Synergistic antitumor effect on cervical cancer by rational combination of PD1 blockade and CRISPR-Cas9-mediated HPV knockout

Cancer Gene Ther. 2020 Apr;27(3-4):168-178. doi: 10.1038/s41417-019-0131-9. Epub 2019 Aug 27.

Abstract

Targeted therapy results in objective responses in cervical cancer. However, the responses are short. In contrast, treatment with immune checkpoint inhibitors results in a lower responses rate, but the responses tend to be more durable. Based on these findings, we hypothesized that HPV16 E6/E7-targeted therapy may synergize with the PD-1 pathway blockade to enhance antitumor activity. To test hypothesis, we described for the first time the effects of the CRISPR/Cas9 that was targeted to the HPV and PD1 in vitro and in vivo. Our data showed that gRNA/cas9 targeted HPV16 E6/E7 induced cervical cancer cell SiHa apoptosis, and suggested that overexpression of PD-L1, induced by HPV16 E6/E7, may be responsible for lymphocyte dysfunction. In established SiHa cell- xenografted humanized SCID mice, Administration of gRNA-PD-1 together with gRNA-HPV16 E6/E7 treatment improved the survival and suppressed the tumor growth obviously. In addition, combination treatment increased the population of dendritic cells, CD8+ and CD4+ T lymphocyte cells. According, it enhanced the expression of Th1-associated immune-stimulating genes while reducing the transcription of regulatory/suppressive immune genes, reshaping tumor microenvironment from an immunosuppressive to a stimulatory state. These results demonstrate potent synergistic effects of combination therapy using HPV16 E6/E7-targeted therapy and immune checkpoint blockade PD1, supporting a direct translation of this combination strategy in clinic for the treatment of cervical cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Apoptosis / immunology
  • B7-H1 Antigen / antagonists & inhibitors
  • B7-H1 Antigen / genetics*
  • B7-H1 Antigen / immunology
  • CRISPR-Cas Systems / genetics
  • Cell Line, Tumor
  • Combined Modality Therapy / methods
  • Female
  • Gene Knockout Techniques
  • Genetic Therapy / methods*
  • Genetic Vectors / administration & dosage
  • Genetic Vectors / genetics
  • Human papillomavirus 16 / genetics*
  • Humans
  • Mice
  • Oncogene Proteins, Viral / genetics
  • Papillomavirus E7 Proteins / genetics
  • Papillomavirus Infections / immunology
  • Papillomavirus Infections / pathology
  • Papillomavirus Infections / therapy*
  • Papillomavirus Infections / virology
  • Plasmids / genetics
  • RNA, Guide, CRISPR-Cas Systems / genetics
  • Repressor Proteins / genetics
  • Tumor Microenvironment / genetics
  • Tumor Microenvironment / immunology
  • Uterine Cervical Neoplasms / immunology
  • Uterine Cervical Neoplasms / pathology
  • Uterine Cervical Neoplasms / therapy*
  • Uterine Cervical Neoplasms / virology

Substances

  • B7-H1 Antigen
  • CD274 protein, human
  • E6 protein, Human papillomavirus type 16
  • Oncogene Proteins, Viral
  • Papillomavirus E7 Proteins
  • RNA, Guide, CRISPR-Cas Systems
  • Repressor Proteins
  • oncogene protein E7, Human papillomavirus type 16