title: Experimental study on inhibition effects of the XAF1 gene against lung cancer cell proliferation.
abstract: OBJECTIVE
  To investigate the effect of high expression of XAF1 in vivo or in vitro on lung cancer cell growth and apoptosis.
  
  
  METHODS
  1. The A549 human lung cancer cell line was transfected with Ad5/F35 - XAF1, or Ad5/ F35 - Null at the same multiplicity of infection (MOI); (hereinafter referred to as transient transfected cell strain); XAF1 gene mRNA and protein expression was detected by reverse transcription polymerase chain reaction (RT- PCR) and Western blotting respectively. 2. Methyl thiazolyl tetrazolium (MTT) and annexin V-FITC/PI double staining were used to detect cell proliferation and apoptosis before and after infection of Ad5/F35 - XAF1 with Western blotting for apoptosis related proteins, caspase 3, caspase - 8 and PARP. 3. After the XAF1 gene was transfected into lung cancer A549 cells by lentiviral vectors, and selected by screening with Blasticidin, reverse transcription polymerase chain reaction (RT-PCR) and Western blotting were applied to detect mRNA and protein expression, to establish a line with a stable high expression of XAF1 (hereinafter referred to as stable expression cell strain). Twenty nude mice were randomly divided into groups A and B, 10 in each group: A549/ XAF1 stable expression cell strain was subcutaneously injected in group A, and A549/Ctrl stable cell line stable expression cell strain in group B (control group), to observe transplanted tumor growth in nude mice.
  
  
  RESULTS
  The mRNA and protein expression of XAF1 in A549 cells transfected by Ad5/F35 - XAF1 was significantly higher than in the control group. XAF1 mediated by adenovirus vector demonstrated a dose dependent inhibition of lung cancer cell proliferation and induction of apoptosis. This was accompanied by cleavage of caspase -3, -8, -9 and PARP, suggesting activation of intrinsic or extrinsic apoptotic pathways. A cell strain of lung cancer highly expressing XAF1 was established, and this demonstrated delayed tumor growth after transplantation in vivo.
  
  
  CONCLUSIONS
  Adenovirus mediated XAF1 gene expression could inhibit proliferation and induce apoptosis in lung cancer cells in vitro; highly stable expression of XAF1 could also significantly inhibit the growth of transplanted tumors in nude mouse, with no obvious adverse reactions observed. Therefore, the XAF1 gene could become a new target for lung cancer treatment.
authors.affiliation: Department of Cardiothoracic Surgery, Second Affiliated Hospital, Soochow University, Suzhou, China E-mail : chen_ybing_00668@126.com.
authors.forename: Wen-Tao
authors.initials: WT
authors.lastname: Yang
authors.forename: Dong-Lai
authors.initials: DL
authors.lastname: Chen
authors.forename: Fu-Quan
authors.initials: FQ
authors.lastname: Zhang
authors.forename: Ying-Chen
authors.initials: YC
authors.lastname: Xia
authors.forename: Rong-Ying
authors.initials: RY
authors.lastname: Zhu
authors.forename: Duan-Shan
authors.initials: DS
authors.lastname: Zhou
authors.forename: Yong-Bing
authors.initials: YB
authors.lastname: Chen
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins; D015153:Blotting, Western; D049109:Cell Proliferation; D005260:Female; D005434:Flow Cytometry; D015316:Genetic Therapy; D006801:Humans; D007124:Immunoenzyme Techniques; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism; D008175:Lung Neoplasms / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger; C417551:XAF1 protein, human