The adeno-associated virus Rep78 gene inhibits cellular transformation induced by bovine papillomavirus

Adeno-associated virus type 2 (AAV) is a helper dependent parvovirus which can inhibit the oncogenic and transforming potential of its helper viruses: adenoviruses (Ad) and herpesviruses. Here we have assayed AAV's ability to inhibit cellular transformation induced by bovine papillomavirus type 1 (BPV-1), a member of another family of DNA viruses. AAV was able to markedly inhibit BPV-1-induced transformation of contact-inhibited murine fibroblasts either by infection with virus particles or by DNA transfection. This inhibition was mapped to the full-length, unspliced, rep gene product, Rep78, of AAV. DNA replication by AAV or by BPV-1 was not required for inhibition of transformation to take place.