title: Inhibition by doxycycline of angiogenesis in the chicken chorioallantoic membrane (CAM).
abstract: Doxycycline, a tetracycline derivative, has many properties in addition to its antibiotic activity, including inhibition of matrix metalloproteinases (MMPs) and the ability to chelate divalent cations including Ca(2+). It has been shown to inhibit endothelial cell growth in vitro, and reduce the development of experimental tumours, especially bone metastasis in a model of breast cancer. We examined the effects of doxycycline on angiogenesis in the chicken chorioallantoic membrane (CAM) model, and showed that doxycycline will cause loss of the chorionic plexus in CAMs when applied at day 8 of incubation, and the duration of this inhibition was dose-dependent. Repeated doses prolonged the inhibition, but following removal of the doxycycline there was rapid recovery of the chorionic plexus. The effects of doxycycline are in part mimicked by the MMP inhibitor 1,10-phenanthroline, and more closely by the Ca(2+)-chelating agent EGTA. Doxycycline was equally effective in causing loss of the chorionic plexus by day 11 in CAMs, a time at which the blood vessels are established. Doxycycline has important potential as an antiangiogenic treatment. It is capable of inhibiting angiogenesis in an in vivo model, including the removal of comparatively mature endothelial cells. The response is sensitive to the dosing regimen and the effect is rapidly reversible.
authors.affiliation: Juravinski Cancer Centre, McMaster University, Hamilton, Ontario, Canada L8V 5C2.
authors.forename: Mary
authors.initials: M
authors.lastname: Richardson
authors.forename: David
authors.initials: D
authors.lastname: Wong
authors.forename: Samantha
authors.initials: S
authors.lastname: Lacroix
authors.forename: Jolanta
authors.initials: J
authors.lastname: Stanisz
authors.forename: Gurmit
authors.initials: G
authors.lastname: Singh
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018929:Cell Culture Techniques; D002642:Chick Embryo; D002645:Chickens; D049033:Chorioallantoic Membrane / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004318:Doxycycline / Q000494:pharmacology*; D005260:Female; D023421:Models, Animal; D018919:Neovascularization, Physiologic / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D004318:Doxycycline