Novel Affibody Molecules Targeting the HPV16 E6 Oncoprotein Inhibited the Proliferation of Cervical Cancer Cells

Jinshun Zhu; Saidu Kamara; Qi Wang; Yanru Guo; Qingfeng Li; Linlin Wang; Jingjing Chen; Qianqian Du; Wangqi Du; Shao Chen; Shanli Zhu; Jun Chen; Maoping Chu; Lifang Zhang

doi:10.3389/fcell.2021.677867

Novel Affibody Molecules Targeting the HPV16 E6 Oncoprotein Inhibited the Proliferation of Cervical Cancer Cells

Front Cell Dev Biol. 2021 May 24:9:677867. doi: 10.3389/fcell.2021.677867. eCollection 2021.

Authors

Jinshun Zhu^{1

2}, Saidu Kamara¹, Qi Wang¹, Yanru Guo¹, Qingfeng Li¹, Linlin Wang², Jingjing Chen¹, Qianqian Du¹, Wangqi Du¹, Shao Chen¹, Shanli Zhu¹, Jun Chen¹, Maoping Chu², Lifang Zhang¹

Affiliations

¹ Department of Microbiology and Immunology, Institute of Molecular Virology and Immunology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, China.
² Children's Heart Center, Institute of Cardiovascular Development and Translational Medicine, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.

Abstract

Despite prophylactic vaccination campaigns, high-risk human papillomavirus (HPV)-induced cervical cancer remains a significant health threat among women, especially in developing countries. The initial occurrence and consequent progression of this cancer type primarily rely on, E6 and E7, two key viral oncogenes expressed constitutively, inducing carcinogenesis. Thus, E6/E7 have been proposed as ideal targets for HPV-related cancer diagnosis and treatment. In this study, three novel HPV16 E6-binding affibody molecules (Z_HPV16E61115, Z_HPV16E61171, and Z_HPV16E61235) were isolated from a randomized phage display library and cloned for bacterial production. These affibody molecules showed high binding affinity and specificity for recombinant and native HPV16 E6 as determined by surface plasmon resonance, indirect immunofluorescence, immunohistochemistry, and near-infrared small animal optical imaging in vitro and in vivo. Moreover, by binding to HPV16 E6 protein, Z_HPV16E61235 blocked E6-mediated p53 degradation, which increased the expression of some key p53 target genes, including BAX, PUMA and p21, and thereby selectively reduced the viability and proliferation of HPV16-positive cells. Importantly, Z_HPV16E61235 was applied in combination with HPV16 E7-binding affibody Z_HPV16E7384 to simultaneously target the HPV16 E6/E7 oncoproteins, and this combination inhibited cell proliferation more potently than either modality alone. Mechanistic studies revealed that the synergistic antiproliferative activity depends primarily on the induction of cell apoptosis and senescence but not cell cycle arrest. Our findings provide strong evidence that three novel HPV16 E6-binding affibody molecules could form a novel basis for the development of rational strategies for molecular imaging and targeted therapy in HPV16-positive preneoplastic and neoplastic lesions.

Keywords: HPV; affibody molecules; cervical cancer; molecular imaging; oncoprotein E6; targeted therapy.