Epstein-Barr virus DNase (BGLF5) induces genomic instability in human epithelial cells.
Epstein-Barr Virus (EBV) DNase (BGLF5) is an alkaline nuclease and has been suggested to be important in the viral life cycle. However, its effect on host cells remains unknown. Serological and histopathological studies implied that EBV DNase seems to be correlated with carcinogenesis. Therefore, we investigate the effect of EBV DNase on epithelial cells. Here, we report that expression of EBV DNase induces increased formation of micronucleus, an indicator of genomic instability, in human epithelial cells. We also demonstrate, using gammaH2AX formation and comet assay, that EBV DNase induces DNA damage. Furthermore, using host cell reactivation assay, we find that EBV DNase expression repressed damaged DNA repair in various epithelial cells. Western blot and quantitative PCR analyses reveal that expression of repair-related genes is reduced significantly in cells expressing EBV DNase. Host shut-off mutants eliminate shut-off expression of repair genes and repress damaged DNA repair, suggesting that shut-off function of BGLF5 contributes to repression of DNA repair. In addition, EBV DNase caused chromosomal aberrations and increased the microsatellite instability (MSI) and frequency of genetic mutation in human epithelial cells. Together, we propose that EBV DNase induces genomic instability in epithelial cells, which may be through induction of DNA damage and also repression of DNA repair, subsequently increases MSI and genetic mutations, and may contribute consequently to the carcinogenesis of human epithelial cells.
Wu
Chung-Chun
CC
National Institute of Cancer Research, National Health Research Institutes, Zhunan, Taiwan.
Liu
Ming-Tsan
MT
Chang
Yu-Ting
YT
Fang
Chih-Yeu
CY
Chou
Sheng-Ping
SP
Liao
Hsin-Wei
HW
Kuo
Kuan-Lin
KL
Hsu
Shih-Lung
SL
Chen
Yi-Ren
YR
Wang
Pei-Wen
PW
Chen
Yu-Lian
YL
Chuang
Hsin-Ying
HY
Lee
Chia-Huei
CH
Chen
Ming
M
Wayne Chang
Wun-Shaing
WS
Chen
Jen-Yang
JY
D002460:Cell Line; D002869:Chromosome Aberrations; D053960:DNA Breaks; D004249:DNA Damage; D004260:DNA Repair / Q000235:genetics; D003851:Deoxyribonucleases / Q000378:metabolism*; D004847:Epithelial Cells / Q000737:chemistry / Q000378:metabolism; D042822:Genomic Instability; D006801:Humans; D048629:Micronuclei, Chromosome-Defective; D053842:Microsatellite Instability; D009154:Mutation; D014176:Protein Biosynthesis; D014158:Transcription, Genetic; D014466:Ultraviolet Rays; D014764:Viral Proteins / Q000378:metabolism*
D014764:Viral Proteins; D003851:Deoxyribonucleases; C083203:deoxyribonuclease, Epstein-Barr virus