title: Hypoxia-inducible factor-1 target genes as indicators of tumor vessel response to vascular endothelial growth factor inhibition.
abstract: Antiangiogenic therapy improves survival in patients with advanced stage cancers. Currently, there are no reliable predictors or markers for tumor vessel response to antiangiogenic therapy. To model effective antiangiogenic therapy, we disrupted the VEGF gene in three representative cancer cell lines. HCT116 xenografts had low proportions of endothelial tubes covered by pericytes that stained with alpha-smooth muscle actin (SMA) antibody. Upon disruption of VEGF, HCT116(VEGF-/-) xenografts had significantly decreased tumor microvessel perfusion compared with their parental counterparts. Furthermore, HCT116(VEGF-/-) xenografts mounted a tumor-reactive response to hypoxia, characterized by the induction of hypoxia-inducible factor-1 (HIF-1) target genes. One highly induced protein was DPP4, a measurable serum protein that has well-described roles in cancer progression. In contrast, LS174T and MKN45 tumor xenografts had high proportion of endothelial tubes that were covered by SMA+ pericytes. Upon disruption of VEGF, LS174T(VEGF-/-) and MKN45(VEGF-/-) xenografts maintained tumor microvessel perfusion. As such, there were no changes in intratumoral hypoxia or HIF-1 alpha induction. Together, these data show that the extent of tumor vessel response to angiogenic inhibition could be correlated with (a) the preexisting coverage of tumor endothelial tubes with SMA+ pericytes and (b) differential tumor induction of HIF-1 target genes. The data further show that DPP4 is a novel marker of HIF-1 induction. Altogether, these preclinical findings suggest novel clinical trials for predicting and monitoring tumor vessel responses to antiangiogenic therapy.
authors.affiliation: Department of Internal Medicine, The University of Michigan Medical Center, Ann Arbor, MI 48109, USA.
authors.forename: Duyen T
authors.initials: DT
authors.lastname: Dang
authors.forename: Sang Y
authors.initials: SY
authors.lastname: Chun
authors.forename: Kyunghee
authors.initials: K
authors.lastname: Burkitt
authors.forename: Masako
authors.initials: M
authors.lastname: Abe
authors.forename: Shaowei
authors.initials: S
authors.lastname: Chen
authors.forename: Pamela
authors.initials: P
authors.lastname: Havre
authors.forename: Nicola J
authors.initials: NJ
authors.lastname: Mabjeesh
authors.forename: Elisabeth I
authors.initials: EI
authors.lastname: Heath
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Vogelzang
authors.forename: Marcia
authors.initials: M
authors.lastname: Cruz-Correa
authors.forename: Douglas W
authors.initials: DW
authors.lastname: Blayney
authors.forename: William D
authors.initials: WD
authors.lastname: Ensminger
authors.forename: Brad
authors.initials: B
authors.lastname: St Croix
authors.forename: Nam H
authors.initials: NH
authors.lastname: Dang
authors.forename: Long H
authors.initials: LH
authors.lastname: Dang
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D015687:Cell Hypoxia / Q000235:genetics; D045744:Cell Line, Tumor; D018819:Dipeptidyl Peptidase 4 / Q000096:biosynthesis / Q000235:genetics; D004730:Endothelium, Vascular / Q000473:pathology; D005260:Female; D015316:Genetic Therapy; D045325:HCT116 Cells; D019073:HT29 Cells; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000096:biosynthesis / Q000235:genetics*; D051379:Mice; D009369:Neoplasms / Q000098:blood supply* / Q000235:genetics / Q000378:metabolism / Q000628:therapy*; D009389:Neovascularization, Pathologic / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors* / Q000235:genetics; D023041:Xenograft Model Antitumor Assays
chemical_list: C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D042461:Vascular Endothelial Growth Factor A; C042807:DPP4 protein, human; D018819:Dipeptidyl Peptidase 4