Adenovirus-mediated Expression of both Antisense Ornithine Decarboxylase (ODC) and S-adenosylmethionine Decarboxylase (AdoMetDC) Inhibits Lung Cancer Cell Growth and Invasion In vitro and In vivo

Polyamine biosynthesis is controlled primarily by ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (AdoMetDC). Antisense ODC and AdoMetDC sequences were cloned into an adenoviral vector (Ad-ODC-AdoMetDCas). To evaluated the effect of recombinant adenovirus Ad-ODC-AdoMetDCas which can simultaneously express both antisense ornithine decarboxylase (ODC) and sadenosylmethionine decarboxylase (AdoMetDC), the human lung cancer cell line A-549, was infected with Ad-ODC-AdoMetDCas as well as with control vector. Viable cell counting, determination of polyamine concentrations, cell apoptosis, and Matrigel invasion assays were performed in order to assess properties of tumor growth and invasiveness. Furthermore, Ad-ODC-AdoMetDCas's anti-tumor effect was also evaluated in vivo in a nude mice xenograft model. It was demonstrated that adenovirus-mediated ODC and AdoMetDC antisense expression could inhibit tumor cell growth, lead to cell apoptosis and reduce tumor cell invasiveness. Polyamine levels were significantly decreased in Ad-ODC-AdoMetDCas-treated cells compared with controls. This adenovirus also induced tumor regression in established tumors in nude mice. It was suggested that as a new anticancer reagent, the recombinant adenovirus Ad-ODC-AdoMetDCas holds promising hope for the therapy of lung cancers.