Antiviral Research

The anti-tumor efficacy of a recombinant oncolytic herpes simplex virus mediated CRISPR/Cas9 delivery targeting in HPV16-positive cervical cancer

Cervical cancer, often driven by high-risk human papillomavirus (HPV) infections such as HPV16 or HPV18, remains a leading cause of cancer-related deaths. HPV16, found in about 90% of cervical cancer patients, harbors key oncogenic related genes (E6, E7, E2, E5) and an upstream regulatory region (URR) that contribute to cancer progression. This study introduces a novel approach using a recombinant oncolytic herpes simplex virus type 1 (HSV-1) named SONC103, armed with a CRISPR/Cas9 gene editing system. The aim was to target and disrupt integrated HPV16 genes in cervical cancer cells. Results demonstrated SONC103's capability to specifically and effectively knock down HPV16 oncogenes, thereby reducing cell proliferation and promoting apoptosis. Analyses further revealed loss of HPV16 DNA probes in infected cells' chromosomes, significant regulation of cellular processes related to tumor apoptosis, and downregulation of E6/E7 oncoproteins while increasing tumor suppressor proteins P53 and pRB. Notably, SONC103 exhibited substantial inhibition of tumor growth in a murine xenograft cervical cancer model. This study showcases the potential of the recombinant oncolytic HSV-1 virus (SONC103) in combating HPV16-positive cervical cancer by targeting oncogenes and facilitating oncolysis.

In vitro and in vivo growth inhibition of human cervical cancer cells via human papillomavirus E6/E7 mRNAs’ cleavage by CRISPR/Cas13a system

Sustained infection of high-risk human papillomavirus (HR-HPVs), especially HPV16 and HPV18, is a major cause of cervical cancer. E6 and E7 oncoproteins, encoded by the HPV genome, are critical for transformation and maintenance of malignant phenotypes of cervical cancer. Here, we used an emerging programmable clustered regularly interspaced short palindromic repeat (CRISPR)/Cas13a system to cleave HPV 16/18 E6/E7 messenger RNAs (mRNAs). The results showed that customized CRISPR/Cas13a system effectively and specifically knocked down HPV 16/18 E6/E7 mRNAs, inducing growth inhibition and apoptosis in HPV16-positive SiHa and HPV18-positive HeLa Cell lines, but not in HPV-negative C33A cell line. Simultaneously, we detected downregulation of E6/E7 oncoproteins and upregulation of tumor suppressor P53 and RB proteins. In addition, we used subcutaneous xenograft tumor growth assays to find that the weight and volume of tumors in the SiHa-16E6CR1 group knocked down by the CRISPR/Cas13a system were significantly lower than those in the SiHa-VECTOR group lacking crRNA. Our study demonstrated that targeting HPV E6/E7 mRNAs by the CRISPR/Cas13a system may be a candidate therapeutic strategy for HPV-related cervical cancer.