title: [Experimental study on A549 cell death mediated by xenoantigen α-gal  in human serum].
abstract: OBJECTIVE
  The absence of α-gal in humans is caused by the inactivity of α-1,3GT gene. However, humans have pre-existing and abundant anti-gal antibodies. Xenotransplantation procedures have indicated the high potential of introducing α-1,3GT gene to synthesize α-gal for cancer gene therapy by mimicking hyper-acute rejection. The aim of this study is to construct a lung cancer A549 cell line that expressed α-gal, and to observe the antitumor mechanisms mediated by human serum.
  
  
  METHODS
  A549 cells were transfected with pEGFP-N1-GT plasmids constructed in a previous study. A stable transgenic cell line, A549-GT, was then selected and cultivated. The biological characteristics of A549-GT cells, including morphology and proliferation, were examined. α-1,3GT mRNA expression was detected by RT-PCR. Direct immunofluorescence staining and flow cytometry (FCM) were used to analyze the synthesis of α-gal in A549-GT. The binding of human serum IgM and C3 with A549-GT were also detected.
  
  
  RESULTS
  α-1,3GT mRNA was expressed in A549-GT. Direct immunofluorescence staining and FCM indicated a high and stable α-gal expression rate in A549-GT. Compared with parental A549 cells, the biological characteristics of A549-GT were unaltered. α-Gal expression was not detected in the human fetal lung fibroblast cell line MRC-5 even though A549-GT and its culture medium were cultivated with the enzyme. Immunofluorescence staining and FCM also indicated abundant binding between A549-GT treated with human serum and IgM/C3.
  
  
  CONCLUSIONS
  α-Gal expression in tumor cells by gene transduction can induce complement-dependent cytototic antitumor effects.
authors.affiliation: Department of Oncology, Taihe Hospital, Affiliated to Hubei Medical College, Shiyan 442000, China.
authors.forename: Shengming
authors.initials: S
authors.lastname: Zhu
authors.forename: Ling
authors.initials: L
authors.lastname: Xie
authors.forename: Hong
authors.initials: H
authors.lastname: Zheng
authors.forename: Feng
authors.initials: F
authors.lastname: Qin
authors.forename: Mei
authors.initials: M
authors.lastname: Liu
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Luo
authors.forename: Yanping
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000818:Animals; D015478:Antigens, Heterophile / Q000097:blood* / Q000235:genetics / Q000276:immunology*; D016923:Cell Death / Q000276:immunology; D045744:Cell Line, Tumor; D003176:Complement C3 / Q000276:immunology; D000939:Epitopes / Q000276:immunology; D005690:Galactose / Q000097:blood* / Q000235:genetics / Q000276:immunology*; D005700:Galactosyltransferases / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000276:immunology; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood; D008175:Lung Neoplasms / Q000473:pathology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D015478:Antigens, Heterophile; D003176:Complement C3; D000939:Epitopes; D007075:Immunoglobulin M; D012333:RNA, Messenger; D005700:Galactosyltransferases; D005690:Galactose