A novel HPV16 E7-affitoxin for targeted therapy of HPV16-induced human cervical cancer

Abstract

Cervical cancer, the second most common cause of cancer death in women worldwide, is significantly associated with infection of high-risk human papillomaviruses (HPVs), especially the most common genotype, HPV 16. To date, there is no established noninvasive therapy to treat cervical cancer.Methods: Here, we report a novel affitoxin that targets HPV16 E7 protein, one of the primary target proteins in molecular targeted therapy for HPV-induced cervical cancer. The affitoxin, ZHPV16E7 affitoxin384 was generated by fusing the modified Pseudomonas Exotoxin A (PE38KDEL) to the HPV16 E7-specific affibody. The expressed and purified ZHPV16E7 affitoxin384 was characterized using numerous methods. SPR assay, indirect immunofluorescence assay, and near-infrared (NIR) optical imaging were respectively performed to assess the targeting ability of ZHPV16E7 affitoxin384 to HPV16 E7 protein both in vitro and in vivo. Cell viability assays and SiHa tumor-bearing nude mice were used to evaluate the efficacy of ZHPV16 E7 affitoxin384 in vitro and in vivo, respectively.Results: Using in vitro methods the SPR assay and indirect immunofluorescence assay showed that ZHPV16E7 affitoxin384 targeted HPV16 E7 with high binding affinity and specificity. Significant reduction of cell viability in HPV16 positive cells was observed in the presence of ZHPV16 E7 affitoxin384. By NIR optical imaging, ZHPV16 E7 affitoxin384 specifically targeted HPV16 positive tumors in vivo. ZHPV16E7 affitoxin384 showed significant in vivo antitumor efficacy in two kinds of tumor-bearing nude mouse models.Conclusions: ZHPV16E7 affitoxin384 is a potent anti-cervical cancer therapeutic agent that could be effective against HPV16 positive tumors in humans.

Generation of novel affibody molecules targeting the EBV LMP2A N-terminal domain with inhibiting effects on the proliferation of nasopharyngeal carcinoma cells

“…For therapeutic applications solely based on blocking the activity of tumour-related target protein as a mechanism of action, the fragment crystallisable (Fc) region of mAbs mediating, for instance, complement-dependent cytotoxicity and antibodydependent cell-mediated cytotoxicity (ADCC) is not required and might even be undesired 21 . Similar to non-Fc-portion antibody derivatives, such as scFv, fragment variable (Fv), and fragment antigen binding (Fab), affibody molecules are very valuable alternatives for such indications, and several affibody-based tumour targeting therapeutic agents with robust biological activity and no immunogenicity issues have been reported 30,38,39 . Affibody molecules do not contain any disulphide bridges, an observation suggesting that they could fold in the reducing environment of the cell cytoplasm 40 .…”

“…Affibody molecules do not contain any disulphide bridges, an observation suggesting that they could fold in the reducing environment of the cell cytoplasm 40 . This could allow for intracellular applications such as in vivo antitumor therapy using an affibody targeting HPV16E7 30 . In our work, given that the 119 amino acids of the LMP2A N-terminal cytoplasmic domain could constitutively activates many kinases and signal transduction molecules involved in cell cycle, proliferation, survival and motility 3 , we investigated the effect of the selected LMP2A-NCDbinding affibodies on EBV-positive NPC cells and explored the underlying mechanism.…”

Immunodiagnosis and Immunotherapeutics Based on Human Papillomavirus for HPV-Induced Cancers

“…Interestingly, affibodies were also applied in HPV-positive tumors via targeting HPV oncoproteins. In a mouse cervical cancer model, Z HPV18E7 and Z HPV16E7 affibodies connected with Pseudomonas exotoxin, also known as affitoxins, were able to deliver Pseudomonas exotoxin, a clinically used anti-cancer agent to tumor tissues effectively, showing great potential for HPV-induced cancer treatment ( 43 , 111 ). These results exemplify the potential use of affitoxins for HPV-induced cancers.…”

Novel nucleic acid detection strategies based on CRISPR‐Cas systems: From construction to application

“…HPV is a family of small DNA tumor viruses that cause certain common human cancers, most notably cervical cancer, which is the second most common cause of cancer death in women worldwide (Hausen, 1999; P. Jiang et al, 2018; Johansson & Schwartz, 2013; Tommasino, 2014). There are approximately 150 HPV types with different genetic variations; among them, HPV16 and HPV18 are the most studied HPV types due to their high level of carcinogenic activity, leading to approximately 70% of all cervical cancers worldwide (Tommasino, 2014; Q. Wang, Zhang, Xu, Long, & Wang, 2018; Woodman, Collins, & Young, 2007).…”