EGFR-targeting, β-defensin-tailored fusion protein exhibits high therapeutic efficacy against EGFR-expressed human carcinoma via mitochondria-mediated apoptosis

• Published in: Acta pharmacologica Sinica 2018-11, Vol.39 (11), p.1777-1786
• Main Authors: Liu, Wen-Juan, Liu, Xiu-Jun, Xu, Jian, Li, Liang, Li, Yi, Zhang, Sheng-Hua, Wang, Jia-Lin, Miao, Qing-Fang, Zhen, Yong-Su
• Format: Article
• Language: English
• Subjects: Aminoglycosides - metabolism; Aminoglycosides - therapeutic use; Animals; Antineoplastic Agents - metabolism; Antineoplastic Agents - therapeutic use; Apoproteins - metabolism; Apoproteins - therapeutic use; Apoptosis; Apoptosis - drug effects; beta-Defensins - metabolism; beta-Defensins - therapeutic use; Biomedical and Life Sciences; Biomedicine; Body weight; Cancer; Carcinoma, Squamous Cell - drug therapy; Cell Line, Tumor; Cell proliferation; Cytotoxicity; Defensins; Enediynes - metabolism; Enediynes - therapeutic use; Epidermal growth factor; Epidermal growth factor receptors; ErbB Receptors - metabolism; Female; Fusion protein; Humans; Immunology; Innate immunity; Internal Medicine; Localization; Lung cancer; Lung carcinoma; Medical Microbiology; Mice; Mice, Nude; Mitochondria; Mitochondria - metabolism; Mitochondria - pathology; Pharmacology/Toxicology; Protein Binding; Recombinant Fusion Proteins - metabolism; Recombinant Fusion Proteins - therapeutic use; Vaccine; Xenograft Model Antitumor Assays; Xenografts
• ISSN: 1671-4083; 1745-7254
• DOI: 10.1038/s41401-018-0069-8

Defensins play an essential role in innate immunity. In this study, a novel recombinant β-defensin that targets the epidermal growth factor receptor (EGFR) was designed and prepared. The EGFR-targeting β-defensin consists of an EGF-derived oligopeptide (Ec), a β-defensin-1 peptide (hBD1) and a lidamycin-derived apoprotein (LDP), which serves as the “scaffold” for the fusion protein (Ec-LDP-hBD1). Ec-LDP-hBD1 effectively bound to EGFR highly expressed human epidermoid carcinoma A431 cells. The cytotoxicity of Ec-LDP-hBD1 to EGFR highly expressed A431 cells was more potent than that to EGFR low-expressed human lung carcinoma A549 and H460 cells (the IC 50 values in A431, A549, and H460 cells were 1.8 ± 0.55, 11.9 ± 0.51, and 5.19 ± 1.21 μmol/L, respectively); in addition, the cytotoxicity of Ec-LDP-hBD1 was much stronger than that of Ec-LDP and hBD1. Moreover, Ec-LDP-hBD1 suppressed cancer cell proliferation and induced mitochondria-mediated apoptosis. Its in vivo anticancer action was evaluated in athymic mice with A431 and H460 xenografts. The mice were administered Ec-LDP-hBD1 (5, 10 mg/kg, i.v.) two times with a weekly interval. Administration of Ec-LDP-hBD1 markedly inhibited the tumor growth without significant body weight changes. The in vivo imaging further revealed that Ec-LDP-hBD1 had a tumor-specific distribution with a clear image of localization. The results demonstrate that the novel recombinant EGFR-targeting β-defensin Ec-LDP-hBD1 displays both selectivity and enhanced cytotoxicity against relevant cancer cells by inducing mitochondria-mediated apoptosis and exhibits high therapeutic efficacy against the EGFR-expressed carcinoma xenograft. This novel format of β-defensin, which induces mitochondrial-mediated apoptosis, may play an active role in EGFR-targeting cancer therapy.