RESUMO
Enhanced angiogenesis is a hallmark of solid tumors and hematological malignancies. Anti-angiogenic therapeutic approaches have recently been shown to be effective for the treatment of certain cancers. Endothelial cells migrating to tumors provide them with new blood vessels that are critical for their growth and survival. We have developed a novel and rapid method to evaluate the anti-angiogenic activity of new agents consisting of a combined chorioallantoic membrane (CAM) and feather bud (FB) assay. Unlike previous assays, this new assay assesses the effects of drugs on the ability of tissues to attract and develop their own blood supply. The CAM already has a well-developed vascular network that is capable of providing blood vessels to the non-vascularized FB, allowing for this tissue to develop feathers. As a result, the exposure of the FB to drugs for 2 days followed by attachment to the CAM for 4 days allows evaluation of the compound's ability to impact blood vessel and feather formation within the CAM-attached FB tissue. Feather formation is determined as well as expression of endothelial cell genes and proteins analyzed. Using agents with known anti-angiogenic activity including fumagillin, minocycline, zoledronic acid, doxorubicin and agents lacking anti-angiogenic activity such as melphalan, we have shown that the CAM/FB assay can accurately and rapidly assess the ability of agents to prevent blood vessel and feather development within non-vascularized tissues.
Assuntos
Inibidores da Angiogênese/farmacologia , Bioensaio/métodos , Membrana Corioalantoide/citologia , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Plumas/embriologia , Neovascularização Fisiológica/efeitos dos fármacos , Inibidores da Angiogênese/isolamento & purificação , Animais , Técnicas de Cultura de Células , Células Cultivadas , Embrião de Galinha , Membrana Corioalantoide/irrigação sanguínea , Membrana Corioalantoide/fisiologia , Cicloexanos/farmacologia , Ácidos Graxos Insaturados/farmacologia , Plumas/irrigação sanguínea , Botões de Extremidades/irrigação sanguínea , Botões de Extremidades/citologia , Botões de Extremidades/efeitos dos fármacos , Melfalan/farmacologia , Minociclina/farmacologia , Modelos Biológicos , Sesquiterpenos/farmacologiaRESUMO
Indian Peafowl (Pavo cristatus) tail covert feathers were studied to investigate the difference between shed and plucked feathers in the context of wildlife offence cases involving the killing of the Indian national bird for the purpose of plucking feathers. Plucked feathers were distinguished from shed feathers by examining their roots under low magnification of a stereoscopic microscope. A chemical test to show the presence of blood on the roots of plucked feathers was used to corroborate the plucked origin of feathers.