Enhancing CRISPR/Cas gene editing through modulating cellular mechanical properties for cancer therapy

Genome editing holds great potential for cancer treatment due to the ability to precisely inactivate or repair cancer-related genes. However, delivery of CRISPR/Cas to solid tumours for efficient cancer therapy remains challenging. Here we targeted tumour tissue mechanics via a multiplexed dendrimer lipid nanoparticle (LNP) approach involving co-delivery of focal adhesion kinase (FAK) siRNA, Cas9 mRNA and sgRNA (siFAK + CRISPR-LNPs) to enable tumour delivery and enhance gene-editing efficacy. We show that gene editing was enhanced >10-fold in tumour spheroids due to increased cellular uptake and tumour penetration of nanoparticles mediated by FAK-knockdown. siFAK + CRISPR-PD-L1-LNPs reduced extracellular matrix stiffness and efficiently disrupted PD-L1 expression by CRISPR/Cas gene editing, which significantly inhibited tumour growth and metastasis in four mouse models of cancer. Overall, we provide evidence that modulating the stiffness of tumour tissue can enhance gene editing in tumours, which offers a new strategy for synergistic LNPs and other nanoparticle systems to treat cancer using gene editing. In vivo delivery of the CRISPR/Cas system is a promising cancer therapy approach, but its efficacy is hampered by low penetrability of nanoparticles in the stiff tumour tissue. Here the authors use dendrimer lipid nanoparticles to couple PD-L1 gene editing with knockdown of FAK, a protein involved in cell adhesion, showing that modulation of the mechanical properties of tumour cells leads to enhanced gene editing and tumour growth inhibition in four different animal models.