title: Overexpression of eIF-5A2 in mice causes accelerated organismal aging by increasing chromosome instability.
abstract: BACKGROUND
  Amplification of 3q26 is one of the most frequent genetic alterations in many human malignancies. Recently, we isolated a novel oncogene eIF-5A2 within the 3q26 region. Functional study has demonstrated the oncogenic role of eIF-5A2 in the initiation and progression of human cancers. In the present study, we aim to investigate the physiological and pathological effect of eIF-5A2 in an eIF-5A2 transgenic mouse model.
  
  
  METHODS
  An eIF-5A2 transgenic mouse model was generated using human eIF-5A2 cDNA. The eIF-5A2 transgenic mice were characterized by histological and immunohistochemistry analyses. The aging phenotypes were further characterized by wound healing, bone X-ray imaging and calcification analysis. Mouse embryo fibroblasts (MEF) were isolated to further investigate molecular mechanism of eIF-5A2 in aging.
  
  
  RESULTS
  Instead of resulting in spontaneous tumor formation, overexpression of eIF-5A2 accelerated the aging process in adult transgenic mice. This included decreased growth rate and body weight, shortened life span, kyphosis, osteoporosis, delay of wound healing and ossification. Investigation of the correlation between cellular senescence and aging showed that cellular senescence is not required for the aging phenotypes in eIF-5A2 mice. Interestingly, we found that activation of eIF-5A2 repressed p19 level and therefore destabilized p53 in transgenic mouse embryo fibroblast (MEF) cells. This subsequently allowed for the accumulation of chromosomal instability, such as errors in cell dividing during metaphase and anaphase. Additionally, a significantly increase in number of aneuploidy cells (p < 0.05) resulted from an increase in the incidences of misaligned and lagging chromosomal materials, anaphase bridges, and micronuclei in the transgenic mice.
  
  
  CONCLUSIONS
  These observations suggest that eIF-5A2 mouse models could accelerate organismal aging by increasing chromosome instability.
authors: Department of Clinical Oncology, Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong, China.
authors: Muhan
authors: M
authors: Chen
authors: Jian-Dong
authors: JD
authors: Huang
authors: Hong Kui
authors: HK
authors: Deng
authors: Suisui
authors: S
authors: Dong
authors: Wen
authors: W
authors: Deng
authors: Sze Lan
authors: SL
authors: Tsang
authors: Michael S Y
authors: MS
authors: Huen
authors: Leilei
authors: L
authors: Chen
authors: Tong
authors: T
authors: Zan
authors: Gui-Xia
authors: GX
authors: Zhu
authors: Xin-Yuan
authors: XY
authors: Guan
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