Preclinical evaluation of the therapeutic effect of adenoviral vectors in human papillomavirus-dependent neoplasias.

Gene therapy with adenoviral vectors can eliminate neoplasic cells through selective replication and/or through pro-apoptotic, immunogenic or suicide gene expression. However, an adenoviral vector may provide anti-cancerous effects even in the absence of replication or therapeutic gene expression. The present study evaluates the therapeutic effects caused by the administration of an adenoviral vector, alone, in HPV- dependent neoplasias (HPV-N). In vivo trials were carried out in two HPV-N mouse models. One model was immunocompetent and the other was immunodeficient. In both models, the effect of intratumoral administration of saline solution (PBS) was compared with administration of an adenoviral vector that had no replicative capacity or therapeutic gene (Ad-BGal). In the immunocompetent mice, Ad-BGal adenoviral vector administration significantly reduced tumor growth, compared with PBS. No differences were observed in the immunodeficient mice. In conclusion, the present study lends support to the use of adenoviral vectors in HPV-N treatment since they are capable of generating an antitumoral effect in immunocompetent individuals, even in the absence of a therapeutic gene or viral vector replication.