Inhibitory Effect of Polyclonal Antibodies Against HER3 Extracellular Subdomains on Breast Cancer Cell Lines

Samaneh Mansouri-Fard,Mohammad-Reza Shokri,Fazel Shokri,Tannaz Bahadori,Mahmood Jeddi-Tehrani,Forough Golsaz-Shirazi,Mojgan Ghaedi,Mohammad Mehdi Amiri,Jalal Khoshnoodi

doi:10.31557/apjcp.2020.21.2.439

Abstract

Objective:Human epidermal growth factor receptor 3 (HER3) is a unique member of the tyrosine kinase receptors with an inactive kinase domain and is the preferable dimerization partner for HER2 which lead to potent tumorigenic signaling. Methods:In this study, the expression plasmids coding for the human HER3 subdomains were transfected into CHO-K1 cells. Produced proteins were characterized by ELISA and SDS-PAGE. Rabbits were immunized and produced polyclonal antibodies (pAbs) that were characterized by ELISA, Immunoblotting and flowcytometry and their inhibitory effects were assessed by XTT on BT-474 and JIMT-1 breast cancer cell lines. Result:The recombinant subdomains were highly immunogenic in rabbits. The pAbs reacted with the recombinant subdomains as well as commercial HER3 and the native receptor on tumor cell membranes and could significantly inhibit growth of Trastuzumab sensitive (BT-474) and resistant (JIMT-1) breast cancer cell lines in vitro. Conclusion:It seems that HER3 extra cellular domains (ECD) induce a strong anti-tumor antibody response and may prove to be potentially useful for immunotherapeutic applications.

Highlights

Epidermal growth factor receptors (EGFRs) are expressed on the surface of the mammalian cells and play crucial roles in cell division, migration, survival, differentiation and development in the embryonic and adult tissues
After transfection of CHO-K1 host cells with Human epidermal growth factor receptor 3 (HER3)-Full extra cellular domains (ECD) and its subdomain constructs, HER3-Full ECD, DI+II and DIII+IV fusion proteins were successfully produced in these cells (Figure 1a)
Contrary to HER1 and HER2, which have been widely studied, HER3 was neglected for a long period of time due to possession of inactive kinase domain

Summary

Introduction

Epidermal growth factor receptors (EGFRs) are expressed on the surface of the mammalian cells and play crucial roles in cell division, migration, survival, differentiation and development in the embryonic and adult tissues. Uncontrolled signalling of these receptors accounts for various cancers. This family belongs to subclass 1 of receptor kinase super family and have four members: HER1 (ErbB1 or EGFR), HER2 (ErbB2), HER3 (ErbB3) and HER4 (ErbB4) (Hynes and Lane, 2005; Zahnow, 2006). The third group includes Neuregulin-1 (NRG-1) and NRG-2 that bind to both HER3 and HER4 and NRG-3 and NRG-4 that bind only to HER4 (Zahnow, 2006)

Methods

Results

Conclusion