title: Cloning and expression of a novel target fusion protein and its application in anti-tumor therapy.
abstract: BACKGROUND
  Epidermal growth factor (EGF) is a 53 amino acid polypeptide and its receptor EGFR is an established therapeutic target for anti-tumor therapy. Two major categories of EGFR-targeted drugs include monoclonal antibodies (mAbs) and small molecular tyrosine kinase inhibitors (TKIs). However, drug resistance occurs in a significant proportion of patients due to EGFR mutations. Since EGFR can maintain activation while abrogating the activity of mAbs or TKIs, or bypass signaling functions while successfully circumventing the EGF-EGFR switch, developing new mechanism-based inhibitors is necessary.
  
  
  METHODS
  In this study, based on the principle of tumor immunotherapy, a recombinant protein pLLO-hEGF was constructed. The N-terminal portion contains three immunodominant epitopes from listeriolysin O (LLO) and the C-terminal includes EGF. To use EGF as a target vector to recognize EGFR-expressing cancer cells, immunodominant epitopes could enhance immunogenicity of tumor cells for immune cell activation and attack.
  
  
  RESULTS
  Recombinant protein pLLO-hEGF was successfully expressed and showed strong affinity to cancer cells. Also, pLLO-hEGF could significantly stimulate human lymphocyte proliferation and the lymphocytes demonstrated enhanced killing potency in EGFR-expressing cancer cells in vitro and in vivo.
  
  
  CONCLUSIONS
  This study can provide novel strategies and directions in tumor biotherapy.
authors: Department of Pathology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Tsinghua University, Beijing, China.
authors: Rui
authors: R
authors: Sun
authors: Yan
authors: Y
authors: Zhu
authors: Hailiang
authors: H
authors: Feng
authors: Zhenli
authors: Z
authors: Yang
authors: Xiaocui
authors: X
authors: Bian
authors: Pei
authors: P
authors: Gu
authors: Chunjing
authors: C
authors: Wang
authors: Yuqin
authors: Y
authors: Liu
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D001427:Bacterial Toxins / Q000235:genetics*; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D003001:Cloning, Molecular; D004815:Epidermal Growth Factor / Q000235:genetics*; D066246:ErbB Receptors / Q000378:metabolism; D045325:HCT116 Cells; D019073:HT29 Cells; D006360:Heat-Shock Proteins / Q000235:genetics*; D006460:Hemolysin Proteins / Q000235:genetics*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009369:Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000494:pharmacology / Q000627:therapeutic use; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D014183:Transplantation, Heterologous
chemical_list: D000970:Antineoplastic Agents; D001427:Bacterial Toxins; D006360:Heat-Shock Proteins; D006460:Hemolysin Proteins; D011993:Recombinant Fusion Proteins; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; C038705:hlyA protein, Listeria monocytogenes