Inhibition of adenovirus oncogenicity in hamsters by adeno-associated virus DNA.

Adeno-associated virus (AAV) DNA partially inhibited in Syrian golden hamsters the formation of tumors by the human adenovirus (Ad) type 12. Furthermore, defective interfering AAV particles or their DNA also reduced tumorigenesis. Defective AAV particles contain aberrant genomes with extensive deletions of the internal AAV DNA sequences. Variant AAV DNA, containing 30% of the viral genome, decreased the incidence of Ad-induced tumors from 44 to 18%. Defective AAV particles, which have a buoyant density of 1.32 g/cm3 in CsCl and which are highly enriched for the DNA of the terminal regions (map positions, 0-5 and 95-100), completely suppressed Ad oncogenicity. This observation suggested that the AAV DNA sequences close to the terminal region of the genome mediated the inhibition of the Ad oncogenicity.