Novel recombinant immunotoxin of EGFR specific nanobody fused with cucurmosin, construction and antitumor efficiency<i>in vitro</i>

Abstract

// Cuimin Deng 1, * , Jiani Xiong 2, * , Xiaofan Gu 1 , Xiaoying Chen 3 , Shuifa Wu 4 , Zhe Wang 1 , Duanduan Wang 5 , Jinjin Tu 1 , Jieming Xie 1 1 Department of Pharmacology, Fujian Medical University, Fuzhou, Fujian, China 2 Department of Oncology, Fujian Medical University Union Hospital, Fuzhou, Fujian, China 3 Department of Experimental Teaching Center of Basic Medical Science, Fujian Medical University, Fuzhou, Fujian, China 4 Department of Pharmacology, The 180th Hospital of PLA, Quanzhou, Fujian, China 5 Department of Breast Surgery, Fujian Medical University Union Hospital, Fuzhou, Fujian, China * These authors contributed equally to this work Correspondence to: Jieming Xie, email: jmxie@mail.fjmu.edu.cn Keywords: immunotoxins, nanobody, EGFR, cucurmosin Received: November 16, 2016&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Accepted: March 24, 2017&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Published: April 07, 2017 ABSTRACT Epidermal growth factor receptor (EGFR) overexpression is related to the increased aggressiveness, metastases, and poor prognosis in various cancers. In this study, we successfully constructed a new EGFR nanobody-based immunotoxin rE/CUS containing cucurmosin (CUS), The immunotoxin was expressed by prokaryotic system and we obtained a yield of 5 mg protein per liter expression medium. The percentage of it&rsquo;s binding ability totumor cell lines A549, HepG2, SW116, which highly expressed EGFR was 55.6%, 79.6% and 97.1%, respectively, but SW620 was only 4.45%. rE/CUS has the ability to bind A549, HepG2, SW116 cells specifically, and the antigen binding capability was not affected because of extra part of CUS component. The rE/CUS significantly inhibited the cell viability against EGFR over expression tumor cell lines in a dose-and time-dependent manner. Moreover, rE/CUS also induced apoptosis of HepG2 and A549 mightily. Our results demonstrate that rE/CUS is a potential therapeutic strategy for treating EGFR-positive solid tumors.