In vivo tumor suppression by adenovirus-mediated interferon alpha 2b gene delivery

A replication-deficient adenovirus encoding human interferon alpha 2b, driv en by the human cytomegalovirus (CMV) promoter, was constructed and charact erized. This construct was used to infect human cells derived from differen t types of cancer, The production of protein and its secretion into the cul ture medium were tested by Western blotting and immunoassay, Inhibition of cell proliferation and antiviral activity, two of the most important biolog ical activities of interferon, were observed with this construct. PC-3 cell s, derived from human prostatic cancer, or Hep3B cells, derived from human hepatocellular carcinoma, were injected subcutaneously to generate and esta blish in vivo tumors in athymic nude mice. Intratumoral injection with the recombinant adenovirus expressing interferon alpha 2b resulted in complete regression of tumor growth. Our results demonstrate that interferon gene de livery using recombinant adenoviral vectors may be a useful approach to tre at a variety of cancers.