“By using a model of multiple tumors in the same animal, we established a platform for more efficient studies requiring fewer animals,” explained Gimi. “Another benefit of the multiple tumors-same animal model is that it provides more consistency in interpreting results.”
Bioluminescence has a major role in small animal research, and the technique has been widely applied in tumor models. The multiple tumor approach can also be used for high throughput screening of a vast range of anti-cancer drug therapies.
In this study, investigators used dynamic bioluminescence imaging to study the effects of a tumor vascular disrupting agent, provided by OXiGENE, known as CA4P on subcutaneous 9L rat brain tumor xenografts in mice. A single dose of CA4P induced rapid, temporary tumor vascular shutdown, as revealed by a rapid and reproducible decrease of light emission. The vasculature showed distinct recovery within 24 hours post therapy, and multiple tumors behaved similarly.
“The beauty of using bioluminescence is that it is relatively inexpensive, has no background signal, and has been validated against other imaging modalities,” said Gimi.
Looking forward, the collaborators intend to pursue further investigation using combinatorial approaches where all the tumors in a single animal are subject to the same systemic vascular disrupting agent, followed by a second, local, and tailored treatment.
Barjor Gimi is an Associate Professor of Radiology and of Medicine at Dartmouth’s Geisel School of Medicine. His work in cancer is facilitated by Dartmouth-Hitchcock’s Norris Cotton Cancer Center where he is a member of the Cancer Imaging and Radiobiology Research Program.