Eradication of Epstein-Barr virus episome and associated inhibition of infected tumor cell growth by adenovirus vector-mediated transduction of dominant-negative EBNA1.
Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1), a latent viral protein consistently expressed in infected proliferating cells, is essentially required in trans to maintain EBV episomes in cells. We constructed a mutant (mt) EBNA1 and examined whether it exerted dominant-negative effects on maintenance of the viral episome thereby leading to abrogation of EBV-infected tumor cell growth. Using lymphocyte and epithelial cell lines converted with neomycin-resistant recombinant EBV (rEBV) as models, adenovirus vector-mediated transduction of mtEBNA1, but not LacZ, brought about rapid and striking reductions in rEBV-derived wild-type EBNA1 levels and viral genomic loads in converted lines of three major viral latencies. This outcome was further validated at the single-cell level by cellular loss of G418 resistance and viral signals in situ. The mtEBNA1 transduction significantly impaired growth of naturally EBV-harboring Burkitt lymphoma cells in vitro and in vivo, largely in association with the eradication of viral episomes. Expression of mtEBNA1 per se caused no detectable cytotoxicity in EBV-uninfected cells. These results indicate that mtEBNA1 can act as a dominant-negative effector that efficiently impedes the EBV-dependent malignant phenotypes in cells regardless of viral latency or tissue origin. The mutant will afford an additional therapeutic strategy specifically targeting EBV-associated malignancies.
Nasimuzzaman
Md
M
Department of Molecular Microbiology and Infections, Kochi Medical School, Kohasu, Oko-cho, Nankoku, Kochi 783-8505, Japan.
Kuroda
Masayuki
M
Dohno
Sumitaka
S
Yamamoto
Takenobu
T
Iwatsuki
Keiji
K
Matsuzaki
Shigenobu
S
Mohammad
Rashel
R
Kumita
Wakako
W
Mizuguchi
Hiroyuki
H
Hayakawa
Takao
T
Nakamura
Hiroyuki
H
Taguchi
Takahiro
T
Wakiguchi
Hiroshi
H
Imai
Shosuke
S
D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D002051:Burkitt Lymphoma / Q000628:therapy* / Q000821:virology; D002461:Cell Line, Transformed; D049109:Cell Proliferation; D019309:Epstein-Barr Virus Nuclear Antigens / Q000235:genetics* / Q000378:metabolism; D015316:Genetic Therapy; D005822:Genetic Vectors; D004854:Herpesvirus 4, Human / Q000235:genetics*; D006801:Humans; D051379:Mice; D009154:Mutation; D009368:Neoplasm Transplantation; D010957:Plasmids / Q000235:genetics*; D014161:Transduction, Genetic; D014779:Virus Replication
D019309:Epstein-Barr Virus Nuclear Antigens; C417029:EBV-encoded nuclear antigen 1