Pharmacology

Background:

• Lipid nanoparticles (LNPs) are crucial for siRNA delivery but face challenges with cellular uptake, limiting their therapeutic potential.
• Enhancing LNP cellular uptake is key to improving the efficacy of RNA interference (RNAi) therapies.

Purpose of the Study:

• To identify genetic modulators of LNP uptake using a genome-wide CRISPR knockout screen.
• To evaluate the potential of targeting PIK3CA pharmacologically to enhance LNP-mediated siRNA delivery and therapeutic outcomes.

Main Methods:

• Conducted a genome-wide CRISPR knockout screen to identify genes regulating LNP uptake.
• Utilized BAY1082439, a PIK3CA inhibitor, to assess its effect on LNP uptake, siRNA delivery, and gene silencing in vitro.
• Evaluated the in vivo efficacy of co-administering BAY1082439 with siRNA-loaded LNPs in preclinical cancer models.

Main Results:

• Identified PIK3CA as a significant druggable target that modulates LNP uptake.
• Pharmacologic inhibition of PIK3CA with BAY1082439 substantially increased LNP uptake, siRNA delivery, and gene silencing in various cancer cell lines.
• Combined treatment with BAY1082439 and siRNA-loaded LNPs demonstrated improved tumor growth suppression and reduced liver inflammation in vivo.

Conclusions:

• PIK3CA inhibition is a promising strategy to enhance LNP-mediated RNA interference therapies.
• Combining functional genomics with nanomaterial-based therapeutics offers a powerful approach to advance RNA-based medicines.