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

• Published in: Cancer gene therapy 2020-04, Vol.27 (3-4), p.168-178
• Main Authors: Zhen, Shuai, Lu, Jiaojiao, Liu, Yun-Hui, Chen, Wei, Li, Xu
• Format: Article
• Language: English
• Subjects: 13/2; 13/51; 42/41; 631/67/1059; 64/60; 692/699/67; Animals; Antitumor activity; Apoptosis; Apoptosis - drug effects; Apoptosis - immunology; B7-H1 Antigen - antagonists & inhibitors; B7-H1 Antigen - genetics; B7-H1 Antigen - immunology; Biomedical and Life Sciences; Biomedicine; Care and treatment; CD4 antigen; CD8 antigen; Cell Line, Tumor; Cellular proteins; Cervical cancer; Cervix; Combined Modality Therapy - methods; Complications and side effects; CRISPR; CRISPR-Cas Systems - genetics; Dendritic cells; Development and progression; Female; Gene Expression; Gene Knockout Techniques; Gene Therapy; Genetic aspects; Genetic Therapy - methods; Genetic Vectors - administration & dosage; Genetic Vectors - genetics; gRNA; Health aspects; Human papillomavirus 16 - genetics; Humans; Immune checkpoint inhibitors; Innovations; Lymphocytes T; Methods; Mice; Molecular targeted therapy; Oncogene Proteins, Viral - genetics; Papillomavirus E7 Proteins - genetics; Papillomavirus infections; Papillomavirus Infections - immunology; Papillomavirus Infections - pathology; Papillomavirus Infections - therapy; Papillomavirus Infections - virology; PD-1 protein; PD-L1 protein; Plasmids - genetics; Repressor Proteins - genetics; RNA, Guide, CRISPR-Cas Systems - genetics; Synergism; Transcription; Tumor Microenvironment - genetics; Tumor Microenvironment - immunology; Uterine Cervical Neoplasms - immunology; Uterine Cervical Neoplasms - pathology; Uterine Cervical Neoplasms - therapy; Uterine Cervical Neoplasms - virology; Xenografts
• ISSN: 0929-1903; 1476-5500
• DOI: 10.1038/s41417-019-0131-9

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.