Head and neck cancer (HNC) has a high incidence and a poor prognosis.
Epirubicin, a
topoisomerase inhibitor, is a potential
anthracycline chemotherapeutic for HNC treatment. HuR (ELAVL1), an
RNA-binding protein, plays a critical role in promoting
tumor survival, invasion, and resistance. HuR knockout via CRISPR/Cas9 (HuR CRISPR) is a possible strategy for the simultaneous modulation of the various pathways of
tumor progression. Multifunctional nanoparticles modified with pH-sensitive
epidermal growth factor receptor (EGFR)-targeting and nucleus-directed
peptides were designed for the efficient delivery of HuR CRISPR and
epirubicin to human tongue
squamous carcinoma SAS cells and SAS
tumor-bearing mice. The pH-sensitive nanoparticles responded to the acidic pH value as a switch to expose the targeting
peptides. The cellular uptake and transfection efficiency of these nanoparticles in SAS cells increased via EGFR targeting,
ligand-mediated endocytosis, and endosomal escape. These nanoparticles showed low cytotoxicity towards normal oral keratinocyte NOK cells. CRISPR/Cas9 was transported into the nucleus via the nuclear directing
peptide and successfully knocked out HuR to suppress proliferation,
metastasis, and resistance in SAS cells. The multiple inhibition of EGFR/β-
catenin/epithelial-mesenchymal transition pathways was mediated through modulating the EGFR/PI3K/mTOR/AKT axis. The co-treatment of
epirubicin and HuR CRISPR in SAS cells further facilitated apoptosis/necroptosis/autophagy and caused
cancer cell death. In combination with HuR CRISPR nanoparticles, the efficacy and safety of
epirubicin nanoparticles against
cancer in SAS
tumor-bearing mice improved significantly. Collectively, these nanoparticles showed a
tumor pH response, active EGFR targeting, and nuclear localization and thus offered a combinatorial spatiotemporal platform for
chemotherapy and the CRISPR/Cas gene-editing system.