Therapeutic efficacy of CRISPR RNA nanoparticles on cervical cancer disease using ultrasound elastography imaging

Abstract

This work aimed to evaluate the therapeutic efficacy of clustered regularly interspaced short palindromic repeats (CRISPR) ribonucleic acid (RNA) nanoparticles (NPs) in the therapy of cervical cancer (CC) using ultrasound elastography imaging. Using poly(β-amino esters) (PBAE), CRISPR RNA NPs encapsulating Human Papillomavirus 16 (HPV16) E7, namely Poly(β-amino ester) (PBAE)/CRISPR16E7-GFP and PBAE/shRNA-16E7, were prepared. The characterization of these NPs was conducted using transmission electron microscopy (TEM) and laser diffraction particle size analysis. The cytotoxicity of PBAE/CRISPR16E7-GFP and PBAE/shRNA-16E7 NPs on CC cell lines SiHa, HeLa, and CaSki was assessed using the cell counting kit-8 (CCK-8) assay. Sixty female Sprague Dawley (SD) rats were rolled into six groups randomlyas follows: the blank Ctrl group (Group A, no treatment), the model group (Group B, CC model), the pSpCas9-GFP plasmid group (Group C, CC model + pSpCas9-GFP), the PBAE/CRISPR-16E7 group (Group D, CC model + PBAE/CRISPR-16E7), the pSIREN-U6-shRNA-CMV-iRFP plasmid group (Group E, CC model + pSIREN-U6-shRNA-CMV-iRFP), and the PBAE/shRNA-16E7 group (Group F, CC model + PBAE/shRNA-16E7), each consisting of 10 rats. The impact of NPs on the expression levels (ELs) of HPV16E7 and RB1 proteins in tumor tissues was assessed using Western Blot (WB) analysis. Additionally, ultrasound elastography imaging was employed to analyze the strain ratio (SR) and shear wave velocity (SWV) in lesions of various rat groups. The results indicated that the PBAE/CRISPR16E7-GFP NPs exhibited a particle size of 125.64 ± 7.8 nm, a zeta potential of 19.17 ± 3.61 mV, and a polydispersity index (PDI) of 0.281 ± 0.03. These NPs demonstrated a regular spherical structure with a compact morphology. The PBAE/shRNA-16E7 NPs displayed a particle size of 112.93 ± 9.1 nm, a zeta potential of 13.54 ± 1.39 mV, and a PDI of 0.185 ± 0.03. They exhibited a uniform distribution of spherical shape with regularity in size. The plasmids within PBAE/CRISPR16E7-GFP and PBAE/shRNA-16E7 NPs exhibited distinct trends of burst and sustained release. The viability of SiHa, HeLa, and CaSki cells remained unaffected by PBAE/CRISPR16E7-GFP NPs. At various mass ratios, neglectable differences (P > 0.05) were observed in cell viability of SiHa, HeLa, and CaSki cells treated with PBAE/CRISPR16E7-GFP and PBAE/shRNA-16E7 NPs relative to Ctrl group. Relative to Group B, both Groups C and E exhibited a drastic decrease in tumor volume, tumor mass, and HPV16E7 protein ELs (P < 0.05), whereas Groups D and F showed a notably greater reduction in tumor volume, tumor mass, and HPV16E7 protein ELs (P < 0.01). The HPV16E7 protein ELs, SR, and SWV values greatly increased (P < 0.001) in tumors of Group B rats while the EL of RB1 protein notably decreased (P < 0.001) versus Group A. Groups C and E demonstrated elevated HPV16E7 ELs, SR, and SWV values (P < 0.05), with a marked decrease in RB1 protein EL (P < 0.001). Group F exhibited a notable reduction in HPV16E7 protein levels, SR, and SWV values (P < 0.001).The CRISPRRNA NPs composed of PBAE encapsulating HPV16 E7, namely PBAE/CRISPR16E7-GFP and PBAE/shRNA-16E7 plasmids, demonstrated a significant role in CC therapy. These NPs hold potential application value in the treatment of HPV-related CC, indicating their importance in addressing this particular disease.