Enhancement of replication of genetically engineered herpes simplex viruses by ionizing radiation: a new paradigm for destruction of therapeutically intractable tumors

Gene Ther. 1998 Feb;5(2):160-5. doi: 10.1038/sj.gt.3300546.


Human U-87 malignant glioma xenografts in mice were exposed to ionizing radiation, inoculated with a herpes simplex virus 1 mutant R3616 lacking both copies of the gamma 34.5 gene, or received both virus and radiation. Dual treatment caused a significantly greater reduction in volume or total regression of tumors than either radiation or infection alone. The significantly enhanced oncolytic effects of the combined treatment correlate with two-to five-fold enhanced replication in irradiated tumor cells than in tumors receiving virus only. In addition, in situ hybridization with viral DNA probes showed that infected tumor cells were the dominant landscape of irradiated tumors and much less apparent in the nonirradiated tumors administered this virus.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Combined Modality Therapy
  • DNA Probes
  • Glioma / radiotherapy
  • Glioma / therapy*
  • In Situ Hybridization
  • Mice
  • Mice, Nude
  • Mutagenesis, Insertional
  • Neoplasm Transplantation
  • Recombination, Genetic
  • Regression Analysis
  • Simplexvirus / genetics*
  • Tumor Cells, Cultured
  • Virus Replication / genetics
  • Virus Replication / radiation effects*


  • DNA Probes