Invited Speaker

Nanoparticle-Based Chemotherapy Inhibits Tumor-Associated Angio-Genesis in a Murine Vascular Tumor Model
Peace Mabeta, Ndabenhle Sosibo, Robert Tshikhudo and Michael S. Pepper
South Africa

The formation of new blood vessels from existing microvessels, angiogenesis, is a key event associated with tumor growth, invasion and metastasis. Antiangiogenesis has become a key target in therapeutic strategies aimed at inhibiting tumor growth. Bleomycin has recently been shown to inhibit angiogenesis in vitro and in vivo, while gold nanoparticles (Au-NPs) have been shown to interact selectively with heparin-binding glycoproteins and inhibit their activity, leading to an inhibition of angiogenesis.

Bleomycin is a chemotherapeutic drug used in the treatment of various neoplasms, and its clinical application has been limited by the accompanying pulmonary toxicity. We show in this report that gold nanoparticle-conjugated bleomycin is more effective in inhibiting tumor growth. Efficacy was assessed in a syngeneic mouse vascular tumor model, and analysis of tumor volumes 15 days post treatment revealed a significant reduction in tumor growth in mice treated with Bleomycin-Au-NPs as compared with those treated with buffered saline or bleomycin alone (n = 5 per group; p<0.05). Histological evaluation revealed a reduction in vessel counts in tumors from treated mice compared to controls. Hematological data indicated that Bleomycin-Au-NPs inhibit angiogenesis by targeting the activation of the PI3K/Akt signaling pathways.