MDM2-dependent inhibition of p53 is required for Epstein-Barr virus B-cell growth transformation and infected-cell survival.

Published

Journal Article

Epstein-Barr virus (EBV) growth transformation of primary B lymphocytes into indefinitely proliferating lymphoblastoid cell lines (LCLs) depends on the concerted activities of a subset of viral proteins expressed during latency. EBV drives quiescent B cells into S phase, and consequently, a host response is activated that includes expression of p53 and its target genes. Since LCLs retain wild-type p53, it was of interest to determine what contribution the p53 pathway may have in controlling established LCL growth and EBV-mediated transformation of primary B cells. We found that liberation of p53 through chemical antagonism of one of its major ubiquitin ligases, MDM2, using the small-molecule Nutlin-3 led to apoptosis of established LCLs and suppressed EBV-mediated transformation of primary B cells. The activation of latent p53 induced target genes associated with apoptosis. Furthermore, MDM2 antagonism synergized with NF-kappaB inhibition in killing LCLs. NF-kappaB was important to increase steady-state MDM2 protein levels rather than in affecting p53-dependent transcription, suggesting a unique mechanism by which LCLs survive in the presence of a primed p53 pathway. Nutlin sensitivity of EBV-infected cells provides a novel system for studying the pathways that dictate LCL survival and regulate EBV transformation. Finally, MDM2 antagonists may be considered for therapeutic intervention in EBV-associated malignancies expressing wild-type p53.

Full Text

Duke Authors

Cited Authors

  • Forte, E; Luftig, MA

Published Date

  • March 2009

Published In

Volume / Issue

  • 83 / 6

Start / End Page

  • 2491 - 2499

PubMed ID

  • 19144715

Pubmed Central ID

  • 19144715

Electronic International Standard Serial Number (EISSN)

  • 1098-5514

International Standard Serial Number (ISSN)

  • 0022-538X

Digital Object Identifier (DOI)

  • 10.1128/JVI.01681-08

Language

  • eng