title: Complete regression of human neuroblastoma xenografts in athymic mice after local Newcastle disease virus therapy.
abstract: BACKGROUND
  Neuroblastoma is the most common pediatric extra-cranial solid cancer. Using conventional therapies, children older than 1 year of age with advanced neuroblastoma have a poor prognosis. The development of new approaches for treating such children with neuroblastoma continues to be one of the most important goals today in pediatric oncology. Despite numerous anecdotal reports of human tumor regression during viral infections, the use of viruses to directly lyse neuroblastoma cells has never been reported as a potential therapy. Newcastle disease virus (NDV) has been shown to replicate in and kill cultured human and rat neuroblastoma cells but not normal human fibroblasts.
  
  
  OBJECTIVE
  Our purpose was to determine if this selective killing of human neuroblastoma (IMR-32) cells is maintained during the in vivo treatment of established tumors.
  
  
  METHODS
  Two experiments were performed using NDV strain 73-T. Athymic mice with subcutaneous IMR-32 human neuroblastoma xenografts (6-12 mm) were treated intralesionally with live NDV, UV-inactivated NDV, or phosphate-buffered saline (PBS). To study virus replication in situ, mice were given intratumoral or intramuscular injections of NDV. These mice were then killed at various times, and the amount of infectious virus present in tumor or muscle was determined.
  
  
  RESULTS
  After one injection of live NDV, 17 of 18 tumors regressed completely, whereas rapid tumor growth occurred in all 18 mice treated with PBS and in all nine mice treated with UV-inactivated NDV (P < .0001). The one tumor that showed only a partial response to a single injection regressed completely after a second NDV treatment. Six months following virus-induced regression, only one tumor had recurred. No significant acute or chronic side effects of live NDV were noted in athymic mice given doses up to 500 times that used in this study. Virus levels increased more than 80-fold between 5 and 24 hours in virus-injected tumors (P < .04), while no infectious virus was produced in NDV-injected muscle tissue.
  
  
  CONCLUSIONS
  NDV 73-T appears to replicate selectively in human IMR-32 neuroblastoma xenografts, leading directly to a potent antitumor effect as demonstrated by long-lasting, complete tumor regression occurring after a single local injection of virus.
  
  
  CONCLUSIONS
  These experiments may provide an important step in the development of new therapeutic approaches to challenging cancers such as neuroblastoma.
authors.affiliation: Department of Pathology, Rush-Presbyterian-St. Luke's Medical Center, Chicago, IL 60612-3833.
authors.forename: R M
authors.initials: RM
authors.lastname: Lorence
authors.forename: K W
authors.initials: KW
authors.lastname: Reichard
authors.forename: B B
authors.initials: BB
authors.lastname: Katubig
authors.forename: H M
authors.initials: HM
authors.lastname: Reyes
authors.forename: A
authors.initials: A
authors.lastname: Phuangsab
authors.forename: B R
authors.initials: BR
authors.lastname: Mitchell
authors.forename: C J
authors.initials: CJ
authors.lastname: Cascino
authors.forename: R J
authors.initials: RJ
authors.lastname: Walter
authors.forename: M E
authors.initials: ME
authors.lastname: Peeples
mesh_terms: D000818:Animals; D005260:Female; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D009447:Neuroblastoma / Q000628:therapy*; D009522:Newcastle disease virus / Q000528:radiation effects; D012074:Remission Induction; D013997:Time Factors; D014466:Ultraviolet Rays