title: Inhibition of tumor-associated αvβ3 integrin regulates the angiogenic switch by enhancing expression of IGFBP-4 leading to reduced melanoma growth and angiogenesis in vivo.
abstract: A more complete understanding of the mechanisms that regulate the angiogenic switch, which contributes to the conversion of small dormant tumors to actively growing malignancies, is important for the development of more effective anti-angiogenic strategies for cancer therapy. While significant progress has been made in understanding the complex mechanisms by which integrin αvβ3 expressed in endothelial cells governs angiogenesis, less is known concerning the ability of αvβ3 expressed within the tumor cell compartment to modulate the angiogenic output of a tumor. Here we provide evidence that αvβ3 expressed in melanoma cells may contribute to the suppression of IGFBP-4, an important negative regulator of IGF-1 signaling. Given the multiple context-dependent roles for αvβ3 in angiogenesis and tumor progression, our novel findings provide additional molecular insight into how αvβ3 may govern the angiogenic switch by a mechanism associated with a p38 MAPK and matrix metalloproteinases-dependent regulation of the endogenous angiogenesis inhibitor IGFBP-4.
authors.affiliation: Maine Medical Center Research Institute, Center for Molecular Medicine, 81 Research Drive, Scarborough, ME, 04074, USA.
authors.forename: Liangru W
authors.initials: LW
authors.lastname: Contois
authors.forename: Abebe
authors.initials: A
authors.lastname: Akalu
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Caron
authors.forename: Eric
authors.initials: E
authors.lastname: Tweedie
authors.forename: Alexandra
authors.initials: A
authors.lastname: Cretu
authors.forename: Terry
authors.initials: T
authors.lastname: Henderson
authors.forename: Lucy
authors.initials: L
authors.lastname: Liaw
authors.forename: Robert
authors.initials: R
authors.lastname: Friesel
authors.forename: Calvin
authors.initials: C
authors.lastname: Vary
authors.forename: Peter C
authors.initials: PC
authors.lastname: Brooks
mesh_terms: D015153:Blotting, Western; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D017931:DNA Primers / Q000235:genetics; D005455:Fluorescent Antibody Technique; D006801:Humans; D007150:Immunohistochemistry; D018974:Insulin-Like Growth Factor Binding Protein 4 / Q000378:metabolism*; D039302:Integrin alphaVbeta3 / Q000037:antagonists & inhibitors*; D008545:Melanoma / Q000150:complications / Q000503:physiopathology*; D009389:Neovascularization, Pathologic / Q000209:etiology; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055114:X-Ray Microtomography
chemical_list: D017931:DNA Primers; D018974:Insulin-Like Growth Factor Binding Protein 4; D039302:Integrin alphaVbeta3