A CRISPR-Cas13d cancer therapeutic enables selective elimination of uveal melanoma

Area of Science:

• Oncology
• Molecular Biology
• Gene Therapy

Background:

• Uveal melanoma is the most common primary eye cancer in adults.
• Current treatments like surgery and radiotherapy have limited efficacy, with survival rates stagnant for decades.
• The gene RASGRP3 is identified as essential and overexpressed in uveal melanoma cells but not in healthy cells, presenting a potential therapeutic target.

Purpose of the Study:

• To develop a novel therapeutic strategy for uveal melanoma targeting the essential and overexpressed RASGRP3 gene.
• To overcome the challenge of targeting the intracellular and "undruggable" RasGRP3 protein.
• To establish a CRISPR-Cas13d-based RNA-targeting therapeutic for uveal melanoma.

Main Methods:

• Systematic analysis of public gene expression and CRISPR knockout datasets to identify essential genes in uveal melanoma.
• Development of a CRISPR-Cas13d RNA-targeting system to degrade RASGRP3 mRNA.
• Delivery of CRISPR-Cas13d components via optimized lipid nanoparticles *in vitro*.

Main Results:

• The CRISPR-Cas13d therapeutic selectively eliminated over 97% of uveal melanoma cells *in vitro* while sparing healthy cells.
• The therapy utilizes two synergistic mechanisms: direct RASGRP3 mRNA knockdown and collateral RNA degradation.
• This RNA-targeting approach demonstrated superior potency compared to CRISPR-Cas9 and siRNA methods without causing genomic alterations.

Conclusions:

• An effective RNA-targeting therapeutic strategy using CRISPR-Cas13d has been established for uveal melanoma.
• This approach offers a promising new avenue for treating uveal melanoma and potentially other "undruggable" cancers.
• The study highlights the potential of RNA-targeting therapeutics for cancers with limited treatment options.