title: Potent inhibition of human gastric cancer by HER2-directed induction of apoptosis with anti-HER2 antibody and caspase-3 fusion protein.
abstract: OBJECTIVE
  HER2, an oncogene, has been found to be over-expressed in 10-40% of human gastric carcinomas. The aims of this study were to investigate if a fusion protein consisting of anti-HER2 sFv and constitutively active caspase-3 was capable of inducing apoptosis in HER2-expressing human gastric cancer cells and blocking the growth of human gastric cancer xenografts in nude mice.
  
  
  METHODS
  NIH3T3 cells stably transduced with the pcDNA3.1-HER-PE-CP3 recombinant plasmid containing a secretion signal, a single-chain anti-HER2 monoclonal antibody fragment, a Pseudomonas exotoxin A translocation domain and a constitutively active caspase-3 molecule were used to induce apoptosis in human gastric cancer cells both in vitro and in vivo. Immunofluorescence staining and western blotting were used to examine the expression of the recombinant protein HER-PE-CP3. Apoptosis was determined by flow cytometry and TUNEL assay.
  
  
  RESULTS
  Co-cultivation of HER-PE-CP3/ NIH3T3 with human gastric cancer cells led to internalisation of HER-PE-CP3 and apoptosis in HER2-expressing human gastric cancer cells but not in HER2-negative cancer cells. Inoculation of HER-PE-CP3/NIH3T3 in nude mice resulted in potent inhibition of human gastric cancer xenografts and much prolonged survival time of the tumour-bearing mice compared with the control. Significantly more apoptotic cells were detected in xenografts in mice receiving HER-PE-CP3/NIH3T3 than in control mice.
  
  
  CONCLUSIONS
  The HER-PE-CP3 chimeric molecule could induce selective apoptosis and potent growth inhibition of HER2-positive human gastric cancer cells and might represent a novel HER2-directed treatment option for human gastric cancer.
authors: State Key Laboratory of Cancer Biology & Xijing Hospital of Digestive Disease, the Fourth Military Medical University, 15 West Chang-Le Road, Xi'an 710032, PR China.
authors: De-Xin
authors: DX
authors: Zhang
authors: Peng-Tao
authors: PT
authors: Zhao
authors: Lin
authors: L
authors: Xia
authors: Li-Li
authors: LL
authors: Liu
authors: Jie
authors: J
authors: Liang
authors: Hui-Hong
authors: HH
authors: Zhai
authors: Hong-Bo
authors: HB
authors: Zhang
authors: Xue-Gang
authors: XG
authors: Guo
authors: Kai-Chun
authors: KC
authors: Wu
authors: Yan-Ming
authors: YM
authors: Xu
authors: Lin-Tao
authors: LT
authors: Jia
authors: An-Gang
authors: AG
authors: Yang
authors: Si-Yi
authors: SY
authors: Chen
authors: Dai-Ming
authors: DM
authors: Fan
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000627:therapeutic use; D004353:Drug Evaluation, Preclinical / Q000379:methods; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009363:Neoplasm Proteins / Q000378:metabolism; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000276:immunology* / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000494:pharmacology / Q000627:therapeutic use*; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays
chemical_list: D000911:Antibodies, Monoclonal; D000970:Antineoplastic Agents; D053148:Caspase 3; D009363:Neoplasm Proteins; D018719:Erb-b2 Receptor Tyrosine Kinases; D011993:Recombinant Fusion Proteins; C508053:ERBB2 protein, human