CRISPR Takes Another Step Forward

CRISPR can precisely alter DNA, but using it against cancer faces a fundamental problem: how do you deliver the genome-editing machinery to tumour cells without also editing healthy tissue? A newly published review proposes that aptamers, small synthetic DNA or RNA molecules capable of recognising specific cell-surface proteins, could provide part of the solution, guiding nanoparticles carrying CRISPR-Cas9 directly towards cancer cells.

The idea is particularly important for prostate cancer because PSMA is one of the receptors specifically discussed as a potential molecular address. PSMA-targeting aptamers have already been incorporated experimentally into CRISPR delivery systems, suggesting that the same surface protein currently exploited for imaging and radioligand therapy could eventually be used to transport genome-editing machinery into prostate cancer cells.

Once internalised, the nanoparticle would release CRISPR components capable, in principle, of disabling oncogenes, modifying pathways responsible for treatment resistance, restoring or compensating for defective tumour-suppressor mechanisms, or altering genes that help cancer evade the immune system. In other words, instead of using a tumour antigen simply to deliver radiation or a cytotoxic drug, the antigen could become an address for delivering a programmable genetic payload.

The possibilities become even more interesting when tumour heterogeneity is considered. Advanced prostate cancers do not uniformly express PSMA, and expression can change under therapeutic pressure. Future delivery platforms could therefore potentially combine targeting molecules against several prostate-cancer surface antigens, such as PSMA, STEAP1 or other emerging targets, to reach a broader population of malignant cells.

There are major obstacles before this could become a treatment. CRISPR cargo must survive circulation, reach metastatic sites, enter enough tumour cells, escape intracellular compartments and edit the intended DNA without producing dangerous changes elsewhere. Treating disseminated metastatic cancer is vastly more difficult than successfully editing cells in a laboratory or a localised experimental tumour.

Nevertheless, the concept represents an intriguing convergence of precision targeting, nanotechnology and genome editing.

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