5-aza repressed expression and activity of matrix metalloproteinases (MMP) in HPV<sup>+</sup> HNSCC, activated IFN response in some HPV<sup>+</sup> head and neck cancer cells, and inhibited the ability of HPV<sup>+</sup> xenografted tumors to invade mouse blood vessels.<b>Conclusions:</b> 5-aza may provide effective therapy for HPV-associated HNSCC as an alternative or complement to standard cytotoxic therapy.<i></i>.
Differential responsiveness of tumor cells to IFN-α and -β was further supported by the finding that autocrine IFN-β but not IFN-α promoted survival of HNSCC cells during persistent VSV infection.