title: Hypoxia-specific stabilization of HIF-1alpha by human papillomaviruses.
abstract: Human papillomaviruses (HPV) are the causative agents of cervical cancer and have been shown to increase expression of pro-angiogenic factors from infected cells. Many angiogenic factors are regulated by hypoxia inducible factor 1alpha (HIF-1alpha). We investigated whether HPV31 affects the levels of HIF-1alpha under normal and hypoxic conditions. Our studies indicate that cells containing complete HPV31 genomes showed enhanced levels of HIF-1alpha upon treatment with the hypoxia mimic DFO, which resulted from protein stabilization and led to increased expression of some but not all HIF-1alpha target genes. Both HPV E6 and E7 were able independently to enhance induction of HIF-1alpha upon DFO treatment. Enhancement of HIF-1alpha stability was not restricted to high-risk HPV types, as HPV11, a low risk HPV type, mediated a similar effect. These findings shed light on mechanisms by which HPV contributes to angiogenesis both in benign cervical lesions and in cervical cancers.
authors.affiliation: Department of Microbiology-Immunology, Northwestern University, Feinberg School of Medicine, Morton, Chicago, IL 60611, USA.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Nakamura
authors.forename: Jason M
authors.initials: JM
authors.lastname: Bodily
authors.forename: Melanie
authors.initials: M
authors.lastname: Beglin
authors.forename: Satoru
authors.initials: S
authors.lastname: Kyo
authors.forename: Masaki
authors.initials: M
authors.lastname: Inoue
authors.forename: Laimonis A
authors.initials: LA
authors.lastname: Laimins