Fabrication and evaluation of a dual-targeting nanoparticle mediated CRISPR/Cas9 delivery to combat drug resistance in breast cancer cells

Abstract

Breast cancer treatment is hampered by drug resistance which leads to recurrence and metastasis. Alteration of specific gene expression such as ERCC1 evidently acquires drug resistance in breast cancer patients. The genome-editing technique known as the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-associated Cas9 system (CRISPR-Cas9) has shown promise in targeting genes. The current study aimed to design and characterize an efficient cargo through a safe and noninvasive dual-targeted polyplex for CRISPR/Cas9 delivery to downregulate the ERCC1 gene expression, which is overexpressed in MCF-7 cisplatin-resistant cells. In this manner, a carrier based on chitosan (CS) polyplex was modified with hyaluronic acid conjugated triptorelin (HA-LHRH) as dual-targeting agents and loaded with CRISPR/Cas9 plasmids. CS/HA-LHRH/pCRISPR exhibited negligible toxicity and comparable transfection efficiency with LipofectamineTM 3000. Dual-targeted polyplexes have boosted gene transfer by nearly two times that of single-targeted polyplexes (CS/HA/pCRISPR). Also, the dual-targeted polyplexes carrying plasmids of CRISPR/Cas9 enhanced drug sensitivity and decreased ERCC1 mRNA levels in MCF-7 cisplatin-resistant cell line, significantly. Our results suggest that CS/HA-LHRH/pCRISPR-mediated targeting of ERCC1 is practicable and could be potentially adopted as a novel therapeutic tool for removing platinum drug resistance in breast cancer cells.